[dev.ssa] cmd/compile: allocate the flag register in a separate pass
Spilling/restoring flag values is a pain to do during regalloc.
Instead, allocate the flag register in a separate pass. Regalloc then
operates normally on any flag recomputation instructions.
Change-Id: Ia1c3d9e6eff678861193093c0b48a00f90e4156b
Reviewed-on: https://go-review.googlesource.com/17694
Reviewed-by: David Chase <drchase@google.com>
diff --git a/src/cmd/compile/internal/ssa/value.go b/src/cmd/compile/internal/ssa/value.go
index 661a059..fc31863 100644
--- a/src/cmd/compile/internal/ssa/value.go
+++ b/src/cmd/compile/internal/ssa/value.go
@@ -126,6 +126,15 @@
v.Args = v.argstorage[:0]
}
+// copyInto makes a new value identical to v and adds it to the end of b.
+func (v *Value) copyInto(b *Block) *Value {
+ c := b.NewValue0(v.Line, v.Op, v.Type)
+ c.Aux = v.Aux
+ c.AuxInt = v.AuxInt
+ c.AddArgs(v.Args...)
+ return c
+}
+
func (v *Value) Logf(msg string, args ...interface{}) { v.Block.Logf(msg, args...) }
func (v *Value) Fatalf(msg string, args ...interface{}) { v.Block.Fatalf(msg, args...) }
func (v *Value) Unimplementedf(msg string, args ...interface{}) { v.Block.Unimplementedf(msg, args...) }
