cmd/compile: better check for single live memory
Enhance the one-live-memory-at-a-time check to run during many
more phases of the SSA backend. Also make it work in an interblock
fashion.
Change types.IsMemory to return true for tuples containing a memory type.
Fix trim pass to build the merged phi correctly. Doesn't affect
code but allows the check to pass after trim runs.
Switch the AddTuple* ops to take the memory-containing tuple argument second.
Update #20335
Change-Id: I5b03ef3606b75a9e4f765276bb8b183cdc172b43
Reviewed-on: https://go-review.googlesource.com/43495
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
diff --git a/src/cmd/compile/internal/ssa/value.go b/src/cmd/compile/internal/ssa/value.go
index a0ba112..7edc71b 100644
--- a/src/cmd/compile/internal/ssa/value.go
+++ b/src/cmd/compile/internal/ssa/value.go
@@ -319,10 +319,8 @@
}
// MemoryArg returns the memory argument for the Value.
-// The returned value, if non-nil, will be memory-typed,
-// except in the case where v is Select1, in which case
-// the returned value will be a tuple containing a memory
-// type. Otherwise, nil is returned.
+// The returned value, if non-nil, will be memory-typed (or a tuple with a memory-typed second part).
+// Otherwise, nil is returned.
func (v *Value) MemoryArg() *Value {
if v.Op == OpPhi {
v.Fatalf("MemoryArg on Phi")
@@ -331,8 +329,7 @@
if na == 0 {
return nil
}
- if m := v.Args[na-1]; m.Type.IsMemory() ||
- (v.Op == OpSelect1 && m.Type.FieldType(1).IsMemory()) {
+ if m := v.Args[na-1]; m.Type.IsMemory() {
return m
}
return nil
