Andrew Carlotti via Gcc-patches <gcc-patches@gcc.gnu.org> writes:
> Hi all,
>
> This lowers vcombine intrinsics to a GIMPLE vector constructor, which enables
> better optimisation during GIMPLE passes.
>
> Bootstrapped and tested on aarch64-none-linux-gnu, and tested for
> aarch64_be-none-linux-gnu via cross-compilation.
>
>
> gcc/
>
> * config/aarch64/aarch64-builtins.c
> (aarch64_general_gimple_fold_builtin): Add combine.
>
> gcc/testsuite/
>
> * gcc.target/aarch64/advsimd-intrinsics/combine.c:
> New test.
>
> ---
>
> diff --git a/gcc/config/aarch64/aarch64-builtins.cc
> b/gcc/config/aarch64/aarch64-builtins.cc
> index
> 5217dbdb2ac78bba0a669d22af6d769d1fe91a3d..9d52fb8c5a48c9b743defb340a85fb20a1c8f014
> 100644
> --- a/gcc/config/aarch64/aarch64-builtins.cc
> +++ b/gcc/config/aarch64/aarch64-builtins.cc
> @@ -2827,6 +2827,18 @@ aarch64_general_gimple_fold_builtin (unsigned int
> fcode, gcall *stmt,
> gimple_call_set_lhs (new_stmt, gimple_call_lhs (stmt));
> break;
>
> + BUILTIN_VDC (BINOP, combine, 0, AUTO_FP)
> + BUILTIN_VD_I (BINOPU, combine, 0, NONE)
> + BUILTIN_VDC_P (BINOPP, combine, 0, NONE)
> + {
> + if (BYTES_BIG_ENDIAN)
> + std::swap(args[0], args[1]);
We probably shouldn't do this swap in-place, since args refers directly
to the gimple statement.
> + tree ret_type = TREE_TYPE (gimple_call_lhs (stmt));
> + tree ctor = build_constructor_va (ret_type, 2, NULL_TREE, args[0],
> NULL_TREE, args[1]);
Minor formatting nit: lines should be under 80 chars.
Looks good otherwise, thanks, and sorry for the slow review.
Richard
> + new_stmt = gimple_build_assign (gimple_call_lhs (stmt), ctor);
> + }
> + break;
> +
> /*lower store and load neon builtins to gimple. */
> BUILTIN_VALL_F16 (LOAD1, ld1, 0, LOAD)
> BUILTIN_VDQ_I (LOAD1_U, ld1, 0, LOAD)
> diff --git a/gcc/testsuite/gcc.target/aarch64/advsimd-intrinsics/combine.c
> b/gcc/testsuite/gcc.target/aarch64/advsimd-intrinsics/combine.c
> new file mode 100644
> index
> 0000000000000000000000000000000000000000..d08faf7a4a160a1e83428ed9b270731bbf7b8c8a
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/aarch64/advsimd-intrinsics/combine.c
> @@ -0,0 +1,18 @@
> +/* { dg-do compile { target { aarch64*-*-* } } } */
> +/* { dg-final { check-function-bodies "**" "" {-O[^0]} } } */
> +/* { dg-skip-if "" { *-*-* } { "-fno-fat-lto-objects" } } */
> +
> +#include <arm_neon.h>
> +
> +/*
> +** foo:
> +** umov w0, v1\.s\[1\]
> +** ret
> +*/
> +
> +int32_t foo (int32x2_t a, int32x2_t b)
> +{
> + int32x4_t c = vcombine_s32(a, b);
> + return vgetq_lane_s32(c, 3);
> +}
> +
