diff options
Diffstat (limited to 'src/cmd/compile')
| -rw-r--r-- | src/cmd/compile/internal/ssa/regalloc.go | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/ssa/regalloc.go b/src/cmd/compile/internal/ssa/regalloc.go index 294c522a90..05765bb701 100644 --- a/src/cmd/compile/internal/ssa/regalloc.go +++ b/src/cmd/compile/internal/ssa/regalloc.go @@ -1544,6 +1544,7 @@ func (s *regAllocState) regalloc(f *Func) { } } } + // Avoid future fixed uses if we can. if m&^desired.avoid != 0 { m &^= desired.avoid @@ -1551,6 +1552,19 @@ func (s *regAllocState) regalloc(f *Func) { // Save input 0 to a new register so we can clobber it. c := s.allocValToReg(v.Args[0], m, true, v.Pos) s.copies[c] = false + + // Normally we use the register of the old copy of input 0 as the target. + // However, if input 0 is already in its desired register then we use + // the register of the new copy instead. + if rp, ok := s.f.getHome(args[0].ID).(*Register); ok { + r := register(rp.num) + for _, r2 := range dinfo[idx].in[0] { + if r == r2 { + args[0] = c + break + } + } + } } ok: |