diff --git a/src/cmd/compile/internal/ssa/gen/AMD64.rules b/src/cmd/compile/internal/ssa/gen/AMD64.rules
index 1d24d780c6..07981d2e81 100644
--- a/src/cmd/compile/internal/ssa/gen/AMD64.rules
+++ b/src/cmd/compile/internal/ssa/gen/AMD64.rules
@@ -1254,7 +1254,10 @@
 (CMPWconst (ANDLconst _ [m]) [n]) && 0 <= int16(m) && int16(m) < int16(n) -> (FlagLT_ULT)
 (CMPBconst (ANDLconst _ [m]) [n]) && 0 <= int8(m) && int8(m) < int8(n) -> (FlagLT_ULT)
 
-(TEST(Q|L)const [c] (MOV(Q|L)const [c])) -> (FlagEQ)
+// TESTQ c c sets flags like CMPQ c 0.
+(TEST(Q|L)const [c] (MOV(Q|L)const [c])) && c == 0 -> (FlagEQ)
+(TEST(Q|L)const [c] (MOV(Q|L)const [c])) && c < 0 -> (FlagLT_UGT)
+(TEST(Q|L)const [c] (MOV(Q|L)const [c])) && c > 0 -> (FlagGT_UGT)
 
 // TODO: DIVxU also.
 
diff --git a/src/cmd/compile/internal/ssa/rewriteAMD64.go b/src/cmd/compile/internal/ssa/rewriteAMD64.go
index bd1f4c08e2..16a3f64158 100644
--- a/src/cmd/compile/internal/ssa/rewriteAMD64.go
+++ b/src/cmd/compile/internal/ssa/rewriteAMD64.go
@@ -26562,15 +26562,38 @@ func rewriteValueAMD64_OpAMD64TESTL(v *Value) bool {
 func rewriteValueAMD64_OpAMD64TESTLconst(v *Value) bool {
 	v_0 := v.Args[0]
 	// match: (TESTLconst [c] (MOVLconst [c]))
+	// cond: c == 0
 	// result: (FlagEQ)
 	for {
 		c := v.AuxInt
-		if v_0.Op != OpAMD64MOVLconst || v_0.AuxInt != c {
+		if v_0.Op != OpAMD64MOVLconst || v_0.AuxInt != c || !(c == 0) {
 			break
 		}
 		v.reset(OpAMD64FlagEQ)
 		return true
 	}
+	// match: (TESTLconst [c] (MOVLconst [c]))
+	// cond: c < 0
+	// result: (FlagLT_UGT)
+	for {
+		c := v.AuxInt
+		if v_0.Op != OpAMD64MOVLconst || v_0.AuxInt != c || !(c < 0) {
+			break
+		}
+		v.reset(OpAMD64FlagLT_UGT)
+		return true
+	}
+	// match: (TESTLconst [c] (MOVLconst [c]))
+	// cond: c > 0
+	// result: (FlagGT_UGT)
+	for {
+		c := v.AuxInt
+		if v_0.Op != OpAMD64MOVLconst || v_0.AuxInt != c || !(c > 0) {
+			break
+		}
+		v.reset(OpAMD64FlagGT_UGT)
+		return true
+	}
 	// match: (TESTLconst [-1] x)
 	// cond: x.Op != OpAMD64MOVLconst
 	// result: (TESTL x x)
@@ -26644,15 +26667,38 @@ func rewriteValueAMD64_OpAMD64TESTQ(v *Value) bool {
 func rewriteValueAMD64_OpAMD64TESTQconst(v *Value) bool {
 	v_0 := v.Args[0]
 	// match: (TESTQconst [c] (MOVQconst [c]))
+	// cond: c == 0
 	// result: (FlagEQ)
 	for {
 		c := v.AuxInt
-		if v_0.Op != OpAMD64MOVQconst || v_0.AuxInt != c {
+		if v_0.Op != OpAMD64MOVQconst || v_0.AuxInt != c || !(c == 0) {
 			break
 		}
 		v.reset(OpAMD64FlagEQ)
 		return true
 	}
+	// match: (TESTQconst [c] (MOVQconst [c]))
+	// cond: c < 0
+	// result: (FlagLT_UGT)
+	for {
+		c := v.AuxInt
+		if v_0.Op != OpAMD64MOVQconst || v_0.AuxInt != c || !(c < 0) {
+			break
+		}
+		v.reset(OpAMD64FlagLT_UGT)
+		return true
+	}
+	// match: (TESTQconst [c] (MOVQconst [c]))
+	// cond: c > 0
+	// result: (FlagGT_UGT)
+	for {
+		c := v.AuxInt
+		if v_0.Op != OpAMD64MOVQconst || v_0.AuxInt != c || !(c > 0) {
+			break
+		}
+		v.reset(OpAMD64FlagGT_UGT)
+		return true
+	}
 	// match: (TESTQconst [-1] x)
 	// cond: x.Op != OpAMD64MOVQconst
 	// result: (TESTQ x x)