cmd/compile: convert nilcheck elim rules to typed aux

Passes toolstash-check.

Change-Id: Ic7efb0e4778844366f581c6310a1a2f3bfc1868a
Reviewed-on: https://go-review.googlesource.com/c/go/+/229686
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

src/cmd/compile/internal/ssa/gen/generic.rules

@@ -1923,31 +1923,31 @@
 	&& mem.Op == OpStaticCall
 	&& isSameSym(mem.Aux, "runtime.newobject")
 	&& c == config.ctxt.FixedFrameSize() + config.RegSize // offset of return value
-	-> mem
+	=> mem
 (Store (Load (OffPtr [c] (SP)) mem) x mem)
 	&& isConstZero(x)
 	&& mem.Op == OpStaticCall
 	&& isSameSym(mem.Aux, "runtime.newobject")
 	&& c == config.ctxt.FixedFrameSize() + config.RegSize // offset of return value
-	-> mem
+	=> mem
 (Store (OffPtr (Load (OffPtr [c] (SP)) mem)) x mem)
 	&& isConstZero(x)
 	&& mem.Op == OpStaticCall
 	&& isSameSym(mem.Aux, "runtime.newobject")
 	&& c == config.ctxt.FixedFrameSize() + config.RegSize // offset of return value
-	-> mem
+	=> mem
 // nil checks just need to rewrite to something useless.
 // they will be deadcode eliminated soon afterwards.
 (NilCheck (Load (OffPtr [c] (SP)) (StaticCall {sym} _)) _)
-	&& isSameSym(sym, "runtime.newobject")
+	&& symNamed(sym, "runtime.newobject")
 	&& c == config.ctxt.FixedFrameSize() + config.RegSize // offset of return value
 	&& warnRule(fe.Debug_checknil(), v, "removed nil check")
-	-> (Invalid)
+	=> (Invalid)
 (NilCheck (OffPtr (Load (OffPtr [c] (SP)) (StaticCall {sym} _))) _)
-	&& isSameSym(sym, "runtime.newobject")
+	&& symNamed(sym, "runtime.newobject")
 	&& c == config.ctxt.FixedFrameSize() + config.RegSize // offset of return value
 	&& warnRule(fe.Debug_checknil(), v, "removed nil check")
-	-> (Invalid)
+	=> (Invalid)
 
 // Evaluate constant address comparisons.
 (EqPtr  x x) -> (ConstBool [1])

src/cmd/compile/internal/ssa/rewrite.go

@@ -373,6 +373,11 @@ func canMergeLoad(target, load *Value) bool {
 	return true
 }
 
+// symNamed reports whether sym's name is name.
+func symNamed(sym Sym, name string) bool {
+	return sym.String() == name
+}
+
 // isSameSym reports whether sym is the same as the given named symbol
 func isSameSym(sym interface{}, name string) bool {
 	s, ok := sym.(fmt.Stringer)

src/cmd/compile/internal/ssa/rewritegeneric.go

@@ -16009,7 +16009,7 @@ func rewriteValuegeneric_OpNilCheck(v *Value) bool {
 		return true
 	}
 	// match: (NilCheck (Load (OffPtr [c] (SP)) (StaticCall {sym} _)) _)
-	// cond: isSameSym(sym, "runtime.newobject") && c == config.ctxt.FixedFrameSize() + config.RegSize && warnRule(fe.Debug_checknil(), v, "removed nil check")
+	// cond: symNamed(sym, "runtime.newobject") && c == config.ctxt.FixedFrameSize() + config.RegSize && warnRule(fe.Debug_checknil(), v, "removed nil check")
 	// result: (Invalid)
 	for {
 		if v_0.Op != OpLoad {
@@ -16020,7 +16020,7 @@ func rewriteValuegeneric_OpNilCheck(v *Value) bool {
 		if v_0_0.Op != OpOffPtr {
 			break
 		}
-		c := v_0_0.AuxInt
+		c := auxIntToInt64(v_0_0.AuxInt)
 		v_0_0_0 := v_0_0.Args[0]
 		if v_0_0_0.Op != OpSP {
 			break
@@ -16029,15 +16029,15 @@ func rewriteValuegeneric_OpNilCheck(v *Value) bool {
 		if v_0_1.Op != OpStaticCall {
 			break
 		}
-		sym := v_0_1.Aux
+		sym := auxToSym(v_0_1.Aux)
-		if !(isSameSym(sym, "runtime.newobject") && c == config.ctxt.FixedFrameSize()+config.RegSize && warnRule(fe.Debug_checknil(), v, "removed nil check")) {
+		if !(symNamed(sym, "runtime.newobject") && c == config.ctxt.FixedFrameSize()+config.RegSize && warnRule(fe.Debug_checknil(), v, "removed nil check")) {
 			break
 		}
 		v.reset(OpInvalid)
 		return true
 	}
 	// match: (NilCheck (OffPtr (Load (OffPtr [c] (SP)) (StaticCall {sym} _))) _)
-	// cond: isSameSym(sym, "runtime.newobject") && c == config.ctxt.FixedFrameSize() + config.RegSize && warnRule(fe.Debug_checknil(), v, "removed nil check")
+	// cond: symNamed(sym, "runtime.newobject") && c == config.ctxt.FixedFrameSize() + config.RegSize && warnRule(fe.Debug_checknil(), v, "removed nil check")
 	// result: (Invalid)
 	for {
 		if v_0.Op != OpOffPtr {
@@ -16052,7 +16052,7 @@ func rewriteValuegeneric_OpNilCheck(v *Value) bool {
 		if v_0_0_0.Op != OpOffPtr {
 			break
 		}
-		c := v_0_0_0.AuxInt
+		c := auxIntToInt64(v_0_0_0.AuxInt)
 		v_0_0_0_0 := v_0_0_0.Args[0]
 		if v_0_0_0_0.Op != OpSP {
 			break
@@ -16061,8 +16061,8 @@ func rewriteValuegeneric_OpNilCheck(v *Value) bool {
 		if v_0_0_1.Op != OpStaticCall {
 			break
 		}
-		sym := v_0_0_1.Aux
+		sym := auxToSym(v_0_0_1.Aux)
-		if !(isSameSym(sym, "runtime.newobject") && c == config.ctxt.FixedFrameSize()+config.RegSize && warnRule(fe.Debug_checknil(), v, "removed nil check")) {
+		if !(symNamed(sym, "runtime.newobject") && c == config.ctxt.FixedFrameSize()+config.RegSize && warnRule(fe.Debug_checknil(), v, "removed nil check")) {
 			break
 		}
 		v.reset(OpInvalid)
@@ -21606,7 +21606,7 @@ func rewriteValuegeneric_OpStore(v *Value) bool {
 		if v_0_0.Op != OpOffPtr {
 			break
 		}
-		c := v_0_0.AuxInt
+		c := auxIntToInt64(v_0_0.AuxInt)
 		v_0_0_0 := v_0_0.Args[0]
 		if v_0_0_0.Op != OpSP {
 			break
@@ -21634,7 +21634,7 @@ func rewriteValuegeneric_OpStore(v *Value) bool {
 		if v_0_0_0.Op != OpOffPtr {
 			break
 		}
-		c := v_0_0_0.AuxInt
+		c := auxIntToInt64(v_0_0_0.AuxInt)
 		v_0_0_0_0 := v_0_0_0.Args[0]
 		if v_0_0_0_0.Op != OpSP {
 			break
@@ -24091,7 +24091,7 @@ func rewriteValuegeneric_OpZero(v *Value) bool {
 		if v_0_0.Op != OpOffPtr {
 			break
 		}
-		c := v_0_0.AuxInt
+		c := auxIntToInt64(v_0_0.AuxInt)
 		v_0_0_0 := v_0_0.Args[0]
 		if v_0_0_0.Op != OpSP || mem != v_1 || !(mem.Op == OpStaticCall && isSameSym(mem.Aux, "runtime.newobject") && c == config.ctxt.FixedFrameSize()+config.RegSize) {
 			break