> Am 22.09.2026 um 16:29 schrieb Juergen Christ <[email protected]>:
>
> If vec_perm intrinsic is called with a constant permutation vector, try to
> optimize this such that the permutation vector can be removed altogether.
Looks like folding the intrinsic to a VEC_PERM_EXPR would do this automatically?
> gcc/ChangeLog:
>
> * config/s390/s390.cc (s390_expand_builtin): Optimize vec_perm
> builtin.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/s390/zvector/vec_perm-1.c: New test.
>
> Bootstrapped and regtested on s390x. Ok for trunk?
>
> Signed-off-by: Juergen Christ <[email protected]>
> ---
> gcc/config/s390/s390.cc | 8 ++
> .../gcc.target/s390/zvector/vec_perm-1.c | 79 +++++++++++++++++++
> 2 files changed, 87 insertions(+)
> create mode 100644 gcc/testsuite/gcc.target/s390/zvector/vec_perm-1.c
>
> diff --git a/gcc/config/s390/s390.cc b/gcc/config/s390/s390.cc
> index 2e7997979918..94ffdaba53b8 100644
> --- a/gcc/config/s390/s390.cc
> +++ b/gcc/config/s390/s390.cc
> @@ -972,6 +972,14 @@ s390_expand_builtin (tree exp, rtx target, rtx subtarget
> ATTRIBUTE_UNUSED,
> if (arity >= MAX_ARGS)
> return NULL_RTX;
>
> + vec_perm_builder sel;
> + if (arity == 2 && icode == CODE_FOR_vec_permv16qi
> + && TREE_CODE(arg) == VECTOR_CST
> + && tree_to_vec_perm_builder (&sel, arg))
> + return expand_vec_perm_const (mode, op[0], op[1], sel,
> + TYPE_MODE (TREE_TYPE (arg)),
> + target);
> +
> if (O_IMM_P (op_flags)
> && TREE_CODE (arg) != INTEGER_CST)
> {
> diff --git a/gcc/testsuite/gcc.target/s390/zvector/vec_perm-1.c
> b/gcc/testsuite/gcc.target/s390/zvector/vec_perm-1.c
> new file mode 100644
> index 000000000000..9c6d17381f53
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/s390/zvector/vec_perm-1.c
> @@ -0,0 +1,79 @@
> +/* Test whether vec_perm with constant permutation mask gets optimized. */
> +
> +/* { dg-do compile { target { s390*-*-* } } } */
> +/* { dg-options "-march=z14 -mzarch -mzvector" } */
> +
> +#include <vecintrin.h>
> +
> +typedef signed char v16qi __attribute__((vector_size(16)));
> +typedef unsigned char uv16qi __attribute__((vector_size(16)));
> +typedef char bv16qi __attribute__((vector_size(16),s390_vector_bool));
> +
> +typedef signed short int v8hi __attribute__((vector_size(16)));
> +typedef unsigned short int uv8hi __attribute__((vector_size(16)));
> +typedef short int bv8hi __attribute__((vector_size(16),s390_vector_bool));
> +
> +typedef signed int v4si __attribute__((vector_size(16)));
> +typedef unsigned int uv4si __attribute__((vector_size(16)));
> +typedef int bv4si __attribute__((vector_size(16),s390_vector_bool));
> +
> +typedef signed long long v2di __attribute__((vector_size(16)));
> +typedef unsigned long long uv2di __attribute__((vector_size(16)));
> +typedef long long bv2di __attribute__((vector_size(16),s390_vector_bool));
> +
> +typedef float v4sf __attribute__((vector_size(16)));
> +typedef double v2df __attribute__((vector_size(16)));
> +
> +#define T(t) \
> + t \
> + mergehi_##t (t in) \
> + { \
> + return vec_perm (in, in, \
> + (__vector unsigned char) \
> + {0,1,2,3,4,5,6,7,16,17,18,19,20,21,22,23}); \
> + } \
> + t \
> + mergelow_##t (t in) \
> + { \
> + return vec_perm (in, in, \
> + (__vector unsigned char) \
> + {8,9,10,11,12,13,14,15,24,25,26,27,28,29,30,31}); \
> + } \
> + t \
> + pack_hi_##t (t in) \
> + { \
> + return vec_perm (in, in, \
> + (__vector unsigned char) \
> + {1,3,5,7,9,11,13,15,17,19,21,23,25,27,29,31}); \
> + } \
> + t \
> + pack_si_##t (t in) \
> + { \
> + return vec_perm (in, in, \
> + (__vector unsigned char) \
> + {2,3,6,7,10,11,14,15,18,19,22,23,26,27,30,31}); \
> + } \
> + t \
> + pack_di_##t (t in) \
> + { \
> + return vec_perm (in, in, \
> + (__vector unsigned char) \
> + {4,5,6,7,12,13,14,15,20,21,22,23,28,29,30,31}); \
> + }
> +
> +T(v16qi)
> +T(uv16qi)
> +T(bv16qi)
> +T(v8hi)
> +T(uv8hi)
> +T(bv8hi)
> +T(v4si)
> +T(uv4si)
> +T(bv4si)
> +T(v2di)
> +T(uv2di)
> +T(bv2di)
> +T(v4sf)
> +T(v2df)
> +
> +/* { dg-final { scan-assembler-not {vperm} } } */
> --
> 2.43.7
>
