[dev.regabi] cmd/compile: remove original addrtaken bit

Switch the source of truth to the new addrtaken bit. Remove the old one.

Change-Id: Ie53679ab14cfcd34b55e912e7ecb962a22db7db3
Reviewed-on: https://go-review.googlesource.com/c/go/+/275696
Trust: Keith Randall <khr@golang.org>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>

5 files changed, 1 insertions, 24 deletions

diff --git a/src/cmd/compile/internal/inline/inl.go b/src/cmd/compile/internal/inline/inl.go
index 7324369ced..8f3a4b4d8c 100644
--- a/src/cmd/compile/internal/inline/inl.go
+++ b/src/cmd/compile/internal/inline/inl.go
@@ -1012,7 +1012,6 @@ func inlvar(var_ ir.Node) ir.Node {
 	n.Class_ = ir.PAUTO
 	n.SetUsed(true)
 	n.Curfn = ir.CurFunc // the calling function, not the called one
-	n.SetAddrtaken(var_.Name().Addrtaken())
 	n.SetAddrtaken2(var_.Name().Addrtaken())
 
 	ir.CurFunc.Dcl = append(ir.CurFunc.Dcl, n)
diff --git a/src/cmd/compile/internal/ir/name.go b/src/cmd/compile/internal/ir/name.go
index 8b1084deeb..6e41fd650b 100644
--- a/src/cmd/compile/internal/ir/name.go
+++ b/src/cmd/compile/internal/ir/name.go
@@ -285,7 +285,7 @@ func (n *Name) Used() bool                  { return n.flags&nameUsed != 0 }
 func (n *Name) IsClosureVar() bool          { return n.flags&nameIsClosureVar != 0 }
 func (n *Name) IsOutputParamHeapAddr() bool { return n.flags&nameIsOutputParamHeapAddr != 0 }
 func (n *Name) Assigned() bool              { return n.flags&nameAssigned != 0 }
-func (n *Name) Addrtaken() bool             { return n.checkAddrtaken() && n.flags&nameAddrtaken != 0 }
+func (n *Name) Addrtaken() bool             { return n.flags&nameAddrtaken2 != 0 }
 func (n *Name) InlFormal() bool             { return n.flags&nameInlFormal != 0 }
 func (n *Name) InlLocal() bool              { return n.flags&nameInlLocal != 0 }
 func (n *Name) OpenDeferSlot() bool         { return n.flags&nameOpenDeferSlot != 0 }
@@ -300,24 +300,12 @@ func (n *Name) SetUsed(b bool)                  { n.flags.set(nameUsed, b) }
 func (n *Name) SetIsClosureVar(b bool)          { n.flags.set(nameIsClosureVar, b) }
 func (n *Name) SetIsOutputParamHeapAddr(b bool) { n.flags.set(nameIsOutputParamHeapAddr, b) }
 func (n *Name) SetAssigned(b bool)              { n.flags.set(nameAssigned, b) }
-func (n *Name) SetAddrtaken(b bool)             { n.flags.set(nameAddrtaken, b) }
 func (n *Name) SetAddrtaken2(b bool)            { n.flags.set(nameAddrtaken2, b) }
 func (n *Name) SetInlFormal(b bool)             { n.flags.set(nameInlFormal, b) }
 func (n *Name) SetInlLocal(b bool)              { n.flags.set(nameInlLocal, b) }
 func (n *Name) SetOpenDeferSlot(b bool)         { n.flags.set(nameOpenDeferSlot, b) }
 func (n *Name) SetLibfuzzerExtraCounter(b bool) { n.flags.set(nameLibfuzzerExtraCounter, b) }
 
-func (n *Name) checkAddrtaken() bool {
-	// The two different ways of computing addrtaken bits might diverge during computation,
-	// but any time we look at them, they should be identical.
-	x := n.flags&nameAddrtaken != 0
-	y := n.flags&nameAddrtaken2 != 0
-	if x != y {
-		panic("inconsistent addrtaken")
-	}
-	return true
-}
-
 // MarkReadonly indicates that n is an ONAME with readonly contents.
 func (n *Name) MarkReadonly() {
 	if n.Op() != ONAME {
diff --git a/src/cmd/compile/internal/typecheck/expr.go b/src/cmd/compile/internal/typecheck/expr.go
index 5752139c0b..12bfae67a8 100644
--- a/src/cmd/compile/internal/typecheck/expr.go
+++ b/src/cmd/compile/internal/typecheck/expr.go
@@ -35,14 +35,6 @@ func tcAddr(n *ir.AddrExpr) ir.Node {
 			if ir.Orig(r) != r {
 				base.Fatalf("found non-orig name node %v", r) // TODO(mdempsky): What does this mean?
 			}
-			r.Name().SetAddrtaken(true)
-			if r.Name().IsClosureVar() && !CaptureVarsComplete {
-				// Mark the original variable as Addrtaken so that capturevars
-				// knows not to pass it by value.
-				// But if the capturevars phase is complete, don't touch it,
-				// in case l.Name's containing function has not yet been compiled.
-				r.Name().Defn.Name().SetAddrtaken(true)
-			}
 		}
 		n.X = DefaultLit(n.X, nil)
 		if n.X.Type() == nil {
diff --git a/src/cmd/compile/internal/typecheck/func.go b/src/cmd/compile/internal/typecheck/func.go
index ce6f4027da..0819380885 100644
--- a/src/cmd/compile/internal/typecheck/func.go
+++ b/src/cmd/compile/internal/typecheck/func.go
@@ -134,7 +134,6 @@ func CaptureVars(fn *ir.Func) {
 		if outermost.Class_ != ir.PPARAMOUT && !outermost.Name().Addrtaken() && !outermost.Name().Assigned() && v.Type().Width <= 128 {
 			v.SetByval(true)
 		} else {
-			outermost.Name().SetAddrtaken(true)
 			outermost.Name().SetAddrtaken2(true)
 			outer = NodAddr(outer)
 		}
diff --git a/src/cmd/compile/internal/walk/order.go b/src/cmd/compile/internal/walk/order.go
index 82180c113e..58c1c597fc 100644
--- a/src/cmd/compile/internal/walk/order.go
+++ b/src/cmd/compile/internal/walk/order.go
@@ -517,7 +517,6 @@ func (o *orderState) call(nn ir.Node) {
 			if arg.X.Type().IsUnsafePtr() {
 				x := o.copyExpr(arg.X)
 				arg.X = x
-				x.Name().SetAddrtaken(true)  // ensure SSA keeps the x variable
 				x.Name().SetAddrtaken2(true) // ensure SSA keeps the x variable
 				n.Body.Append(typecheck.Stmt(ir.NewUnaryExpr(base.Pos, ir.OVARLIVE, x)))
 			}