Re: [PATCH 2/2] Fix _mm256_zeroupper by representing the instructions as call_insns in which the call has a special vzeroupper ABI.

[Hongtao Liu <crazylht@gmail.com>]

On Fri, Jun 4, 2021 at 2:27 PM Uros Bizjak via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> On Thu, Jun 3, 2021 at 8:54 AM liuhongt <hongtao.liu@intel.com> wrote:
> >
> > When __builtin_ia32_vzeroupper is called explicitly, the corresponding
> > vzeroupper pattern does not carry any CLOBBERS or SETs before LRA,
> > which leads to incorrect optimization in pass_reload. In order to
> > solve this problem, this patch refine instructions as call_insns in
> > which the call has a special vzeroupper ABI.
> >
> > gcc/ChangeLog:
> >
> >         PR target/82735
> >         * config/i386/i386-expand.c (ix86_expand_builtin): Remove
> >         assignment of cfun->machine->has_explicit_vzeroupper.
> >         * config/i386/i386-features.c
> >         (ix86_add_reg_usage_to_vzerouppers): Delete.
> >         (ix86_add_reg_usage_to_vzeroupper): Ditto.
> >         (rest_of_handle_insert_vzeroupper): Remove
> >         ix86_add_reg_usage_to_vzerouppers, add df_analyze at the end
> >         of the function.
> >         (gate): Remove cfun->machine->has_explicit_vzeroupper.
> >         * config/i386/i386-protos.h (ix86_expand_avx_vzeroupper):
> >         Declared.
> >         * config/i386/i386.c (ix86_insn_callee_abi): New function.
> >         (ix86_initialize_callee_abi): Ditto.
> >         (ix86_expand_avx_vzeroupper): Ditto.
> >         (ix86_hard_regno_call_part_clobbered): Adjust for vzeroupper
> >         ABI.
> >         (TARGET_INSN_CALLEE_ABI): Define as ix86_insn_callee_abi.
> >         (ix86_emit_mode_set): Call ix86_expand_avx_vzeroupper
> >         directly.
> >         * config/i386/i386.h (struct GTY(()) machine_function): Delete
> >         has_explicit_vzeroupper.
> >         * config/i386/i386.md (enum unspec): New member
> >         UNSPEC_CALLEE_ABI.
> >         (I386_DEFAULT,I386_VZEROUPPER,I386_UNKNOWN): New
> >         define_constants for insn callee abi index.
> >         * config/i386/predicates.md (vzeroupper_pattern): Adjust.
> >         * config/i386/sse.md (UNSPECV_VZEROUPPER): Deleted.
> >         (avx_vzeroupper): Call ix86_expand_avx_vzeroupper.
> >         (*avx_vzeroupper): Rename to ..
> >         (avx_vzeroupper_callee_abi): .. this, and adjust pattern as
> >         call_insn which has a special vzeroupper ABI.
> >         (*avx_vzeroupper_1): Deleted.
> >
> > gcc/testsuite/ChangeLog:
> >
> >         PR target/82735
> >         * gcc.target/i386/pr82735-1.c: New test.
> >         * gcc.target/i386/pr82735-2.c: New test.
> >         * gcc.target/i386/pr82735-3.c: New test.
> >         * gcc.target/i386/pr82735-4.c: New test.
> >         * gcc.target/i386/pr82735-5.c: New test.
>
> LGTM, with a small nit below.
>
> Thanks,
> Uros.
>
> > ---
> >  gcc/config/i386/i386-expand.c             |  4 -
> >  gcc/config/i386/i386-features.c           | 99 +++--------------------
> >  gcc/config/i386/i386-protos.h             |  1 +
> >  gcc/config/i386/i386.c                    | 55 ++++++++++++-
> >  gcc/config/i386/i386.h                    |  4 -
> >  gcc/config/i386/i386.md                   | 10 +++
> >  gcc/config/i386/predicates.md             |  5 +-
> >  gcc/config/i386/sse.md                    | 59 ++++----------
> >  gcc/testsuite/gcc.target/i386/pr82735-1.c | 29 +++++++
> >  gcc/testsuite/gcc.target/i386/pr82735-2.c | 22 +++++
> >  gcc/testsuite/gcc.target/i386/pr82735-3.c |  5 ++
> >  gcc/testsuite/gcc.target/i386/pr82735-4.c | 48 +++++++++++
> >  gcc/testsuite/gcc.target/i386/pr82735-5.c | 54 +++++++++++++
> >  13 files changed, 252 insertions(+), 143 deletions(-)
> >  create mode 100644 gcc/testsuite/gcc.target/i386/pr82735-1.c
> >  create mode 100644 gcc/testsuite/gcc.target/i386/pr82735-2.c
> >  create mode 100644 gcc/testsuite/gcc.target/i386/pr82735-3.c
> >  create mode 100644 gcc/testsuite/gcc.target/i386/pr82735-4.c
> >  create mode 100644 gcc/testsuite/gcc.target/i386/pr82735-5.c
> >
> > diff --git a/gcc/config/i386/i386-expand.c b/gcc/config/i386/i386-expand.c
> > index 9f3d41955a2..d25d59aa4e7 100644
> > --- a/gcc/config/i386/i386-expand.c
> > +++ b/gcc/config/i386/i386-expand.c
> > @@ -13282,10 +13282,6 @@ rdseed_step:
> >
> >        return 0;
> >
> > -    case IX86_BUILTIN_VZEROUPPER:
> > -      cfun->machine->has_explicit_vzeroupper = true;
> > -      break;
> > -
> >      default:
> >        break;
> >      }
> > diff --git a/gcc/config/i386/i386-features.c b/gcc/config/i386/i386-features.c
> > index 77783a154b6..a25769ae478 100644
> > --- a/gcc/config/i386/i386-features.c
> > +++ b/gcc/config/i386/i386-features.c
> > @@ -1768,92 +1768,22 @@ convert_scalars_to_vector (bool timode_p)
> >    return 0;
> >  }
> >
> > -/* Modify the vzeroupper pattern in INSN so that it describes the effect
> > -   that the instruction has on the SSE registers.  LIVE_REGS are the set
> > -   of registers that are live across the instruction.
> > -
> > -   For a live register R we use:
> > -
> > -     (set (reg:V2DF R) (reg:V2DF R))
> > -
> > -   which preserves the low 128 bits but clobbers the upper bits.  */
> > -
> > -static void
> > -ix86_add_reg_usage_to_vzeroupper (rtx_insn *insn, bitmap live_regs)
> > -{
> > -  rtx pattern = PATTERN (insn);
> > -  unsigned int nregs = TARGET_64BIT ? 16 : 8;
> > -  unsigned int npats = nregs;
> > -  for (unsigned int i = 0; i < nregs; ++i)
> > -    {
> > -      unsigned int regno = GET_SSE_REGNO (i);
> > -      if (!bitmap_bit_p (live_regs, regno))
> > -       npats--;
> > -    }
> > -  if (npats == 0)
> > -    return;
> > -  rtvec vec = rtvec_alloc (npats + 1);
> > -  RTVEC_ELT (vec, 0) = XVECEXP (pattern, 0, 0);
> > -  for (unsigned int i = 0, j = 0; i < nregs; ++i)
> > -    {
> > -      unsigned int regno = GET_SSE_REGNO (i);
> > -      if (!bitmap_bit_p (live_regs, regno))
> > -       continue;
> > -      rtx reg = gen_rtx_REG (V2DImode, regno);
> > -      ++j;
> > -      RTVEC_ELT (vec, j) = gen_rtx_SET (reg, reg);
> > -    }
> > -  XVEC (pattern, 0) = vec;
> > -  INSN_CODE (insn) = -1;
> > -  df_insn_rescan (insn);
> > -}
> > -
> > -/* Walk the vzeroupper instructions in the function and annotate them
> > -   with the effect that they have on the SSE registers.  */
> > -
> > -static void
> > -ix86_add_reg_usage_to_vzerouppers (void)
> > -{
> > -  basic_block bb;
> > -  rtx_insn *insn;
> > -  auto_bitmap live_regs;
> > -
> > -  df_analyze ();
> > -  FOR_EACH_BB_FN (bb, cfun)
> > -    {
> > -      bitmap_copy (live_regs, df_get_live_out (bb));
> > -      df_simulate_initialize_backwards (bb, live_regs);
> > -      FOR_BB_INSNS_REVERSE (bb, insn)
> > -       {
> > -         if (!NONDEBUG_INSN_P (insn))
> > -           continue;
> > -         if (vzeroupper_pattern (PATTERN (insn), VOIDmode))
> > -           ix86_add_reg_usage_to_vzeroupper (insn, live_regs);
> > -         df_simulate_one_insn_backwards (bb, insn, live_regs);
> > -       }
> > -    }
> > -}
> > -
> >  static unsigned int
> >  rest_of_handle_insert_vzeroupper (void)
> >  {
> > -  if (TARGET_VZEROUPPER
> > -      && flag_expensive_optimizations
> > -      && !optimize_size)
> > -    {
> > -      /* vzeroupper instructions are inserted immediately after reload to
> > -        account for possible spills from 256bit or 512bit registers.  The pass
> > -        reuses mode switching infrastructure by re-running mode insertion
> > -        pass, so disable entities that have already been processed.  */
> > -      for (int i = 0; i < MAX_386_ENTITIES; i++)
> > -       ix86_optimize_mode_switching[i] = 0;
> > +  /* vzeroupper instructions are inserted immediately after reload to
> > +     account for possible spills from 256bit or 512bit registers.  The pass
> > +     reuses mode switching infrastructure by re-running mode insertion
> > +     pass, so disable entities that have already been processed.  */
> > +  for (int i = 0; i < MAX_386_ENTITIES; i++)
> > +    ix86_optimize_mode_switching[i] = 0;
> >
> > -      ix86_optimize_mode_switching[AVX_U128] = 1;
> > +  ix86_optimize_mode_switching[AVX_U128] = 1;
> >
> > -      /* Call optimize_mode_switching.  */
> > -      g->get_passes ()->execute_pass_mode_switching ();
> > -    }
> > -  ix86_add_reg_usage_to_vzerouppers ();
> > +  /* Call optimize_mode_switching.  */
> > +  g->get_passes ()->execute_pass_mode_switching ();
> > +
> > +  df_analyze ();
> >    return 0;
> >  }
> >
> > @@ -1882,11 +1812,8 @@ public:
> >    /* opt_pass methods: */
> >    virtual bool gate (function *)
> >      {
> > -      return TARGET_AVX
> > -            && ((TARGET_VZEROUPPER
> > -                 && flag_expensive_optimizations
> > -                 && !optimize_size)
> > -                || cfun->machine->has_explicit_vzeroupper);
> > +      return TARGET_AVX && TARGET_VZEROUPPER
> > +       && flag_expensive_optimizations && !optimize_size;
> >      }
> >
> >    virtual unsigned int execute (function *)
> > diff --git a/gcc/config/i386/i386-protos.h b/gcc/config/i386/i386-protos.h
> > index 7782cf1163f..e6ac9390777 100644
> > --- a/gcc/config/i386/i386-protos.h
> > +++ b/gcc/config/i386/i386-protos.h
> > @@ -216,6 +216,7 @@ extern rtx ix86_split_stack_guard (void);
> >  extern void ix86_move_vector_high_sse_to_mmx (rtx);
> >  extern void ix86_split_mmx_pack (rtx[], enum rtx_code);
> >  extern void ix86_split_mmx_punpck (rtx[], bool);
> > +extern void ix86_expand_avx_vzeroupper (void);
> >
> >  #ifdef TREE_CODE
> >  extern void init_cumulative_args (CUMULATIVE_ARGS *, tree, rtx, tree, int);
> > diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
> > index 743d8a25fe3..f0b66dd0d56 100644
> > --- a/gcc/config/i386/i386.c
> > +++ b/gcc/config/i386/i386.c
> > @@ -14426,7 +14426,7 @@ ix86_emit_mode_set (int entity, int mode, int prev_mode ATTRIBUTE_UNUSED,
> >        break;
> >      case AVX_U128:
> >        if (mode == AVX_U128_CLEAN)
> > -       emit_insn (gen_avx_vzeroupper ());
> > +       ix86_expand_avx_vzeroupper ();
> >        break;
> >      case I387_ROUNDEVEN:
> >      case I387_TRUNC:
> > @@ -19494,15 +19494,63 @@ ix86_hard_regno_mode_ok (unsigned int regno, machine_mode mode)
> >    return false;
> >  }
> >
> > +/* Implement TARGET_INSN_CALLEE_ABI.  */
> > +
> > +const predefined_function_abi &
> > +ix86_insn_callee_abi (const rtx_insn *insn)
> > +{
> > +  unsigned int abi_id = 0;
> > +  rtx pat = PATTERN (insn);
> > +  if (vzeroupper_pattern (pat, VOIDmode))
> > +    abi_id = I386_VZEROUPPER;
> > +
> > +  return function_abis[abi_id];
> > +}
> > +
> > +/* Initialize function_abis with corresponding abi_id,
> > +   currently only handle vzeroupper.  */
> > +void
> > +ix86_initialize_callee_abi (unsigned int abi_id)
> > +{
> > +  gcc_assert (abi_id == I386_VZEROUPPER);
> > +  predefined_function_abi &vzeroupper_abi = function_abis[abi_id];
> > +  if (!vzeroupper_abi.initialized_p ())
> > +    {
> > +      HARD_REG_SET full_reg_clobbers;
> > +      CLEAR_HARD_REG_SET (full_reg_clobbers);
> > +      vzeroupper_abi.initialize (I386_VZEROUPPER, full_reg_clobbers);
> > +    }
> > +}
> > +
> > +void
> > +ix86_expand_avx_vzeroupper (void)
> > +{
> > +  /* Initialize vzeroupper_abi here.  */
> > +  ix86_initialize_callee_abi (I386_VZEROUPPER);
> > +  rtx_insn *insn = emit_call_insn (gen_avx_vzeroupper_callee_abi ());
> > +  /* Return false for non-local goto in can_nonlocal_goto.  */
> > +  make_reg_eh_region_note (insn, 0, INT_MIN);
> > +  /* Flag used for call_insn indicates it's a fake call.  */
> > +  RTX_FLAG (insn, used) = 1;
> > +}
> > +
> > +
> >  /* Implement TARGET_HARD_REGNO_CALL_PART_CLOBBERED.  The only ABI that
> >     saves SSE registers across calls is Win64 (thus no need to check the
> >     current ABI here), and with AVX enabled Win64 only guarantees that
> >     the low 16 bytes are saved.  */
> >
> >  static bool
> > -ix86_hard_regno_call_part_clobbered (unsigned int, unsigned int regno,
> > +ix86_hard_regno_call_part_clobbered (unsigned int abi_id, unsigned int regno,
> >                                      machine_mode mode)
> >  {
> > +  /* Special ABI for vzeroupper which only clobber higher part of sse regs.  */
> > +  if (abi_id == I386_VZEROUPPER)
> > +      return (GET_MODE_SIZE (mode) > 16
> > +             && ((TARGET_64BIT
> > +                  && (IN_RANGE (regno, FIRST_REX_SSE_REG, LAST_REX_SSE_REG)))
> > +                 || (IN_RANGE (regno, FIRST_SSE_REG, LAST_SSE_REG))));
> > +
> >    return SSE_REGNO_P (regno) && GET_MODE_SIZE (mode) > 16;
> >  }
> >
> > @@ -23916,6 +23964,9 @@ ix86_run_selftests (void)
> >  #define TARGET_HARD_REGNO_CALL_PART_CLOBBERED \
> >    ix86_hard_regno_call_part_clobbered
> >
> > +#undef TARGET_INSN_CALLEE_ABI
> > +#define TARGET_INSN_CALLEE_ABI ix86_insn_callee_abi
> > +
> >  #undef TARGET_CAN_CHANGE_MODE_CLASS
> >  #define TARGET_CAN_CHANGE_MODE_CLASS ix86_can_change_mode_class
> >
> > diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
> > index 53d503fc6e0..919d0b2418a 100644
> > --- a/gcc/config/i386/i386.h
> > +++ b/gcc/config/i386/i386.h
> > @@ -2659,10 +2659,6 @@ struct GTY(()) machine_function {
> >    /* True if the function needs a stack frame.  */
> >    BOOL_BITFIELD stack_frame_required : 1;
> >
> > -  /* True if __builtin_ia32_vzeroupper () has been expanded in current
> > -     function.  */
> > -  BOOL_BITFIELD has_explicit_vzeroupper : 1;
> > -
> >    /* True if we should act silently, rather than raise an error for
> >       invalid calls.  */
> >    BOOL_BITFIELD silent_p : 1;
> > diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
> > index 2fc8fae30f3..5d9f5aa39ac 100644
> > --- a/gcc/config/i386/i386.md
> > +++ b/gcc/config/i386/i386.md
> > @@ -191,6 +191,10 @@ (define_c_enum "unspec" [
> >    ;; For MOVDIRI and MOVDIR64B support
> >    UNSPEC_MOVDIRI
> >    UNSPEC_MOVDIR64B
> > +
> > +  ;; For insn_callee_abi:
> > +  UNSPEC_CALLEE_ABI
> > +
> >  ])
> >
> >  (define_c_enum "unspecv" [
> > @@ -447,6 +451,12 @@ (define_constants
> >     (FIRST_PSEUDO_REG           76)
> >    ])
> >
> > +;; Insn callee abi index.
> > +(define_constants
> > +  [(I386_DEFAULT       0)
> > +   (I386_VZEROUPPER    1)
> > +   (I386_UNKNOWN       2)])
>
> Please name these ABI_DEFAULT, ABI_VZEROUPPER and ABI_UNKNOWN.
Yes, thanks for the review.
I'll hold this patch until middle-end part is approved.
>
> > +
> >  ;; Insns whose names begin with "x86_" are emitted by gen_FOO calls
> >  ;; from i386.c.
> >
> > diff --git a/gcc/config/i386/predicates.md b/gcc/config/i386/predicates.md
> > index abd307ebdb8..8b787553f32 100644
> > --- a/gcc/config/i386/predicates.md
> > +++ b/gcc/config/i386/predicates.md
> > @@ -1599,8 +1599,9 @@ (define_predicate "vzeroall_pattern"
> >  ;; return true if OP is a vzeroupper pattern.
> >  (define_predicate "vzeroupper_pattern"
> >    (and (match_code "parallel")
> > -       (match_code "unspec_volatile" "a")
> > -       (match_test "XINT (XVECEXP (op, 0, 0), 1) == UNSPECV_VZEROUPPER")))
> > +       (match_code "unspec" "b")
> > +       (match_test "XINT (XVECEXP (op, 0, 1), 1) == UNSPEC_CALLEE_ABI")
> > +       (match_test "INTVAL (XVECEXP (XVECEXP (op, 0, 1), 0, 0)) == I386_VZEROUPPER")))
> >
> >  ;; Return true if OP is an addsub vec_merge operation
> >  (define_predicate "addsub_vm_operator"
> > diff --git a/gcc/config/i386/sse.md b/gcc/config/i386/sse.md
> > index a4503ddcb73..949347a3247 100644
> > --- a/gcc/config/i386/sse.md
> > +++ b/gcc/config/i386/sse.md
> > @@ -205,7 +205,6 @@ (define_c_enum "unspecv" [
> >    UNSPECV_MONITOR
> >    UNSPECV_MWAIT
> >    UNSPECV_VZEROALL
> > -  UNSPECV_VZEROUPPER
> >
> >    ;; For KEYLOCKER
> >    UNSPECV_LOADIWKEY
> > @@ -20857,14 +20856,22 @@ (define_insn "*avx_vzeroall"
> >  ;; if the upper 128bits are unused.  Initially we expand the instructions
> >  ;; as though they had no effect on the SSE registers, but later add SETs and
> >  ;; CLOBBERs to the PARALLEL to model the real effect.
> > +
> >  (define_expand "avx_vzeroupper"
> > -  [(parallel [(unspec_volatile [(const_int 0)] UNSPECV_VZEROUPPER)])]
> > -  "TARGET_AVX")
> > +  [(parallel [(call (mem:QI (const_int 0))
> > +                   (const_int 0))
> > +            (unspec [(const_int I386_VZEROUPPER)] UNSPEC_CALLEE_ABI)])]
> > +  "TARGET_AVX"
> > +{
> > +  ix86_expand_avx_vzeroupper ();
> > +  DONE;
> > +})
> >
> > -(define_insn "*avx_vzeroupper"
> > -  [(match_parallel 0 "vzeroupper_pattern"
> > -     [(unspec_volatile [(const_int 0)] UNSPECV_VZEROUPPER)])]
> > -  "TARGET_AVX && XVECLEN (operands[0], 0) == (TARGET_64BIT ? 16 : 8) + 1"
> > +(define_insn "avx_vzeroupper_callee_abi"
> > +  [(call (mem:QI (const_int 0))
> > +        (const_int 0))
> > +    (unspec [(const_int I386_VZEROUPPER)] UNSPEC_CALLEE_ABI)]
> > +  "TARGET_AVX"
> >    "vzeroupper"
> >    [(set_attr "type" "sse")
> >     (set_attr "modrm" "0")
> > @@ -20873,44 +20880,6 @@ (define_insn "*avx_vzeroupper"
> >     (set_attr "btver2_decode" "vector")
> >     (set_attr "mode" "OI")])
> >
> > -(define_insn_and_split "*avx_vzeroupper_1"
> > -  [(match_parallel 0 "vzeroupper_pattern"
> > -     [(unspec_volatile [(const_int 0)] UNSPECV_VZEROUPPER)])]
> > -  "TARGET_AVX && XVECLEN (operands[0], 0) != (TARGET_64BIT ? 16 : 8) + 1"
> > -  "#"
> > -  "&& epilogue_completed"
> > -  [(match_dup 0)]
> > -{
> > -  /* For IPA-RA purposes, make it clear the instruction clobbers
> > -     even XMM registers not mentioned explicitly in the pattern.  */
> > -  unsigned int nregs = TARGET_64BIT ? 16 : 8;
> > -  unsigned int npats = XVECLEN (operands[0], 0);
> > -  rtvec vec = rtvec_alloc (nregs + 1);
> > -  RTVEC_ELT (vec, 0) = XVECEXP (operands[0], 0, 0);
> > -  for (unsigned int i = 0, j = 1; i < nregs; ++i)
> > -    {
> > -      unsigned int regno = GET_SSE_REGNO (i);
> > -      if (j < npats
> > -         && REGNO (SET_DEST (XVECEXP (operands[0], 0, j))) == regno)
> > -       {
> > -         RTVEC_ELT (vec, i + 1) = XVECEXP (operands[0], 0, j);
> > -         j++;
> > -       }
> > -      else
> > -       {
> > -         rtx reg = gen_rtx_REG (V2DImode, regno);
> > -         RTVEC_ELT (vec, i + 1) = gen_rtx_CLOBBER (VOIDmode, reg);
> > -       }
> > -    }
> > -  operands[0] = gen_rtx_PARALLEL (VOIDmode, vec);
> > -}
> > -  [(set_attr "type" "sse")
> > -   (set_attr "modrm" "0")
> > -   (set_attr "memory" "none")
> > -   (set_attr "prefix" "vex")
> > -   (set_attr "btver2_decode" "vector")
> > -   (set_attr "mode" "OI")])
> > -
> >  (define_mode_attr pbroadcast_evex_isa
> >    [(V64QI "avx512bw") (V32QI "avx512bw") (V16QI "avx512bw")
> >     (V32HI "avx512bw") (V16HI "avx512bw") (V8HI "avx512bw")
> > diff --git a/gcc/testsuite/gcc.target/i386/pr82735-1.c b/gcc/testsuite/gcc.target/i386/pr82735-1.c
> > new file mode 100644
> > index 00000000000..1a63b9ae9c9
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.target/i386/pr82735-1.c
> > @@ -0,0 +1,29 @@
> > +/* { dg-do run } */
> > +/* { dg-options "-O2 -mavx" } */
> > +/* { dg-require-effective-target avx } */
> > +
> > +#include "avx-check.h"
> > +
> > +void
> > +__attribute__ ((noipa))
> > +mtest(char *dest)
> > +{
> > +  __m256i ymm1 = _mm256_set1_epi8((char)0x1);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32), ymm1);
> > +  _mm256_zeroupper();
> > +  __m256i ymm2 = _mm256_set1_epi8((char)0x1);
> > +  _mm256_storeu_si256((__m256i *)dest, ymm2);
> > +}
> > +
> > +void
> > +avx_test ()
> > +{
> > +  char buf[64];
> > +  for (int i = 0; i != 64; i++)
> > +    buf[i] = 2;
> > +  mtest (buf);
> > +
> > +  for (int i = 0; i < 32; ++i)
> > +    if (buf[i] != 1)
> > +      __builtin_abort ();
> > +}
> > diff --git a/gcc/testsuite/gcc.target/i386/pr82735-2.c b/gcc/testsuite/gcc.target/i386/pr82735-2.c
> > new file mode 100644
> > index 00000000000..ac9d006f794
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.target/i386/pr82735-2.c
> > @@ -0,0 +1,22 @@
> > +/* { dg-do compile } */
> > +/* { dg-options "-mavx -O2" } */
> > +
> > +#include <immintrin.h>
> > +
> > +void test(char *dest)
> > +{
> > +  /* xmm1 can be propagated to xmm2 by CSE.  */
> > +  __m128i xmm1 = _mm_set_epi8(0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8,
> > +                             0x9, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16);
> > +  _mm_storeu_si128((__m128i *)(dest + 32), xmm1);
> > +  _mm256_zeroupper();
> > +  _mm256_zeroupper();
> > +  _mm256_zeroupper();
> > +  _mm256_zeroupper();
> > +  _mm256_zeroupper();
> > +  __m128i xmm2 = xmm1;
> > +  _mm_storeu_si128((__m128i *)dest, xmm2);
> > +}
> > +
> > +/* Darwin local constant symbol is "lC0", ELF targets ".LC0" */
> > +/* { dg-final { scan-assembler-times {(?n)vmovdqa\t\.?[Ll]C0[^,]*, %xmm[0-9]} 1 } } */
> > diff --git a/gcc/testsuite/gcc.target/i386/pr82735-3.c b/gcc/testsuite/gcc.target/i386/pr82735-3.c
> > new file mode 100644
> > index 00000000000..e3f801e6924
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.target/i386/pr82735-3.c
> > @@ -0,0 +1,5 @@
> > +/* { dg-do compile } */
> > +/* { dg-options "-mavx -O2 -mabi=ms" } */
> > +/* { dg-final { scan-assembler-not {(?n)xmm([6-9]|1[0-5])} } } */
> > +
> > +#include "pr82735-2.c"
> > diff --git a/gcc/testsuite/gcc.target/i386/pr82735-4.c b/gcc/testsuite/gcc.target/i386/pr82735-4.c
> > new file mode 100644
> > index 00000000000..78c0a6cb2c8
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.target/i386/pr82735-4.c
> > @@ -0,0 +1,48 @@
> > +/* { dg-do compile { target { ! ia32 } } }  */
> > +/* { dg-options "-mavx -O2 -mabi=ms -mno-avx512f -masm=att" } */
> > +/* { dg-final { scan-assembler-times {(?n)(?:vmovdqa[1-9]*|vmovap[sd])[\t ]*%xmm[0-9]+, [0-9]*\(%rsp\)} 10 } } */
> > +/* { dg-final { scan-assembler-times {(?n)(?:vmovdqa[1-9]*|vmovap[sd])[\t ]*[0-9]*\(%rsp\), %xmm[0-9]+} 10 } } */
> > +
> > +#include <immintrin.h>
> > +
> > +void test(char *dest)
> > +{
> > +  __m256i ymm0, ymm1, ymm2, ymm3, ymm4, ymm5, ymm6, ymm7, ymm8, ymm9, ymm10, ymm11, ymm12, ymm13, ymm14, ymm15;
> > +  asm volatile ("vmovdqa\t%%ymm0, %0\n\t"
> > +               "vmovdqa\t%%ymm0, %1\n\t"
> > +               "vmovdqa\t%%ymm0, %2\n\t"
> > +               "vmovdqa\t%%ymm0, %3\n\t"
> > +               "vmovdqa\t%%ymm0, %4\n\t"
> > +               "vmovdqa\t%%ymm0, %5\n\t"
> > +               "vmovdqa\t%%ymm0, %6\n\t"
> > +               "vmovdqa\t%%ymm0, %7\n\t"
> > +               "vmovdqa\t%%ymm0, %8\n\t"
> > +               "vmovdqa\t%%ymm0, %9\n\t"
> > +               "vmovdqa\t%%ymm0, %10\n\t"
> > +               "vmovdqa\t%%ymm0, %11\n\t"
> > +               "vmovdqa\t%%ymm0, %12\n\t"
> > +               "vmovdqa\t%%ymm0, %13\n\t"
> > +               "vmovdqa\t%%ymm0, %14\n\t"
> > +               "vmovdqa\t%%ymm0, %15\n\t"
> > +               : "=v" (ymm1), "=v" (ymm2), "=v"(ymm3), "=v" (ymm4), "=v" (ymm5),
> > +                 "=v" (ymm6), "=v" (ymm7), "=v"(ymm8), "=v" (ymm9), "=v" (ymm10),
> > +                 "=v" (ymm11), "=v" (ymm12), "=v"(ymm13), "=v" (ymm14), "=v" (ymm15),
> > +                 "=v"(ymm0)
> > +               ::);
> > +  _mm256_zeroupper();
> > +  _mm256_storeu_si256((__m256i *)dest, ymm1);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32), ymm2);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 2), ymm3);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 3), ymm4);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 4), ymm5);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 5), ymm6);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 6), ymm7);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 7), ymm8);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 8), ymm9);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 9), ymm10);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 10), ymm11);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 11), ymm12);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 12), ymm13);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 13), ymm14);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 14), ymm15);
> > +}
> > diff --git a/gcc/testsuite/gcc.target/i386/pr82735-5.c b/gcc/testsuite/gcc.target/i386/pr82735-5.c
> > new file mode 100644
> > index 00000000000..2a58cbe52d0
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.target/i386/pr82735-5.c
> > @@ -0,0 +1,54 @@
> > +/* { dg-do compile { target { ! ia32 } } }  */
> > +/* { dg-options "-mavx -O2 -mabi=ms -mno-avx512f -masm=att" } */
> > +/* { dg-final { scan-assembler-times {(?n)(?:vmovdqa[1-9]*|vmovap[sd])[\t ]*%xmm[0-9]+, [0-9]*\(%rsp\)} 10 } } */
> > +/* { dg-final { scan-assembler-times {(?n)(?:vmovdqa[1-9]*|vmovap[sd])[\t ]*[0-9]*\(%rsp\), %xmm[0-9]+} 10 } } */
> > +
> > +#include <immintrin.h>
> > +
> > +void test(char *dest)
> > +{
> > +  __m256i ymm0, ymm1, ymm2, ymm3, ymm4, ymm5, ymm6, ymm7, ymm8, ymm9, ymm10, ymm11, ymm12, ymm13, ymm14, ymm15;
> > +  asm volatile ("vmovdqa\t%%ymm0, %0\n\t"
> > +               "vmovdqa\t%%ymm0, %1\n\t"
> > +               "vmovdqa\t%%ymm0, %2\n\t"
> > +               "vmovdqa\t%%ymm0, %3\n\t"
> > +               "vmovdqa\t%%ymm0, %4\n\t"
> > +               "vmovdqa\t%%ymm0, %5\n\t"
> > +               "vmovdqa\t%%ymm0, %6\n\t"
> > +               "vmovdqa\t%%ymm0, %7\n\t"
> > +               "vmovdqa\t%%ymm0, %8\n\t"
> > +               "vmovdqa\t%%ymm0, %9\n\t"
> > +               "vmovdqa\t%%ymm0, %10\n\t"
> > +               "vmovdqa\t%%ymm0, %11\n\t"
> > +               "vmovdqa\t%%ymm0, %12\n\t"
> > +               "vmovdqa\t%%ymm0, %13\n\t"
> > +               "vmovdqa\t%%ymm0, %14\n\t"
> > +               "vmovdqa\t%%ymm0, %15\n\t"
> > +               : "=v" (ymm1), "=v" (ymm2), "=v"(ymm3), "=v" (ymm4), "=v" (ymm5),
> > +                 "=v" (ymm6), "=v" (ymm7), "=v"(ymm8), "=v" (ymm9), "=v" (ymm10),
> > +                 "=v" (ymm11), "=v" (ymm12), "=v"(ymm13), "=v" (ymm14), "=v" (ymm15),
> > +                 "=v"(ymm0)
> > +               ::);
> > +  _mm256_zeroupper();
> > +  _mm256_zeroupper();
> > +  _mm256_zeroupper();
> > +  _mm256_zeroupper();
> > +  _mm256_zeroupper();
> > +  _mm256_zeroupper();
> > +  _mm256_zeroupper();
> > +  _mm256_storeu_si256((__m256i *)dest, ymm1);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32), ymm2);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 2), ymm3);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 3), ymm4);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 4), ymm5);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 5), ymm6);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 6), ymm7);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 7), ymm8);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 8), ymm9);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 9), ymm10);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 10), ymm11);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 11), ymm12);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 12), ymm13);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 13), ymm14);
> > +  _mm256_storeu_si256((__m256i *)(dest + 32 * 14), ymm15);
> > +}
> > --
> > 2.18.1
> >



-- 
BR,
Hongtao