[Bug tree-optimization/120808] New: SLP unable to combine .FMA and .FMS to VEC_FMADDSUB

[amonakov at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120808

            Bug ID: 120808
           Summary: SLP unable to combine .FMA and .FMS to VEC_FMADDSUB
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: amonakov at gcc dot gnu.org
  Target Milestone: ---

void f(double x[restrict], double *y, double *z)
{
    x[0] = x[0] * y[0] + z[0];
    x[1] = x[1] * y[1] - z[1];
}

with -O2 -mfma -ffp-contract=on yields two individual FMAs rather than
fmsubaddpd.