RE: [PATCH] Enhance final_value_replacement_loop to handle bitop with an invariant induction.[PR105735]

["Kong, Lingling" <lingling.kong@intel.com>]

Thanks a lot, pushed to trunk.

> Hi Richard,
> 
> Thanks again for your reviewing.
> 
> > Yes, use else if for the bitwise induction.  Can you also make the new
> > case conditional on 'def'
> > (the compute_overall_effect_of_inner_loop) being chrec_dont_know?  If
> > that call produced something useful it will not be of either of the two special
> forms.
> > Thus like
> >
> >   if (def != chrec_dont_know)
> >     /* Already OK.  */
> >     ;
> >  else if ((bitinv_def = ...)
> >     ..
> >  else if (tree_fits_uhwi_p (niter)
> >              ... bitwise induction case...)
> >     ...
> >
> Yes, I fixed it in new patch. Thanks.
> Ok for master ?
> 
> Thanks,
> Lingling
> 
> > -----Original Message-----
> > From: Richard Biener <richard.guenther@gmail.com>
> > Sent: Wednesday, September 14, 2022 4:16 PM
> > To: Kong, Lingling <lingling.kong@intel.com>
> > Cc: gcc-patches@gcc.gnu.org; Liu, Hongtao <hongtao.liu@intel.com>
> > Subject: Re: [PATCH] Enhance final_value_replacement_loop to handle
> > bitop with an invariant induction.[PR105735]
> >
> > On Tue, Sep 13, 2022 at 9:54 AM Kong, Lingling
> > <lingling.kong@intel.com>
> > wrote:
> > >
> > > Hi Richard,
> > >
> > > Thanks you so much for reviewing this patch.  I really appreciate
> > > it. For these
> > review comments, I have made some changes.
> > >
> > > > That's a single-stmt match, you shouldn't use match.pd matching for this.
> > > > Instead just do
> > > >
> > > >   if (is_gimple_assign (stmt)
> > > >       && ((code = gimple_assign_rhs_code (stmt)), true)
> > > >       && (code == BIT_AND_EXPR || code == BIT_IOR_EXPR || code ==
> > > > BIT_XOR_EXPR))
> > >
> > > Yes, I fixed it and dropped modification for match.pd.
> > >
> > > > and pick gimple_assign_rhs{1,2} (stmt) as the operands.  The :c in
> > > > bit_op:c is redundant btw. - while the name suggests "with
> > > > invariant" you don't actually check for that.  But again, given
> > > > canonicalization rules the invariant will be rhs2 so above add
> > > >
> > > >         && TREE_CODE (gimple_assign_rhs2 (stmt)) == INTEGER_CST
> > >
> > > For " with invariant", this needed op1 is invariant, and I used
> > `expr_invariant_in_loop_p (loop, match_op[0])` for check.
> > > And op2 just be PHI is ok. If op2 is INTEGER_CST, existing gcc can
> > > be directly
> > optimized and do not need modification.
> > >
> > > > you probably need dg-require-effective-target longlong, but is it
> > > > necessary to use long long for the testcases in the first place?
> > > > The IV seems to be unused, if it should match the variables bit
> > > > size use sizeof
> > > > (type) * 8
> > >
> > > Yes, It is not necessary to use long long for the testcases. I
> > > changed type to
> > unsigned int.
> > >
> > > > > +  inv = PHI_ARG_DEF_FROM_EDGE (header_phi, loop_preheader_edge
> > > > > + (loop));  return fold_build2 (code1, type, inv, match_op[0]);
> > > > > + }
> > > >
> > > > The } goes to the next line.
> > >
> > > Sorry, It might be something wrong with my use of gcc send-email format.
> > >
> > > > > +      tree bitinv_def;
> > > > > +      if ((bitinv_def
> > > >
> > > > please use else if here
> > >
> > > Sorry, If use the else if here, there is no corresponding above if.
> > > I'm not sure if
> > you mean change bitwise induction expression if to else if.
> >
> > Yes, use else if for the bitwise induction.  Can you also make the new
> > case conditional on 'def'
> > (the compute_overall_effect_of_inner_loop) being chrec_dont_know?  If
> > that call produced something useful it will not be of either of the two special
> forms.
> > Thus like
> >
> >   if (def != chrec_dont_know)
> >     /* Already OK.  */
> >     ;
> >  else if ((bitinv_def = ...)
> >     ..
> >  else if (tree_fits_uhwi_p (niter)
> >              ... bitwise induction case...)
> >     ...
> >
> > ?
> >
> > Otherwise looks OK now.
> >
> > Thanks,
> > Richard.
> >
> > > Do you agree with these changes?  Thanks again for taking a look.
> > >
> > > Thanks,
> > > Lingling
> > >
> > > > -----Original Message-----
> > > > From: Richard Biener <richard.guenther@gmail.com>
> > > > Sent: Tuesday, August 23, 2022 3:27 PM
> > > > To: Kong, Lingling <lingling.kong@intel.com>
> > > > Cc: Liu, Hongtao <hongtao.liu@intel.com>; gcc-patches@gcc.gnu.org
> > > > Subject: Re: [PATCH] Enhance final_value_replacement_loop to
> > > > handle bitop with an invariant induction.[PR105735]
> > > >
> > > > On Thu, Aug 18, 2022 at 8:48 AM Kong, Lingling via Gcc-patches
> > > > <gcc- patches@gcc.gnu.org> wrote:
> > > > >
> > > > > Hi,
> > > > >
> > > > > This patch is for pr105735/pr101991. It will enable below optimization:
> > > > > {
> > > > > -  long unsigned int bit;
> > > > > -
> > > > > -  <bb 2> [local count: 32534376]:
> > > > > -
> > > > > -  <bb 3> [local count: 1041207449]:
> > > > > -  # tmp_10 = PHI <tmp_7(5), tmp_4(D)(2)>
> > > > > -  # bit_12 = PHI <bit_8(5), 0(2)>
> > > > > -  tmp_7 = bit2_6(D) & tmp_10;
> > > > > -  bit_8 = bit_12 + 1;
> > > > > -  if (bit_8 != 32)
> > > > > -    goto <bb 5>; [96.97%]
> > > > > -  else
> > > > > -    goto <bb 4>; [3.03%]
> > > > > -
> > > > > -  <bb 5> [local count: 1009658865]:
> > > > > -  goto <bb 3>; [100.00%]
> > > > > -
> > > > > -  <bb 4> [local count: 32534376]:
> > > > > -  # tmp_11 = PHI <tmp_7(3)>
> > > > > -  return tmp_11;
> > > > > +  tmp_11 = tmp_4(D) & bit2_6(D);  return tmp_11;
> > > > >
> > > > > }
> > > > >
> > > > > Ok for master ?
> > > > >
> > > > > gcc/ChangeLog:
> > > > >
> > > > >         PR middle-end/105735
> > > > >         * match.pd (bitop_with_inv_p): New match.
> > > > >         * tree-scalar-evolution.cc (gimple_bitop_with_inv_p): Declare.
> > > > >         (analyze_and_compute_bitop_with_inv_effect): New function.
> > > > >         (final_value_replacement_loop): Enhanced to handle bitop
> > > > >         with inv induction.
> > > > >
> > > > > gcc/testsuite/ChangeLog:
> > > > >
> > > > >         * gcc.target/i386/pr105735-1.c: New test.
> > > > >         * gcc.target/i386/pr105735-2.c: New test.
> > > > > ---
> > > > >  gcc/match.pd                               |  4 +
> > > > >  gcc/testsuite/gcc.target/i386/pr105735-1.c | 88
> > > > > ++++++++++++++++++++++
> > > > gcc/testsuite/gcc.target/i386/pr105735-2.c | 28 +++++++
> > > > >  gcc/tree-scalar-evolution.cc               | 59 +++++++++++++++
> > > > >  4 files changed, 179 insertions(+)  create mode 100644
> > > > > gcc/testsuite/gcc.target/i386/pr105735-1.c
> > > > >  create mode 100644 gcc/testsuite/gcc.target/i386/pr105735-2.c
> > > > >
> > > > > diff --git a/gcc/match.pd b/gcc/match.pd index
> > > > > 562138a8034..cfe593ebb02 100644
> > > > > --- a/gcc/match.pd
> > > > > +++ b/gcc/match.pd
> > > > > @@ -8050,6 +8050,10 @@ and,
> > > > >   (bit_not
> > > > >    (nop_convert1? (bit_xor@0 (convert2? (lshift integer_onep@1
> > > > > @2))
> > > > > @3))))
> > > > >
> > > > > +(for bit_op (bit_and bit_ior bit_xor)  (match (bitop_with_inv_p
> > > > > +@0
> > > > > +@1)
> > > > > +  (bit_op:c @0 @1)))
> > > > > +
> > > >
> > > > That's a single-stmt match, you shouldn't use match.pd matching for this.
> > > > Instead just do
> > > >
> > > >   if (is_gimple_assign (stmt)
> > > >       && ((code = gimple_assign_rhs_code (stmt)), true)
> > > >       && (code == BIT_AND_EXPR || code == BIT_IOR_EXPR || code ==
> > > > BIT_XOR_EXPR))
> > > >    ..
> > > >
> > > > and pick gimple_assign_rhs{1,2} (stmt) as the operands.  The :c in
> > > > bit_op:c is redundant btw. - while the name suggests "with
> > > > invariant" you don't actually check for that.  But again, given
> > > > canonicalization rules the invariant will be rhs2 so above add
> > > >
> > > >         && TREE_CODE (gimple_assign_rhs2 (stmt)) == INTEGER_CST
> > > >
> > > > for example.
> > > >
> > > > >  /* n - (((n > C1) ? n : C1) & -C2) ->  n & C1 for unsigned case.
> > > > >     n - (((n > C1) ? n : C1) & -C2) ->  (n <= C1) ? n : (n & C1)
> > > > > for signed case.  */  (simplify diff --git
> > > > > a/gcc/testsuite/gcc.target/i386/pr105735-1.c
> > > > > b/gcc/testsuite/gcc.target/i386/pr105735-1.c
> > > > > new file mode 100644
> > > > > index 00000000000..8d2123ed351
> > > > > --- /dev/null
> > > > > +++ b/gcc/testsuite/gcc.target/i386/pr105735-1.c
> > > > > @@ -0,0 +1,88 @@
> > > > > +/* { dg-do compile } */
> > > > > +/* { dg-options "-O1 -fdump-tree-sccp-details" } */
> > > > > +/* { dg-final { scan-tree-dump-times {final value replacement} 8 "sccp"
> > > > > +} } */
> > > > > +
> > > > > +unsigned long long
> > > > > +__attribute__((noipa))
> > > > > +foo (unsigned long long tmp, unsigned long long bit2) {
> > > >
> > > > you probably need dg-require-effective-target longlong, but is it
> > > > necessary to use long long for the testcases in the first place?
> > > > The IV seems to be unused, if it should match the variables bit size
> > > > use sizeof
> > > > (type) * 8
> > > >
> > > > > +  for (int bit = 0; bit < 64; bit++)
> > > > > +    tmp &= bit2;
> > > > > +  return tmp;
> > > > > +}
> > > > > +
> > > > > +unsigned long long
> > > > > +__attribute__((noipa))
> > > > > +foo1 (unsigned long long tmp, unsigned long long bit2) {
> > > > > +  for (int bit = 63; bit >= 0; bit -=3)
> > > > > +    tmp &= bit2;
> > > > > +  return tmp;
> > > > > +}
> > > > > +
> > > > > +unsigned long long
> > > > > +__attribute__((noipa))
> > > > > +foo2 (unsigned long long tmp, unsigned long long bit2) {
> > > > > +  for (int bit = 0; bit < 64; bit++)
> > > > > +    tmp |= bit2;
> > > > > +  return tmp;
> > > > > +}
> > > > > +
> > > > > +unsigned long long
> > > > > +__attribute__((noipa))
> > > > > +foo3 (unsigned long long tmp, unsigned long long bit2) {
> > > > > +  for (int bit = 63; bit >= 0; bit -=3)
> > > > > +    tmp |= bit2;
> > > > > +  return tmp;
> > > > > +}
> > > > > +
> > > > > +unsigned long long
> > > > > +__attribute__((noipa))
> > > > > +foo4 (unsigned long long tmp, unsigned long long bit2) {
> > > > > +  for (int bit = 0; bit < 64; bit++)
> > > > > +    tmp ^= bit2;
> > > > > +  return tmp;
> > > > > +}
> > > > > +
> > > > > +unsigned long long
> > > > > +__attribute__((noipa))
> > > > > +foo5 (unsigned long long tmp, unsigned long long bit2) {
> > > > > +  for (int bit = 0; bit < 63; bit++)
> > > > > +    tmp ^= bit2;
> > > > > +  return tmp;
> > > > > +}
> > > > > +
> > > > > +unsigned long long
> > > > > +__attribute__((noipa))
> > > > > +f (unsigned long long tmp, long long bit, unsigned long long
> > > > > +bit2) {
> > > > > +  unsigned long long res = tmp;
> > > > > +  for (long long i = 0; i < bit; i++)
> > > > > +    res &= bit2;
> > > > > +  return res;
> > > > > +}
> > > > > +
> > > > > +unsigned long long
> > > > > +__attribute__((noipa))
> > > > > +f1 (unsigned long long tmp, long long bit, unsigned long long
> > > > > +bit2) {
> > > > > +  unsigned long long res = tmp;
> > > > > +  for (long long i = 0; i < bit; i++)
> > > > > +    res |= bit2;
> > > > > +  return res;
> > > > > +}
> > > > > +
> > > > > +unsigned long long
> > > > > +__attribute__((noipa))
> > > > > +f2 (unsigned long long tmp, long long bit, unsigned long long
> > > > > +bit2) {
> > > > > +  unsigned long long res = tmp;
> > > > > +  for (long long i = 0; i < bit; i++)
> > > > > +    res ^= bit2;
> > > > > +  return res;
> > > > > +}
> > > > > +
> > > > > diff --git a/gcc/testsuite/gcc.target/i386/pr105735-2.c
> > > > > b/gcc/testsuite/gcc.target/i386/pr105735-2.c
> > > > > new file mode 100644
> > > > > index 00000000000..79c1d300b1b
> > > > > --- /dev/null
> > > > > +++ b/gcc/testsuite/gcc.target/i386/pr105735-2.c
> > > > > @@ -0,0 +1,28 @@
> > > > > +/* { dg-do run } */
> > > > > +/* { dg-options "-O1" } */
> > > > > +
> > > > > +#include "pr105735-1.c"
> > > > > +
> > > > > +int main()
> > > > > +{
> > > > > +  unsigned long long tmp = 0x1101101ULL;
> > > > > +  unsigned long long bit2 = 0x1111111011110111ULL;
> > > > > +  if (foo (tmp, bit2) != 0x1100101ULL)
> > > > > +    __builtin_abort ();
> > > > > +  if (foo1 (tmp, bit2) != 0x1100101ULL)
> > > > > +    __builtin_abort ();
> > > > > +  if (foo2 (tmp, bit2) != 0x1111111011111111ULL)
> > > > > +    __builtin_abort ();
> > > > > +  if (foo3 (tmp, bit2) != 0x1111111011111111ULL)
> > > > > +    __builtin_abort ();
> > > > > +  if (foo4 (tmp, bit2) != 0x1101101ULL)
> > > > > +    __builtin_abort ();
> > > > > +  if (foo5 (tmp, bit2) != 0x1111111010011010ULL)
> > > > > +    __builtin_abort ();
> > > > > +  if (f (tmp, 64, bit2) != 0x1100101ULL)
> > > > > +    __builtin_abort ();
> > > > > +  if (f1 (tmp, 64, bit2) != 0x1111111011111111ULL)
> > > > > +    __builtin_abort ();
> > > > > +  if (f2 (tmp, 64, bit2) != 0x1101101ULL)
> > > > > +    __builtin_abort ();
> > > > > +}
> > > > > diff --git a/gcc/tree-scalar-evolution.cc
> > > > > b/gcc/tree-scalar-evolution.cc index fc59d035b19..81220f08d2e
> > > > > 100644
> > > > > --- a/gcc/tree-scalar-evolution.cc
> > > > > +++ b/gcc/tree-scalar-evolution.cc
> > > > > @@ -3635,6 +3635,53 @@ enum bit_op_kind
> > > > >    return fold_build2 (code1, type, inv, wide_int_to_tree (type,
> > > > > bits));  }
> > > > >
> > > > > +/* Match.pd function to match bitop with invariant expression
> > > > > +  .i.e.
> > > > > +  tmp_7 = _0 & _1; */
> > > > > +extern bool gimple_bitop_with_inv_p (tree, tree *, tree
> > > > > +(*)(tree));
> > > > > +
> > > > > +/* Return the inductive expression of bitop with invariant if possible,
> > > > > +   otherwise returns DEF.  */
> > > > > +static tree
> > > > > +analyze_and_compute_bitop_with_inv_effect (class loop* loop, tree
> > phidef,
> > > > > +                                          tree niter) {
> > > > > +  tree match_op[2],inv;
> > > > > +  tree type = TREE_TYPE (phidef);
> > > > > +  gphi* header_phi = NULL;
> > > > > +  /* match thing like op0 (match[0]), op1(match[1]),
> > > > > +phidef(PHIDEF)
> > > > > +
> > > > > +    op1 =  PHI <phidef, inv>
> > > > > +    phidef = op0 & op1
> > > > > +    if op0 is an invariant, it could change to
> > > > > +    phidef = op0 & inv.  */
> > > > > +  if (!gimple_bitop_with_inv_p (phidef, &match_op[0], NULL)
> > > > > +      || TREE_CODE (match_op[1]) != SSA_NAME
> > > > > +      || !expr_invariant_in_loop_p (loop, match_op[0])
> > > > > +      || !(header_phi = dyn_cast <gphi *> (SSA_NAME_DEF_STMT
> > > > (match_op[1])))
> > > > > +      || gimple_phi_num_args (header_phi) != 2)
> > > > > +    return NULL_TREE;
> > > > > +
> > > > > +  if (PHI_ARG_DEF_FROM_EDGE (header_phi, loop_latch_edge (loop))
> > > > > + !=
> > > > phidef)
> > > > > +    return NULL_TREE;
> > > > > +
> > > > > +  enum tree_code code1
> > > > > +    = gimple_assign_rhs_code (SSA_NAME_DEF_STMT (phidef));
> > > > > +
> > > > > +  if (code1 == BIT_XOR_EXPR)
> > > > > +    {
> > > > > +       if (!tree_fits_uhwi_p (niter))
> > > > > +       return NULL_TREE;
> > > > > +       unsigned HOST_WIDE_INT niter_num;
> > > > > +       niter_num = tree_to_uhwi (niter);
> > > > > +       if (niter_num % 2 != 0)
> > > > > +       match_op[0] =  build_zero_cst (type);
> > > > > +    }
> > > > > +
> > > > > +  inv = PHI_ARG_DEF_FROM_EDGE (header_phi, loop_preheader_edge
> > > > > + (loop));  return fold_build2 (code1, type, inv, match_op[0]); }
> > > >
> > > > The } goes to the next line.
> > > >
> > > > > +
> > > > >  /* Do final value replacement for LOOP, return true if we did
> > > > > anything.  */
> > > > >
> > > > >  bool
> > > > > @@ -3687,6 +3734,18 @@ final_value_replacement_loop (class loop
> > *loop)
> > > > >                                               &folded_casts);
> > > > >        def = compute_overall_effect_of_inner_loop (ex_loop, def);
> > > > >
> > > > > +      /* Handle bitop with invariant induction expression.
> > > > > +
> > > > > +       .i.e
> > > > > +       for (int i =0 ;i < 32; i++)
> > > > > +         tmp &= bit2;
> > > > > +       if bit2 is an invariant in loop which could simple to
> > > > > +       tmp &= bit2.  */
> > > > > +      tree bitinv_def;
> > > > > +      if ((bitinv_def
> > > >
> > > > please use else if here
> > > >
> > > > otherwise looks OK.
> > > >
> > > > > +          = analyze_and_compute_bitop_with_inv_effect (loop, phidef,
> niter)))
> > > > > +       def = bitinv_def;
> > > > > +
> > > > >        /* Handle bitwise induction expression.
> > > > >
> > > > >          .i.e.
> > > > > --
> > > > > 2.18.2
> > > > >