diff --git a/src/cmd/compile/internal/ssa/_gen/LOONG64.rules b/src/cmd/compile/internal/ssa/_gen/LOONG64.rules
index cab63a503f3..e81377d87d1 100644
--- a/src/cmd/compile/internal/ssa/_gen/LOONG64.rules
+++ b/src/cmd/compile/internal/ssa/_gen/LOONG64.rules
@@ -843,6 +843,14 @@
 
 (MOVBUreg (ANDconst [c] x)) => (ANDconst [c&0xff] x)
 
+// Avoid extending when already sufficiently masked.
+(MOVBreg  x:(ANDconst [c] y)) && c >= 0 && int64(int8(c)) == c => x
+(MOVHreg  x:(ANDconst [c] y)) && c >= 0 && int64(int16(c)) == c => x
+(MOVWreg  x:(ANDconst [c] y)) && c >= 0 && int64(int32(c)) == c => x
+(MOVBUreg x:(ANDconst [c] y)) && c >= 0 && int64(uint8(c)) == c => x
+(MOVHUreg x:(ANDconst [c] y)) && c >= 0 && int64(uint16(c)) == c => x
+(MOVWUreg x:(ANDconst [c] y)) && c >= 0 && int64(uint32(c)) == c => x
+
 // Prefetch instructions (hint specified using aux field)
 // For PRELD{,X} A value of hint indicates:
 //    hint=0 is defined as load prefetch to L1-cache
diff --git a/src/cmd/compile/internal/ssa/rewriteLOONG64.go b/src/cmd/compile/internal/ssa/rewriteLOONG64.go
index 7c46ed77272..8599725b901 100644
--- a/src/cmd/compile/internal/ssa/rewriteLOONG64.go
+++ b/src/cmd/compile/internal/ssa/rewriteLOONG64.go
@@ -2378,6 +2378,21 @@ func rewriteValueLOONG64_OpLOONG64MOVBUreg(v *Value) bool {
 		v.AddArg(x)
 		return true
 	}
+	// match: (MOVBUreg x:(ANDconst [c] y))
+	// cond: c >= 0 && int64(uint8(c)) == c
+	// result: x
+	for {
+		x := v_0
+		if x.Op != OpLOONG64ANDconst {
+			break
+		}
+		c := auxIntToInt64(x.AuxInt)
+		if !(c >= 0 && int64(uint8(c)) == c) {
+			break
+		}
+		v.copyOf(x)
+		return true
+	}
 	return false
 }
 func rewriteValueLOONG64_OpLOONG64MOVBload(v *Value) bool {
@@ -2526,6 +2541,21 @@ func rewriteValueLOONG64_OpLOONG64MOVBreg(v *Value) bool {
 		v.AuxInt = int64ToAuxInt(int64(int8(c)))
 		return true
 	}
+	// match: (MOVBreg x:(ANDconst [c] y))
+	// cond: c >= 0 && int64(int8(c)) == c
+	// result: x
+	for {
+		x := v_0
+		if x.Op != OpLOONG64ANDconst {
+			break
+		}
+		c := auxIntToInt64(x.AuxInt)
+		if !(c >= 0 && int64(int8(c)) == c) {
+			break
+		}
+		v.copyOf(x)
+		return true
+	}
 	return false
 }
 func rewriteValueLOONG64_OpLOONG64MOVBstore(v *Value) bool {
@@ -3614,6 +3644,21 @@ func rewriteValueLOONG64_OpLOONG64MOVHUreg(v *Value) bool {
 		v.AuxInt = int64ToAuxInt(int64(uint16(c)))
 		return true
 	}
+	// match: (MOVHUreg x:(ANDconst [c] y))
+	// cond: c >= 0 && int64(uint16(c)) == c
+	// result: x
+	for {
+		x := v_0
+		if x.Op != OpLOONG64ANDconst {
+			break
+		}
+		c := auxIntToInt64(x.AuxInt)
+		if !(c >= 0 && int64(uint16(c)) == c) {
+			break
+		}
+		v.copyOf(x)
+		return true
+	}
 	return false
 }
 func rewriteValueLOONG64_OpLOONG64MOVHload(v *Value) bool {
@@ -3806,6 +3851,21 @@ func rewriteValueLOONG64_OpLOONG64MOVHreg(v *Value) bool {
 		v.AuxInt = int64ToAuxInt(int64(int16(c)))
 		return true
 	}
+	// match: (MOVHreg x:(ANDconst [c] y))
+	// cond: c >= 0 && int64(int16(c)) == c
+	// result: x
+	for {
+		x := v_0
+		if x.Op != OpLOONG64ANDconst {
+			break
+		}
+		c := auxIntToInt64(x.AuxInt)
+		if !(c >= 0 && int64(int16(c)) == c) {
+			break
+		}
+		v.copyOf(x)
+		return true
+	}
 	return false
 }
 func rewriteValueLOONG64_OpLOONG64MOVHstore(v *Value) bool {
@@ -4821,6 +4881,21 @@ func rewriteValueLOONG64_OpLOONG64MOVWUreg(v *Value) bool {
 		v.AuxInt = int64ToAuxInt(int64(uint32(c)))
 		return true
 	}
+	// match: (MOVWUreg x:(ANDconst [c] y))
+	// cond: c >= 0 && int64(uint32(c)) == c
+	// result: x
+	for {
+		x := v_0
+		if x.Op != OpLOONG64ANDconst {
+			break
+		}
+		c := auxIntToInt64(x.AuxInt)
+		if !(c >= 0 && int64(uint32(c)) == c) {
+			break
+		}
+		v.copyOf(x)
+		return true
+	}
 	return false
 }
 func rewriteValueLOONG64_OpLOONG64MOVWload(v *Value) bool {
@@ -5046,6 +5121,21 @@ func rewriteValueLOONG64_OpLOONG64MOVWreg(v *Value) bool {
 		v.AuxInt = int64ToAuxInt(int64(int32(c)))
 		return true
 	}
+	// match: (MOVWreg x:(ANDconst [c] y))
+	// cond: c >= 0 && int64(int32(c)) == c
+	// result: x
+	for {
+		x := v_0
+		if x.Op != OpLOONG64ANDconst {
+			break
+		}
+		c := auxIntToInt64(x.AuxInt)
+		if !(c >= 0 && int64(int32(c)) == c) {
+			break
+		}
+		v.copyOf(x)
+		return true
+	}
 	return false
 }
 func rewriteValueLOONG64_OpLOONG64MOVWstore(v *Value) bool {