cmd/compile: handle mem copies in amd64 backend

Fixes noopt builder.

Change-Id: If13373b2597f0fcc9b1b2f9c860f2bd043e43c6c
Reviewed-on: https://go-review.googlesource.com/22338
Reviewed-by: Keith Randall <khr@golang.org>

diff --git a/src/cmd/compile/internal/amd64/ssa.go b/src/cmd/compile/internal/amd64/ssa.go
index 723a2ddec52ebfbd05e3e301b0314c32a56a9ef6..21dbc6238ce1ee1b9da8af8361d7cfe6d5cc626a 100644 (file)
--- a/src/cmd/compile/internal/amd64/ssa.go
+++ b/src/cmd/compile/internal/amd64/ssa.go
@@ -667,6 +667,9 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
                p.To.Offset = v.AuxInt
 
        case ssa.OpCopy, ssa.OpAMD64MOVQconvert: // TODO: use MOVQreg for reg->reg copies instead of OpCopy?
+               if v.Type.IsMemory() {
+                       return
+               }
                x := gc.SSARegNum(v.Args[0])
                y := gc.SSARegNum(v)
                if x != y {