diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/cmd/compile/internal/ssa/regalloc.go | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/src/cmd/compile/internal/ssa/regalloc.go b/src/cmd/compile/internal/ssa/regalloc.go index fe30b89cdd..bcb5dec09d 100644 --- a/src/cmd/compile/internal/ssa/regalloc.go +++ b/src/cmd/compile/internal/ssa/regalloc.go @@ -2576,22 +2576,25 @@ func (e *edgeState) processDest(loc Location, vid ID, splice **Value, pos src.XP e.s.f.Fatalf("can't find source for %s->%s: %s\n", e.p, e.b, v.LongString()) } if dstReg { - // Handle incompatible registers. + // We want to rematerialize v into a register that is incompatible with v's op's register mask. + // Instead of setting the wrong register for the rematerialized v, we should find the right register + // for it and emit an additional copy to move to the desired register. // For #70451. - if e.s.regspec(v).outputs[0].regs®Mask(1<<register(loc.(*Register).num)) == 0 && c != nil { + if e.s.regspec(v).outputs[0].regs®Mask(1<<register(loc.(*Register).num)) == 0 { _, srcReg := src.(*Register) - if !srcReg { + if srcReg { + // It exists in a valid register already, so just copy it to the desired register + // If src is a Register, c must have already been set. + x = e.p.NewValue1(pos, OpCopy, c.Type, c) + } else { // We need a tmp register x = v.copyInto(e.p) r := e.findRegFor(x.Type) e.erase(r) - // Rematerialize to a tmp register + // Rematerialize to the tmp register e.set(r, vid, x, false, pos) // Copy from tmp to the desired register x = e.p.NewValue1(pos, OpCopy, x.Type, x) - } else { - // It exist in a valid register already, so just copy it to the desired register - x = e.p.NewValue1(pos, OpCopy, c.Type, c) } } else { x = v.copyInto(e.p) |