https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126474
Bug ID: 126474
Summary: wrong vec_cond+VIEW_CONVERT+negate -> .COND_NEG fold
Product: gcc
Version: 17.0
Status: UNCONFIRMED
Keywords: aarch64-sve, wrong-code
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: ktkachov at gcc dot gnu.org
Target Milestone: ---
Target: aarch64
#include <arm_sve.h>
__attribute__((noipa))
svint32_t f (svbool_t p, svfloat32_t a, svint32_t b)
{
svfloat32_t n = -a; /* NEGATE_EXPR <svfloat32_t> */
return svsel_s32 (p, svreinterpret_s32_f32 (n), b);
}
int main (void)
{
float av[64];
int bv[64], rv[64];
for (int i = 0; i < 64; i++) { av[i] = 1.0f; bv[i] = 77; rv[i] = 0; }
svbool_t p = svwhilelt_b32 (0, 1); /* lane 0 active only */
svfloat32_t a = svld1_f32 (svptrue_b32 (), av);
svint32_t b = svld1_s32 (svptrue_b32 (), bv);
svint32_t r = f (p, a, b);
svst1_s32 (svptrue_b32 (), rv, r);
__builtin_printf ("%d %d\n", rv[0], rv[1]);
/* -1.0f has the bit pattern 0xbf800000 == -1082130432. */
if (rv[0] != (int) 0xbf800000 || rv[1] != 77)
__builtin_abort ();
return 0;
}
aborts for -O2 -march=armv8-a+sve but passes at -O0.
vec_cond+VIEW_CONVERT+negate -> .COND_NEG builds the IFN in the VEC_COND_EXPR
type instead of the negate type, turning a float negate into an integer negate
