> On 2 Oct 2025, at 23:09, Richard Sandiford <[email protected]> wrote:
>
> External email: Use caution opening links or attachments
>
>
> Jennifer Schmitz <[email protected]> writes:
>> diff --git a/gcc/config/aarch64/aarch64-sve-builtins.cc
>> b/gcc/config/aarch64/aarch64-sve-builtins.cc
>> index 22d75197188..5efc5ba3846 100644
>> --- a/gcc/config/aarch64/aarch64-sve-builtins.cc
>> +++ b/gcc/config/aarch64/aarch64-sve-builtins.cc
>> @@ -4356,7 +4356,11 @@ function_expander::use_cond_insn (insn_code icode,
>> unsigned int merge_argno)
>> add_input_operand (icode, pred);
>> for (unsigned int i = 0; i < nops; ++i)
>> add_input_operand (icode, args[opno + i]);
>> - add_input_operand (icode, fallback_arg);
>> + if (insn_operand_matches (icode, opno + nops + 1, fallback_arg)
>
> "m_ops.length ()" would be more direct than "opno + nops + 1"
>
>> + && fallback_arg == CONST0_RTX (mode))
>
> Very minor, sorry, but: IMO it's more natural (and should be cheaper)
> to test this first and insn_operand_matches second.
>
> OK with those changes from my POV, but please leave a day or so for
> others to comment. As far as backports go: IMO it's good for GCC 15
> and GCC 14. Not sure whether it's important enough to risk GCC 13,
> given that the next release in the series will be the last.
Thanks, I made the changes and pushed it to trunk (9b102d2e1e3..ad2991b2749).
I also tested the patch on releases/gcc-15 and releases/gcc-14, no regression.
OK to backport it to GCC15 and GCC14?
Thanks,
Jennifer
>
> Thanks,
> Richard
>
>> + add_fixed_operand (fallback_arg);
>> + else
>> + add_input_operand (icode, fallback_arg);
>> return generate_insn (icode);
>> }
>>
>> diff --git a/gcc/testsuite/gcc.target/aarch64/sve2/pr121599.c
>> b/gcc/testsuite/gcc.target/aarch64/sve2/pr121599.c
>> new file mode 100644
>> index 00000000000..90c5ac97e4f
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/aarch64/sve2/pr121599.c
>> @@ -0,0 +1,31 @@
>> +/* PR target/121599. */
>> +/* { dg-do compile } */
>> +/* { dg-options "-O2" } */
>> +/* { dg-final { check-function-bodies "**" "" "" } } */
>> +
>> +#include <arm_sve.h>
>> +
>> +/*
>> +** foo:
>> +** movi d([0-9]+), #0
>> +** movprfx z0\.b, p0/z, z0\.b
>> +** usqadd z0\.b, p0/m, z0\.b, z\1\.b
>> +** ret
>> +*/
>> +svuint8_t foo (svbool_t pg, svuint8_t op1)
>> +{
>> + return svsqadd_u8_z (pg, op1, svdup_s8 (0));
>> +}
>> +
>> +/*
>> +** bar:
>> +** movi d([0-9]+), #0
>> +** movprfx z0\.b, p0/z, z0\.b
>> +** suqadd z0\.b, p0/m, z0\.b, z\1\.b
>> +** ret
>> +*/
>> +svint8_t bar (svbool_t pg, svint8_t op1)
>> +{
>> + return svuqadd_n_s8_z (pg, op1, 0);
>> +}
>> +
