> On 20 Aug 2024, at 17:44, saurabh....@arm.com wrote:
>
> External email: Use caution opening links or attachments
>
>
> The AArch64 FEAT_FAMINMAX extension is optional from Armv9.2-a and
> mandatory from Armv9.5-a. It introduces instructions for computing the
> floating point absolute maximum and minimum of the two vectors
> element-wise.
>
> This patch adds code generation support for famax and famin in terms of
> existing RTL operators.
>
> famax/famin is equivalent to first taking abs of the operands and then
> taking smax/smin on the results of abs.
>
> famax/famin (a, b) = smax/smin (abs (a), abs (b))
>
> This fusion of operators is only possible when -march=armv9-a+faminmax
> flags are passed. We also need to pass -ffast-math flag; if we don't,
> then a statement like
>
> c[i] = __builtin_fmaxf16 (a[i], b[i]);
>
> is RTL expanded to UNSPEC_FMAXNM instead of smax (likewise for smin).
>
> This code generation is only available on -O2 or -O3 as that is when
> auto-vectorization is enabled.
>
> gcc/ChangeLog:
>
> * config/aarch64/aarch64-simd.md
> (*aarch64_faminmax_fused): Instruction pattern for faminmax
> codegen.
> * config/aarch64/iterators.md: Attribute for faminmax codegen.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/aarch64/simd/faminmax-codegen-no-flag.c: New test.
> * gcc.target/aarch64/simd/faminmax-codegen.c: New test.
Ok. Thank you for you work on this.
Kyrill
> ---
> gcc/config/aarch64/aarch64-simd.md | 10 +
> gcc/config/aarch64/iterators.md | 3 +
> .../aarch64/simd/faminmax-codegen-no-flag.c | 217 ++++++++++++++++++
> .../aarch64/simd/faminmax-codegen.c | 197 ++++++++++++++++
> 4 files changed, 427 insertions(+)
> create mode 100644
> gcc/testsuite/gcc.target/aarch64/simd/faminmax-codegen-no-flag.c
> create mode 100644 gcc/testsuite/gcc.target/aarch64/simd/faminmax-codegen.c
>
> <v4-0002-aarch64-Add-codegen-support-for-AdvSIMD-faminmax.patch>
