diff options
Diffstat (limited to 'src/cmd/compile/internal/ssa/regalloc.go')
| -rw-r--r-- | src/cmd/compile/internal/ssa/regalloc.go | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/ssa/regalloc.go b/src/cmd/compile/internal/ssa/regalloc.go index 7bf778609e..90b5947f1c 100644 --- a/src/cmd/compile/internal/ssa/regalloc.go +++ b/src/cmd/compile/internal/ssa/regalloc.go @@ -1699,6 +1699,24 @@ sinking: } p := d.Preds[0].b // block in loop exiting to d. + // Check that the spill value is still live at the start of d. + // If it isn't, we can't move the spill here because some other value + // may be using the same stack slot. See issue 20472. + // The spill value can't be defined in d, so that makes our lives easier. + for _, x := range stacklive[d.ID] { + if x == vsp.ID { + goto stillLive + } + } + for _, v := range d.Values { + if v.Op == OpLoadReg && v.Args[0] == vsp { + goto stillLive + } + } + // Spill is not live - abort sinking this spill. + continue sinking + stillLive: + endregs := s.endRegs[p.ID] for _, regrec := range endregs { if regrec.v == e && regrec.r != noRegister && regrec.c == e { // TODO: regrec.c != e implies different spill possible. |