[dev.ssa] cmd/compile: clean up zeroing. Use duffzero when appropriate.
Change-Id: I4deb03340e87f43179d5e22bf81843c17b5581fc
Reviewed-on: https://go-review.googlesource.com/14756
Reviewed-by: David Chase <drchase@google.com>
diff --git a/src/cmd/compile/internal/gc/ssa.go b/src/cmd/compile/internal/gc/ssa.go
index b9da5ed..51cf01a 100644
--- a/src/cmd/compile/internal/gc/ssa.go
+++ b/src/cmd/compile/internal/gc/ssa.go
@@ -3613,22 +3613,12 @@
ssa.OpAMD64CVTTSS2SL, ssa.OpAMD64CVTTSD2SL, ssa.OpAMD64CVTTSS2SQ, ssa.OpAMD64CVTTSD2SQ,
ssa.OpAMD64CVTSS2SD, ssa.OpAMD64CVTSD2SS:
opregreg(v.Op.Asm(), regnum(v), regnum(v.Args[0]))
- case ssa.OpAMD64MOVXzero:
- nb := v.AuxInt
- offset := int64(0)
- reg := regnum(v.Args[0])
- for nb >= 8 {
- nb, offset = movZero(x86.AMOVQ, 8, nb, offset, reg)
- }
- for nb >= 4 {
- nb, offset = movZero(x86.AMOVL, 4, nb, offset, reg)
- }
- for nb >= 2 {
- nb, offset = movZero(x86.AMOVW, 2, nb, offset, reg)
- }
- for nb >= 1 {
- nb, offset = movZero(x86.AMOVB, 1, nb, offset, reg)
- }
+ case ssa.OpAMD64DUFFZERO:
+ p := Prog(obj.ADUFFZERO)
+ p.To.Type = obj.TYPE_ADDR
+ p.To.Sym = Linksym(Pkglookup("duffzero", Runtimepkg))
+ p.To.Offset = v.AuxInt
+
case ssa.OpCopy: // TODO: lower to MOVQ earlier?
if v.Type.IsMemory() {
return
@@ -3830,11 +3820,6 @@
case ssa.OpAMD64InvertFlags:
v.Fatalf("InvertFlags should never make it to codegen %v", v)
case ssa.OpAMD64REPSTOSQ:
- p := Prog(x86.AXORL) // TODO: lift out zeroing into its own instruction?
- p.From.Type = obj.TYPE_REG
- p.From.Reg = x86.REG_AX
- p.To.Type = obj.TYPE_REG
- p.To.Reg = x86.REG_AX
Prog(x86.AREP)
Prog(x86.ASTOSQ)
case ssa.OpAMD64REPMOVSB:
