cmd/compile: use a boolean as a avoid clobbering flags mov marker
The Value type implements Aux interface because it is being used as a
"avoid clobbering flags" marker by amd64, x86 and s390x SSA parts.
Create a boolean that implements the Aux interface. Use it as the marker
instead. We no longer need Value to implement Aux.
Resolves a TODO.
See CL 275756 for more info.
Change-Id: I8a1eddf7e738b8aa31e82f3c4c590bafd2cdc56b
Reviewed-on: https://go-review.googlesource.com/c/go/+/461156
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Run-TryBot: Jakub Ciolek <jakub@ciolek.dev>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
diff --git a/src/cmd/compile/internal/amd64/ssa.go b/src/cmd/compile/internal/amd64/ssa.go
index cad410c..e256c09 100644
--- a/src/cmd/compile/internal/amd64/ssa.go
+++ b/src/cmd/compile/internal/amd64/ssa.go
@@ -30,7 +30,7 @@
v := b.Values[i]
if flive && (v.Op == ssa.OpAMD64MOVLconst || v.Op == ssa.OpAMD64MOVQconst) {
// The "mark" is any non-nil Aux value.
- v.Aux = v
+ v.Aux = ssa.AuxMark
}
if v.Type.IsFlags() {
flive = false
diff --git a/src/cmd/compile/internal/s390x/ssa.go b/src/cmd/compile/internal/s390x/ssa.go
index ba50b00..fc42557 100644
--- a/src/cmd/compile/internal/s390x/ssa.go
+++ b/src/cmd/compile/internal/s390x/ssa.go
@@ -26,7 +26,7 @@
v := b.Values[i]
if flive && v.Op == ssa.OpS390XMOVDconst {
// The "mark" is any non-nil Aux value.
- v.Aux = v
+ v.Aux = ssa.AuxMark
}
if v.Type.IsFlags() {
flive = false
diff --git a/src/cmd/compile/internal/ssa/rewrite.go b/src/cmd/compile/internal/ssa/rewrite.go
index 84bf204..13095c0 100644
--- a/src/cmd/compile/internal/ssa/rewrite.go
+++ b/src/cmd/compile/internal/ssa/rewrite.go
@@ -729,6 +729,13 @@
CanBeAnSSAAux()
}
+// for now only used to mark moves that need to avoid clobbering flags
+type auxMark bool
+
+func (auxMark) CanBeAnSSAAux() {}
+
+var AuxMark auxMark
+
// stringAux wraps string values for use in Aux.
type stringAux string
diff --git a/src/cmd/compile/internal/ssa/value.go b/src/cmd/compile/internal/ssa/value.go
index 643fa36..0567b3e 100644
--- a/src/cmd/compile/internal/ssa/value.go
+++ b/src/cmd/compile/internal/ssa/value.go
@@ -554,9 +554,6 @@
return true
}
-// TODO(mdempsky): Shouldn't be necessary; see discussion at golang.org/cl/275756
-func (*Value) CanBeAnSSAAux() {}
-
// AutoVar returns a *Name and int64 representing the auto variable and offset within it
// where v should be spilled.
func AutoVar(v *Value) (*ir.Name, int64) {
diff --git a/src/cmd/compile/internal/x86/ssa.go b/src/cmd/compile/internal/x86/ssa.go
index 40a483f..ee95a4a 100644
--- a/src/cmd/compile/internal/x86/ssa.go
+++ b/src/cmd/compile/internal/x86/ssa.go
@@ -28,7 +28,7 @@
v := b.Values[i]
if flive && v.Op == ssa.Op386MOVLconst {
// The "mark" is any non-nil Aux value.
- v.Aux = v
+ v.Aux = ssa.AuxMark
}
if v.Type.IsFlags() {
flive = false
