On 19/07/2024 14:07, Torbjörn SVENSSON wrote:
> Ok for trunk and releases/gcc-14?
>
> --
>
> On Cortex-A7 with -mfloat-abi=hard and -mfpu=neon, the following
> instructions are generated for the test case:
>
> vldr d16, .L3
> vst1.32 {d16}, [r0]
>
> For Cortex-A7 with -mfloat-abi=soft, it's instead:
>
> movs r2, #1
> movs r3, #0
> strd r2, r3, [r0]
>
> Both these are valid and should not cause the test to fail.
> For Cortex-M0/3/4/7/33, they all generate the same instructions as
> Cortex-A7 with -mfloat-abi=soft.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/arm/pr40457-2.c: Add vst1 to allowed instructions.
>
> Signed-off-by: Torbjörn SVENSSON <[email protected]>
> ---
> gcc/testsuite/gcc.target/arm/pr40457-2.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/gcc/testsuite/gcc.target/arm/pr40457-2.c
> b/gcc/testsuite/gcc.target/arm/pr40457-2.c
> index 31624d35127..6aed42a4fbc 100644
> --- a/gcc/testsuite/gcc.target/arm/pr40457-2.c
> +++ b/gcc/testsuite/gcc.target/arm/pr40457-2.c
> @@ -7,4 +7,4 @@ void foo(int* p)
> p[1] = 0;
> }
>
> -/* { dg-final { scan-assembler "strd|stm" } } */
> +/* { dg-final { scan-assembler "strd|stm|vst1" } } */
Whilst the code generated is functionally correct, I'm not sure the compiler
should be generating that. This new code needs more code space (the constant
isn't shown, but it needs 8 bytes in the literal pool). I suspect this means
the SLP cost model for arm is in need of attention.
R.
