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From: Richard Biener <rguenther@suse.de>
To: Tamar Christina <Tamar.Christina@arm.com>
Cc: "gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>,
	nd <nd@arm.com>,  Richard Sandiford <Richard.Sandiford@arm.com>
Subject: RE: [PATCH 1/2]middle-end: Support early break/return auto-vectorization.
Date: Wed, 14 Dec 2022 09:41:00 +0000 (UTC)	[thread overview]
Message-ID: <nycvar.YFH.7.77.849.2212140934320.8669@jbgna.fhfr.qr> (raw)
In-Reply-To: <VI1PR08MB5325308942BD4887854E3DEFFFE39@VI1PR08MB5325.eurprd08.prod.outlook.com>

On Tue, 13 Dec 2022, Tamar Christina wrote:

> Hi Richi,
> 
> This is a respin of the mid-end patch.  Changes since previous version:
>  - The mismatch in Boolean types is now fixed, and it generates an OR reduction when it needs to.
>  - I've refactored things around to be a bit neater
>  - I've switched to using iterate_fix_dominators which has simplified the loop peeling code a ton.
>  - I've moved the conditionals into the loop structure and use them from there.
>  - I've moved the analysis part early into vect_analyze_data_ref_dependences
>  - I've switched to moving the scalar code instead of the vector code, as moving vector required us to track a lot more complicated things like internal functions.  It was also a lot more work when the loop is unrolled or VF is increased due to unpacking.  I have verified as much as I can that we don't seem to run into trouble doing this.
> 
> Outstanding things:
>   - Split off the SCEV parts from the rest of the patch (and determine the "normal" exit based on the counting IV instead)
>   - Merge vectorizable_early_exit and transform_early_exit
> 
> I'm sending this patch out for you to take a look at the issue we were discussing the issue on IRC (which you can reproduce with testcase gcc.dg/vect/vect-early-break_16.c)
> 
> That should be the last outstanding issue.   Meanwhile I'll finish up the splitting of SCEV and merging the two functions. 
> 
> Any additional comments is appreciated. Will hopefully finish the refactoring today and send out the split patch tomorrow.

Few comments inline.

As said in the earlier review I dislike the "normal_exit" notion and
that the loop machinery is in charge of deciding on it.
get_loop_exit_condition should be unnecessary - the vectorizer should
know the exit it considers normal.  The dumping should be also adjusted,
eventually to also dump the edge as %d -> %d.

> Thanks,
> Tamar
> 
> --- inline copy of patch ---
> 
> diff --git a/gcc/cfgloop.h b/gcc/cfgloop.h
> index 528b1219bc37ad8f114d5cf381c0cff899db31ee..9c7f019a51abfe2de8e1dd7135dea2463b0256a0 100644
> --- a/gcc/cfgloop.h
> +++ b/gcc/cfgloop.h
> @@ -385,6 +385,7 @@ extern basic_block *get_loop_body_in_custom_order (const class loop *, void *,
>  
>  extern auto_vec<edge> get_loop_exit_edges (const class loop *, basic_block * = NULL);
>  extern edge single_exit (const class loop *);
> +extern edge normal_exit (const class loop *);
>  extern edge single_likely_exit (class loop *loop, const vec<edge> &);
>  extern unsigned num_loop_branches (const class loop *);
>  
> diff --git a/gcc/cfgloop.cc b/gcc/cfgloop.cc
> index 57bf7b1855d4dd20fb3f42388124932d0ca2b48a..97a7373fb6d9514da602d5be01050f2ec66094bc 100644
> --- a/gcc/cfgloop.cc
> +++ b/gcc/cfgloop.cc
> @@ -1812,6 +1812,20 @@ single_exit (const class loop *loop)
>      return NULL;
>  }
>  
> +/* Returns the normal exit edge of LOOP, or NULL if LOOP has either no exit.
> +   If loops do not have the exits recorded, NULL is returned always.  */
> +
> +edge
> +normal_exit (const class loop *loop)
> +{
> +  struct loop_exit *exit = loop->exits->next;
> +
> +  if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS))
> +    return NULL;
> +
> +  return exit->e;
> +}
> +
>  /* Returns true when BB has an incoming edge exiting LOOP.  */
>  
>  bool
> diff --git a/gcc/doc/loop.texi b/gcc/doc/loop.texi
> index 6e8657a074d2447db7ae9b75cbfbb71282b84287..e1de2ac40f87f879ab691f68bd41b3bc21a83bf7 100644
> --- a/gcc/doc/loop.texi
> +++ b/gcc/doc/loop.texi
> @@ -211,6 +211,10 @@ relation, and breath-first search order, respectively.
>  @item @code{single_exit}: Returns the single exit edge of the loop, or
>  @code{NULL} if the loop has more than one exit.  You can only use this
>  function if @code{LOOPS_HAVE_RECORDED_EXITS} is used.
> +function if LOOPS_HAVE_MARKED_SINGLE_EXITS property is used.
> +@item @code{normal_exit}: Returns the natural exit edge of the loop,
> +even if the loop has more than one exit.  The natural exit is the exit
> +that would normally be taken where the loop to be fully executed.
>  @item @code{get_loop_exit_edges}: Enumerates the exit edges of a loop.
>  @item @code{just_once_each_iteration_p}: Returns true if the basic block
>  is executed exactly once during each iteration of a loop (that is, it
> @@ -623,4 +627,4 @@ maximum verbosity the details of a data dependence relations array,
>  @code{dump_dist_dir_vectors} prints only the classical distance and
>  direction vectors for a data dependence relations array, and
>  @code{dump_data_references} prints the details of the data references
> -contained in a data reference array.
> +contained in a data reference array
> diff --git a/gcc/doc/sourcebuild.texi b/gcc/doc/sourcebuild.texi
> index ffe69d6fcb9c46cf97ba570e85b56e586a0c9b99..a82c7b8f1efa01b02b772c9dd0f5b3dcde817091 100644
> --- a/gcc/doc/sourcebuild.texi
> +++ b/gcc/doc/sourcebuild.texi
> @@ -1637,6 +1637,10 @@ Target supports hardware vectors of @code{float} when
>  @option{-funsafe-math-optimizations} is not in effect.
>  This implies @code{vect_float}.
>  
> +@item vect_early_break
> +Target supports hardware vectorization of loops with early breaks.
> +This requires an implementation of the cbranch optab for vectors.
> +
>  @item vect_int
>  Target supports hardware vectors of @code{int}.
>  
> diff --git a/gcc/genemit.cc b/gcc/genemit.cc
> index 909ac89a16bf9c7830b1710f174e19cbc4a82a51..cf72a9154243d282bc10674c3c83773b76848840 100644
> --- a/gcc/genemit.cc
> +++ b/gcc/genemit.cc
> @@ -905,6 +905,7 @@ from the machine description file `md'.  */\n\n");
>    printf ("#include \"tm-constrs.h\"\n");
>    printf ("#include \"ggc.h\"\n");
>    printf ("#include \"target.h\"\n\n");
> +  printf ("#include \"rtx-vector-builder.h\"\n\n");
>  
>    /* Read the machine description.  */
>  
> diff --git a/gcc/gimple.h b/gcc/gimple.h
> index adbeb063186d4a8e009e4dd184d73609d2c5d78c..a68b29a9136026e5b4d7dcd27e7352dc07a17b52 100644
> --- a/gcc/gimple.h
> +++ b/gcc/gimple.h
> @@ -4756,6 +4756,30 @@ gimple_phi_arg_has_location (const gphi *phi, size_t i)
>    return gimple_phi_arg_location (phi, i) != UNKNOWN_LOCATION;
>  }
>  
> +
> +/* Check if the gimple PHI or any arguments to the phi has a VDEF.  */
> +static inline bool
> +gimple_phi_has_vdef (const gphi *phi)
> +{
> +  for (unsigned i = 0; i < gimple_phi_num_args (phi); i++)
> +    {
> +      tree arg = gimple_phi_arg_def (phi, i);
> +      if (TREE_CODE (arg) != SSA_NAME)
> +	continue;
> +
> +      gimple *def = SSA_NAME_DEF_STMT (arg);
> +      if (gimple_vdef (def))
> +	return true;
> +      if (auto phi = dyn_cast<const gphi *> (def))
> +	{
> +	  if (gimple_phi_has_vdef (phi))

That's going to be exponential for duplicate args across a chain of
PHIs.  It definitely doesn't look like a generic enough helper to
share in gimple.h

> +	    return true;
> +	}
> +    }
> +  return false;
> +}
> +
> +
>  /* Return the number of arguments that can be accessed by gimple_arg.  */
>  
>  static inline unsigned
> diff --git a/gcc/testsuite/g++.dg/vect/vect-early-break_1.cc b/gcc/testsuite/g++.dg/vect/vect-early-break_1.cc
> new file mode 100644
> index 0000000000000000000000000000000000000000..6a83648ca36e2c8feeb78335fccf3f3b82a97d2e
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/vect/vect-early-break_1.cc
> @@ -0,0 +1,61 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-w -O2" } */
> +
> +void fancy_abort(char *, int, const char *) __attribute__((__noreturn__));
> +template <unsigned N, typename> struct poly_int_pod { int coeffs[N]; };
> +template <unsigned N, typename> class poly_int : public poly_int_pod<N, int> {
> +public:
> +  template <typename Ca> poly_int &operator+=(const poly_int_pod<N, Ca> &);
> +};
> +template <unsigned N, typename C>
> +template <typename Ca>
> +poly_int<N, C> &poly_int<N, C>::operator+=(const poly_int_pod<N, Ca> &a) {
> +  for (int i = 0; i < N; i++)
> +    this->coeffs[i] += a.coeffs[i];
> +  return *this;
> +}
> +template <unsigned N, typename Ca, typename Cb>
> +poly_int<N, long> exact_div(poly_int_pod<N, Ca>, Cb) {
> +  poly_int<N, long> r;
> +  return r;
> +}
> +struct vec_prefix {
> +  unsigned m_num;
> +};
> +struct vl_ptr;
> +struct va_heap {
> +  typedef vl_ptr default_layout;
> +};
> +template <typename, typename A, typename = typename A::default_layout>
> +struct vec;
> +template <typename T, typename A> struct vec<T, A, int> {
> +  T &operator[](unsigned);
> +  vec_prefix m_vecpfx;
> +  T m_vecdata[];
> +};
> +template <typename T, typename A> T &vec<T, A, int>::operator[](unsigned ix) {
> +  m_vecpfx.m_num ? fancy_abort("", 9, __FUNCTION__), 0 : 0;
> +  return m_vecdata[ix];
> +}
> +template <typename T> struct vec<T, va_heap> {
> +  T &operator[](unsigned ix) { return m_vec[ix]; }
> +  vec<T, va_heap, int> m_vec;
> +};
> +class auto_vec : public vec<poly_int<2, long>, va_heap> {};
> +template <typename> class vector_builder : public auto_vec {};
> +class int_vector_builder : public vector_builder<int> {
> +public:
> +  int_vector_builder(poly_int<2, long>, int, int);
> +};
> +bool vect_grouped_store_supported() {
> +  int i;
> +  poly_int<2, long> nelt;
> +  int_vector_builder sel(nelt, 2, 3);
> +  for (i = 0; i < 6; i++)
> +    sel[i] += exact_div(nelt, 2);
> +}
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> diff --git a/gcc/testsuite/g++.dg/vect/vect-early-break_2.cc b/gcc/testsuite/g++.dg/vect/vect-early-break_2.cc
> new file mode 100644
> index 0000000000000000000000000000000000000000..6a83648ca36e2c8feeb78335fccf3f3b82a97d2e
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/vect/vect-early-break_2.cc
> @@ -0,0 +1,61 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-w -O2" } */
> +
> +void fancy_abort(char *, int, const char *) __attribute__((__noreturn__));
> +template <unsigned N, typename> struct poly_int_pod { int coeffs[N]; };
> +template <unsigned N, typename> class poly_int : public poly_int_pod<N, int> {
> +public:
> +  template <typename Ca> poly_int &operator+=(const poly_int_pod<N, Ca> &);
> +};
> +template <unsigned N, typename C>
> +template <typename Ca>
> +poly_int<N, C> &poly_int<N, C>::operator+=(const poly_int_pod<N, Ca> &a) {
> +  for (int i = 0; i < N; i++)
> +    this->coeffs[i] += a.coeffs[i];
> +  return *this;
> +}
> +template <unsigned N, typename Ca, typename Cb>
> +poly_int<N, long> exact_div(poly_int_pod<N, Ca>, Cb) {
> +  poly_int<N, long> r;
> +  return r;
> +}
> +struct vec_prefix {
> +  unsigned m_num;
> +};
> +struct vl_ptr;
> +struct va_heap {
> +  typedef vl_ptr default_layout;
> +};
> +template <typename, typename A, typename = typename A::default_layout>
> +struct vec;
> +template <typename T, typename A> struct vec<T, A, int> {
> +  T &operator[](unsigned);
> +  vec_prefix m_vecpfx;
> +  T m_vecdata[];
> +};
> +template <typename T, typename A> T &vec<T, A, int>::operator[](unsigned ix) {
> +  m_vecpfx.m_num ? fancy_abort("", 9, __FUNCTION__), 0 : 0;
> +  return m_vecdata[ix];
> +}
> +template <typename T> struct vec<T, va_heap> {
> +  T &operator[](unsigned ix) { return m_vec[ix]; }
> +  vec<T, va_heap, int> m_vec;
> +};
> +class auto_vec : public vec<poly_int<2, long>, va_heap> {};
> +template <typename> class vector_builder : public auto_vec {};
> +class int_vector_builder : public vector_builder<int> {
> +public:
> +  int_vector_builder(poly_int<2, long>, int, int);
> +};
> +bool vect_grouped_store_supported() {
> +  int i;
> +  poly_int<2, long> nelt;
> +  int_vector_builder sel(nelt, 2, 3);
> +  for (i = 0; i < 6; i++)
> +    sel[i] += exact_div(nelt, 2);
> +}
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> diff --git a/gcc/testsuite/g++.dg/vect/vect-early-break_3.cc b/gcc/testsuite/g++.dg/vect/vect-early-break_3.cc
> new file mode 100644
> index 0000000000000000000000000000000000000000..a12e5ca434b2ac37c03dbaa12273fd8e5aa2018c
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/vect/vect-early-break_3.cc
> @@ -0,0 +1,16 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-w -O2" } */
> +
> +int aarch64_advsimd_valid_immediate_hs_val32;
> +bool aarch64_advsimd_valid_immediate_hs() {
> +  for (int shift = 0; shift < 32; shift += 8)
> +    if (aarch64_advsimd_valid_immediate_hs_val32 & shift)
> +      return aarch64_advsimd_valid_immediate_hs_val32;
> +  for (;;)
> +    ;
> +}
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break-run_1.c b/gcc/testsuite/gcc.dg/vect/vect-early-break-run_1.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..2495b36a72eae94cb7abc4a0d17a5c979fd78083
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break-run_1.c
> @@ -0,0 +1,11 @@
> +/* { dg-do run } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast -save-temps" } */
> +
> +#define N 803
> +#define P 0
> +#include "vect-early-break-template_1.c"
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break-run_10.c b/gcc/testsuite/gcc.dg/vect/vect-early-break-run_10.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..9bcd7f7e57ef9a1d4649d18569b3406050e54603
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break-run_10.c
> @@ -0,0 +1,11 @@
> +/* { dg-do run } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast -save-temps" } */
> +
> +#define N 800
> +#define P 799
> +#include "vect-early-break-template_2.c"
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break-run_2.c b/gcc/testsuite/gcc.dg/vect/vect-early-break-run_2.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..63f63101a467909f328be7f3acbc5bcb721967ff
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break-run_2.c
> @@ -0,0 +1,11 @@
> +/* { dg-do run } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast -save-temps" } */
> +
> +#define N 803
> +#define P 802
> +#include "vect-early-break-template_1.c"
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break-run_3.c b/gcc/testsuite/gcc.dg/vect/vect-early-break-run_3.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..626b95e9b8517081d41d794e9e0264d6301c8589
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break-run_3.c
> @@ -0,0 +1,11 @@
> +/* { dg-do run } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast -save-temps" } */
> +
> +#define N 803
> +#define P 5
> +#include "vect-early-break-template_1.c"
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break-run_4.c b/gcc/testsuite/gcc.dg/vect/vect-early-break-run_4.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..7e0e6426120551152a7bd800c15d9ed6ab15bada
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break-run_4.c
> @@ -0,0 +1,11 @@
> +/* { dg-do run } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast -save-temps" } */
> +
> +#define N 803
> +#define P 278
> +#include "vect-early-break-template_1.c"
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break-run_5.c b/gcc/testsuite/gcc.dg/vect/vect-early-break-run_5.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..242cf486f9c40055df0aef5fd238d1aff7a7c7da
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break-run_5.c
> @@ -0,0 +1,11 @@
> +/* { dg-do run } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast -save-temps" } */
> +
> +#define N 800
> +#define P 799
> +#include "vect-early-break-template_1.c"
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break-run_6.c b/gcc/testsuite/gcc.dg/vect/vect-early-break-run_6.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..9fe7136b7213a463ca6573c60476b7c8f531ddcb
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break-run_6.c
> @@ -0,0 +1,11 @@
> +/* { dg-do run } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast -save-temps" } */
> +
> +#define N 803
> +#define P 0
> +#include "vect-early-break-template_2.c"
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break-run_7.c b/gcc/testsuite/gcc.dg/vect/vect-early-break-run_7.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..02f93d77dba31b938f6fd9e8c7f5e4acde4aeec9
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break-run_7.c
> @@ -0,0 +1,11 @@
> +/* { dg-do run } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast -save-temps" } */
> +
> +#define N 803
> +#define P 802
> +#include "vect-early-break-template_2.c"
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break-run_8.c b/gcc/testsuite/gcc.dg/vect/vect-early-break-run_8.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..a614925465606b54c638221ffb95a5e8d3bee797
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break-run_8.c
> @@ -0,0 +1,11 @@
> +/* { dg-do run } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast -save-temps" } */
> +
> +#define N 803
> +#define P 5
> +#include "vect-early-break-template_2.c"
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break-run_9.c b/gcc/testsuite/gcc.dg/vect/vect-early-break-run_9.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..94e2b9c301456eda8f9ad7eaa67604563f0afee7
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break-run_9.c
> @@ -0,0 +1,11 @@
> +/* { dg-do run } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast -save-temps" } */
> +
> +#define N 803
> +#define P 278
> +#include "vect-early-break-template_2.c"
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break-template_1.c b/gcc/testsuite/gcc.dg/vect/vect-early-break-template_1.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..af70a8e2a5a9dc9756edb5580f2de02ddcc95de9
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break-template_1.c
> @@ -0,0 +1,47 @@
> +#ifndef N
> +#define N 803
> +#endif
> +
> +#ifndef P
> +#define P 0
> +#endif
> +
> +unsigned vect_a[N] = {0};
> +unsigned vect_b[N] = {0};
> +  
> +__attribute__((noipa, noinline))
> +unsigned test4(unsigned x)
> +{
> + unsigned ret = 0;
> + for (int i = 0; i < N; i++)
> + {
> +   vect_b[i] = x + i;
> +   if (vect_a[i] > x)
> +     break;
> +   vect_a[i] = x;
> +   
> + }
> + return ret;
> +}
> +
> +extern void abort ();
> +
> +int main ()
> +{
> +
> +  int x = 1;
> +  int idx = P;
> +  vect_a[idx] = x + 1;
> +
> +  test4(x);
> +
> +  if (vect_b[idx] != (x + idx))
> +    abort ();
> +
> +  if (vect_a[idx] != x + 1)
> +    abort ();
> +
> +  if (idx > 0 && vect_a[idx-1] != x)
> +    abort ();
> +
> +}
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break-template_2.c b/gcc/testsuite/gcc.dg/vect/vect-early-break-template_2.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..d0f924d904437e71567d27cc1f1089e5607dca0d
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break-template_2.c
> @@ -0,0 +1,50 @@
> +#ifndef N
> +#define N 803
> +#endif
> +
> +#ifndef P
> +#define P 0
> +#endif
> +
> +unsigned vect_a[N] = {0};
> +unsigned vect_b[N] = {0};
> +  
> +__attribute__((noipa, noinline))
> +unsigned test4(unsigned x)
> +{
> + unsigned ret = 0;
> + for (int i = 0; i < N; i++)
> + {
> +   vect_b[i] = x + i;
> +   if (vect_a[i] > x)
> +     return i;
> +   vect_a[i] = x;
> +   
> + }
> + return ret;
> +}
> +
> +extern void abort ();
> +
> +int main ()
> +{
> +
> +  int x = 1;
> +  int idx = P;
> +  vect_a[idx] = x + 1;
> +
> +  unsigned res = test4(x);
> +
> +  if (res != idx)
> +    abort ();
> +
> +  if (vect_b[idx] != (x + idx))
> +    abort ();
> +
> +  if (vect_a[idx] != x + 1)
> +    abort ();
> +
> +  if (idx > 0 && vect_a[idx-1] != x)
> +    abort ();
> +
> +}
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_1.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_1.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..51e7d6489b99c25b9b4b3d1c839f98562b6d4dd7
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_1.c
> @@ -0,0 +1,27 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast" } */
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> +
> +#ifndef N
> +#define N 803
> +#endif
> +unsigned vect_a[N];
> +unsigned vect_b[N];
> +  
> +unsigned test4(unsigned x)
> +{
> + unsigned ret = 0;
> + for (int i = 0; i < N; i++)
> + {
> +   vect_b[i] = x + i;
> +   if (vect_a[i] > x)
> +     break;
> +   vect_a[i] = x;
> +   
> + }
> + return ret;
> +}
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_10.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_10.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..9e4ad1763202dfdab3ed7961ead5114fcc61a11b
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_10.c
> @@ -0,0 +1,28 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast" } */
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> +
> +#ifndef N
> +#define N 803
> +#endif
> +unsigned vect_a[N];
> +unsigned vect_b[N];
> +  
> +unsigned test4(unsigned x,int y, int z)
> +{
> + unsigned ret = 0;
> + for (int i = 0; i < N; i++)
> + {
> +   vect_b[i] = x + i;
> +   if (vect_a[i] > x)
> +     break;
> +   vect_a[i] = x;
> + }
> +
> + ret = x + y * z;
> + return ret;
> +}
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_11.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_11.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..a613dd9909fb09278dd92a81a24ef854994a9890
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_11.c
> @@ -0,0 +1,31 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast" } */
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> +
> +#ifndef N
> +#define N 803
> +#endif
> +unsigned vect_a[N];
> +unsigned vect_b[N];
> +  
> +unsigned test4(unsigned x, int y)
> +{
> + unsigned ret = 0;
> +for (int o = 0; o < y; o++)
> +{
> + ret += o;
> + for (int i = 0; i < N; i++)
> + {
> +   vect_b[i] = x + i;
> +   if (vect_a[i] > x)
> +     break;
> +   vect_a[i] = x;
> +   
> + }
> +}
> + return ret;
> +}
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_12.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_12.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..cc10f3238f1cb8e1307e024a3ebcb5c25a39d1b2
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_12.c
> @@ -0,0 +1,31 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast" } */
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> +
> +#ifndef N
> +#define N 803
> +#endif
> +unsigned vect_a[N];
> +unsigned vect_b[N];
> +  
> +unsigned test4(unsigned x, int y)
> +{
> + unsigned ret = 0;
> +for (int o = 0; o < y; o++)
> +{
> + ret += o;
> + for (int i = 0; i < N; i++)
> + {
> +   vect_b[i] = x + i;
> +   if (vect_a[i] > x)
> +     return vect_a[i];
> +   vect_a[i] = x;
> +   
> + }
> +}
> + return ret;
> +}
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_13.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_13.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..6967b7395ed7c19e38a436d6edcfe7c1580c7113
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_13.c
> @@ -0,0 +1,27 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast" } */
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> +
> +#ifndef N
> +#define N 803
> +#endif
> +unsigned vect_a[N];
> +unsigned vect_b[N];
> +  
> +unsigned test4(unsigned x)
> +{
> + unsigned ret = 0;
> + for (int i = 0; i < N; i++)
> + {
> +   vect_b[i] = x + i;
> +   if (vect_a[i] > x)
> +     return vect_a[i] * x;
> +   vect_a[i] = x;
> +   
> + }
> + return ret;
> +}
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_14.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_14.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..03cce5cf6cadecb520b46be666bf608e3bc6a511
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_14.c
> @@ -0,0 +1,25 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast" } */
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> +
> +#define N 803
> +unsigned vect_a[N];
> +unsigned vect_b[N];
> +  
> +int test4(unsigned x)
> +{
> + unsigned ret = 0;
> + for (int i = 0; i < N; i++)
> + {
> +   vect_b[i] = x + i;
> +   if (vect_a[i] > x)
> +     return i;
> +   vect_a[i] += x * vect_b[i];
> +   
> + }
> + return ret;
> +}
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_15.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_15.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..dec6872e1115ff66695f5a500ffa7ca01c0f8d3a
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_15.c
> @@ -0,0 +1,25 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast" } */
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> +
> +#define N 803
> +unsigned vect_a[N];
> +unsigned vect_b[N];
> +  
> +int test4(unsigned x)
> +{
> + int ret = 0;
> + for (int i = 0; i < N; i++)
> + {
> +   vect_b[i] = x + i;
> +   if (vect_a[i] > x)
> +     return i;
> +   vect_a[i] += x * vect_b[i];
> +   
> + }
> + return ret;
> +}
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_16.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_16.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..30812d12a39bd94b4b8a3aade6512b162697d659
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_16.c
> @@ -0,0 +1,25 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast" } */
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> +
> +#define N 1024
> +unsigned vect_a[N];
> +unsigned vect_b[N];
> + 
> +unsigned test4(unsigned x)
> +{
> + unsigned ret = 0;
> + for (int i = 0; i < N; i++)
> + {
> +   vect_b[i] = x + i;
> +   if (vect_a[i] > x)
> +     return vect_a[i];
> +   vect_a[i] = x;
> +   ret += vect_a[i] + vect_b[i];
> + }
> + return ret;
> +}
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_17.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_17.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..510227a18435a8e47c5a754580180c6d340c0823
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_17.c
> @@ -0,0 +1,25 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast" } */
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> +
> +#define N 1024
> +unsigned vect_a[N];
> +unsigned vect_b[N];
> + 
> +unsigned test4(unsigned x)
> +{
> + unsigned ret = 0;
> + for (int i = 0; i < N; i++)
> + {
> +   vect_b[i] = x + i;
> +   if (vect_a[i] > x)
> +     return vect_a[i];
> +   vect_a[i] = x;
> +   ret = vect_a[i] + vect_b[i];
> + }
> + return ret;
> +}
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_2.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_2.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..7268f6ae2485d0274fd85ea53cc1e44ef4b84d5c
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_2.c
> @@ -0,0 +1,27 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast" } */
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> +
> +#include <complex.h>
> +
> +#define N 1024
> +complex double vect_a[N];
> +complex double vect_b[N];
> +  
> +complex double test4(complex double x)
> +{
> + complex double ret = 0;
> + for (int i = 0; i < N; i++)
> + {
> +   vect_b[i] += x + i;
> +   if (vect_a[i] == x)
> +     return i;
> +   vect_a[i] += x * vect_b[i];
> +   
> + }
> + return ret;
> +}
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_3.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_3.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..3c6d28bd2d6e6e794146baf89e43c3b70293b7d9
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_3.c
> @@ -0,0 +1,20 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast" } */
> +
> +/* { dg-final { scan-tree-dump-not "LOOP VECTORIZED" "vect" } } */
> +
> +unsigned test4(char x, char *vect, int n)
> +{  
> + unsigned ret = 0;
> + for (int i = 0; i < n; i++)
> + {
> +   if (vect[i] > x)
> +     return 1;
> +
> +   vect[i] = x;
> + }
> + return ret;
> +}
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_4.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_4.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..216c56faf330449bf1969b7e51ff1e94270dc861
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_4.c
> @@ -0,0 +1,23 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast" } */
> +
> +/* { dg-final { scan-tree-dump-not "LOOP VECTORIZED" "vect" } } */
> +
> +#define N 1024
> +unsigned vect[N];
> +
> +unsigned test4(unsigned x)
> +{
> + unsigned ret = 0;
> + for (int i = 0; i < N; i++)
> + {
> +   if (i > 16 && vect[i] > x)
> +     break;
> +
> +   vect[i] = x;
> + }
> + return ret;
> +}
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_5.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_5.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..4a36d6979db1fd1f97ba2a290f78ac3b84f6de24
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_5.c
> @@ -0,0 +1,24 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast" } */
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> +
> +#define N 1024
> +unsigned vect_a[N];
> +unsigned vect_b[N];
> + 
> +unsigned test4(unsigned x)
> +{
> + unsigned ret = 0;
> + for (int i = 0; i < N; i++)
> + {
> +   vect_b[i] = x + i;
> +   if (vect_a[i] > x)
> +     return vect_a[i];
> +   vect_a[i] = x;
> + }
> + return ret;
> +}
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_6.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_6.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..09632d9afda7e07f1a8417514ef77356f00045bd
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_6.c
> @@ -0,0 +1,26 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast" } */
> +
> +/* { dg-final { scan-tree-dump-not "LOOP VECTORIZED" "vect" } } */
> +
> +#define N 1024
> +unsigned vect_a[N];
> +unsigned vect_b[N];
> +  
> +unsigned test4(unsigned x)
> +{
> + unsigned ret = 0;
> + for (int i = 0; i < (N/2); i+=2)
> + {
> +   vect_b[i] = x + i;
> +   vect_b[i+1] = x + i+1;
> +   if (vect_a[i] > x || vect_a[i+1] > x)
> +     break;
> +   vect_a[i] += x * vect_b[i];
> +   vect_a[i+1] += x * vect_b[i+1]; 
> + }
> + return ret;
> +}
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_7.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_7.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..10fd8b42952c42f3d3a014da103931ca394423d5
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_7.c
> @@ -0,0 +1,27 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast" } */
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> +
> +#include <complex.h>
> +
> +#define N 1024
> +complex double vect_a[N];
> +complex double vect_b[N];
> +  
> +complex double test4(complex double x)
> +{
> + complex double ret = 0;
> + for (int i = 0; i < N; i++)
> + {
> +   vect_b[i] += x + i;
> +   if (vect_a[i] == x)
> +     break;
> +   vect_a[i] += x * vect_b[i];
> +   
> + }
> + return ret;
> +}
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_8.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_8.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..ae706b2952cfcecf20546a67a735b8d902cbb607
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_8.c
> @@ -0,0 +1,27 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast" } */
> +
> +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
> +
> +#include <complex.h>
> +
> +#define N 1024
> +char vect_a[N];
> +char vect_b[N];
> +  
> +char test4(char x, char * restrict res)
> +{
> + char ret = 0;
> + for (int i = 0; i < N; i++)
> + {
> +   vect_b[i] += x + i;
> +   if (vect_a[i] > x)
> +     break;
> +   vect_a[i] += x * vect_b[i];
> +   res[i] *= vect_b[i];
> + }
> + return ret;
> +}
> diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_9.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_9.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..350f02f3c7caef457adbe1be802bba51cd818393
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_9.c
> @@ -0,0 +1,27 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target vect_early_break } */
> +/* { dg-require-effective-target vect_int } */
> +
> +/* { dg-additional-options "-Ofast" } */
> +
> +/* { dg-final { scan-tree-dump-not "LOOP VECTORIZED" "vect" } } */
> +
> +#ifndef N
> +#define N 803
> +#endif
> +unsigned vect_a[N];
> +unsigned vect_b[N];
> +  
> +unsigned test4(unsigned x)
> +{
> + unsigned ret = 0;
> + for (int i = 0; i < N; i++)
> + {
> +   vect_a[i] = x + i;
> +   if (vect_a[i] > x)
> +     break;
> +   vect_a[i] = x;
> +   
> + }
> + return ret;
> +}
> diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
> index 2a058c67c53466fe41b748d37ab660afd4e3403f..49b3099bf5187b1273ff07808692d62f2cfdfa55 100644
> --- a/gcc/testsuite/lib/target-supports.exp
> +++ b/gcc/testsuite/lib/target-supports.exp
> @@ -3659,6 +3659,17 @@ proc check_effective_target_vect_int { } {
>  	}}]
>  }
>  
> +# Return 1 if the target supports hardware vectorization of early breaks,
> +# 0 otherwise.
> +#
> +# This won't change for different subtargets so cache the result.
> +
> +proc check_effective_target_vect_early_break { } {
> +    return [check_cached_effective_target_indexed vect_early_break {
> +      expr {
> +	[istarget aarch64*-*-*]
> +	}}]
> +}
>  # Return 1 if the target supports hardware vectorization of complex additions of
>  # byte, 0 otherwise.
>  #
> diff --git a/gcc/tree-scalar-evolution.h b/gcc/tree-scalar-evolution.h
> index 0f90207bc733db3cf85979d9b0b962aefa0831d6..5af7d2bba0d62195704a8d41ef6e600327169770 100644
> --- a/gcc/tree-scalar-evolution.h
> +++ b/gcc/tree-scalar-evolution.h
> @@ -23,6 +23,7 @@ along with GCC; see the file COPYING3.  If not see
>  
>  extern tree number_of_latch_executions (class loop *);
>  extern gcond *get_loop_exit_condition (const class loop *);
> +extern gcond *get_edge_condition (edge);
>  
>  extern void scev_initialize (void);
>  extern bool scev_initialized_p (void);
> diff --git a/gcc/tree-scalar-evolution.cc b/gcc/tree-scalar-evolution.cc
> index f75398afb7c9fdf42e69e940e2232942143049f6..105cee39277741535252fea56c17f7c047003ce1 100644
> --- a/gcc/tree-scalar-evolution.cc
> +++ b/gcc/tree-scalar-evolution.cc
> @@ -884,7 +884,7 @@ scev_dfs::add_to_evolution (tree chrec_before, enum tree_code code,
>    return res;
>  }
>  
> -
> +
> 
>  /* Follow the ssa edge into the binary expression RHS0 CODE RHS1.
>     Return true if the strongly connected component has been found.  */
>  
> @@ -1293,8 +1293,15 @@ scev_dfs::follow_ssa_edge_expr (gimple *at_stmt, tree expr,
>  gcond *
>  get_loop_exit_condition (const class loop *loop)
>  {
> +  return get_edge_condition (normal_exit (loop));
> +}
> +
> +/* If the statement just before the EXIT_EDGE contains a condition then
> +   return the condition, otherwise NULL. */
> +
> +gcond *
> +get_edge_condition (edge exit_edge){
>    gcond *res = NULL;
> -  edge exit_edge = single_exit (loop);
>  
>    if (dump_file && (dump_flags & TDF_SCEV))
>      fprintf (dump_file, "(get_loop_exit_condition \n  ");
> diff --git a/gcc/tree-vect-data-refs.cc b/gcc/tree-vect-data-refs.cc
> index 18b0f962670ffc86fe5cc4e633097f3ce45341fe..2a2f3b4acb5905a2ba1f9d3b54a08a55028cd462 100644
> --- a/gcc/tree-vect-data-refs.cc
> +++ b/gcc/tree-vect-data-refs.cc
> @@ -570,6 +570,144 @@ vect_analyze_data_ref_dependence (struct data_dependence_relation *ddr,
>    return opt_result::success ();
>  }
>  
> +/* This function tries to validate whether an early break vectorization
> +   is possible for the current instruction sequence. Returns True i
> +   possible, otherwise False.
> +
> +   Requirements:
> +     - Any memory access must be to a fixed size buffer.
> +     - There must not be any loads and stores to the same object.
> +     - Multiple loads are allowed as long as they don't alias.
> +
> +
> +   Arguments:
> +     - LOOP_VINFO: loop information for the current loop.
> +     - CHAIN: Currently detected sequence of instructions that belong
> +	      to the current early break.
> +     - LOADS: List of all loads found during traversal.
> +     - BASES: List of all load datareferences found during traversal.
> +     - GSTMT: Current position to inspect for validity.  The sequence
> +	      will be moved upwards from this point.  */
> +
> +static bool
> +validate_early_exit_stmts (loop_vec_info loop_vinfo, hash_set<tree> *chain,
> +			   vec<tree> *loads, vec<data_reference *> *bases,
> +			   gimple_stmt_iterator *gstmt)
> +{
> +  if (gsi_end_p (*gstmt))
> +    return true;
> +
> +  gimple *stmt = gsi_stmt (*gstmt);
> +  if (gimple_has_ops (stmt))
> +    {
> +      tree dest = NULL_TREE;
> +      /* Try to find the SSA_NAME being defined.  For Statements with an LHS
> +	 use the LHS, if not, assume that the first argument of a call is the
> +	 value being defined.  e.g. MASKED_LOAD etc.  */
> +      if (gimple_has_lhs (stmt))
> +	{
> +	  if (is_gimple_assign (stmt))
> +	    dest = gimple_assign_lhs (stmt);
> +	  else if (const gcall *call = dyn_cast <const gcall *> (stmt))
> +	    dest = gimple_call_lhs (call);
> +	}
> +      else if (const gcall *call = dyn_cast <const gcall *> (stmt))
> +	dest = gimple_arg (call, 0);
> +
> +      /* Don't move the scalar instructions.  */
> +      bool move
> +	= dest && (VECTOR_TYPE_P (TREE_TYPE (dest))
> +		   || POINTER_TYPE_P (TREE_TYPE (dest)));
> +
> +      /* If we found the defining statement of a something that's part of the
> +	 chain then expand the chain with the new SSA_VARs being used.  */
> +      if (chain->contains (dest))
> +	{
> +	  for (unsigned x = 0; x < gimple_num_args (stmt); x++)
> +	    if (TREE_CODE (gimple_arg (stmt, x)) == SSA_NAME)
> +	      chain->add (gimple_arg (stmt, x));
> +
> +	  if (dump_enabled_p ())
> +	      dump_printf_loc (MSG_NOTE, vect_location,
> +				"found chain %G", stmt);
> +
> +	  move = false;
> +	}
> +
> +      stmt_vec_info stmt_vinfo = loop_vinfo->lookup_stmt (stmt);
> +      if (!stmt_vinfo)
> +	{
> +	   if (dump_enabled_p ())
> +	     dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
> +			      "early breaks only supported. Unknown"
> +			      " statement: %G", stmt);
> +	   return false;
> +	}
> +
> +      auto dr_ref = STMT_VINFO_DATA_REF (stmt_vinfo);
> +      if (dr_ref)
> +	{
> +	   /* We currenly only support statically allocated objects due to
> +	      not having first-faulting loads support or peeling for alignment
> +	      support.  Compute the isize of the referenced object (it could be
> +	      dynamically allocated).  */
> +	   tree obj = DR_BASE_ADDRESS (dr_ref);
> +	   if (!obj || TREE_CODE (obj) != ADDR_EXPR)
> +	     {
> +	       if (dump_enabled_p ())
> +		 dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
> +				  "early breaks only supported on statically"
> +				  " allocated objects.\n");
> +	       return false;
> +	     }
> +
> +	   tree refop = TREE_OPERAND (obj, 0);
> +	   tree refbase = get_base_address (refop);
> +	   if (!refbase || !DECL_P (refbase) || !DECL_SIZE (refbase)
> +	       || TREE_CODE (DECL_SIZE (refbase)) != INTEGER_CST)
> +	     {
> +	       if (dump_enabled_p ())
> +		 dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
> +				  "early breaks only supported on statically"
> +				  " allocated objects.\n");
> +	       return false;
> +	     }
> +
> +	   if (!move && DR_IS_READ (dr_ref))
> +	     {
> +		loads->safe_push (dest);
> +		bases->safe_push (dr_ref);
> +	     }
> +	   else if (DR_IS_WRITE (dr_ref))
> +	     {
> +		for (auto dr : bases)
> +		  if (same_data_refs_base_objects (dr, dr_ref))
> +		    return false;
> +	     }
> +	}
> +
> +      if (move)
> +	{
> +	  if (dump_enabled_p ())
> +	    dump_printf_loc (MSG_NOTE, vect_location,
> +		             "analyzing stmt %G", stmt);
> +
> +	  for (tree ref : loads)
> +	    if (stmt_may_clobber_ref_p (stmt, ref, true))
> +	      {
> +	        if (dump_enabled_p ())
> +		  dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
> +				   "early breaks not supported as memory used"
> +				   " may alias.\n");
> +	        return false;
> +	      }
> +	}
> +    }
> +
> +  gsi_prev (gstmt);
> +  return validate_early_exit_stmts (loop_vinfo, chain, loads, bases, gstmt);
> +}
> +
>  /* Function vect_analyze_data_ref_dependences.
>  
>     Examine all the data references in the loop, and make sure there do not
> @@ -614,6 +752,32 @@ vect_analyze_data_ref_dependences (loop_vec_info loop_vinfo,
>  	  return res;
>        }
>  
> +  /* If we have early break statements in the loop, check to see if they
> +     are of a form we can vectorizer.  */
> +  if (LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
> +    {
> +      hash_set<tree> chain;
> +      auto_vec<tree> loads;
> +      auto_vec<data_reference *> bases;
> +
> +      for (gcond *c : LOOP_VINFO_LOOP_CONDS (loop_vinfo))
> +	{
> +	  stmt_vec_info loop_cond_info = loop_vinfo->lookup_stmt (c);
> +	  if (STMT_VINFO_TYPE (loop_cond_info) != loop_exit_ctrl_vec_info_type)
> +	    continue;
> +
> +	  gimple *stmt = STMT_VINFO_STMT (loop_cond_info);
> +	  gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
> +
> +	  if (!validate_early_exit_stmts (loop_vinfo, &chain, &loads, &bases,
> +					  &gsi))
> +	    return opt_result::failure_at (stmt,
> +				 	   "can't safely apply code motion to "
> +					   "dependencies of %G to vectorize "
> +					   "the early exit.\n", stmt);
> +	}
> +    }
> +
>    return opt_result::success ();
>  }
>  
> @@ -2072,7 +2236,7 @@ vect_enhance_data_refs_alignment (loop_vec_info loop_vinfo)
>  
>    /* Check if we can possibly peel the loop.  */
>    if (!vect_can_advance_ivs_p (loop_vinfo)
> -      || !slpeel_can_duplicate_loop_p (loop, single_exit (loop))
> +      || !slpeel_can_duplicate_loop_p (loop_vinfo, normal_exit (loop))
>        || loop->inner)
>      do_peeling = false;
>  
> diff --git a/gcc/tree-vect-generic.cc b/gcc/tree-vect-generic.cc
> index 6ad6372c55eef94a742a8fa35e79d66aa24e2f3b..632fbf38d91c08f54e731d69ab56f2b8c554d456 100644
> --- a/gcc/tree-vect-generic.cc
> +++ b/gcc/tree-vect-generic.cc
> @@ -500,7 +500,7 @@ expand_vector_comparison (gimple_stmt_iterator *gsi, tree type, tree op0,
>  	    }
>  	  t = gimplify_build1 (gsi, VIEW_CONVERT_EXPR, type, t);
>  	}
> -      else
> +      else if (TYPE_VECTOR_SUBPARTS (type).is_constant ())
>  	t = expand_vector_piecewise (gsi, do_compare, type,
>  				     TREE_TYPE (TREE_TYPE (op0)), op0, op1,
>  				     code, false);
> diff --git a/gcc/tree-vect-loop-manip.cc b/gcc/tree-vect-loop-manip.cc
> index 1d96130c985e2defd141cfdf602224c73b4b41f2..2b121b0c44ea69b0af93f52fd8596f5495867125 100644
> --- a/gcc/tree-vect-loop-manip.cc
> +++ b/gcc/tree-vect-loop-manip.cc
> @@ -770,7 +770,7 @@ vect_set_loop_condition_partial_vectors (class loop *loop,
>    add_header_seq (loop, header_seq);
>  
>    /* Get a boolean result that tells us whether to iterate.  */
> -  edge exit_edge = single_exit (loop);
> +  edge exit_edge = normal_exit (loop);
>    tree_code code = (exit_edge->flags & EDGE_TRUE_VALUE) ? EQ_EXPR : NE_EXPR;
>    tree zero_ctrl = build_zero_cst (TREE_TYPE (test_ctrl));
>    gcond *cond_stmt = gimple_build_cond (code, test_ctrl, zero_ctrl,
> @@ -789,7 +789,7 @@ vect_set_loop_condition_partial_vectors (class loop *loop,
>    if (final_iv)
>      {
>        gassign *assign = gimple_build_assign (final_iv, orig_niters);
> -      gsi_insert_on_edge_immediate (single_exit (loop), assign);
> +      gsi_insert_on_edge_immediate (exit_edge, assign);
>      }
>  
>    return cond_stmt;
> @@ -799,7 +799,8 @@ vect_set_loop_condition_partial_vectors (class loop *loop,
>     loop handles exactly VF scalars per iteration.  */
>  
>  static gcond *
> -vect_set_loop_condition_normal (class loop *loop, tree niters, tree step,
> +vect_set_loop_condition_normal (loop_vec_info loop_vinfo,
> +				class loop *loop, tree niters, tree step,
>  				tree final_iv, bool niters_maybe_zero,
>  				gimple_stmt_iterator loop_cond_gsi)
>  {
> @@ -807,7 +808,7 @@ vect_set_loop_condition_normal (class loop *loop, tree niters, tree step,
>    gcond *cond_stmt;
>    gcond *orig_cond;
>    edge pe = loop_preheader_edge (loop);
> -  edge exit_edge = single_exit (loop);
> +  edge exit_edge = normal_exit (loop);
>    gimple_stmt_iterator incr_gsi;
>    bool insert_after;
>    enum tree_code code;
> @@ -872,7 +873,11 @@ vect_set_loop_condition_normal (class loop *loop, tree niters, tree step,
>  	 In both cases the loop limit is NITERS - STEP.  */
>        gimple_seq seq = NULL;
>        limit = force_gimple_operand (niters, &seq, true, NULL_TREE);
> -      limit = gimple_build (&seq, MINUS_EXPR, TREE_TYPE (limit), limit, step);
> +      /* For VLA leave limit == niters.  Though I wonder if maybe I should
> +	 force partial loops here and use vect_set_loop_condition_partial_vectors
> +	 instead.  The problem is that the VL check is useless here.  */
> +      if (!LOOP_VINFO_EARLY_BREAKS (loop_vinfo) && !LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo))
> +	limit = gimple_build (&seq, MINUS_EXPR, TREE_TYPE (limit), limit, step);
>        if (seq)
>  	{
>  	  basic_block new_bb = gsi_insert_seq_on_edge_immediate (pe, seq);
> @@ -907,7 +912,8 @@ vect_set_loop_condition_normal (class loop *loop, tree niters, tree step,
>    gsi_insert_before (&loop_cond_gsi, cond_stmt, GSI_SAME_STMT);
>  
>    /* Record the number of latch iterations.  */
> -  if (limit == niters)
> +  if (limit == niters
> +      || LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
>      /* Case A: the loop iterates NITERS times.  Subtract one to get the
>         latch count.  */
>      loop->nb_iterations = fold_build2 (MINUS_EXPR, niters_type, niters,
> @@ -918,10 +924,17 @@ vect_set_loop_condition_normal (class loop *loop, tree niters, tree step,
>      loop->nb_iterations = fold_build2 (TRUNC_DIV_EXPR, niters_type,
>  				       limit, step);
>  
> -  if (final_iv)
> +  auto_vec<edge> exits = get_loop_exit_edges (loop);
> +  /* For multiple exits we've already maintained LCSSA form and handled
> +     the scalar iteration update in the code that deals with the merge
> +     block and its updated guard.  I could move that code here instead
> +     of in vect_update_ivs_after_early_break but I have to still deal
> +     with the updates to the counter `i`.  So for now I'll keep them
> +     together.  */
> +  if (final_iv && exits.length () == 1)
>      {
>        gassign *assign;
> -      edge exit = single_exit (loop);
> +      edge exit = normal_exit (loop);
>        gcc_assert (single_pred_p (exit->dest));
>        tree phi_dest
>  	= integer_zerop (init) ? final_iv : copy_ssa_name (indx_after_incr);
> @@ -972,13 +985,15 @@ vect_set_loop_condition (class loop *loop, loop_vec_info loop_vinfo,
>    gcond *orig_cond = get_loop_exit_condition (loop);
>    gimple_stmt_iterator loop_cond_gsi = gsi_for_stmt (orig_cond);
>  
> -  if (loop_vinfo && LOOP_VINFO_USING_PARTIAL_VECTORS_P (loop_vinfo))
> +  if (loop_vinfo
> +      && LOOP_VINFO_USING_PARTIAL_VECTORS_P (loop_vinfo))
>      cond_stmt = vect_set_loop_condition_partial_vectors (loop, loop_vinfo,
>  							 niters, final_iv,
>  							 niters_maybe_zero,
>  							 loop_cond_gsi);
>    else
> -    cond_stmt = vect_set_loop_condition_normal (loop, niters, step, final_iv,
> +    cond_stmt = vect_set_loop_condition_normal (loop_vinfo, loop, niters,
> +						step, final_iv,
>  						niters_maybe_zero,
>  						loop_cond_gsi);
>  
> @@ -1066,7 +1081,7 @@ slpeel_tree_duplicate_loop_to_edge_cfg (class loop *loop,
>    edge exit, new_exit;
>    bool duplicate_outer_loop = false;
>  
> -  exit = single_exit (loop);
> +  exit = normal_exit (loop);
>    at_exit = (e == exit);
>    if (!at_exit && e != loop_preheader_edge (loop))
>      return NULL;
> @@ -1104,11 +1119,11 @@ slpeel_tree_duplicate_loop_to_edge_cfg (class loop *loop,
>    bbs[0] = preheader;
>    new_bbs = XNEWVEC (basic_block, scalar_loop->num_nodes + 1);
>  
> -  exit = single_exit (scalar_loop);
> +  exit = normal_exit (scalar_loop);
>    copy_bbs (bbs, scalar_loop->num_nodes + 1, new_bbs,
>  	    &exit, 1, &new_exit, NULL,
>  	    at_exit ? loop->latch : e->src, true);
> -  exit = single_exit (loop);
> +  exit = normal_exit (loop);
>    basic_block new_preheader = new_bbs[0];
>  
>    /* Before installing PHI arguments make sure that the edges
> @@ -1176,10 +1191,30 @@ slpeel_tree_duplicate_loop_to_edge_cfg (class loop *loop,
>  	      add_phi_arg (phi, orig_arg, new_exit, orig_locus);
>  	    }
>  	}
> +
> +      /* if have multiple exist, we now need to point the additional exits
> +	 from the old loop to the loop pre-header of the new copied loop.
> +	 Currently we only support simple early break vectorization so all
> +	 additional exits must exit the loop. Additionally we can only place
> +	 copies at the end.  i.e. we cannot do prologue peeling.  */
> +      auto_vec<edge> exits = get_loop_exit_edges (loop);
> +      bool multiple_exits_p = exits.length () > 1;
> +
> +      for (unsigned i = 1; i < exits.length (); i++)
> +	{
> +	  redirect_edge_and_branch (exits[i], new_preheader);
> +	  flush_pending_stmts (exits[i]);
> +	}
> +
> +      /* Main exit must be the last to be rewritten as it's the first phi node
> +	 entry.  The rest are in array order.  */
>        redirect_edge_and_branch_force (e, new_preheader);
>        flush_pending_stmts (e);
> +
>        set_immediate_dominator (CDI_DOMINATORS, new_preheader, e->src);
> -      if (was_imm_dom || duplicate_outer_loop)
> +
> +      auto_vec<edge> new_exits = get_loop_exit_edges (new_loop);
> +      if ((was_imm_dom || duplicate_outer_loop) && !multiple_exits_p)
>  	set_immediate_dominator (CDI_DOMINATORS, exit_dest, new_exit->src);
>  
>        /* And remove the non-necessary forwarder again.  Keep the other
> @@ -1189,6 +1224,23 @@ slpeel_tree_duplicate_loop_to_edge_cfg (class loop *loop,
>        delete_basic_block (preheader);
>        set_immediate_dominator (CDI_DOMINATORS, scalar_loop->header,
>  			       loop_preheader_edge (scalar_loop)->src);
> +
> +      /* Finally after wiring the new epilogue we need to update its main exit
> +	 to the original function exit we recorded.  Other exits are already
> +	 correct.  */
> +      if (multiple_exits_p)
> +	{
> +	  auto_vec<basic_block> doms;
> +	  for (edge e : exits)
> +	    doms.safe_push (e->dest);
> +	  for (edge e : new_exits)
> +	    doms.safe_push (e->dest);
> +	  doms.safe_push (exit_dest);
> +	  /* Likely a fall-through edge, so update if needed.  */
> +	  if (single_succ_p (exit_dest))
> +	    doms.safe_push (single_succ (exit_dest));
> +	  iterate_fix_dominators (CDI_DOMINATORS, doms, false);
> +	}
>      }
>    else /* Add the copy at entry.  */
>      {
> @@ -1310,20 +1362,24 @@ slpeel_add_loop_guard (basic_block guard_bb, tree cond,
>   */
>  
>  bool
> -slpeel_can_duplicate_loop_p (const class loop *loop, const_edge e)
> +slpeel_can_duplicate_loop_p (const loop_vec_info loop_vinfo, const_edge e)
>  {
> -  edge exit_e = single_exit (loop);
> +  class loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
> +  edge exit_e = normal_exit (loop);
>    edge entry_e = loop_preheader_edge (loop);
>    gcond *orig_cond = get_loop_exit_condition (loop);
>    gimple_stmt_iterator loop_exit_gsi = gsi_last_bb (exit_e->src);
>    unsigned int num_bb = loop->inner? 5 : 2;
>  
> +  if (LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
> +    num_bb += 1;
> +
>    /* All loops have an outer scope; the only case loop->outer is NULL is for
>       the function itself.  */
>    if (!loop_outer (loop)
>        || loop->num_nodes != num_bb
>        || !empty_block_p (loop->latch)
> -      || !single_exit (loop)
> +      || (!single_exit (loop) && !LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
>        /* Verify that new loop exit condition can be trivially modified.  */
>        || (!orig_cond || orig_cond != gsi_stmt (loop_exit_gsi))
>        || (e != exit_e && e != entry_e))
> @@ -1528,6 +1584,12 @@ vect_update_ivs_after_vectorizer (loop_vec_info loop_vinfo,
>    gphi_iterator gsi, gsi1;
>    class loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
>    basic_block update_bb = update_e->dest;
> +
> +  /* For early exits we'll update the IVs in
> +     vect_update_ivs_after_early_break.  */
> +  if (LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
> +    return;
> +
>    basic_block exit_bb = single_exit (loop)->dest;
>  
>    /* Make sure there exists a single-predecessor exit bb:  */
> @@ -1613,6 +1675,186 @@ vect_update_ivs_after_vectorizer (loop_vec_info loop_vinfo,
>        /* Fix phi expressions in the successor bb.  */
>        adjust_phi_and_debug_stmts (phi1, update_e, ni_name);
>      }
> +  return;
> +}
> +
> +/*   Function vect_update_ivs_after_early_break.
> +
> +     "Advance" the induction variables of LOOP to the value they should take
> +     after the execution of LOOP.  This is currently necessary because the
> +     vectorizer does not handle induction variables that are used after the
> +     loop.  Such a situation occurs when the last iterations of LOOP are
> +     peeled, because of the early exit.  With an early exit we always peel the
> +     loop.
> +
> +     Input:
> +     - LOOP_VINFO - a loop info structure for the loop that is going to be
> +		    vectorized. The last few iterations of LOOP were peeled.
> +     - LOOP - a loop that is going to be vectorized. The last few iterations
> +	      of LOOP were peeled.
> +     - VF - The loop vectorization factor.
> +     - NITERS_ORIG - the number of iterations that LOOP executes (before it is
> +		     vectorized). i.e, the number of times the ivs should be
> +		     bumped.
> +     - NITERS_VECTOR - The number of iterations that the vector LOOP executes.
> +     - UPDATE_E - a successor edge of LOOP->exit that is on the (only) path
> +		  coming out from LOOP on which there are uses of the LOOP ivs
> +		  (this is the path from LOOP->exit to epilog_loop->preheader).
> +
> +		  The new definitions of the ivs are placed in LOOP->exit.
> +		  The phi args associated with the edge UPDATE_E in the bb
> +		  UPDATE_E->dest are updated accordingly.
> +
> +     Output:
> +       - If available, the LCSSA phi node for the loop IV temp.
> +
> +     Assumption 1: Like the rest of the vectorizer, this function assumes
> +     a single loop exit that has a single predecessor.
> +
> +     Assumption 2: The phi nodes in the LOOP header and in update_bb are
> +     organized in the same order.
> +
> +     Assumption 3: The access function of the ivs is simple enough (see
> +     vect_can_advance_ivs_p).  This assumption will be relaxed in the future.
> +
> +     Assumption 4: Exactly one of the successors of LOOP exit-bb is on a path
> +     coming out of LOOP on which the ivs of LOOP are used (this is the path
> +     that leads to the epilog loop; other paths skip the epilog loop).  This
> +     path starts with the edge UPDATE_E, and its destination (denoted update_bb)
> +     needs to have its phis updated.
> + */
> +
> +static tree
> +vect_update_ivs_after_early_break (loop_vec_info loop_vinfo, class loop *,
> +				   poly_int64 vf, tree niters_orig,
> +				   tree niters_vector, edge update_e)
> +{
> +  gphi_iterator gsi, gsi1;
> +  tree ni_name, ivtmp = NULL;
> +  class loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
> +  basic_block update_bb = update_e->dest;
> +  auto_vec<edge> exits = get_loop_exit_edges (loop);
> +
> +  basic_block exit_bb = exits[0]->dest;
> +
> +  if (!LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
> +    return NULL;
> +
> +  for (gsi = gsi_start_phis (loop->header), gsi1 = gsi_start_phis (update_bb);
> +       !gsi_end_p (gsi) && !gsi_end_p (gsi1);
> +       gsi_next (&gsi), gsi_next (&gsi1))
> +    {
> +      tree init_expr;
> +      tree step_expr;
> +      tree type;
> +      tree var, ni;
> +      gimple_stmt_iterator last_gsi;
> +
> +      gphi *phi = gsi1.phi ();
> +      tree phi_ssa = PHI_ARG_DEF_FROM_EDGE (phi, loop_preheader_edge (loop));
> +      gphi *phi1 = as_a <gphi *> (SSA_NAME_DEF_STMT (phi_ssa));
> +      stmt_vec_info phi_info = loop_vinfo->lookup_stmt (gsi.phi ());
> +      if (dump_enabled_p ())
> +	dump_printf_loc (MSG_NOTE, vect_location,
> +			 "vect_update_ivs_after_early_break: phi: %G",
> +			 (gimple *)phi);
> +
> +      /* Skip reduction and virtual phis.  */
> +      if (!iv_phi_p (phi_info))
> +	{
> +	  if (dump_enabled_p ())
> +	    dump_printf_loc (MSG_NOTE, vect_location,
> +			     "reduc or virtual phi. skip.\n");
> +	  continue;
> +	}
> +
> +      /* For multiple exits where we handle early exits we need to carry on
> +	 with the previous IV as loop iteration was not done because we exited
> +	 early.  As such just grab the original IV.  */
> +      if (STMT_VINFO_TYPE (phi_info) != undef_vec_info_type)
> +	{
> +	  type = TREE_TYPE (gimple_phi_result (phi));
> +	  step_expr = STMT_VINFO_LOOP_PHI_EVOLUTION_PART (phi_info);
> +	  step_expr = unshare_expr (step_expr);
> +
> +	  /* We previously generated the new merged phi in the same BB as the
> +	     guard.  So use that to perform the scaling on rather than the
> +	     normal loop phi which don't take the early breaks into account.  */
> +	  init_expr = gimple_phi_result (phi1); //PHI_ARG_DEF_FROM_EDGE (phi1, loop_preheader_edge (loop));
> +
> +	  ni = fold_build2 (MULT_EXPR, TREE_TYPE (step_expr),
> +			    fold_convert (TREE_TYPE (step_expr), init_expr),
> +			    build_int_cst (TREE_TYPE (step_expr), vf));
> +
> +	  var = create_tmp_var (type, "tmp");
> +
> +	  last_gsi = gsi_last_bb (exit_bb);
> +	  gimple_seq new_stmts = NULL;
> +	  ni_name = force_gimple_operand (ni, &new_stmts, false, var);
> +	  /* Exit_bb shouldn't be empty.  */
> +	  if (!gsi_end_p (last_gsi))
> +	    gsi_insert_seq_after (&last_gsi, new_stmts, GSI_SAME_STMT);
> +	  else
> +	    gsi_insert_seq_before (&last_gsi, new_stmts, GSI_SAME_STMT);
> +
> +	  /* Fix phi expressions in the successor bb.  */
> +	  adjust_phi_and_debug_stmts (phi, update_e, ni_name);
> +	}
> +      else if (STMT_VINFO_TYPE (phi_info) == undef_vec_info_type)
> +	{
> +	  type = TREE_TYPE (gimple_phi_result (phi));
> +	  step_expr = STMT_VINFO_LOOP_PHI_EVOLUTION_PART (phi_info);
> +	  step_expr = unshare_expr (step_expr);
> +
> +	  /* We previously generated the new merged phi in the same BB as the
> +	     guard.  So use that to perform the scaling on rather than the
> +	     normal loop phi which don't take the early breaks into account.  */
> +	  init_expr = PHI_ARG_DEF_FROM_EDGE (phi1, loop_preheader_edge (loop));
> +
> +	  if (vf.is_constant ())
> +	    {
> +	      ni = fold_build2 (MULT_EXPR, TREE_TYPE (step_expr),
> +				fold_convert (TREE_TYPE (step_expr),
> +					      niters_vector),
> +				build_int_cst (TREE_TYPE (step_expr), vf));
> +
> +	      ni = fold_build2 (MINUS_EXPR, TREE_TYPE (step_expr),
> +				fold_convert (TREE_TYPE (step_expr),
> +					      niters_orig),
> +				fold_convert (TREE_TYPE (step_expr), ni));
> +	    }
> +	  else
> +	    /* If the loop's VF isn't constant then the loop must have been
> +	       masked, so at the end of the loop we know we have finished
> +	       the entire loop and found nothing.  */
> +	    ni = build_zero_cst (TREE_TYPE (step_expr));
> +
> +	  gcc_assert (TREE_CODE (ni) == INTEGER_CST);
> +
> +	  var = create_tmp_var (type, "tmp");
> +
> +	  last_gsi = gsi_last_bb (exit_bb);
> +	  gimple_seq new_stmts = NULL;
> +	  ni_name = force_gimple_operand (ni, &new_stmts, false, var);
> +	  /* Exit_bb shouldn't be empty.  */
> +	  if (!gsi_end_p (last_gsi))
> +	    gsi_insert_seq_after (&last_gsi, new_stmts, GSI_SAME_STMT);
> +	  else
> +	    gsi_insert_seq_before (&last_gsi, new_stmts, GSI_SAME_STMT);
> +
> +	  adjust_phi_and_debug_stmts (phi1, update_e, ni_name);
> +
> +	  for (unsigned i = 1; i < exits.length (); i++)
> +	    adjust_phi_and_debug_stmts (phi1, exits[i],
> +					build_int_cst (TREE_TYPE (step_expr),
> +						       vf));
> +	  ivtmp = gimple_phi_result (phi1);
> +	}
> +      else
> +	continue;
> +    }
> +
> +  return ivtmp;
>  }
>  
>  /* Return a gimple value containing the misalignment (measured in vector
> @@ -2096,7 +2338,7 @@ vect_gen_vector_loop_niters_mult_vf (loop_vec_info loop_vinfo,
>    class loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
>    tree type = TREE_TYPE (niters_vector);
>    tree log_vf = build_int_cst (type, exact_log2 (vf));
> -  basic_block exit_bb = single_exit (loop)->dest;
> +  basic_block exit_bb = normal_exit (loop)->dest;
>  
>    gcc_assert (niters_vector_mult_vf_ptr != NULL);
>    tree niters_vector_mult_vf = fold_build2 (LSHIFT_EXPR, type,
> @@ -2123,19 +2365,46 @@ find_guard_arg (class loop *loop, class loop *epilog ATTRIBUTE_UNUSED,
>  		gphi *lcssa_phi)
>  {
>    gphi_iterator gsi;
> -  edge e = single_exit (loop);
> +  edge e = normal_exit (loop);
>  
> -  gcc_assert (single_pred_p (e->dest));
>    for (gsi = gsi_start_phis (e->dest); !gsi_end_p (gsi); gsi_next (&gsi))
>      {
>        gphi *phi = gsi.phi ();
> -      if (operand_equal_p (PHI_ARG_DEF (phi, 0),
> -			   PHI_ARG_DEF (lcssa_phi, 0), 0))
> +      /* Nested loops with multiple exits can have different no# phi node
> +	 arguments between the main loop and epilog as epilog falls to the
> +	 second loop.  */
> +      if (gimple_phi_num_args (phi) > e->dest_idx
> +	  && operand_equal_p (PHI_ARG_DEF (phi, e->dest_idx),
> +			      PHI_ARG_DEF (lcssa_phi, 0), 0))
>  	return PHI_RESULT (phi);
>      }
>    return NULL_TREE;
>  }
>  
> +/* Starting from the current edge walk all instructions and find the last
> +   VUSE/VDEF in the basic block.  */
> +
> +static tree
> +gimple_find_last_mem_use (edge e)
> +{
> +  basic_block bb = e->src;
> +  tree res = NULL;
> +  gimple_stmt_iterator iter = gsi_last_bb (bb);
> +  do
> +  {
> +    gimple *stmt = gsi_stmt (iter);
> +    if ((res = gimple_vdef (stmt)))
> +      return res;
> +
> +    if ((res = gimple_vuse (stmt)))
> +      return res;
> +
> +    gsi_prev (&iter);
> +  } while (!gsi_end_p (iter));
> +
> +  return NULL;
> +}
> +
>  /* Function slpeel_tree_duplicate_loop_to_edge_cfg duplciates FIRST/SECOND
>     from SECOND/FIRST and puts it at the original loop's preheader/exit
>     edge, the two loops are arranged as below:
> @@ -2185,6 +2454,7 @@ find_guard_arg (class loop *loop, class loop *epilog ATTRIBUTE_UNUSED,
>  static void
>  slpeel_update_phi_nodes_for_loops (loop_vec_info loop_vinfo,
>  				   class loop *first, class loop *second,
> +				   tree *lcssa_ivtmp,
>  				   bool create_lcssa_for_iv_phis)
>  {
>    gphi_iterator gsi_update, gsi_orig;
> @@ -2192,10 +2462,18 @@ slpeel_update_phi_nodes_for_loops (loop_vec_info loop_vinfo,
>  
>    edge first_latch_e = EDGE_SUCC (first->latch, 0);
>    edge second_preheader_e = loop_preheader_edge (second);
> -  basic_block between_bb = single_exit (first)->dest;
> +  auto_vec<edge> exits = get_loop_exit_edges (first);
> +  basic_block between_bb = exits[0]->dest;
> +
> +  bool early_exit = LOOP_VINFO_EARLY_BREAKS (loop_vinfo);
> +  /* For early exits when we create the merge BB we must maintain it in
> +     LCSSA form, otherwise the final vectorizer passes will create the
> +     wrong PHI nodes here.  */
> +  create_lcssa_for_iv_phis = create_lcssa_for_iv_phis || early_exit;
>  
>    gcc_assert (between_bb == second_preheader_e->src);
> -  gcc_assert (single_pred_p (between_bb) && single_succ_p (between_bb));
> +  gcc_assert ((single_pred_p (between_bb) && single_succ_p (between_bb))
> +	      || early_exit);
>    /* Either the first loop or the second is the loop to be vectorized.  */
>    gcc_assert (loop == first || loop == second);
>  
> @@ -2215,10 +2493,40 @@ slpeel_update_phi_nodes_for_loops (loop_vec_info loop_vinfo,
>  	{
>  	  tree new_res = copy_ssa_name (PHI_RESULT (orig_phi));
>  	  gphi *lcssa_phi = create_phi_node (new_res, between_bb);
> -	  add_phi_arg (lcssa_phi, arg, single_exit (first), UNKNOWN_LOCATION);
> +
> +	  /* The first exit is always the loop latch, so handle that
> +	     seperately.  */
> +	  gcc_assert (arg);
> +	  add_phi_arg (lcssa_phi, arg, exits[0], UNKNOWN_LOCATION);
> +
> +	  /* The early exits are processed in order starting from exit 1.  */
> +	  for (unsigned i = 1; i < exits.length (); i++)
> +	    {
> +	      tree phi_arg;
> +	      if (gimple_phi_has_vdef (orig_phi))
> +		phi_arg = gimple_find_last_mem_use (exits[i]);
> +	      else
> +		/* For induction values just copy the previous one as the
> +		   current iteration did not finish.  We'll update as needed
> +		   later on.  */
> +		phi_arg = gimple_phi_result (orig_phi);
> +	      /* If we didn't find any just copy the existing one and leave
> +		 it to the others to fix it up.  */
> +	      if (!phi_arg)
> +		phi_arg = gimple_phi_result (orig_phi);
> +	      add_phi_arg (lcssa_phi, phi_arg, exits[i], UNKNOWN_LOCATION);
> +	    }
>  	  arg = new_res;
>  	}
>  
> +      /* Normally able to distinguish between the iterator counter and the
> +	 ivtemps bu looking at the STMT_VINFO_TYPE of the phi node.
> +	 however for some reason this isn't consistently set.  Is there a
> +	 better way??.  */
> +      if (lcssa_ivtmp
> +	  && iv_phi_p (vect_phi_info))
> +	*lcssa_ivtmp = arg;
> +
>        /* Update PHI node in the second loop by replacing arg on the loop's
>  	 incoming edge.  */
>        adjust_phi_and_debug_stmts (update_phi, second_preheader_e, arg);
> @@ -2228,7 +2536,8 @@ slpeel_update_phi_nodes_for_loops (loop_vec_info loop_vinfo,
>       for correct vectorization of live stmts.  */
>    if (loop == first)
>      {
> -      basic_block orig_exit = single_exit (second)->dest;
> +      auto_vec<edge> new_exits = get_loop_exit_edges (second);
> +      basic_block orig_exit = new_exits[0]->dest;
>        for (gsi_orig = gsi_start_phis (orig_exit);
>  	   !gsi_end_p (gsi_orig); gsi_next (&gsi_orig))
>  	{
> @@ -2243,7 +2552,15 @@ slpeel_update_phi_nodes_for_loops (loop_vec_info loop_vinfo,
>  
>  	  tree new_res = copy_ssa_name (orig_arg);
>  	  gphi *lcphi = create_phi_node (new_res, between_bb);
> -	  add_phi_arg (lcphi, orig_arg, single_exit (first), UNKNOWN_LOCATION);
> +	  /* The first exit is always the loop latch, so handle that
> +	     seperately.  */
> +	  add_phi_arg (lcphi, orig_arg, new_exits[0], UNKNOWN_LOCATION);
> +	  /* The early exits are processed in order starting from exit 1.  */
> +	  for (unsigned i = 1; i < new_exits.length (); i++)
> +	    {
> +	      tree phi_arg = gimple_phi_result (orig_phi);
> +	      add_phi_arg (lcphi, phi_arg, exits[i], UNKNOWN_LOCATION);
> +	    }
>  	}
>      }
>  }
> @@ -2393,13 +2710,11 @@ slpeel_update_phi_nodes_for_guard2 (class loop *loop, class loop *epilog,
>    gcc_assert (single_succ_p (merge_bb));
>    edge e = single_succ_edge (merge_bb);
>    basic_block exit_bb = e->dest;
> -  gcc_assert (single_pred_p (exit_bb));
> -  gcc_assert (single_pred (exit_bb) == single_exit (epilog)->dest);
>  
>    for (gsi = gsi_start_phis (exit_bb); !gsi_end_p (gsi); gsi_next (&gsi))
>      {
>        gphi *update_phi = gsi.phi ();
> -      tree old_arg = PHI_ARG_DEF (update_phi, 0);
> +      tree old_arg = PHI_ARG_DEF (update_phi, e->dest_idx);
>  
>        tree merge_arg = NULL_TREE;
>  
> @@ -2438,12 +2753,14 @@ static void
>  slpeel_update_phi_nodes_for_lcssa (class loop *epilog)
>  {
>    gphi_iterator gsi;
> -  basic_block exit_bb = single_exit (epilog)->dest;
> +  auto_vec<edge> exits = get_loop_exit_edges (epilog);
>  
> -  gcc_assert (single_pred_p (exit_bb));
> -  edge e = EDGE_PRED (exit_bb, 0);
> -  for (gsi = gsi_start_phis (exit_bb); !gsi_end_p (gsi); gsi_next (&gsi))
> -    rename_use_op (PHI_ARG_DEF_PTR_FROM_EDGE (gsi.phi (), e));
> +  for (unsigned i = 0; i < exits.length (); i++)
> +    {
> +      basic_block exit_bb = exits[i]->dest;
> +      for (gsi = gsi_start_phis (exit_bb); !gsi_end_p (gsi); gsi_next (&gsi))
> +	rename_use_op (PHI_ARG_DEF_PTR_FROM_EDGE (gsi.phi (), exits[i]));
> +    }
>  }
>  
>  /* EPILOGUE_VINFO is an epilogue loop that we now know would need to
> @@ -2621,6 +2938,14 @@ vect_do_peeling (loop_vec_info loop_vinfo, tree niters, tree nitersm1,
>      bound_epilog += vf - 1;
>    if (LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo))
>      bound_epilog += 1;
> +  /* For early breaks the scalar loop needs to execute at most VF times
> +     to find the element that caused the break.  */
> +  if (LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
> +    {
> +      bound_epilog = vf;
> +      /* Force a scalar epilogue as we can't vectorize the index finding.  */
> +      vect_epilogues = false;
> +    }
>    bool epilog_peeling = maybe_ne (bound_epilog, 0U);
>    poly_uint64 bound_scalar = bound_epilog;
>  
> @@ -2780,16 +3105,24 @@ vect_do_peeling (loop_vec_info loop_vinfo, tree niters, tree nitersm1,
>  				  bound_prolog + bound_epilog)
>  		      : (!LOOP_REQUIRES_VERSIONING (loop_vinfo)
>  			 || vect_epilogues));
> +
> +  /* We only support early break vectorization on known bounds at this time.
> +     This means that if the vector loop can't be entered then we won't generate
> +     it at all.  So for now force skip_vector off because the additional control
> +     flow messes with the BB exits and we've already analyzed them.  */
> + skip_vector = skip_vector && !LOOP_VINFO_EARLY_BREAKS (loop_vinfo);
> +
>    /* Epilog loop must be executed if the number of iterations for epilog
>       loop is known at compile time, otherwise we need to add a check at
>       the end of vector loop and skip to the end of epilog loop.  */
>    bool skip_epilog = (prolog_peeling < 0
>  		      || !LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo)
>  		      || !vf.is_constant ());
> -  /* PEELING_FOR_GAPS is special because epilog loop must be executed.  */
> -  if (LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo))
> +  /* PEELING_FOR_GAPS and peeling for early breaks are special because epilog
> +     loop must be executed.  */
> +  if (LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo)
> +      || LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
>      skip_epilog = false;
> -
>    class loop *scalar_loop = LOOP_VINFO_SCALAR_LOOP (loop_vinfo);
>    auto_vec<profile_count> original_counts;
>    basic_block *original_bbs = NULL;
> @@ -2828,7 +3161,7 @@ vect_do_peeling (loop_vec_info loop_vinfo, tree niters, tree nitersm1,
>    if (prolog_peeling)
>      {
>        e = loop_preheader_edge (loop);
> -      if (!slpeel_can_duplicate_loop_p (loop, e))
> +      if (!slpeel_can_duplicate_loop_p (loop_vinfo, e))
>  	{
>  	  dump_printf_loc (MSG_MISSED_OPTIMIZATION, loop_loc,
>  			   "loop can't be duplicated to preheader edge.\n");
> @@ -2843,7 +3176,7 @@ vect_do_peeling (loop_vec_info loop_vinfo, tree niters, tree nitersm1,
>  	  gcc_unreachable ();
>  	}
>        prolog->force_vectorize = false;
> -      slpeel_update_phi_nodes_for_loops (loop_vinfo, prolog, loop, true);
> +      slpeel_update_phi_nodes_for_loops (loop_vinfo, prolog, loop, NULL, true);
>        first_loop = prolog;
>        reset_original_copy_tables ();
>  
> @@ -2902,11 +3235,13 @@ vect_do_peeling (loop_vec_info loop_vinfo, tree niters, tree nitersm1,
>  
>    if (epilog_peeling)
>      {
> -      e = single_exit (loop);
> -      if (!slpeel_can_duplicate_loop_p (loop, e))
> +      auto_vec<edge> exits = get_loop_exit_edges (loop);
> +      e = exits[0];
> +      if (!slpeel_can_duplicate_loop_p (loop_vinfo, e))
>  	{
> -	  dump_printf_loc (MSG_MISSED_OPTIMIZATION, loop_loc,
> -			   "loop can't be duplicated to exit edge.\n");
> +	  if (dump_enabled_p ())
> +	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, loop_loc,
> +			     "loop can't be duplicated to exit edge.\n");
>  	  gcc_unreachable ();
>  	}
>        /* Peel epilog and put it on exit edge of loop.  If we are vectorizing
> @@ -2920,12 +3255,16 @@ vect_do_peeling (loop_vec_info loop_vinfo, tree niters, tree nitersm1,
>        epilog = slpeel_tree_duplicate_loop_to_edge_cfg (loop, epilog, e);
>        if (!epilog)
>  	{
> -	  dump_printf_loc (MSG_MISSED_OPTIMIZATION, loop_loc,
> -			   "slpeel_tree_duplicate_loop_to_edge_cfg failed.\n");
> +	  if (dump_enabled_p ())
> +	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, loop_loc,
> +			     "slpeel_tree_duplicate_loop_to_edge_cfg failed.\n");
>  	  gcc_unreachable ();
>  	}
>        epilog->force_vectorize = false;
> -      slpeel_update_phi_nodes_for_loops (loop_vinfo, loop, epilog, false);
> +
> +      tree early_break_iv_name;
> +      slpeel_update_phi_nodes_for_loops (loop_vinfo, loop, epilog,
> +					 &early_break_iv_name, false);
>  
>        /* Scalar version loop may be preferred.  In this case, add guard
>  	 and skip to epilog.  Note this only happens when the number of
> @@ -2978,6 +3317,7 @@ vect_do_peeling (loop_vec_info loop_vinfo, tree niters, tree nitersm1,
>        vect_gen_vector_loop_niters (loop_vinfo, niters,
>  				   niters_vector, step_vector,
>  				   niters_no_overflow);
> +
>        if (!integer_onep (*step_vector))
>  	{
>  	  /* On exit from the loop we will have an easy way of calcalating
> @@ -2987,9 +3327,13 @@ vect_do_peeling (loop_vec_info loop_vinfo, tree niters, tree nitersm1,
>  	  SSA_NAME_DEF_STMT (niters_vector_mult_vf) = gimple_build_nop ();
>  	  *niters_vector_mult_vf_var = niters_vector_mult_vf;
>  	}
> +      else if (LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
> +	vect_gen_vector_loop_niters_mult_vf (loop_vinfo, early_break_iv_name,
> +					     &niters_vector_mult_vf);
>        else
>  	vect_gen_vector_loop_niters_mult_vf (loop_vinfo, *niters_vector,
>  					     &niters_vector_mult_vf);
> +
>        /* Update IVs of original loop as if they were advanced by
>  	 niters_vector_mult_vf steps.  */
>        gcc_checking_assert (vect_can_advance_ivs_p (loop_vinfo));
> @@ -2997,12 +3341,93 @@ vect_do_peeling (loop_vec_info loop_vinfo, tree niters, tree nitersm1,
>        vect_update_ivs_after_vectorizer (loop_vinfo, niters_vector_mult_vf,
>  					update_e);
>  
> +      /* For early breaks we must create a guard to check how many iterations
> +	 of the scalar loop are yet to be performed.  */
> +      if (LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
> +	{
> +	  gcc_assert (early_break_iv_name);
> +	  tree ivtmp =
> +	    vect_update_ivs_after_early_break (loop_vinfo, epilog, vf, niters,
> +					       *niters_vector, update_e);
> +	  tree guard_cond = fold_build2 (EQ_EXPR, boolean_type_node,
> +					 fold_convert (TREE_TYPE (niters),
> +						       ivtmp),
> +					 build_zero_cst (TREE_TYPE (niters)));
> +	  basic_block guard_bb = normal_exit (loop)->dest;
> +	  auto_vec<edge> new_exits = get_loop_exit_edges (epilog);
> +	  /* If we had a fallthrough edge, the guard will the threaded through
> +	     and so we may need to find the actual final edge.  */
> +	  edge final_edge = new_exits[0];
> +	  basic_block guard_to;
> +	  bool fn_exit_p = false;
> +	  if (gsi_end_p (gsi_start_nondebug_bb (final_edge->dest))
> +	      && !gsi_end_p (gsi_start_phis (final_edge->dest))
> +	      && single_succ_p (final_edge->dest))
> +	    {
> +	      auto gsi = gsi_start_phis (final_edge->dest);
> +	      while (!gsi_end_p (gsi))
> +		gsi_remove (&gsi, true);
> +	      guard_to = final_edge->dest;
> +	      fn_exit_p = true;
> +	    }
> +	  else
> +	    guard_to = split_edge (normal_exit (epilog));
> +	  edge guard_e = slpeel_add_loop_guard (guard_bb, guard_cond, guard_to,
> +						guard_bb, prob_epilog.invert (),
> +						irred_flag);
> +	  basic_block dest = single_succ (guard_to);
> +	  /* If we have a single pred then the previous block is the immediate
> +	     dominator.   This may or may not be the guard bb.  However if we
> +	     have multiple pred then the guard BB must be the dominator as all
> +	     previous exits got rewrited to the guard BB.  */
> +	  if (single_pred_p (dest))
> +	    set_immediate_dominator (CDI_DOMINATORS, dest, guard_to);
> +	  else
> +	    set_immediate_dominator (CDI_DOMINATORS, dest, guard_bb);
> +
> +	  /* We must update all the edges from the new guard_bb.  */
> +	  slpeel_update_phi_nodes_for_guard2 (loop, epilog, guard_e,
> +					      final_edge);
> +
> +	  /* If we have an additional functione exit block, then thread the updates
> +	     through to the block.  Leaving it up to the LCSSA cleanup pass will
> +	     get the wrong values here as it can't handle the merge block we just
> +	     made correctly.  */
> +	  if (fn_exit_p)
> +	    {
> +		gphi_iterator gsi_update, gsi_orig, gsi_vect;
> +		for (gsi_orig = gsi_start_phis (epilog->header),
> +		     gsi_update = gsi_start_phis (guard_e->dest),
> +		     gsi_vect = gsi_start_phis (loop->header);
> +		     !gsi_end_p (gsi_orig) && !gsi_end_p (gsi_update)
> +		     && !gsi_end_p (gsi_vect);
> +		     gsi_next (&gsi_orig), gsi_next (&gsi_update),
> +		     gsi_next (&gsi_vect))
> +		  {
> +		    gphi *orig_phi = gsi_orig.phi ();
> +		    gphi *update_phi = gsi_update.phi ();
> +		    gphi *vect_phi = gsi_vect.phi ();
> +		    stmt_vec_info phi_info = loop_vinfo->lookup_stmt (vect_phi);
> +
> +		    if (iv_phi_p (phi_info))
> +		      continue;
> +
> +		    tree phi_arg = PHI_ARG_DEF_FROM_EDGE (orig_phi, update_e);
> +		    SET_PHI_ARG_DEF (update_phi, update_e->dest_idx, phi_arg);
> +
> +		    phi_arg = PHI_ARG_DEF_FROM_EDGE (orig_phi, guard_e);
> +		    SET_PHI_ARG_DEF (update_phi, guard_e->dest_idx, phi_arg);
> +		  }
> +	    }
> +	  flush_pending_stmts (guard_e);
> +	}
> +
>        if (skip_epilog)
>  	{
>  	  guard_cond = fold_build2 (EQ_EXPR, boolean_type_node,
>  				    niters, niters_vector_mult_vf);
> -	  guard_bb = single_exit (loop)->dest;
> -	  guard_to = split_edge (single_exit (epilog));
> +	  guard_bb = normal_exit (loop)->dest;
> +	  guard_to = split_edge (normal_exit (epilog));
>  	  guard_e = slpeel_add_loop_guard (guard_bb, guard_cond, guard_to,
>  					   skip_vector ? anchor : guard_bb,
>  					   prob_epilog.invert (),
> @@ -3010,7 +3435,7 @@ vect_do_peeling (loop_vec_info loop_vinfo, tree niters, tree nitersm1,
>  	  if (vect_epilogues)
>  	    epilogue_vinfo->skip_this_loop_edge = guard_e;
>  	  slpeel_update_phi_nodes_for_guard2 (loop, epilog, guard_e,
> -					      single_exit (epilog));
> +					      normal_exit (epilog));
>  	  /* Only need to handle basic block before epilog loop if it's not
>  	     the guard_bb, which is the case when skip_vector is true.  */
>  	  if (guard_bb != bb_before_epilog)
> @@ -3023,7 +3448,6 @@ vect_do_peeling (loop_vec_info loop_vinfo, tree niters, tree nitersm1,
>  	}
>        else
>  	slpeel_update_phi_nodes_for_lcssa (epilog);
> -
>        unsigned HOST_WIDE_INT bound;
>        if (bound_scalar.is_constant (&bound))
>  	{
> @@ -3114,7 +3538,6 @@ vect_do_peeling (loop_vec_info loop_vinfo, tree niters, tree nitersm1,
>  
>    adjust_vec.release ();
>    free_original_copy_tables ();
> -
>    return vect_epilogues ? epilog : NULL;
>  }
>  
> diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
> index aacbb12580c89a7a12b11cc096502d669a9e1e21..f37bd10575044c2561f792cb8ba4870becfc4a30 100644
> --- a/gcc/tree-vect-loop.cc
> +++ b/gcc/tree-vect-loop.cc
> @@ -844,80 +844,106 @@ vect_fixup_scalar_cycles_with_patterns (loop_vec_info loop_vinfo)
>     in NUMBER_OF_ITERATIONSM1.  Place the condition under which the
>     niter information holds in ASSUMPTIONS.
>  
> -   Return the loop exit condition.  */
> +   Return the loop exit conditions.  */
>  
>  
> -static gcond *
> +static vec<gcond *>
>  vect_get_loop_niters (class loop *loop, tree *assumptions,
>  		      tree *number_of_iterations, tree *number_of_iterationsm1)
>  {
> -  edge exit = single_exit (loop);
> +  auto_vec<edge> exits = get_loop_exit_edges (loop);
> +  vec<gcond *> conds;
> +  conds.create (exits.length ());
>    class tree_niter_desc niter_desc;
>    tree niter_assumptions, niter, may_be_zero;
> -  gcond *cond = get_loop_exit_condition (loop);
>  
>    *assumptions = boolean_true_node;
>    *number_of_iterationsm1 = chrec_dont_know;
>    *number_of_iterations = chrec_dont_know;
> +
>    DUMP_VECT_SCOPE ("get_loop_niters");
>  
> -  if (!exit)
> -    return cond;
> +  if (exits.is_empty ())
> +    return conds;
> +
> +  if (dump_enabled_p ())
> +    dump_printf_loc (MSG_NOTE, vect_location, "Loop has %d exits.\n",
> +		     exits.length ());
>  
> -  may_be_zero = NULL_TREE;
> -  if (!number_of_iterations_exit_assumptions (loop, exit, &niter_desc, NULL)
> -      || chrec_contains_undetermined (niter_desc.niter))
> -    return cond;
> +  edge exit;
> +  unsigned int i;
> +  FOR_EACH_VEC_ELT (exits, i, exit)
> +    {
> +      gcond *cond = get_edge_condition (exit);
> +      if (cond)
> +	conds.safe_push (cond);
>  
> -  niter_assumptions = niter_desc.assumptions;
> -  may_be_zero = niter_desc.may_be_zero;
> -  niter = niter_desc.niter;
> +      if (dump_enabled_p ())
> +	dump_printf_loc (MSG_NOTE, vect_location, "Analyzing exit %d...\n", i);
>  
> -  if (may_be_zero && integer_zerop (may_be_zero))
> -    may_be_zero = NULL_TREE;
> +      may_be_zero = NULL_TREE;
> +      if (!number_of_iterations_exit_assumptions (loop, exit, &niter_desc, NULL)
> +          || chrec_contains_undetermined (niter_desc.niter))
> +	continue;
>  
> -  if (may_be_zero)
> -    {
> -      if (COMPARISON_CLASS_P (may_be_zero))
> +      niter_assumptions = niter_desc.assumptions;
> +      may_be_zero = niter_desc.may_be_zero;
> +      niter = niter_desc.niter;
> +
> +      if (may_be_zero && integer_zerop (may_be_zero))
> +	may_be_zero = NULL_TREE;
> +
> +      if (may_be_zero)
>  	{
> -	  /* Try to combine may_be_zero with assumptions, this can simplify
> -	     computation of niter expression.  */
> -	  if (niter_assumptions && !integer_nonzerop (niter_assumptions))
> -	    niter_assumptions = fold_build2 (TRUTH_AND_EXPR, boolean_type_node,
> -					     niter_assumptions,
> -					     fold_build1 (TRUTH_NOT_EXPR,
> -							  boolean_type_node,
> -							  may_be_zero));
> +	  if (COMPARISON_CLASS_P (may_be_zero))
> +	    {
> +	      /* Try to combine may_be_zero with assumptions, this can simplify
> +		 computation of niter expression.  */
> +	      if (niter_assumptions && !integer_nonzerop (niter_assumptions))
> +		niter_assumptions = fold_build2 (TRUTH_AND_EXPR, boolean_type_node,
> +						 niter_assumptions,
> +						 fold_build1 (TRUTH_NOT_EXPR,
> +							      boolean_type_node,
> +							      may_be_zero));
> +	      else
> +		niter = fold_build3 (COND_EXPR, TREE_TYPE (niter), may_be_zero,
> +				     build_int_cst (TREE_TYPE (niter), 0),
> +				     rewrite_to_non_trapping_overflow (niter));
> +
> +	      may_be_zero = NULL_TREE;
> +	    }
> +	  else if (integer_nonzerop (may_be_zero) && i == 0)
> +	    {
> +	      *number_of_iterationsm1 = build_int_cst (TREE_TYPE (niter), 0);
> +	      *number_of_iterations = build_int_cst (TREE_TYPE (niter), 1);
> +	      continue;
> +	    }
>  	  else
> -	    niter = fold_build3 (COND_EXPR, TREE_TYPE (niter), may_be_zero,
> -				 build_int_cst (TREE_TYPE (niter), 0),
> -				 rewrite_to_non_trapping_overflow (niter));
> +	    continue;
> +       }
>  
> -	  may_be_zero = NULL_TREE;
> -	}
> -      else if (integer_nonzerop (may_be_zero))
> +      /* Loop assumptions are based off the normal exit.  */
> +      if (i == 0)
>  	{
> -	  *number_of_iterationsm1 = build_int_cst (TREE_TYPE (niter), 0);
> -	  *number_of_iterations = build_int_cst (TREE_TYPE (niter), 1);
> -	  return cond;
> +	  *assumptions = niter_assumptions;
> +	  *number_of_iterationsm1 = niter;
> +
> +	  /* We want the number of loop header executions which is the number
> +	     of latch executions plus one.
> +	     ???  For UINT_MAX latch executions this number overflows to zero
> +	     for loops like do { n++; } while (n != 0);  */
> +	  if (niter && !chrec_contains_undetermined (niter))
> +	    niter = fold_build2 (PLUS_EXPR, TREE_TYPE (niter),
> +				 unshare_expr (niter),
> +				 build_int_cst (TREE_TYPE (niter), 1));
> +	  *number_of_iterations = niter;
>  	}
> -      else
> -	return cond;
>      }
>  
> -  *assumptions = niter_assumptions;
> -  *number_of_iterationsm1 = niter;
> -
> -  /* We want the number of loop header executions which is the number
> -     of latch executions plus one.
> -     ???  For UINT_MAX latch executions this number overflows to zero
> -     for loops like do { n++; } while (n != 0);  */
> -  if (niter && !chrec_contains_undetermined (niter))
> -    niter = fold_build2 (PLUS_EXPR, TREE_TYPE (niter), unshare_expr (niter),
> -			  build_int_cst (TREE_TYPE (niter), 1));
> -  *number_of_iterations = niter;
> +  if (dump_enabled_p ())
> +    dump_printf_loc (MSG_NOTE, vect_location, "All loop exits successfully analyzed.\n");
>  
> -  return cond;
> +  return conds;
>  }
>  
>  /* Function bb_in_loop_p
> @@ -1455,7 +1481,8 @@ vect_compute_single_scalar_iteration_cost (loop_vec_info loop_vinfo)
>  
>     Verify that certain CFG restrictions hold, including:
>     - the loop has a pre-header
> -   - the loop has a single entry and exit
> +   - the loop has a single entry
> +   - nested loops can have only a single exit.
>     - the loop exit condition is simple enough
>     - the number of iterations can be analyzed, i.e, a countable loop.  The
>       niter could be analyzed under some assumptions.  */
> @@ -1484,11 +1511,6 @@ vect_analyze_loop_form (class loop *loop, vect_loop_form_info *info)
>                             |
>                          (exit-bb)  */
>  
> -      if (loop->num_nodes != 2)
> -	return opt_result::failure_at (vect_location,
> -				       "not vectorized:"
> -				       " control flow in loop.\n");
> -
>        if (empty_block_p (loop->header))
>  	return opt_result::failure_at (vect_location,
>  				       "not vectorized: empty loop.\n");
> @@ -1559,11 +1581,13 @@ vect_analyze_loop_form (class loop *loop, vect_loop_form_info *info)
>          dump_printf_loc (MSG_NOTE, vect_location,
>  			 "Considering outer-loop vectorization.\n");
>        info->inner_loop_cond = inner.loop_cond;
> +
> +      if (!single_exit (loop))
> +	return opt_result::failure_at (vect_location,
> +				       "not vectorized: multiple exits.\n");
> +
>      }
>  
> -  if (!single_exit (loop))
> -    return opt_result::failure_at (vect_location,
> -				   "not vectorized: multiple exits.\n");
>    if (EDGE_COUNT (loop->header->preds) != 2)
>      return opt_result::failure_at (vect_location,
>  				   "not vectorized:"
> @@ -1579,21 +1603,45 @@ vect_analyze_loop_form (class loop *loop, vect_loop_form_info *info)
>  				   "not vectorized: latch block not empty.\n");
>  
>    /* Make sure the exit is not abnormal.  */
> -  edge e = single_exit (loop);
> -  if (e->flags & EDGE_ABNORMAL)
> +  auto_vec<edge> exits = get_loop_exit_edges (loop);
> +  edge nexit = normal_exit (loop);
> +  for (edge e : exits)
> +    {
> +      if (e->flags & EDGE_ABNORMAL)
> +	return opt_result::failure_at (vect_location,
> +				       "not vectorized:"
> +				       " abnormal loop exit edge.\n");
> +      /* Early break BB must be after the main exit BB.  In theory we should
> +	 be able to vectorize the inverse order, but the current flow in the
> +	 the vectorizer always assumes you update success PHI nodes, not
> +	 preds.  */
> +      if (e != nexit && !dominated_by_p (CDI_DOMINATORS, nexit->src, e->src))
> +	return opt_result::failure_at (vect_location,
> +				       "not vectorized:"
> +				       " abnormal loop exit edge order.\n");
> +    }
> +
> +  if (exits.length () > 2)
>      return opt_result::failure_at (vect_location,
>  				   "not vectorized:"
> -				   " abnormal loop exit edge.\n");
> -
> -  info->loop_cond
> +				   " too many exits. Only 1 additional exit"
> +				   " supported.\n");
> +  if (loop->num_nodes != 2 + exits.length () - 1)
> +    return opt_result::failure_at (vect_location,
> +				   "not vectorized:"
> +				   " unsupported control flow in loop.\n");
> +  info->conds
>      = vect_get_loop_niters (loop, &info->assumptions,
>  			    &info->number_of_iterations,
>  			    &info->number_of_iterationsm1);
> -  if (!info->loop_cond)
> +
> +  if (info->conds.is_empty ())
>      return opt_result::failure_at
>        (vect_location,
>         "not vectorized: complicated exit condition.\n");
>  
> +  info->loop_cond = info->conds[0];
> +
>    if (integer_zerop (info->assumptions)
>        || !info->number_of_iterations
>        || chrec_contains_undetermined (info->number_of_iterations))
> @@ -1638,8 +1686,22 @@ vect_create_loop_vinfo (class loop *loop, vec_info_shared *shared,
>    if (!integer_onep (info->assumptions) && !main_loop_info)
>      LOOP_VINFO_NITERS_ASSUMPTIONS (loop_vinfo) = info->assumptions;
>  
> -  stmt_vec_info loop_cond_info = loop_vinfo->lookup_stmt (info->loop_cond);
> -  STMT_VINFO_TYPE (loop_cond_info) = loop_exit_ctrl_vec_info_type;
> +  bool loop_iv_cond = true;
> +  for (gcond *cond : info->conds)
> +    {
> +      if (!loop_iv_cond)
> +	{
> +	  stmt_vec_info loop_cond_info = loop_vinfo->lookup_stmt (cond);
> +	  STMT_VINFO_TYPE (loop_cond_info) = loop_exit_ctrl_vec_info_type;
> +	  LOOP_VINFO_LOOP_CONDS (loop_vinfo).safe_push (cond);
> +	}
> +      loop_iv_cond = false;
> +    }
> +
> +  /* Check to see if we're vectorizing multiple exits.  */
> +  LOOP_VINFO_EARLY_BREAKS (loop_vinfo)
> +    = !LOOP_VINFO_LOOP_CONDS (loop_vinfo).is_empty ();
> +
>    if (info->inner_loop_cond)
>      {
>        stmt_vec_info inner_loop_cond_info
> @@ -2270,10 +2332,13 @@ vect_determine_partial_vectors_and_peeling (loop_vec_info loop_vinfo,
>    bool need_peeling_or_partial_vectors_p
>      = vect_need_peeling_or_partial_vectors_p (loop_vinfo);
>  
> -  /* Decide whether to vectorize the loop with partial vectors.  */
> +  /* Decide whether to vectorize the loop with partial vectors.  Currently
> +     early break vectorization does not support partial vectors as we have
> +     to peel a scalar loop that we can't vectorize.  */
>    LOOP_VINFO_USING_PARTIAL_VECTORS_P (loop_vinfo) = false;
>    LOOP_VINFO_EPIL_USING_PARTIAL_VECTORS_P (loop_vinfo) = false;
>    if (LOOP_VINFO_CAN_USE_PARTIAL_VECTORS_P (loop_vinfo)
> +      && !LOOP_VINFO_EARLY_BREAKS (loop_vinfo)
>        && need_peeling_or_partial_vectors_p)
>      {
>        /* For partial-vector-usage=1, try to push the handling of partial
> @@ -2746,13 +2811,14 @@ start_over:
>  
>    /* If an epilogue loop is required make sure we can create one.  */
>    if (LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo)
> -      || LOOP_VINFO_PEELING_FOR_NITER (loop_vinfo))
> +      || LOOP_VINFO_PEELING_FOR_NITER (loop_vinfo)
> +      || LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
>      {
>        if (dump_enabled_p ())
>          dump_printf_loc (MSG_NOTE, vect_location, "epilog loop required\n");
>        if (!vect_can_advance_ivs_p (loop_vinfo)
> -	  || !slpeel_can_duplicate_loop_p (LOOP_VINFO_LOOP (loop_vinfo),
> -					   single_exit (LOOP_VINFO_LOOP
> +	  || !slpeel_can_duplicate_loop_p (loop_vinfo,
> +					   normal_exit (LOOP_VINFO_LOOP
>  							 (loop_vinfo))))
>          {
>  	  ok = opt_result::failure_at (vect_location,
> @@ -3239,6 +3305,8 @@ vect_analyze_loop (class loop *loop, vec_info_shared *shared)
>  		     "***** Choosing vector mode %s\n",
>  		     GET_MODE_NAME (first_loop_vinfo->vector_mode));
>  
> +  loop_form_info.conds.release ();
> +
>    /* Only vectorize epilogues if PARAM_VECT_EPILOGUES_NOMASK is
>       enabled, SIMDUID is not set, it is the innermost loop and we have
>       either already found the loop's SIMDLEN or there was no SIMDLEN to
> @@ -3350,6 +3418,8 @@ vect_analyze_loop (class loop *loop, vec_info_shared *shared)
>  			   (first_loop_vinfo->epilogue_vinfos[0]->vector_mode));
>      }
>  
> +  loop_form_info.conds.release ();
> +
>    return first_loop_vinfo;
>  }
>  
> @@ -5407,7 +5477,7 @@ vect_create_epilog_for_reduction (loop_vec_info loop_vinfo,
>    basic_block exit_bb;
>    tree scalar_dest;
>    tree scalar_type;
> -  gimple *new_phi = NULL, *phi;
> +  gimple *new_phi = NULL, *phi = NULL;
>    gimple_stmt_iterator exit_gsi;
>    tree new_temp = NULL_TREE, new_name, new_scalar_dest;
>    gimple *epilog_stmt = NULL;
> @@ -5629,7 +5699,7 @@ vect_create_epilog_for_reduction (loop_vec_info loop_vinfo,
>           Store them in NEW_PHIS.  */
>    if (double_reduc)
>      loop = outer_loop;
> -  exit_bb = single_exit (loop)->dest;
> +  exit_bb = normal_exit (loop)->dest;
>    exit_gsi = gsi_after_labels (exit_bb);
>    reduc_inputs.create (slp_node ? vec_num : ncopies);
>    for (unsigned i = 0; i < vec_num; i++)
> @@ -5645,10 +5715,37 @@ vect_create_epilog_for_reduction (loop_vec_info loop_vinfo,
>  	  phi = create_phi_node (new_def, exit_bb);
>  	  if (j)
>  	    def = gimple_get_lhs (STMT_VINFO_VEC_STMTS (rdef_info)[j]);
> -	  SET_PHI_ARG_DEF (phi, single_exit (loop)->dest_idx, def);
> +	  SET_PHI_ARG_DEF (phi, normal_exit (loop)->dest_idx, def);
>  	  new_def = gimple_convert (&stmts, vectype, new_def);
>  	  reduc_inputs.quick_push (new_def);
>  	}
> +	/* Update the other exits.  */
> +	if (LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
> +	  {
> +	    auto_vec<edge> exits = get_loop_exit_edges (loop);
> +	    gphi_iterator gsi, gsi1;
> +	    for (unsigned i = 1; i < exits.length (); i++)
> +	      {
> +		/* Find the phi node to propaget into the exit block for each
> +		   exit edge.  */
> +		edge exit = exits[i];
> +		for (gsi = gsi_start_phis (exit_bb),
> +		     gsi1 = gsi_start_phis (exit->src);
> +		     !gsi_end_p (gsi) && !gsi_end_p (gsi1);
> +		     gsi_next (&gsi), gsi_next (&gsi1))
> +		  {
> +		    /* There really should be a function to just get the number
> +		       of phis inside a bb.  */
> +		    if (phi && phi == gsi.phi ())
> +		      {
> +			gphi *phi1 = gsi1.phi ();
> +			SET_PHI_ARG_DEF (phi, exit->dest_idx,
> +					 PHI_RESULT (phi1));
> +			break;
> +		      }
> +		  }
> +	      }
> +	  }
>        gsi_insert_seq_before (&exit_gsi, stmts, GSI_SAME_STMT);
>      }
>  
> @@ -9358,8 +9455,22 @@ vectorizable_induction (loop_vec_info loop_vinfo,
>      dump_printf_loc (MSG_NOTE, vect_location, "transform induction phi.\n");
>  
>    pe = loop_preheader_edge (iv_loop);
> -  /* Find the first insertion point in the BB.  */
> +  /* Find the first insertion point in the BB.  If we're vectorzing a block that
> +     contains an early exit, the IV needs to be materialized in the fall
> +     through block as we shouldn't update the IV if we're exiting.  */
>    basic_block bb = gimple_bb (phi);
> +  if (LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
> +    {
> +      for (gcond *cond : LOOP_VINFO_LOOP_CONDS (loop_vinfo))
> +	{
> +	  basic_block cond_bb = gimple_bb (cond);
> +	  if (cond_bb == bb)
> +	    {
> +	      bb = FALLTHRU_EDGE (cond_bb)->dest;
> +	      break;
> +	    }
> +	}
> +    }
>    si = gsi_after_labels (bb);
>  
>    /* For SLP induction we have to generate several IVs as for example
> @@ -9999,13 +10110,24 @@ vectorizable_live_operation (vec_info *vinfo,
>  	   new_tree = lane_extract <vec_lhs', ...>;
>  	   lhs' = new_tree;  */
>  
> +      /* When vectorizing an early break, any live statement that is used
> +	 outside of the loop are dead.  The loop will never get to them.
> +	 We could change the liveness value during analysis instead but since
> +	 the below code is invalid anyway just ignore it during codegen.  */
> +      if (LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
> +	return true;
> +
>        class loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
> -      basic_block exit_bb = single_exit (loop)->dest;
> +      basic_block exit_bb = normal_exit (loop)->dest;
>        gcc_assert (single_pred_p (exit_bb));
>  
>        tree vec_lhs_phi = copy_ssa_name (vec_lhs);
>        gimple *phi = create_phi_node (vec_lhs_phi, exit_bb);
> -      SET_PHI_ARG_DEF (phi, single_exit (loop)->dest_idx, vec_lhs);
> +      /* For early exits we need to compute the right exit.  The current
> +	 approach punts to a scalar loop instead.  If we were to vectorize
> +	 the exit condition below needs to take into account the difference
> +	 between a `break` edge and a `return` edge.  */
> +      SET_PHI_ARG_DEF (phi, normal_exit (loop)->dest_idx, vec_lhs);
>  
>        gimple_seq stmts = NULL;
>        tree new_tree;
> @@ -10444,7 +10566,8 @@ scale_profile_for_vect_loop (class loop *loop, unsigned vf)
>        scale_loop_frequencies (loop, p);
>      }
>  
> -  edge exit_e = single_exit (loop);
> +  edge exit_e = normal_exit (loop);
> +
>    exit_e->probability = profile_probability::always () / (new_est_niter + 1);
>  
>    edge exit_l = single_pred_edge (loop->latch);
> @@ -10747,6 +10870,115 @@ update_epilogue_loop_vinfo (class loop *epilogue, tree advance)
>    epilogue_vinfo->shared->save_datarefs ();
>  }
>  
> +/*  When vectorizing early break statements instructions that happen before
> +    the early break in the current BB need to be moved to after the early
> +    break.  This function deals with that and assumes that any validaty
> +    checks has already been performed.
> +
> +    While moving the instructions if it encounters a VUSE or VDEF it then
> +    corrects the VUSES as it moves the statements along.  CHAINED contains
> +    the list of SSA_NAMES that belong to the dependency chain of the early
> +    break conditional.  GDEST is the location in which to insert the new
> +    statements.  GSTMT is the iterator to walk up to find statements to
> +    consider moving.  REACHING_VUSE contains the dominating VUSE found so far
> +    and CURRENT_VDEF contains the last VDEF we've seen.  These are updated in
> +    pre-order and updated in post-order after moving the instruction.  */
> +
> +static void
> +move_early_exit_stmts (hash_set<tree> *chained, gimple_stmt_iterator *gdest,
> +		       gimple_stmt_iterator *gstmt, tree *reaching_vuse,
> +		       tree *current_vdef)
> +{
> +  if (gsi_end_p (*gstmt))
> +    return;
> +
> +  gimple *stmt = gsi_stmt (*gstmt);
> +  if (gimple_has_ops (stmt))
> +    {
> +      tree dest = NULL_TREE;
> +      /* Try to find the SSA_NAME being defined.  For Statements with an LHS
> +	 use the LHS, if not, assume that the first argument of a call is the
> +	 value being defined.  e.g. MASKED_LOAD etc.  */
> +      if (gimple_has_lhs (stmt))
> +	{
> +	  if (is_gimple_assign (stmt))
> +	    dest = gimple_assign_lhs (stmt);
> +	  else if (const gcall *call = dyn_cast <const gcall *> (stmt))
> +	    dest = gimple_call_lhs (call);
> +	}
> +      else if (const gcall *call = dyn_cast <const gcall *> (stmt))
> +	dest = gimple_arg (call, 0);
> +
> +      /* Don't move the scalar instructions.  */
> +      bool move = dest != NULL_TREE;
> +
> +      /* If we found the defining statement of a something that's part of the
> +	 chain then expand the chain with the new SSA_VARs being used.  */
> +      if (chained->contains (dest))
> +	{
> +	  for (unsigned x = 0; x < gimple_num_args (stmt); x++)
> +	    if (TREE_CODE (gimple_arg (stmt, x)) == SSA_NAME)
> +	      chained->add (gimple_arg (stmt, x));
> +
> +	  if (dump_enabled_p ())
> +	    dump_printf_loc (MSG_NOTE, vect_location,
> +			     "found chain %G", stmt);
> +	  update_stmt (stmt);
> +	  move = false;
> +	}
> +
> +      if (move)
> +	{
> +	  if (dump_enabled_p ())
> +	    dump_printf_loc (MSG_NOTE, vect_location,
> +			     "moving stmt %G", stmt);
> +	  gsi_move_before (gstmt, gdest);
> +	  gsi_prev (gdest);
> +	  tree vdef = gimple_vdef (stmt);
> +
> +	  /* If we've moved a VDEF, extract the defining MEM and update
> +	     usages of it.  TODO: I think this may need some constraints? */
> +	  if (vdef)
> +	    {
> +	      *current_vdef = vdef;
> +	      *reaching_vuse = gimple_vuse (stmt);
> +	      imm_use_iterator imm_iter;
> +	      gimple *use_stmt;
> +	      FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, vdef)
> +		{
> +		   if (!is_a <gphi *> (use_stmt))
> +		     continue;
> +		   gphi *phi_stmt = as_a <gphi *> (use_stmt);
> +
> +		   if (dump_enabled_p ())
> +		     dump_printf_loc (MSG_NOTE, vect_location,
> +				"updating vuse %G", use_stmt);
> +
> +		   for (unsigned i = 0; i < gimple_phi_num_args (phi_stmt); i++)
> +		    if (gimple_phi_arg_def (phi_stmt, i) == vdef)
> +		      {
> +			SET_USE (PHI_ARG_DEF_PTR (phi_stmt, i), gimple_vuse (stmt));
> +			break;
> +		      }
> +		}
> +	    }
> +	  update_stmt (stmt);
> +	}
> +    }
> +
> +  gsi_prev (gstmt);
> +  move_early_exit_stmts (chained, gdest, gstmt, reaching_vuse, current_vdef);
> +
> +  if (gimple_vuse (stmt)
> +      && reaching_vuse && *reaching_vuse
> +      && gimple_vuse (stmt) == *current_vdef)
> +    {
> +      unlink_stmt_vdef (stmt);
> +      gimple_set_vuse (stmt, *reaching_vuse);
> +      update_stmt (stmt);
> +    }
> +}
> +
>  /* Function vect_transform_loop.
>  
>     The analysis phase has determined that the loop is vectorizable.
> @@ -10793,7 +11025,7 @@ vect_transform_loop (loop_vec_info loop_vinfo, gimple *loop_vectorized_call)
>    /* Make sure there exists a single-predecessor exit bb.  Do this before 
>       versioning.   */
>    edge e = single_exit (loop);
> -  if (! single_pred_p (e->dest))
> +  if (e && ! single_pred_p (e->dest))
>      {
>        split_loop_exit_edge (e, true);
>        if (dump_enabled_p ())
> @@ -10819,7 +11051,7 @@ vect_transform_loop (loop_vec_info loop_vinfo, gimple *loop_vectorized_call)
>    if (LOOP_VINFO_SCALAR_LOOP (loop_vinfo))
>      {
>        e = single_exit (LOOP_VINFO_SCALAR_LOOP (loop_vinfo));
> -      if (! single_pred_p (e->dest))
> +      if (e && ! single_pred_p (e->dest))
>  	{
>  	  split_loop_exit_edge (e, true);
>  	  if (dump_enabled_p ())
> @@ -10885,6 +11117,26 @@ vect_transform_loop (loop_vec_info loop_vinfo, gimple *loop_vectorized_call)
>        vect_schedule_slp (loop_vinfo, LOOP_VINFO_SLP_INSTANCES (loop_vinfo));
>      }
>  
> +  /* Handle any code motion that we need to for early-break vectorization after
> +     we've done peeling but just before we start vectorizing.  */
> +  if (LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
> +    {
> +      hash_set<tree> chained;
> +      for (gcond *cond : LOOP_VINFO_LOOP_CONDS (loop_vinfo))
> +	{
> +	  basic_block cond_bb = gimple_bb (cond);
> +	  basic_block dest_bb = FALLTHRU_EDGE (cond_bb)->dest;
> +	  gimple_stmt_iterator dest_gsi = gsi_start_bb (dest_bb);
> +
> +	  gimple_stmt_iterator gsi2 = gsi_for_stmt (cond);
> +	  for (unsigned i = 0; i < gimple_num_ops (cond); i++)
> +	    chained.add (gimple_op (cond, i));
> +	  tree vdef;
> +	  tree vuse = gimple_vuse (cond);
> +	  move_early_exit_stmts (&chained, &dest_gsi, &gsi2, &vuse, &vdef);
> +	}
> +    }
> +
>    /* FORNOW: the vectorizer supports only loops which body consist
>       of one basic block (header + empty latch). When the vectorizer will
>       support more involved loop forms, the order by which the BBs are
> @@ -11152,7 +11404,8 @@ vect_transform_loop (loop_vec_info loop_vinfo, gimple *loop_vectorized_call)
>  
>    /* Loops vectorized with a variable factor won't benefit from
>       unrolling/peeling.  */
> -  if (!vf.is_constant ())
> +  if (!vf.is_constant ()
> +      && !LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
>      {
>        loop->unroll = 1;
>        if (dump_enabled_p ())
> diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
> index 5485da58b38a0db2ea1a357ee8647ae47b563a8f..6a3a6065ce2ee7dd53ebf83c8796d57fc9805750 100644
> --- a/gcc/tree-vect-stmts.cc
> +++ b/gcc/tree-vect-stmts.cc
> @@ -342,9 +342,28 @@ vect_stmt_relevant_p (stmt_vec_info stmt_info, loop_vec_info loop_vinfo,
>    *live_p = false;
>  
>    /* cond stmt other than loop exit cond.  */
> -  if (is_ctrl_stmt (stmt_info->stmt)
> -      && STMT_VINFO_TYPE (stmt_info) != loop_exit_ctrl_vec_info_type)
> -    *relevant = vect_used_in_scope;
> +  if (is_ctrl_stmt (stmt_info->stmt))
> +    {
> +      /* Ideally EDGE_LOOP_EXIT would have been set on the exit edge, but
> +	 it looks like loop_manip doesn't do that..  So we have to do it
> +	 the hard way.  */
> +      basic_block bb = gimple_bb (stmt_info->stmt);
> +      basic_block *bbs = LOOP_VINFO_BBS (loop_vinfo);
> +      edge exit = BRANCH_EDGE (bb);
> +      unsigned nbbs = loop->num_nodes;
> +      bool exit_bb = true;
> +      for (unsigned i = 0; i < nbbs; i++)
> +	{
> +	  if (exit->dest == bbs[i])
> +	    {
> +	      exit_bb = false;
> +	      break;
> +	    }
> +	}
> +
> +      if (exit_bb)
> +	*relevant = vect_used_in_scope;
> +    }
>  
>    /* changing memory.  */
>    if (gimple_code (stmt_info->stmt) != GIMPLE_PHI)
> @@ -357,6 +376,11 @@ vect_stmt_relevant_p (stmt_vec_info stmt_info, loop_vec_info loop_vinfo,
>  	*relevant = vect_used_in_scope;
>        }
>  
> +  auto_vec<edge> exits = get_loop_exit_edges (loop);
> +  auto_bitmap exit_bbs;
> +  for (edge exit : exits)
> +    bitmap_set_bit (exit_bbs, exit->dest->index);
> +
>    /* uses outside the loop.  */
>    FOR_EACH_PHI_OR_STMT_DEF (def_p, stmt_info->stmt, op_iter, SSA_OP_DEF)
>      {
> @@ -375,7 +399,7 @@ vect_stmt_relevant_p (stmt_vec_info stmt_info, loop_vec_info loop_vinfo,
>  	      /* We expect all such uses to be in the loop exit phis
>  		 (because of loop closed form)   */
>  	      gcc_assert (gimple_code (USE_STMT (use_p)) == GIMPLE_PHI);
> -	      gcc_assert (bb == single_exit (loop)->dest);
> +	      gcc_assert (bitmap_bit_p (exit_bbs, bb->index));
>  
>                *live_p = true;
>  	    }
> @@ -10790,6 +10814,223 @@ vectorizable_condition (vec_info *vinfo,
>    return true;
>  }
>  
> +/* Check to see if the current early break given in STMT_INFO is valid for
> +   vectorization.  */
> +
> +static bool
> +vectorizable_early_exit (vec_info *vinfo,
> +			stmt_vec_info stmt_info, slp_tree /* slp_node */,
> +			slp_instance /* slp_node_instance */,
> +			stmt_vector_for_cost * /* cost_vec */)
> +{
> +  loop_vec_info loop_vinfo = dyn_cast <loop_vec_info> (vinfo);
> +
> +  if (!loop_vinfo
> +      || !is_a <gcond *> (STMT_VINFO_STMT (stmt_info)))
> +    return false;
> +
> +  if (STMT_VINFO_DEF_TYPE (stmt_info) != vect_early_exit_def)
> +    return false;
> +
> +  /* refactor and merge with vect_transform_early_break.  */
> +  gimple_match_op op;
> +  if (!gimple_extract_op (stmt_info->stmt, &op))
> +    gcc_unreachable ();
> +  gcc_assert (op.code.is_tree_code ());
> +
> +  tree vectype_in = STMT_VINFO_VECTYPE (stmt_info);
> +  gcc_assert (vectype_in);
> +
> +  stmt_vec_info operand0_info
> +    = loop_vinfo->lookup_stmt (SSA_NAME_DEF_STMT (op.ops[0]));
> +  if (!operand0_info)
> +    return false;
> +  tree vectype_op = STMT_VINFO_VECTYPE (operand0_info);
> +
> +  //tree vectype = STMT_VINFO_VECTYPE (stmt_info);
> +  tree truth_type = truth_type_for (vectype_op);
> +  machine_mode mode = TYPE_MODE (truth_type);
> +  if (direct_optab_handler (cbranch_optab, mode) == CODE_FOR_nothing)
> +    {
> +      if (dump_enabled_p ())
> +	  dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
> +				 "can't vectorize early exit because the "
> +				 "target doesn't support flag setting vector "
> +				 "comparisons.\n");
> +      return false;
> +    }
> +
> +  if (!expand_vec_cmp_expr_p (vectype_op, truth_type, NE_EXPR))
> +    {
> +      if (dump_enabled_p ())
> +	  dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
> +				 "can't vectorize early exit because the "
> +				 "target does not support boolean vector "
> +				 "comparisons for type %T.\n", truth_type);
> +      return false;
> +    }
> +
> +  if (direct_optab_handler (ior_optab, mode) == CODE_FOR_nothing)
> +    {
> +      if (dump_enabled_p ())
> +	  dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
> +				 "can't vectorize early exit because the "
> +				 "target does not support boolean vector OR for "
> +				 "type %T.\n", truth_type);
> +      return false;
> +    }
> +
> +  return true;
> +}
> +
> +
> +/* Transform the definition stmt STMT_INFO of an early exit
> +   value.  */
> +
> +static bool
> +vect_transform_early_break (loop_vec_info loop_vinfo,
> +			    stmt_vec_info stmt_info, gimple_stmt_iterator *gsi,
> +			    gimple **vec_stmt, slp_tree slp_node)
> +{
> +  tree vectype_out = STMT_VINFO_VECTYPE (stmt_info);
> +  int i;
> +  int ncopies, nopcopies;
> +  int vec_num;
> +  stmt_vec_info operand0_info;
> +
> +  if (!STMT_VINFO_RELEVANT_P (stmt_info))
> +    return false;
> +
> +  gimple_match_op op;
> +  if (!gimple_extract_op (stmt_info->stmt, &op))
> +    gcc_unreachable ();
> +  gcc_assert (op.code.is_tree_code ());
> +  auto code = tree_code (op.code);
> +
> +  tree vectype_in = STMT_VINFO_VECTYPE (stmt_info);
> +  gcc_assert (vectype_in);
> +
> +  operand0_info = loop_vinfo->lookup_stmt (SSA_NAME_DEF_STMT (op.ops[0]));
> +  tree vectype_op = STMT_VINFO_VECTYPE (operand0_info);
> +
> +  if (slp_node)
> +    {
> +      ncopies = 1;
> +      nopcopies = 1;
> +      vec_num = SLP_TREE_NUMBER_OF_VEC_STMTS (slp_node);
> +    }
> +  else
> +    {
> +      /* Because of the difference between types when doing a boolean reduction
> +	 we must determine the number of copies based on the type operands of
> +	 operands of the comparison and not the comparison itself.  */
> +      ncopies = vect_get_num_copies (loop_vinfo, vectype_in);
> +      nopcopies = vect_get_num_copies (loop_vinfo, vectype_op);
> +      vec_num = 1;
> +    }
> +
> +  vec_loop_masks *masks = &LOOP_VINFO_MASKS (loop_vinfo);
> +  bool masked_loop_p = LOOP_VINFO_FULLY_MASKED_P (loop_vinfo);
> +
> +  if (ncopies != nopcopies)
> +    vectype_out = vectype_op;
> +
> +  /* Transform.  */
> +  tree new_temp = NULL_TREE;
> +  auto_vec<tree> vec_oprnds0;
> +  auto_vec<tree> vec_oprnds1;
> +  tree def0;
> +
> +  if (dump_enabled_p ())
> +    dump_printf_loc (MSG_NOTE, vect_location, "transform early-exit.\n");
> +
> +  gimple *stmt = STMT_VINFO_STMT (stmt_info);
> +  basic_block cond_bb = gimple_bb (stmt);
> +  gimple_stmt_iterator  cond_gsi = gsi_last_bb (cond_bb);
> +
> +  vect_get_vec_defs (loop_vinfo, stmt_info, slp_node, nopcopies,
> +		     op.ops[0], &vec_oprnds0, vectype_out,
> +		     op.ops[1], &vec_oprnds1, vectype_out,
> +		     NULL, NULL, NULL);
> +
> +  gimple *new_stmt = NULL;
> +  tree cst_0 = build_zero_cst (truth_type_for (vectype_out));
> +  tree cst_m1 = build_minus_one_cst (truth_type_for (vectype_out));
> +
> +  FOR_EACH_VEC_ELT (vec_oprnds0, i, def0)
> +    {
> +      tree vop[3] = { def0, vec_oprnds1[i], NULL_TREE };
> +	{
> +	  tree cond
> +	    = make_temp_ssa_name (truth_type_for (vectype_out), NULL, "mask");
> +	  gimple *vec_cmp = gimple_build_assign (cond, code, vop[0], vop[1]);
> +	  vect_finish_stmt_generation (loop_vinfo, stmt_info, vec_cmp,
> +				       &cond_gsi);
> +          if (masked_loop_p)
> +	    {
> +	      tree mask = vect_get_loop_mask (gsi, masks, vec_num * ncopies,
> +					      vectype_op, i);
> +	      cond = prepare_vec_mask (loop_vinfo, TREE_TYPE (mask), mask,
> +				       cond, &cond_gsi);
> +	    }
> +
> +	  new_temp
> +	    = make_temp_ssa_name (truth_type_for (vectype_out), NULL, "vexit");
> +	  new_stmt = gimple_build_assign (new_temp, VEC_COND_EXPR,
> +					  cond, cst_m1, cst_0);
> +	  vect_finish_stmt_generation (loop_vinfo, stmt_info, new_stmt,
> +				       &cond_gsi);
> +	}
> +
> +      if (slp_node)
> +	SLP_TREE_VEC_STMTS (slp_node).quick_push (new_stmt);
> +      else
> +	STMT_VINFO_VEC_STMTS (stmt_info).safe_push (new_stmt);
> +    }
> +
> +  /* Determine if we need to reduce the final value.  */
> +  if (ncopies != nopcopies)
> +    {
> +      vec<gimple *> stmts;
> +      if (slp_node)
> +	stmts = SLP_TREE_VEC_STMTS (slp_node);
> +      else
> +	stmts = STMT_VINFO_VEC_STMTS (stmt_info);
> +
> +      /* We build the reductions in a way to maintain as much parallelism as
> +	 possible.  */
> +      auto_vec<gimple *> workset (stmts.length ());
> +      workset.splice (stmts);
> +      while (workset.length () > 1)
> +	{
> +	  new_temp = make_temp_ssa_name (truth_type_for (vectype_out), NULL,
> +					 "vexit_reduc");
> +	  gimple *arg0 = workset.pop ();
> +	  gimple *arg1 = workset.pop ();
> +	  new_stmt = gimple_build_assign (new_temp, BIT_IOR_EXPR,
> +					  gimple_assign_lhs (arg0),
> +					  gimple_assign_lhs (arg1));
> +	  vect_finish_stmt_generation (loop_vinfo, stmt_info, new_stmt,
> +				       &cond_gsi);
> +	  workset.quick_insert (0, new_stmt);
> +	}
> +    }
> +
> +  gcc_assert (new_stmt);
> +  tree lhs = gimple_assign_lhs (new_stmt);
> +
> +  tree t = fold_build2 (NE_EXPR, boolean_type_node, lhs,
> +			build_zero_cst (truth_type_for (vectype_out)));
> +  t = canonicalize_cond_expr_cond (t);
> +  gimple_cond_set_condition_from_tree ((gcond*)stmt, t);
> +  update_stmt (stmt);
> +
> +  if (!slp_node)
> +    *vec_stmt = STMT_VINFO_VEC_STMTS (stmt_info)[0];
> +
> +  return true;
> +}
> +
>  /* vectorizable_comparison.
>  
>     Check if STMT_INFO is comparison expression that can be vectorized.
> @@ -11167,11 +11408,14 @@ vect_analyze_stmt (vec_info *vinfo,
>  			     node_instance, cost_vec);
>        if (!res)
>  	return res;
> -   }
> +    }
> +  else if (is_ctrl_stmt (stmt_info->stmt))
> +    STMT_VINFO_DEF_TYPE (stmt_info) = vect_early_exit_def;
>  
>    switch (STMT_VINFO_DEF_TYPE (stmt_info))
>      {
>        case vect_internal_def:
> +      case vect_early_exit_def:
>          break;
>  
>        case vect_reduction_def:
> @@ -11204,6 +11448,7 @@ vect_analyze_stmt (vec_info *vinfo,
>      {
>        gcall *call = dyn_cast <gcall *> (stmt_info->stmt);
>        gcc_assert (STMT_VINFO_VECTYPE (stmt_info)
> +		  || gimple_code (stmt_info->stmt) == GIMPLE_COND
>  		  || (call && gimple_call_lhs (call) == NULL_TREE));
>        *need_to_vectorize = true;
>      }
> @@ -11246,7 +11491,9 @@ vect_analyze_stmt (vec_info *vinfo,
>  	  || vectorizable_lc_phi (as_a <loop_vec_info> (vinfo),
>  				  stmt_info, NULL, node)
>  	  || vectorizable_recurr (as_a <loop_vec_info> (vinfo),
> -				   stmt_info, NULL, node, cost_vec));
> +				   stmt_info, NULL, node, cost_vec)
> +	  || vectorizable_early_exit (vinfo, stmt_info,
> +				      node, node_instance, cost_vec));
>    else
>      {
>        if (bb_vinfo)
> @@ -11269,7 +11516,10 @@ vect_analyze_stmt (vec_info *vinfo,
>  					 NULL, NULL, node, cost_vec)
>  	      || vectorizable_comparison (vinfo, stmt_info, NULL, NULL, node,
>  					  cost_vec)
> -	      || vectorizable_phi (vinfo, stmt_info, NULL, node, cost_vec));
> +	      || vectorizable_phi (vinfo, stmt_info, NULL, node, cost_vec)
> +	      || vectorizable_early_exit (vinfo, stmt_info, node,
> +					  node_instance, cost_vec));
> +
>      }
>  
>    if (node)
> @@ -11427,6 +11677,12 @@ vect_transform_stmt (vec_info *vinfo,
>        gcc_assert (done);
>        break;
>  
> +    case loop_exit_ctrl_vec_info_type:
> +      done = vect_transform_early_break (as_a <loop_vec_info> (vinfo), stmt_info,
> +				         gsi, &vec_stmt, slp_node);
> +      gcc_assert (done);
> +      break;
> +
>      default:
>        if (!STMT_VINFO_LIVE_P (stmt_info))
>  	{
> @@ -11825,6 +12081,9 @@ vect_is_simple_use (tree operand, vec_info *vinfo, enum vect_def_type *dt,
>  	case vect_first_order_recurrence:
>  	  dump_printf (MSG_NOTE, "first order recurrence\n");
>  	  break;
> +	case vect_early_exit_def:
> +	  dump_printf (MSG_NOTE, "early exit\n");
> +	  break;
>  	case vect_unknown_def_type:
>  	  dump_printf (MSG_NOTE, "unknown\n");
>  	  break;
> @@ -12504,6 +12763,8 @@ vect_get_vector_types_for_stmt (vec_info *vinfo, stmt_vec_info stmt_info,
>    *nunits_vectype_out = NULL_TREE;
>  
>    if (gimple_get_lhs (stmt) == NULL_TREE
> +      /* Allow vector conditionals through here.  */
> +      && !is_ctrl_stmt (stmt)
>        /* MASK_STORE has no lhs, but is ok.  */
>        && !gimple_call_internal_p (stmt, IFN_MASK_STORE))
>      {
> @@ -12520,7 +12781,7 @@ vect_get_vector_types_for_stmt (vec_info *vinfo, stmt_vec_info stmt_info,
>  	}
>  
>        return opt_result::failure_at (stmt,
> -				     "not vectorized: irregular stmt.%G", stmt);
> +				     "not vectorized: irregular stmt: %G", stmt);
>      }
>  
>    tree vectype;
> @@ -12549,6 +12810,8 @@ vect_get_vector_types_for_stmt (vec_info *vinfo, stmt_vec_info stmt_info,
>  	scalar_type = TREE_TYPE (DR_REF (dr));
>        else if (gimple_call_internal_p (stmt, IFN_MASK_STORE))
>  	scalar_type = TREE_TYPE (gimple_call_arg (stmt, 3));
> +      else if (is_ctrl_stmt (stmt))
> +	scalar_type = TREE_TYPE (gimple_cond_rhs (stmt));
>        else
>  	scalar_type = TREE_TYPE (gimple_get_lhs (stmt));
>  
> diff --git a/gcc/tree-vectorizer.h b/gcc/tree-vectorizer.h
> index 016961da8510ca7dd2d07e716cbe35623ed2d9a5..3f4fc90c7ada9713b9ce58f86272648dab0ca6b7 100644
> --- a/gcc/tree-vectorizer.h
> +++ b/gcc/tree-vectorizer.h
> @@ -63,6 +63,7 @@ enum vect_def_type {
>    vect_internal_def,
>    vect_induction_def,
>    vect_reduction_def,
> +  vect_early_exit_def,
>    vect_double_reduction_def,
>    vect_nested_cycle,
>    vect_first_order_recurrence,
> @@ -836,6 +837,13 @@ public:
>       we need to peel off iterations at the end to form an epilogue loop.  */
>    bool peeling_for_niter;
>  
> +  /* When the loop has early breaks that we can vectorize we need to peel
> +     the loop for the break finding loop.  */
> +  bool early_breaks;
> +
> +  /* List of loop IV conditionals found in the loop.  */
> +  auto_vec<gcond *> conds;
> +
>    /* True if there are no loop carried data dependencies in the loop.
>       If loop->safelen <= 1, then this is always true, either the loop
>       didn't have any loop carried data dependencies, or the loop is being
> @@ -921,6 +929,8 @@ public:
>  #define LOOP_VINFO_REDUCTION_CHAINS(L)     (L)->reduction_chains
>  #define LOOP_VINFO_PEELING_FOR_GAPS(L)     (L)->peeling_for_gaps
>  #define LOOP_VINFO_PEELING_FOR_NITER(L)    (L)->peeling_for_niter
> +#define LOOP_VINFO_EARLY_BREAKS(L)         (L)->early_breaks
> +#define LOOP_VINFO_LOOP_CONDS(L)           (L)->conds
>  #define LOOP_VINFO_NO_DATA_DEPENDENCIES(L) (L)->no_data_dependencies
>  #define LOOP_VINFO_SCALAR_LOOP(L)	   (L)->scalar_loop
>  #define LOOP_VINFO_SCALAR_LOOP_SCALING(L)  (L)->scalar_loop_scaling
> @@ -970,7 +980,7 @@ public:
>  typedef opt_pointer_wrapper <loop_vec_info> opt_loop_vec_info;
>  
>  static inline loop_vec_info
> -loop_vec_info_for_loop (class loop *loop)
> +loop_vec_info_for_loop (const class loop *loop)
>  {
>    return (loop_vec_info) loop->aux;
>  }
> @@ -2107,7 +2117,7 @@ class auto_purge_vect_location
>     in tree-vect-loop-manip.cc.  */
>  extern void vect_set_loop_condition (class loop *, loop_vec_info,
>  				     tree, tree, tree, bool);
> -extern bool slpeel_can_duplicate_loop_p (const class loop *, const_edge);
> +extern bool slpeel_can_duplicate_loop_p (const loop_vec_info, const_edge);
>  class loop *slpeel_tree_duplicate_loop_to_edge_cfg (class loop *,
>  						     class loop *, edge);
>  class loop *vect_loop_versioning (loop_vec_info, gimple *);
> @@ -2306,6 +2316,7 @@ struct vect_loop_form_info
>    tree number_of_iterations;
>    tree number_of_iterationsm1;
>    tree assumptions;
> +  vec<gcond *> conds;
>    gcond *loop_cond;
>    gcond *inner_loop_cond;
>  };
> diff --git a/gcc/tree-vectorizer.cc b/gcc/tree-vectorizer.cc
> index 6ec49511d74bd2e0e5dd51823a6c41180f08716c..4aa46c7c0d8235d3b783ce930e5df3480e1b3ef9 100644
> --- a/gcc/tree-vectorizer.cc
> +++ b/gcc/tree-vectorizer.cc
> @@ -1382,7 +1382,9 @@ pass_vectorize::execute (function *fun)
>  	 predicates that need to be shared for optimal predicate usage.
>  	 However reassoc will re-order them and prevent CSE from working
>  	 as it should.  CSE only the loop body, not the entry.  */
> -      bitmap_set_bit (exit_bbs, single_exit (loop)->dest->index);
> +      auto_vec<edge> exits = get_loop_exit_edges (loop);
> +      for (edge exit : exits)
> +	bitmap_set_bit (exit_bbs, exit->dest->index);
>  
>        edge entry = EDGE_PRED (loop_preheader_edge (loop)->src, 0);
>        do_rpo_vn (fun, entry, exit_bbs);
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg,
Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman;
HRB 36809 (AG Nuernberg)

      reply	other threads:[~2022-12-14  9:41 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-02 14:45 Tamar Christina
2022-11-02 14:46 ` [PATCH 2/2]AArch64 Add implementation for vector cbranch Tamar Christina
2022-11-02 21:50 ` [PATCH 1/2]middle-end: Support early break/return auto-vectorization Bernhard Reutner-Fischer
2022-11-02 22:32   ` Jeff Law
2022-11-03  8:51     ` Tamar Christina
2022-11-08 17:36 ` Tamar Christina
2022-11-15 11:11   ` Tamar Christina
2022-11-16 12:17     ` Richard Biener
2022-11-16 18:52       ` Jeff Law
2022-11-18 15:04 ` Richard Biener
2022-11-18 18:23   ` Tamar Christina
2022-11-19 10:49     ` Tamar Christina
2022-11-24  9:02     ` Richard Biener
2022-11-24 11:56       ` Tamar Christina
2022-11-25  9:33         ` Richard Biener
2022-11-25 10:32           ` Tamar Christina
2022-12-13 15:01             ` Tamar Christina
2022-12-14  9:41               ` Richard Biener [this message]

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