cmd/compile: (fixed) spill output parameters passed in registers as autos

Repair of CL 300749.

ALSO:
found evidence that stack maps for bodyless methods are wrong.
gofmt in test/abi
removed never-executed code in types/size.go

Updates #44816.
Updates #40724.

Change-Id: Ifeb5fee60f60e7c7b58ee0457f58a3265d6cf3f6
Reviewed-on: https://go-review.googlesource.com/c/go/+/302071
Trust: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

1 files changed, 14 insertions, 5 deletions

diff --git a/src/cmd/compile/internal/liveness/plive.go b/src/cmd/compile/internal/liveness/plive.go
index 48a26cf66a..f3fbb8b9b1 100644
--- a/src/cmd/compile/internal/liveness/plive.go
+++ b/src/cmd/compile/internal/liveness/plive.go
@@ -405,11 +405,17 @@ func (lv *liveness) pointerMap(liveout bitvec.BitVec, vars []*ir.Name, args, loc
 		}
 		node := vars[i]
 		switch node.Class {
+		case ir.PPARAM, ir.PPARAMOUT:
+			if !node.IsOutputParamInRegisters() {
+				if node.FrameOffset() < 0 {
+					lv.f.Fatalf("Node %v has frameoffset %d\n", node.Sym().Name, node.FrameOffset())
+				}
+				typebits.Set(node.Type(), node.FrameOffset(), args)
+				break
+			}
+			fallthrough // PPARAMOUT in registers acts memory-allocates like an AUTO
 		case ir.PAUTO:
 			typebits.Set(node.Type(), node.FrameOffset()+lv.stkptrsize, locals)
-
-		case ir.PPARAM, ir.PPARAMOUT:
-			typebits.Set(node.Type(), node.FrameOffset(), args)
 		}
 	}
 }
@@ -1083,8 +1089,10 @@ func (lv *liveness) emit() (argsSym, liveSym *obj.LSym) {
 	for _, n := range lv.vars {
 		switch n.Class {
 		case ir.PPARAM, ir.PPARAMOUT:
-			if maxArgNode == nil || n.FrameOffset() > maxArgNode.FrameOffset() {
-				maxArgNode = n
+			if !n.IsOutputParamInRegisters() {
+				if maxArgNode == nil || n.FrameOffset() > maxArgNode.FrameOffset() {
+					maxArgNode = n
+				}
 			}
 		}
 	}
@@ -1282,6 +1290,7 @@ func isfat(t *types.Type) bool {
 	return false
 }
 
+// TODO THIS IS ALL WRONG AND NEEDS TO USE ABI.
 func WriteFuncMap(fn *ir.Func) {
 	if ir.FuncName(fn) == "_" || fn.Sym().Linkname != "" {
 		return