[Bug target/96339] [SVE] Optimise svlast[ab]

[cvs-commit at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96339

--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Tejas Belagod <bela...@gcc.gnu.org>:

https://gcc.gnu.org/g:22d85c10a004f4f5eaf6b68b62a0792faf048bf8

commit r14-1744-g22d85c10a004f4f5eaf6b68b62a0792faf048bf8
Author: Tejas Belagod <tbela...@arm.com>
Date:   Tue May 11 11:09:03 2021 +0100

    AArch64: [PR96339] Optimise svlast[ab]

      This PR optimizes an SVE intrinsics sequence where
        svlasta (svptrue_pat_b8 (SV_VL1), x)
      a scalar is selected based on a constant predicate and a variable vector.
      This sequence is optimized to return the correspoding element of a NEON
      vector. For eg.
        svlasta (svptrue_pat_b8 (SV_VL1), x)
      returns
        umov    w0, v0.b[1]
      Likewise,
        svlastb (svptrue_pat_b8 (SV_VL1), x)
      returns
         umov    w0, v0.b[0]
      This optimization only works provided the constant predicate maps to a
range
      that is within the bounds of a 128-bit NEON register.

    gcc/ChangeLog:

            PR target/96339
            * config/aarch64/aarch64-sve-builtins-base.cc (svlast_impl::fold):
Fold sve
            calls that have a constant input predicate vector.
            (svlast_impl::is_lasta): Query to check if intrinsic is svlasta.
            (svlast_impl::is_lastb): Query to check if intrinsic is svlastb.
            (svlast_impl::vect_all_same): Check if all vector elements are
equal.

    gcc/testsuite/ChangeLog:

            PR target/96339
            * gcc.target/aarch64/sve/acle/general-c/svlast.c: New.
            * gcc.target/aarch64/sve/acle/general-c/svlast128_run.c: New.
            * gcc.target/aarch64/sve/acle/general-c/svlast256_run.c: New.
            * gcc.target/aarch64/sve/pcs/return_4.c (caller_bf16): Fix asm
            to expect optimized code for function body.
            * gcc.target/aarch64/sve/pcs/return_4_128.c (caller_bf16):
Likewise.
            * gcc.target/aarch64/sve/pcs/return_4_256.c (caller_bf16):
Likewise.
            * gcc.target/aarch64/sve/pcs/return_4_512.c (caller_bf16):
Likewise.
            * gcc.target/aarch64/sve/pcs/return_4_1024.c (caller_bf16):
Likewise.
            * gcc.target/aarch64/sve/pcs/return_4_2048.c (caller_bf16):
Likewise.
            * gcc.target/aarch64/sve/pcs/return_5.c (caller_bf16): Likewise.
            * gcc.target/aarch64/sve/pcs/return_5_128.c (caller_bf16):
Likewise.
            * gcc.target/aarch64/sve/pcs/return_5_256.c (caller_bf16):
Likewise.
            * gcc.target/aarch64/sve/pcs/return_5_512.c (caller_bf16):
Likewise.
            * gcc.target/aarch64/sve/pcs/return_5_1024.c (caller_bf16):
Likewise.
            * gcc.target/aarch64/sve/pcs/return_5_2048.c (caller_bf16):
Likewise.