cmd/compile/internal/gc: move intLiteral to gc.Node

intLiteral is used by the gins wrappers in arm64, ppc64 and
mips64. Refactor the function to a method on gc.Node and update
the callers to use the common copy.

Change-Id: I2db90d801a9cb18f8526eb921e13daa75ca1cf6f
Reviewed-on: https://go-review.googlesource.com/14744Reviewed-by: Aram Hăvărneanu <aram@mgk.ro>
Reviewed-by: Dave Cheney <dave@cheney.net>
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/compile/internal/arm64/gsubr.go

@@ -467,30 +467,18 @@ hard:
 	return
 }
 
-func intLiteral(n *gc.Node) (x int64, ok bool) {
-	switch {
-	case n == nil:
-		return
-	case gc.Isconst(n, gc.CTINT):
-		return n.Int(), true
-	case gc.Isconst(n, gc.CTBOOL):
-		return int64(obj.Bool2int(n.Bool())), true
-	}
-	return
-}
-
 // gins is called by the front end.
 // It synthesizes some multiple-instruction sequences
 // so the front end can stay simpler.
 func gins(as int, f, t *gc.Node) *obj.Prog {
 	if as >= obj.A_ARCHSPECIFIC {
-		if x, ok := intLiteral(f); ok {
+		if x, ok := f.IntLiteral(); ok {
 			ginscon(as, x, t)
 			return nil // caller must not use
 		}
 	}
 	if as == arm64.ACMP {
-		if x, ok := intLiteral(t); ok {
+		if x, ok := t.IntLiteral(); ok {
 			ginscon2(as, f, x)
 			return nil // caller must not use
 		}

src/cmd/compile/internal/gc/const.go

@@ -10,6 +10,19 @@ import (
 	"strings"
 )
 
+// IntLiteral returns the Node's literal value as an interger.
+func (n *Node) IntLiteral() (x int64, ok bool) {
+	switch {
+	case n == nil:
+		return
+	case Isconst(n, CTINT):
+		return n.Int(), true
+	case Isconst(n, CTBOOL):
+		return int64(obj.Bool2int(n.Bool())), true
+	}
+	return
+}
+
 // Int returns n as an int.
 // n must be an integer constant.
 func (n *Node) Int() int64 {

src/cmd/compile/internal/mips64/gsubr.go

@@ -545,30 +545,18 @@ hard:
 	return
 }
 
-func intLiteral(n *gc.Node) (x int64, ok bool) {
-	switch {
-	case n == nil:
-		return
-	case gc.Isconst(n, gc.CTINT):
-		return n.Int(), true
-	case gc.Isconst(n, gc.CTBOOL):
-		return int64(obj.Bool2int(n.Bool())), true
-	}
-	return
-}
-
 // gins is called by the front end.
 // It synthesizes some multiple-instruction sequences
 // so the front end can stay simpler.
 func gins(as int, f, t *gc.Node) *obj.Prog {
 	if as >= obj.A_ARCHSPECIFIC {
-		if x, ok := intLiteral(f); ok {
+		if x, ok := f.IntLiteral(); ok {
 			ginscon(as, x, t)
 			return nil // caller must not use
 		}
 	}
 	if as == ppc64.ACMP || as == ppc64.ACMPU {
-		if x, ok := intLiteral(t); ok {
+		if x, ok := t.IntLiteral(); ok {
 			ginscon2(as, f, x)
 			return nil // caller must not use
 		}

src/cmd/compile/internal/ppc64/gsubr.go

@@ -545,30 +545,18 @@ hard:
 	return
 }
 
-func intLiteral(n *gc.Node) (x int64, ok bool) {
-	switch {
-	case n == nil:
-		return
-	case gc.Isconst(n, gc.CTINT):
-		return n.Int(), true
-	case gc.Isconst(n, gc.CTBOOL):
-		return int64(obj.Bool2int(n.Bool())), true
-	}
-	return
-}
-
 // gins is called by the front end.
 // It synthesizes some multiple-instruction sequences
 // so the front end can stay simpler.
 func gins(as int, f, t *gc.Node) *obj.Prog {
 	if as >= obj.A_ARCHSPECIFIC {
-		if x, ok := intLiteral(f); ok {
+		if x, ok := f.IntLiteral(); ok {
 			ginscon(as, x, t)
 			return nil // caller must not use
 		}
 	}
 	if as == ppc64.ACMP || as == ppc64.ACMPU {
-		if x, ok := intLiteral(t); ok {
+		if x, ok := t.IntLiteral(); ok {
 			ginscon2(as, f, x)
 			return nil // caller must not use
 		}