From e62db923dcaecf03a28a92d86e2fe17d6b1c9f35 Mon Sep 17 00:00:00 2001 From: wlott <wlott> Date: Sun, 15 Aug 1993 14:51:17 +0000 Subject: [PATCH] Added transforms that flush (/ 0 foo), (floor 0 foo), etc. --- compiler/srctran.lisp | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/compiler/srctran.lisp b/compiler/srctran.lisp index b403d82ac..0ac14570b 100644 --- a/compiler/srctran.lisp +++ b/compiler/srctran.lisp @@ -7,7 +7,7 @@ ;;; Scott Fahlman or slisp-group@cs.cmu.edu. ;;; (ext:file-comment - "$Header: /Volumes/share2/src/cmucl/cvs2git/cvsroot/src/compiler/srctran.lisp,v 1.43 1993/05/25 21:29:18 wlott Exp $") + "$Header: /Volumes/share2/src/cmucl/cvs2git/cvsroot/src/compiler/srctran.lisp,v 1.44 1993/08/15 14:51:17 wlott Exp $") ;;; ;;; ********************************************************************** ;;; @@ -1052,7 +1052,6 @@ "fold identity operations" result))) - ;;; These are restricted to rationals, because (- 0 0.0) is 0.0, not -0.0, and ;;; (* 0 -4.0) is -0.0. ;;; @@ -1114,6 +1113,21 @@ (give-up)) (if (minusp val) minus-result result))))) + + +(dolist (name '(ash /)) + (deftransform name ((x y) '((constant-argument (integer 0 0)) integer) '* + :eval-name t :when :both) + "fold zero arg" + 0)) + +(dolist (name '(truncate round floor ceiling)) + (deftransform name ((x y) '((constant-argument (integer 0 0)) integer) '* + :eval-name t :when :both) + "fold zero arg" + '(values 0 0))) + + ;;;; Character operations: -- GitLab