cmd/compile: name change isDirect -> isDirectAndComparable

Now that it also restricts to comparable types. Followon to CL 713840.

Change-Id: Idd975c3fd16fb51f55360f2fa0b89ab0bf1d00ed
Reviewed-on: https://go-review.googlesource.com/c/go/+/715700
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Mateusz Poliwczak <mpoliwczak34@gmail.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Keith Randall <khr@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

Author: randall77

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

@@ -2927,15 +2927,15 @@
 // we know the underlying type is pointer-ish.
 (StaticLECall {f} typ_ x y mem)
 	&& isSameCall(f, "runtime.efaceeq")
-	&& isDirectType(typ_)
+	&& isDirectAndComparableType(typ_)
 	&& clobber(v)
 	=> (MakeResult (EqPtr x y) mem)
 
 // We can easily compute the result of ifaceeq if
 // we know the underlying type is pointer-ish.
 (StaticLECall {f} itab x y mem)
 	&& isSameCall(f, "runtime.ifaceeq")
-	&& isDirectIface(itab)
+	&& isDirectAndComparableIface(itab)
 	&& clobber(v)
 	=> (MakeResult (EqPtr x y) mem)
 

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

@@ -2624,18 +2624,18 @@ func rewriteStructStore(v *Value) *Value {
 	return mem
 }
 
-// isDirectType reports whether v represents a type
+// isDirectAndComparableType reports whether v represents a type
 // (a *runtime._type) whose value is stored directly in an
 // interface (i.e., is pointer or pointer-like) and is comparable.
-func isDirectType(v *Value) bool {
-	return isDirectType1(v)
+func isDirectAndComparableType(v *Value) bool {
+	return isDirectAndComparableType1(v)
 }
 
 // v is a type
-func isDirectType1(v *Value) bool {
+func isDirectAndComparableType1(v *Value) bool {
 	switch v.Op {
 	case OpITab:
-		return isDirectType2(v.Args[0])
+		return isDirectAndComparableType2(v.Args[0])
 	case OpAddr:
 		lsym := v.Aux.(*obj.LSym)
 		if ti := lsym.TypeInfo(); ti != nil {
@@ -2647,29 +2647,29 @@ func isDirectType1(v *Value) bool {
 }
 
 // v is an empty interface
-func isDirectType2(v *Value) bool {
+func isDirectAndComparableType2(v *Value) bool {
 	switch v.Op {
 	case OpIMake:
-		return isDirectType1(v.Args[0])
+		return isDirectAndComparableType1(v.Args[0])
 	}
 	return false
 }
 
-// isDirectIface reports whether v represents an itab
+// isDirectAndComparableIface reports whether v represents an itab
 // (a *runtime._itab) for a type whose value is stored directly
 // in an interface (i.e., is pointer or pointer-like) and is comparable.
-func isDirectIface(v *Value) bool {
-	return isDirectIface1(v, 9)
+func isDirectAndComparableIface(v *Value) bool {
+	return isDirectAndComparableIface1(v, 9)
 }
 
 // v is an itab
-func isDirectIface1(v *Value, depth int) bool {
+func isDirectAndComparableIface1(v *Value, depth int) bool {
 	if depth == 0 {
 		return false
 	}
 	switch v.Op {
 	case OpITab:
-		return isDirectIface2(v.Args[0], depth-1)
+		return isDirectAndComparableIface2(v.Args[0], depth-1)
 	case OpAddr:
 		lsym := v.Aux.(*obj.LSym)
 		if ii := lsym.ItabInfo(); ii != nil {
@@ -2685,16 +2685,16 @@ func isDirectIface1(v *Value, depth int) bool {
 }
 
 // v is an interface
-func isDirectIface2(v *Value, depth int) bool {
+func isDirectAndComparableIface2(v *Value, depth int) bool {
 	if depth == 0 {
 		return false
 	}
 	switch v.Op {
 	case OpIMake:
-		return isDirectIface1(v.Args[0], depth-1)
+		return isDirectAndComparableIface1(v.Args[0], depth-1)
 	case OpPhi:
 		for _, a := range v.Args {
-			if !isDirectIface2(a, depth-1) {
+			if !isDirectAndComparableIface2(a, depth-1) {
 				return false
 			}
 		}