diff --git a/src/cmd/compile/internal/ssa/gen/generic.rules b/src/cmd/compile/internal/ssa/gen/generic.rules
index 703be65379..d5cc107fab 100644
--- a/src/cmd/compile/internal/ssa/gen/generic.rules
+++ b/src/cmd/compile/internal/ssa/gen/generic.rules
@@ -526,6 +526,7 @@
 
 (Xor(64|32|16|8) x x) => (Const(64|32|16|8) [0])
 (Xor(64|32|16|8) (Const(64|32|16|8) [0]) x) => x
+(Xor(64|32|16|8) (Com(64|32|16|8)    x)  x) => (Const(64|32|16|8) [-1])
 
 (Add(64|32|16|8) (Const(64|32|16|8) [0]) x) => x
 (Sub(64|32|16|8) x x) => (Const(64|32|16|8) [0])
diff --git a/src/cmd/compile/internal/ssa/rewritegeneric.go b/src/cmd/compile/internal/ssa/rewritegeneric.go
index e9c5fb8d1a..f61b6ca3ec 100644
--- a/src/cmd/compile/internal/ssa/rewritegeneric.go
+++ b/src/cmd/compile/internal/ssa/rewritegeneric.go
@@ -25090,6 +25090,23 @@ func rewriteValuegeneric_OpXor16(v *Value) bool {
 		}
 		break
 	}
+	// match: (Xor16 (Com16 x) x)
+	// result: (Const16 [-1])
+	for {
+		for _i0 := 0; _i0 <= 1; _i0, v_0, v_1 = _i0+1, v_1, v_0 {
+			if v_0.Op != OpCom16 {
+				continue
+			}
+			x := v_0.Args[0]
+			if x != v_1 {
+				continue
+			}
+			v.reset(OpConst16)
+			v.AuxInt = int16ToAuxInt(-1)
+			return true
+		}
+		break
+	}
 	// match: (Xor16 (Const16 [-1]) x)
 	// result: (Com16 x)
 	for {
@@ -25235,6 +25252,23 @@ func rewriteValuegeneric_OpXor32(v *Value) bool {
 		}
 		break
 	}
+	// match: (Xor32 (Com32 x) x)
+	// result: (Const32 [-1])
+	for {
+		for _i0 := 0; _i0 <= 1; _i0, v_0, v_1 = _i0+1, v_1, v_0 {
+			if v_0.Op != OpCom32 {
+				continue
+			}
+			x := v_0.Args[0]
+			if x != v_1 {
+				continue
+			}
+			v.reset(OpConst32)
+			v.AuxInt = int32ToAuxInt(-1)
+			return true
+		}
+		break
+	}
 	// match: (Xor32 (Const32 [-1]) x)
 	// result: (Com32 x)
 	for {
@@ -25380,6 +25414,23 @@ func rewriteValuegeneric_OpXor64(v *Value) bool {
 		}
 		break
 	}
+	// match: (Xor64 (Com64 x) x)
+	// result: (Const64 [-1])
+	for {
+		for _i0 := 0; _i0 <= 1; _i0, v_0, v_1 = _i0+1, v_1, v_0 {
+			if v_0.Op != OpCom64 {
+				continue
+			}
+			x := v_0.Args[0]
+			if x != v_1 {
+				continue
+			}
+			v.reset(OpConst64)
+			v.AuxInt = int64ToAuxInt(-1)
+			return true
+		}
+		break
+	}
 	// match: (Xor64 (Const64 [-1]) x)
 	// result: (Com64 x)
 	for {
@@ -25525,6 +25576,23 @@ func rewriteValuegeneric_OpXor8(v *Value) bool {
 		}
 		break
 	}
+	// match: (Xor8 (Com8 x) x)
+	// result: (Const8 [-1])
+	for {
+		for _i0 := 0; _i0 <= 1; _i0, v_0, v_1 = _i0+1, v_1, v_0 {
+			if v_0.Op != OpCom8 {
+				continue
+			}
+			x := v_0.Args[0]
+			if x != v_1 {
+				continue
+			}
+			v.reset(OpConst8)
+			v.AuxInt = int8ToAuxInt(-1)
+			return true
+		}
+		break
+	}
 	// match: (Xor8 (Const8 [-1]) x)
 	// result: (Com8 x)
 	for {