On Wed, Jun 12, 2024 at 5:12 AM Hongyu Wang <hongyu.w...@intel.com> wrote:
>
> Hi,
>
> For CTEST, we don't have conditional AND so there's no optimization
> opportunity to write a new ctest pattern. Emit ctest when ccmp did
> comparison to const 0 to save bytes.
>
> Bootstrapped & regtested under x86-64-pc-linux-gnu.
>
> Ok for trunk?
>
> gcc/ChangeLog:
>
> * config/i386/i386.md (@ccmp<mode>): Use ctestcc when
> operands[3] is const0_rtx.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/i386/apx-ccmp-1.c: Adjust output to scan ctest.
> * gcc.target/i386/apx-ccmp-2.c: Adjust some condition to
> compare with 0.
> ---
> gcc/config/i386/i386.md | 6 +++++-
> gcc/testsuite/gcc.target/i386/apx-ccmp-1.c | 10 ++++++----
> gcc/testsuite/gcc.target/i386/apx-ccmp-2.c | 4 ++--
> 3 files changed, 13 insertions(+), 7 deletions(-)
>
> diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
> index a64f2ad4f5f..014d48cddd6 100644
> --- a/gcc/config/i386/i386.md
> +++ b/gcc/config/i386/i386.md
> @@ -1522,7 +1522,11 @@ (define_insn "@ccmp<mode>"
> [(match_operand:SI 4 "const_0_to_15_operand")]
> UNSPEC_APX_DFV)))]
> "TARGET_APX_CCMP"
> - "ccmp%C1{<imodesuffix>}\t%G4 {%3, %2|%2, %3}"
> + {
> + if (operands[3] == const0_rtx && !MEM_P (operands[2]))
> + return "ctest%C1{<imodesuffix>}\t%G4 %2, %2";
> + return "ccmp%C1{<imodesuffix>}\t%G4 {%3, %2|%2, %3}";
> + }
This could be implemented as an alternative using "r,C" constraint as
the first constraint for operands[2,3]. Then the register allocator
will match the constraints for you.
Uros.
> [(set_attr "type" "icmp")
> (set_attr "mode" "<MODE>")
> (set_attr "length_immediate" "1")
> diff --git a/gcc/testsuite/gcc.target/i386/apx-ccmp-1.c
> b/gcc/testsuite/gcc.target/i386/apx-ccmp-1.c
> index e4e112f07e0..a8b70576760 100644
> --- a/gcc/testsuite/gcc.target/i386/apx-ccmp-1.c
> +++ b/gcc/testsuite/gcc.target/i386/apx-ccmp-1.c
> @@ -96,9 +96,11 @@ f15 (double a, double b, int c, int d)
>
> /* { dg-final { scan-assembler-times "ccmpg" 2 } } */
> /* { dg-final { scan-assembler-times "ccmple" 2 } } */
> -/* { dg-final { scan-assembler-times "ccmpne" 4 } } */
> -/* { dg-final { scan-assembler-times "ccmpe" 3 } } */
> +/* { dg-final { scan-assembler-times "ccmpne" 2 } } */
> +/* { dg-final { scan-assembler-times "ccmpe" 1 } } */
> /* { dg-final { scan-assembler-times "ccmpbe" 1 } } */
> +/* { dg-final { scan-assembler-times "ctestne" 2 } } */
> +/* { dg-final { scan-assembler-times "cteste" 2 } } */
> /* { dg-final { scan-assembler-times "ccmpa" 1 } } */
> -/* { dg-final { scan-assembler-times "ccmpbl" 2 } } */
> -
> +/* { dg-final { scan-assembler-times "ccmpbl" 1 } } */
> +/* { dg-final { scan-assembler-times "ctestbl" 1 } } */
> diff --git a/gcc/testsuite/gcc.target/i386/apx-ccmp-2.c
> b/gcc/testsuite/gcc.target/i386/apx-ccmp-2.c
> index 0123a686d2c..4a0784394c3 100644
> --- a/gcc/testsuite/gcc.target/i386/apx-ccmp-2.c
> +++ b/gcc/testsuite/gcc.target/i386/apx-ccmp-2.c
> @@ -12,7 +12,7 @@ int foo_apx(int a, int b, int c, int d)
> c += d;
> a += b;
> sum += a + c;
> - if (b != d && sum < c || sum > d)
> + if (b > d && sum != 0 || sum > d)
> {
> b += d;
> sum += b;
> @@ -32,7 +32,7 @@ int foo_noapx(int a, int b, int c, int d)
> c += d;
> a += b;
> sum += a + c;
> - if (b != d && sum < c || sum > d)
> + if (b > d && sum != 0 || sum > d)
> {
> b += d;
> sum += b;
> --
> 2.31.1
>
