BFX	$12, $41, R2, R3   // ERROR "wrong width or LSB"
	BFX	$12, $-2, R2       // ERROR "wrong width or LSB"
	BFXU	$40, $4, R2, R3    // ERROR "wrong width or LSB"
	BFXU	$-40, $4, R2       // ERROR "wrong width or LSB"
	BFX	$-2, $4, R2, R3    // ERROR "wrong width or LSB"
	BFXU	$4, R2, R5, R2     // ERROR "missing or wrong LSB"
	BFXU	$4, R2, R5         // ERROR "missing or wrong LSB"
	BFC	$12, $8, R2, R3    // ERROR "illegal combination"

		return true
	}
	return false
}

// IsARMBFX reports whether the op (as defined by an arm.A* constant) is one the
// BFX-like instructions which are in the form of "op $width, $LSB, (Reg,) Reg".
func IsARMBFX(op obj.As) bool {
	switch op {
	case arm.ABFX, arm.ABFXU, arm.ABFC, arm.ABFI:
		return true
	}
	return false
}