}
		}
	})
	return nil, nil
}

// checkLongShift checks if shift or shift-assign operations shift by more than
// the length of the underlying variable.
func checkLongShift(pass *analysis.Pass, node ast.Node, x, y ast.Expr) {
	if pass.TypesInfo.Types[x].Value != nil {
		// Ignore shifts of constants.
		// These are frequently used for bit-twiddling tricks

DATA shifts<>+0x28(SB)/4, $0xffffffff
DATA shifts<>+0x2c(SB)/4, $0xffffffff

DATA shifts<>+0x30(SB)/4, $0xff0f0e0d
DATA shifts<>+0x34(SB)/4, $0xffffffff
DATA shifts<>+0x38(SB)/4, $0xffffffff
DATA shifts<>+0x3c(SB)/4, $0xffffffff

DATA shifts<>+0x40(SB)/4, $0x0f0e0d0c
DATA shifts<>+0x44(SB)/4, $0xffffffff
DATA shifts<>+0x48(SB)/4, $0xffffffff
DATA shifts<>+0x4c(SB)/4, $0xffffffff

DATA shifts<>+0x58(SB)/8, $0xffffffffffffffff
DATA shifts<>+0x60(SB)/8, $0xffff0f0e0d0c0b0a
DATA shifts<>+0x68(SB)/8, $0xffffffffffffffff
DATA shifts<>+0x70(SB)/8, $0xff0f0e0d0c0b0a09
DATA shifts<>+0x78(SB)/8, $0xffffffffffffffff
DATA shifts<>+0x80(SB)/8, $0x0f0e0d0c0b0a0908
DATA shifts<>+0x88(SB)/8, $0xffffffffffffffff
DATA shifts<>+0x90(SB)/8, $0x0e0d0c0b0a090807
DATA shifts<>+0x98(SB)/8, $0xffffffffffffff0f

	if shift >= 0 && shift < 64 {
		// arm64:"LSL",-"CSEL"
		r1 = val64 << shift
	}
	if shift >= 0 && shift < 32 {
		// arm64:"LSL",-"CSEL"
		r2 = val32 << shift
	}
	if shift >= 0 && shift < 16 {
		// arm64:"LSL",-"CSEL"
		r3 = val16 << shift
	}
	if shift >= 0 && shift < 8 {
		// arm64:"LSL",-"CSEL"
		r4 = val8 << shift
	}
	return r1, r2, r3, r4

}

func sh32x64(n int32) int32 {
	if n < 0 {
		return n
	}
	return n >> uint64(31) // ERROR "Proved Rsh32x64 shifts to zero"
}

func sh16(n int16) int16 {
	if n < 0 {
		return n
	}
	return n >> 15 // ERROR "Proved Rsh16x64 shifts to zero"
}

func sh64noopt(n int64) int64 {
	return n >> 63 // not optimized; n could be negative
}

		// the compiler to generate better code for the shift operation.
		shift := uint(bits.TrailingZeros(uint(base))) & 7
		b := uint64(base)
		m := uint(base) - 1 // == 1<<shift - 1
		for u >= b {
			i--
			a[i] = digits[uint(u)&m]
			u >>= shift
		}
		// u < base
		i--
		a[i] = digits[uint(u)]
	} else {
		// general case
		b := uint64(base)
		for u >= b {
			i--

}

// Expand 48-bit input to 64-bit, with each 6-bit block padded by extra two bits at the top.
// By doing so, we can have the input blocks (four bits each), and the key blocks (six bits each) well-aligned without
// extra shifts/rotations for alignments.
func unpack(x uint64) uint64 {
	return ((x>>(6*1))&0xff)<<(8*0) |
		((x>>(6*3))&0xff)<<(8*1) |
		((x>>(6*5))&0xff)<<(8*2) |
		((x>>(6*7))&0xff)<<(8*3) |
		((x>>(6*0))&0xff)<<(8*4) |

(Rsh16x(64|32|16|8)  x y) && shiftIsBounded(v) => (SRAD (MOVHreg x) y)
(Rsh8x(64|32|16|8)   x y) && shiftIsBounded(v) => (SRAD (MOVBreg x) y)

// Unbounded shifts. Go shifts saturate to 0 or -1 when shifting beyond the number of
// bits in a type, PPC64 shifts do not (see the ISA for details).
//
// Note, y is always non-negative.
//

	case *Map:
		return "map"
	case *Chan:
		return "chan"
	default:
		return check.sprintf("%s", typ) // catch-all
	}
}

// If e != nil, it must be the shift expression; it may be nil for non-constant shifts.
func (check *Checker) shift(x, y *operand, e ast.Expr, op token.Token) {
	// TODO(gri) This function seems overly complex. Revisit.

	var xval constant.Value
	if x.mode == constant_ {

// Non-constant rotate detection.
// We use shiftIsBounded to make sure that neither of the shifts are >64.
// Note: these rules are subtle when the shift amounts are 0/64, as Go shifts
// are different from most native shifts. But it works out.