On Thu, May 5, 2022 at 4:09 PM Uros Bizjak via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> On Thu, May 5, 2022 at 9:50 AM Richard Biener via Gcc-patches
> <gcc-patches@gcc.gnu.org> wrote:
> >
> > On Thu, May 5, 2022 at 9:37 AM liuhongt via Gcc-patches
> > <gcc-patches@gcc.gnu.org> wrote:
> > >
> > > Enable optimization for TImode only under 32-bit target, for 64-bit
> > > target there could be extra ineteger <-> sse move regarding psABI,
> > > not efficient.
> > >
> > > Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,}
> > > Ok for trunk?
> >
> > I wonder if this is better done in STV where we could assess this extra
> > cost?
>
> Yes, this should be handled via STV, Roger Sayle (CC'd) has proposed a
> patch that does just that.
>
My patch also handles OImode, I think that part could be a separate patch.
>
> Uros.
>
> > > gcc/ChangeLog:
> > >
> > > PR target/104610
> > > * config/i386/i386-expand.cc (ix86_expand_branch): Use ptest
> > > for TI/QImode when code is EQ or NE.
> > > * config/i386/i386.md (SDWIM1248): New iterator.
> > > (cbranch<mode>4): Split TImode into a separate expander.
> > > (cbranchti4): New expander.
> > > * config/i386/predicates.md (timode_comparison_operator): New
> > > predicate.
> > > * config/i386/sse.md (cbranch<mode>4): Extend to OImode.
> > >
> > > gcc/testsuite/ChangeLog:
> > >
> > > * gcc.target/i386/pr104610.c: New test.
> > > ---
> > > gcc/config/i386/i386-expand.cc | 13 +++++++++++-
> > > gcc/config/i386/i386.md | 27 ++++++++++++++++++++++--
> > > gcc/config/i386/predicates.md | 6 ++++++
> > > gcc/config/i386/sse.md | 10 +++++++--
> > > gcc/testsuite/gcc.target/i386/pr104610.c | 23 ++++++++++++++++++++
> > > 5 files changed, 74 insertions(+), 5 deletions(-)
> > > create mode 100644 gcc/testsuite/gcc.target/i386/pr104610.c
> > >
> > > diff --git a/gcc/config/i386/i386-expand.cc
> > > b/gcc/config/i386/i386-expand.cc
> > > index bc806ffa283..a2012a158ae 100644
> > > --- a/gcc/config/i386/i386-expand.cc
> > > +++ b/gcc/config/i386/i386-expand.cc
> > > @@ -2264,13 +2264,24 @@ ix86_expand_branch (enum rtx_code code, rtx op0,
> > > rtx op1, rtx label)
> > > {
> > > machine_mode mode = GET_MODE (op0);
> > > rtx tmp;
> > > + machine_mode p_mode = GET_MODE_SIZE (mode) == 32 ? V4DImode : V2DImode;
> > > + /* Using ptest for TImode only for 32-bit target since it's splitted
> > > into
> > > + 4 comparisons. For 64-bit target there could be extra ineteger <->
> > > sse
> > > + move regarding psABI, not efficient. */
> > > + if ((code == EQ || code == NE)
> > > + && ((mode == OImode && TARGET_AVX)
> > > + || (mode == TImode && !TARGET_64BIT && TARGET_SSE4_1)))
> > > + {
> > > + op0 = lowpart_subreg (p_mode, force_reg (mode, op0), mode);
> > > + op1 = lowpart_subreg (p_mode, force_reg (mode, op1), mode);
> > > + mode = p_mode;
> > > + }
> > >
> > > /* Handle special case - vector comparsion with boolean result,
> > > transform
> > > it using ptest instruction. */
> > > if (GET_MODE_CLASS (mode) == MODE_VECTOR_INT)
> > > {
> > > rtx flag = gen_rtx_REG (CCZmode, FLAGS_REG);
> > > - machine_mode p_mode = GET_MODE_SIZE (mode) == 32 ? V4DImode :
> > > V2DImode;
> > >
> > > gcc_assert (code == EQ || code == NE);
> > > /* Generate XOR since we can't check that one operand is zero
> > > vector. */
> > > diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
> > > index b321cda1f22..f91325015c9 100644
> > > --- a/gcc/config/i386/i386.md
> > > +++ b/gcc/config/i386/i386.md
> > > @@ -1069,6 +1069,10 @@ (define_mode_iterator SDWIM [(QI
> > > "TARGET_QIMODE_MATH")
> > > (HI "TARGET_HIMODE_MATH")
> > > SI DI (TI "TARGET_64BIT")])
> > >
> > > +(define_mode_iterator SDWIM1248 [(QI "TARGET_QIMODE_MATH")
> > > + (HI "TARGET_HIMODE_MATH")
> > > + SI DI])
> > > +
> > > ;; Math-dependant single word integer modes.
> > > (define_mode_iterator SWIM [(QI "TARGET_QIMODE_MATH")
> > > (HI "TARGET_HIMODE_MATH")
> > > @@ -1322,8 +1326,8 @@ (define_mode_iterator PTR
> > >
> > > (define_expand "cbranch<mode>4"
> > > [(set (reg:CC FLAGS_REG)
> > > - (compare:CC (match_operand:SDWIM 1 "nonimmediate_operand")
> > > - (match_operand:SDWIM 2 "<general_operand>")))
> > > + (compare:CC (match_operand:SDWIM1248 1 "nonimmediate_operand")
> > > + (match_operand:SDWIM1248 2 "<general_operand>")))
> > > (set (pc) (if_then_else
> > > (match_operator 0 "ordered_comparison_operator"
> > > [(reg:CC FLAGS_REG) (const_int 0)])
> > > @@ -1338,6 +1342,25 @@ (define_expand "cbranch<mode>4"
> > > DONE;
> > > })
> > >
> > > +(define_expand "cbranchti4"
> > > + [(set (reg:CC FLAGS_REG)
> > > + (compare:CC (match_operand:TI 1 "nonimmediate_operand")
> > > + (match_operand:TI 2 "x86_64_general_operand")))
> > > + (set (pc) (if_then_else
> > > + (match_operator 0 "timode_comparison_operator"
> > > + [(reg:CC FLAGS_REG) (const_int 0)])
> > > + (label_ref (match_operand 3))
> > > + (pc)))]
> > > + "TARGET_64BIT || TARGET_SSE4_1"
> > > +{
> > > + if (MEM_P (operands[1]) && MEM_P (operands[2]))
> > > + operands[1] = force_reg (TImode, operands[1]);
> > > +
> > > + ix86_expand_branch (GET_CODE (operands[0]),
> > > + operands[1], operands[2], operands[3]);
> > > + DONE;
> > > +})
> > > +
> > > (define_expand "cstore<mode>4"
> > > [(set (reg:CC FLAGS_REG)
> > > (compare:CC (match_operand:SWIM 2 "nonimmediate_operand")
> > > diff --git a/gcc/config/i386/predicates.md b/gcc/config/i386/predicates.md
> > > index a8cc17a054d..fb3be3a262f 100644
> > > --- a/gcc/config/i386/predicates.md
> > > +++ b/gcc/config/i386/predicates.md
> > > @@ -1414,6 +1414,12 @@ (define_predicate "ix86_comparison_uns_operator"
> > > (define_predicate "bt_comparison_operator"
> > > (match_code "ne,eq"))
> > >
> > > +(define_predicate "timode_comparison_operator"
> > > + (ior (and (match_test "TARGET_SSE4_1")
> > > + (match_operand 0 "bt_comparison_operator"))
> > > + (and (match_test "TARGET_64BIT")
> > > + (match_operand 0 "ordered_comparison_operator"))))
> > > +
> > > (define_predicate "shr_comparison_operator"
> > > (match_code "gtu,leu"))
> > >
> > > diff --git a/gcc/config/i386/sse.md b/gcc/config/i386/sse.md
> > > index 7b791def542..0d194cee769 100644
> > > --- a/gcc/config/i386/sse.md
> > > +++ b/gcc/config/i386/sse.md
> > > @@ -26034,10 +26034,14 @@ (define_expand
> > > "maskstore<mode><avx512fmaskmodelower>"
> > > (match_operand:<avx512fmaskmode> 2 "register_operand")))]
> > > "TARGET_AVX512BW")
> > >
> > > +(define_mode_iterator VI48_OI_AVX
> > > + [(V8SI "TARGET_AVX") (V4DI "TARGET_AVX") (OI "TARGET_AVX")
> > > + V4SI V2DI])
> > > +
> > > (define_expand "cbranch<mode>4"
> > > [(set (reg:CC FLAGS_REG)
> > > - (compare:CC (match_operand:VI48_AVX 1 "register_operand")
> > > - (match_operand:VI48_AVX 2 "nonimmediate_operand")))
> > > + (compare:CC (match_operand:VI48_OI_AVX 1 "register_operand")
> > > + (match_operand:VI48_OI_AVX 2 "nonimmediate_operand")))
> > > (set (pc) (if_then_else
> > > (match_operator 0 "bt_comparison_operator"
> > > [(reg:CC FLAGS_REG) (const_int 0)])
> > > @@ -26045,6 +26049,8 @@ (define_expand "cbranch<mode>4"
> > > (pc)))]
> > > "TARGET_SSE4_1"
> > > {
> > > + if (!vector_operand (operands[2], <MODE>mode))
> > > + operands[2] = force_reg (<MODE>mode, operands[2]);
> > > ix86_expand_branch (GET_CODE (operands[0]),
> > > operands[1], operands[2], operands[3]);
> > > DONE;
> > > diff --git a/gcc/testsuite/gcc.target/i386/pr104610.c
> > > b/gcc/testsuite/gcc.target/i386/pr104610.c
> > > new file mode 100644
> > > index 00000000000..68f548594fd
> > > --- /dev/null
> > > +++ b/gcc/testsuite/gcc.target/i386/pr104610.c
> > > @@ -0,0 +1,23 @@
> > > +/* { dg-do compile } */
> > > +/* { dg-options "-O2 -mmove-max=256 -mstore-max=256" } */
> > > +/* { dg-final { scan-assembler-times {(?n)ptest.*xmm} 1 { target ia32 }
> > > } } */
> > > +/* { dg-final { scan-assembler-times {(?n)vptest.*ymm} 1 } } */
> > > +/* { dg-final { scan-assembler-times {sete} 2 } } */
> > > +/* { dg-final { scan-assembler-not {(?n)je.*L[0-9]} } } */
> > > +/* { dg-final { scan-assembler-not {(?n)jne.*L[0-9]} } } */
> > > +
> > > +
> > > +#include<stdbool.h>
> > > +__attribute__((target("sse4.1")))
> > > +bool f128(char *a)
> > > +{
> > > + char t[] = "012345678901234";
> > > + return __builtin_memcmp(a, &t[0], sizeof(t)) == 0;
> > > +}
> > > +
> > > +__attribute__((target("avx")))
> > > +bool f256(char *a)
> > > +{
> > > + char t[] = "0123456789012345678901234567890";
> > > + return __builtin_memcmp(a, &t[0], sizeof(t)) == 0;
> > > +}
> > > --
> > > 2.18.1
> > >
--
BR,
Hongtao
