https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109764
Bug ID: 109764 Summary: V2SI multiply high is not vectorized on x86_64 Product: gcc Version: 14.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: ubizjak at gmail dot com Target Milestone: --- The folowing testcase: --cut here-- #define N 2 unsigned int ur[N], ua[N], ub[N]; void mulh (void) { int i; for (i = 0; i < N; i++) ur[i] = ((unsigned long) ua[i] * ub[i]) >> 32; } void mulh_slp (void) { ur[0] = ((unsigned long) ua[0] * ub[0]) >> 32; ur[1] = ((unsigned long) ua[1] * ub[1]) >> 32; } --cut here-- should vectorize on x86_64 with the patch I'm going to attach, and with -fno-vect-cost-model. The compiler however does not even consider "<s>mulv2si3_highpart" pattern.