On Thu, Aug 29, 2024 at 9:33 AM liuhongt <hongtao....@intel.com> wrote:
>
> For function arguments/return, when it's BLK mode, it's put in a
> parallel with an expr_list, and the expr_list contains the real mode
> and registers.
> Current ix86_check_avx_upper_register only checked for SSE_REG_P, and
> failed to handle that. The patch extend the handle to each subrtx.
>
> Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,}.
> Ok for trunk?
>
> gcc/ChangeLog:
>
> PR target/116512
> * config/i386/i386.cc (ix86_avx_u128_mode_entry): Iterate
> each subrtx for potential rtx parallel to check avx upper
> register.
> (ix86_avx_u128_mode_exit): Ditto.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/i386/pr116512.c: New test.
> ---
> gcc/config/i386/i386.cc | 28 ++++++++++++++++++++----
> gcc/testsuite/gcc.target/i386/pr116512.c | 26 ++++++++++++++++++++++
> 2 files changed, 50 insertions(+), 4 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/i386/pr116512.c
>
> diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
> index 224a78cc832..94d1a14056e 100644
> --- a/gcc/config/i386/i386.cc
> +++ b/gcc/config/i386/i386.cc
> @@ -15148,8 +15148,18 @@ ix86_avx_u128_mode_entry (void)
> {
> rtx incoming = DECL_INCOMING_RTL (arg);
>
> - if (incoming && ix86_check_avx_upper_register (incoming))
> - return AVX_U128_DIRTY;
> + if (incoming)
> + {
> + /* construct_container may return a parallel with expr_list
> + which contains the real reg and mode */
> + subrtx_var_iterator::array_type array;
> + FOR_EACH_SUBRTX_VAR (iter, array, incoming, ALL)
> + {
> + rtx x = *iter;
> + if (ix86_check_avx_upper_register (x))
> + return AVX_U128_DIRTY;
> + }
> + }
> }
Can the above loop be a part of ix86_check_avx_upper_register, so this
function would scan the full RTX for avx upper register?
Uros,
> return AVX_U128_CLEAN;
> @@ -15184,8 +15194,18 @@ ix86_avx_u128_mode_exit (void)
>
> /* Exit mode is set to AVX_U128_DIRTY if there are 256bit
> or 512 bit modes used in the function return register. */
> - if (reg && ix86_check_avx_upper_register (reg))
> - return AVX_U128_DIRTY;
> + if (reg)
> + {
> + /* construct_container may return a parallel with expr_list
> + which contains the real reg and mode */
> + subrtx_var_iterator::array_type array;
> + FOR_EACH_SUBRTX_VAR (iter, array, reg, ALL)
> + {
> + rtx x = *iter;
> + if (ix86_check_avx_upper_register (x))
> + return AVX_U128_DIRTY;
> + }
> + }
>
> /* Exit mode is set to AVX_U128_DIRTY if there are 256bit or 512bit
> modes used in function arguments, otherwise return AVX_U128_CLEAN.
> diff --git a/gcc/testsuite/gcc.target/i386/pr116512.c
> b/gcc/testsuite/gcc.target/i386/pr116512.c
> new file mode 100644
> index 00000000000..c2bc6c91b64
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr116512.c
> @@ -0,0 +1,26 @@
> +/* { dg-do compile } */
> +/* { dg-options "-march=x86-64-v4 -O2" } */
> +/* { dg-final { scan-assembler-not "vzeroupper" { target { ! ia32 } } } } */
> +
> +#include <immintrin.h>
> +
> +struct B {
> + union {
> + __m512 f;
> + __m512i s;
> + };
> +};
> +
> +struct B foo(int n) {
> + struct B res;
> + res.s = _mm512_set1_epi32(n);
> +
> + return res;
> +}
> +
> +__m512i bar(int n) {
> + struct B res;
> + res.s = _mm512_set1_epi32(n);
> +
> + return res.s;
> +}
> --
> 2.31.1
>
