diff options
Diffstat (limited to 'lisp/calc/calc-bin.el')
| -rw-r--r-- | lisp/calc/calc-bin.el | 38 |
1 files changed, 24 insertions, 14 deletions
diff --git a/lisp/calc/calc-bin.el b/lisp/calc/calc-bin.el index e9083b84c61..60dd17e5ed2 100644 --- a/lisp/calc/calc-bin.el +++ b/lisp/calc/calc-bin.el @@ -1,4 +1,4 @@ -;;; calc-bin.el --- binary functions for Calc +;;; calc-bin.el --- binary functions for Calc -*- lexical-binding:t -*- ;; Copyright (C) 1990-1993, 2001-2020 Free Software Foundation, Inc. @@ -126,8 +126,8 @@ (defun calc-word-size (n) (interactive "P") (calc-wrapper - (or n (setq n (read-string (format "Binary word size: (default %d) " - calc-word-size)))) + (or n (setq n (read-string (format-prompt "Binary word size" + calc-word-size)))) (setq n (if (stringp n) (if (equal n "") calc-word-size @@ -145,9 +145,10 @@ (setq math-half-2-word-size (math-power-of-2 (1- (math-abs n)))) (calc-do-refresh) (calc-refresh-evaltos) - (if (< n 0) - (message "Binary word size is %d bits (two's complement)" (- n)) - (message "Binary word size is %d bits" n)))) + (cond + ((< n 0) (message "Binary word size is %d bits (two's complement)" (- n))) + ((> n 0) (message "Binary word size is %d bits" n)) + (t (message "No fixed binary word size"))))) @@ -262,9 +263,10 @@ (defun math-binary-arg (a w) (if (not (Math-integerp a)) (setq a (math-trunc a))) - (if (< a 0) - (logand a (1- (ash 1 (if w (math-trunc w) calc-word-size)))) - a)) + (let ((w (if w (math-trunc w) calc-word-size))) + (if (and (< a 0) (not (zerop w))) + (logand a (1- (ash 1 w))) + a))) (defun math-binary-modulo-args (f a b w) (let (mod) @@ -285,7 +287,7 @@ (let ((bits (math-integer-log2 mod))) (if bits (if w - (if (/= w bits) + (if (and (/= w bits) (not (zerop w))) (calc-record-why "*Warning: Modulus inconsistent with word size")) (setq w bits)) @@ -371,11 +373,12 @@ (math-clip (calcFunc-lsh a n (- w)) w) (if (Math-integer-negp a) (setq a (math-clip a w))) - (cond ((or (Math-lessp n (- w)) - (Math-lessp w n)) + (cond ((and (or (Math-lessp n (- w)) + (Math-lessp w n)) + (not (zerop w))) 0) ((< n 0) - (math-quotient (math-clip a w) (math-power-of-2 (- n)))) + (ash (math-clip a w) n)) (t (math-clip (math-mul a (math-power-of-2 n)) w)))))) @@ -403,7 +406,8 @@ (setq a (math-clip a w))) (let ((two-to-sizem1 (math-power-of-2 (1- w))) (sh (calcFunc-lsh a n w))) - (cond ((Math-natnum-lessp a two-to-sizem1) + (cond ((or (zerop w) + (zerop (logand a two-to-sizem1))) sh) ((Math-lessp n (- 1 w)) (math-add (math-mul two-to-sizem1 2) -1)) @@ -421,6 +425,8 @@ (if (eq (car-safe a) 'mod) (math-binary-modulo-args 'calcFunc-rot a n w) (setq w (if w (math-trunc w) calc-word-size)) + (when (zerop w) + (error "Rotation requires a nonzero word size")) (or (integerp w) (math-reject-arg w 'fixnump)) (or (Math-integerp a) @@ -452,6 +458,8 @@ (if (Math-natnum-lessp a (math-power-of-2 (- -1 w))) a (math-sub a (math-power-of-2 (- w))))) + ((math-zerop w) + a) ((Math-negp a) (math-binary-arg a w)) ((integerp a) @@ -682,6 +690,8 @@ (defun math-format-twos-complement (a) "Format an integer in two's complement mode." + (when (zerop calc-word-size) + (error "Nonzero word size required")) (let* (;(calc-leading-zeros t) (num (cond |