Rotate-left-32
- Signature
(rotate-left-32 x places) → *
- Arguments
- x — The bit vector to be rotated left.
- places — The number of places to rotate left.
Definitions and Theorems
Function: rotate-left-32$inline
(defun rotate-left-32$inline (x places)
(declare (type (unsigned-byte 32) x)
(type (unsigned-byte 32) places))
(let ((__function__ 'rotate-left-32))
(declare (ignorable __function__))
(mbe
:logic (rotate-left x 32 places)
:exec
(let*
((x (mbe :logic (loghead 32 x) :exec x))
(places (mbe :logic (lnfix places)
:exec places))
(places (mbe :logic (mod places 32)
:exec
(if (< places 32)
(the (integer 0 31) places)
(the (integer 0 31) (rem places 32)))))
(low-num (the (integer 0 32) (- 32 places)))
(mask (the (unsigned-byte 32)
(1- (the (unsigned-byte 33)
(ash 1 low-num)))))
(xl (the (unsigned-byte 32)
(logand x mask)))
(xh (the (unsigned-byte 32)
(logand x
(the (signed-byte 33) (lognot mask)))))
(xh-shift (the (unsigned-byte 32)
(ash xh (the (integer -32 0) (- low-num)))))
(xl-shift (the (unsigned-byte 32)
(ash (the (unsigned-byte 32) xl)
(the (integer 0 32) places))))
(ans (the (unsigned-byte 32)
(logior xl-shift xh-shift))))
ans))))
