cmd/compile: make expandCalls preserve types of pointer stores

This is accomplished by checking for simple stores of pointer types
and leaving them alone.  The failure case was when a *mspan
(not in heap) stored type was replaced by unsafe.Pointer.

Updates #40724.

Change-Id: I529e1705bf58fb0e64e60d48fd550b3a407e57e7
Reviewed-on: https://go-review.googlesource.com/c/go/+/305672
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

diff --git a/src/cmd/compile/internal/ssa/expand_calls.go b/src/cmd/compile/internal/ssa/expand_calls.go
index 3444097ae3e6800cadfa1f057ed8efd500e06661..b6aba0ed16a1c378f65cb9fde164a7908dffe71b 100644 (file)
--- a/src/cmd/compile/internal/ssa/expand_calls.go
+++ b/src/cmd/compile/internal/ssa/expand_calls.go
@@ -1114,6 +1114,9 @@ func expandCalls(f *Func) {
                for _, v := range b.Values {
                        if v.Op == OpStore {
                                t := v.Aux.(*types.Type)
+                               if t.IsPtrShaped() { // Everything already fits, and this ensures pointer type properties aren't discarded (e.g, notinheap)
+                                       continue
+                               }
                                source := v.Args[1]
                                tSrc := source.Type
                                iAEATt := x.isAlreadyExpandedAggregateType(t)
@@ -1422,7 +1425,7 @@ func (x *expandState) newArgToMemOrRegs(baseArg, toReplace *Value, offset int64,
        if x.debug {
                x.indent(3)
                defer x.indent(-3)
-               x.Printf("newArgToMemOrRegs(base=%s; toReplace=%s; t=%s; memOff=%d; regOff=%d)\n", baseArg.String(), toReplace.LongString(), t, offset, regOffset)
+               x.Printf("newArgToMemOrRegs(base=%s; toReplace=%s; t=%s; memOff=%d; regOff=%d)\n", baseArg.String(), toReplace.LongString(), t.String(), offset, regOffset)
        }
        key := selKey{baseArg, offset, t.Width, t}
        w := x.commonArgs[key]

diff --git a/src/cmd/compile/internal/ssa/value.go b/src/cmd/compile/internal/ssa/value.go
index 5a9779dd1e59b477f995c4298f3a5931c8070b5c..ba7f8c0300541c32a716eecb90ab8e67d28884d2 100644 (file)
--- a/src/cmd/compile/internal/ssa/value.go
+++ b/src/cmd/compile/internal/ssa/value.go
@@ -139,6 +139,9 @@ func (v *Value) AuxArm64BitField() arm64BitField {
 
 // long form print.  v# = opcode <type> [aux] args [: reg] (names)
 func (v *Value) LongString() string {
+       if v == nil {
+               return "<NIL VALUE>"
+       }
        s := fmt.Sprintf("v%d = %s", v.ID, v.Op)
        s += " <" + v.Type.String() + ">"
        s += v.auxString()