https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114577
Bug ID: 114577 Summary: Inefficient codegen for SVE/NEON bridge Product: gcc Version: 14.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: tnfchris at gcc dot gnu.org Target Milestone: --- Target: aarch64* The following sequence: #include <arm_neon_sve_bridge.h> svint32_t f (int *a, int *b) { int32x4_t va = vld1q_s32 (a); svint32_t za = svset_neonq_s32 (svundef_s32 (), va); return za; } -O2 -march=armv9-a is expected to be a simple load but generates: f: ldr q31, [x0] ptrue p3.s, vl4 sel z0.s, p3, z31.s, z0.s ret instead of the expected (from clang): f: // @f ldr q0, [x0] ret it looks like GCC's implementation of svset_neonq_s32 with svundef does not become a view_convert/subreg.