2 files changed, 9 insertions, 9 deletions
diff --git a/src/cmd/asm/internal/arch/arm64.go b/src/cmd/asm/internal/arch/arm64.go
index 10458b01a0..0fc6c6a3ed 100644
--- a/src/cmd/asm/internal/arch/arm64.go
+++ b/src/cmd/asm/internal/arch/arm64.go
@@ -133,49 +133,49 @@ func ARM64RegisterExtension(a *obj.Addr, ext string, reg, num int16, isAmount, i
 		if !isAmount {
 			return errors.New("invalid register extension")
 		}
-		a.Reg = arm64.REG_UXTB + (reg & 31) + int16(num<<5)
+		a.Reg = arm64.REG_UXTB + (reg & 31) + num<<5
 		a.Offset = int64(((rm & 31) << 16) | (uint32(num) << 10))
 	case "UXTH":
 		if !isAmount {
 			return errors.New("invalid register extension")
 		}
-		a.Reg = arm64.REG_UXTH + (reg & 31) + int16(num<<5)
+		a.Reg = arm64.REG_UXTH + (reg & 31) + num<<5
 		a.Offset = int64(((rm & 31) << 16) | (1 << 13) | (uint32(num) << 10))
 	case "UXTW":
 		if !isAmount {
 			return errors.New("invalid register extension")
 		}
-		a.Reg = arm64.REG_UXTW + (reg & 31) + int16(num<<5)
+		a.Reg = arm64.REG_UXTW + (reg & 31) + num<<5
 		a.Offset = int64(((rm & 31) << 16) | (2 << 13) | (uint32(num) << 10))
 	case "UXTX":
 		if !isAmount {
 			return errors.New("invalid register extension")
 		}
-		a.Reg = arm64.REG_UXTX + (reg & 31) + int16(num<<5)
+		a.Reg = arm64.REG_UXTX + (reg & 31) + num<<5
 		a.Offset = int64(((rm & 31) << 16) | (3 << 13) | (uint32(num) << 10))
 	case "SXTB":
 		if !isAmount {
 			return errors.New("invalid register extension")
 		}
-		a.Reg = arm64.REG_SXTB + (reg & 31) + int16(num<<5)
+		a.Reg = arm64.REG_SXTB + (reg & 31) + num<<5
 		a.Offset = int64(((rm & 31) << 16) | (4 << 13) | (uint32(num) << 10))
 	case "SXTH":
 		if !isAmount {
 			return errors.New("invalid register extension")
 		}
-		a.Reg = arm64.REG_SXTH + (reg & 31) + int16(num<<5)
+		a.Reg = arm64.REG_SXTH + (reg & 31) + num<<5
 		a.Offset = int64(((rm & 31) << 16) | (5 << 13) | (uint32(num) << 10))
 	case "SXTW":
 		if !isAmount {
 			return errors.New("invalid register extension")
 		}
-		a.Reg = arm64.REG_SXTW + (reg & 31) + int16(num<<5)
+		a.Reg = arm64.REG_SXTW + (reg & 31) + num<<5
 		a.Offset = int64(((rm & 31) << 16) | (6 << 13) | (uint32(num) << 10))
 	case "SXTX":
 		if !isAmount {
 			return errors.New("invalid register extension")
 		}
-		a.Reg = arm64.REG_SXTX + (reg & 31) + int16(num<<5)
+		a.Reg = arm64.REG_SXTX + (reg & 31) + num<<5
 		a.Offset = int64(((rm & 31) << 16) | (7 << 13) | (uint32(num) << 10))
 	case "B8":
 		if isIndex {
diff --git a/src/cmd/asm/internal/asm/parse.go b/src/cmd/asm/internal/asm/parse.go
index 5a6a7b2db9..0c18613f52 100644
--- a/src/cmd/asm/internal/asm/parse.go
+++ b/src/cmd/asm/internal/asm/parse.go
@@ -585,7 +585,7 @@ func (p *Parser) registerShift(name string, prefix rune) int64 {
 		p.errorf("unexpected %s in register shift", tok.String())
 	}
 	if p.arch.Family == sys.ARM64 {
-		return int64(int64(r1&31)<<16 | int64(op)<<22 | int64(uint16(count)))
+		return int64(r1&31)<<16 | int64(op)<<22 | int64(uint16(count))
 	} else {
 		return int64((r1 & 15) | op<<5 | count)
 	}