From: Guillermo J. Rozas <edu/mit/csail/zurich/gjr>
Date: Tue, 18 Feb 1992 22:57:48 +0000 (+0000)
Subject: Remove rewriting rules for FLONUM-ASIN and FLONUM-ACOS.  They cannot
X-Git-Tag: 20090517-FFI~9681
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=32fd2ec8a1efbe64de4195b914cf9cbd474928f0;p=mit-scheme.git

Remove rewriting rules for FLONUM-ASIN and FLONUM-ACOS.  They cannot
be done in quite this way now.
---

diff --git a/v7/src/compiler/machines/i386/rulrew.scm b/v7/src/compiler/machines/i386/rulrew.scm
index 6bc5f3efe..e0ebdd3f2 100644
--- a/v7/src/compiler/machines/i386/rulrew.scm
+++ b/v7/src/compiler/machines/i386/rulrew.scm
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/compiler/machines/i386/rulrew.scm,v 1.8 1992/02/18 21:57:31 jinx Exp $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/compiler/machines/i386/rulrew.scm,v 1.9 1992/02/18 22:57:48 jinx Exp $
 $MC68020-Header: /scheme/src/compiler/machines/bobcat/RCS/rulrew.scm,v 1.4 1991/10/25 06:50:06 cph Exp $
 
 Copyright (c) 1992 Massachusetts Institute of Technology
@@ -260,10 +260,15 @@ MIT in each case. |#
   (QUALIFIER (rtl:constant-flonum-test operand-1 flo:zero?))
   (list 'FLONUM-PRED-2-ARGS predicate operand-1 operand-2))
 
+#|
+;; These don't work as written.  They are not simplified and are
+;; therefore passed whole to the back end, and there is no way to
+;; construct the graph at this level.
+
 ;; acos (x) = atan ((sqrt (1 - x^2)) / x)
 
 (define-rule add-pre-cse-rewriting-rule!
-  (FLONUM-1-ARG FLONUM-ACOS (register (? operand)))
+  (FLONUM-1-ARG FLONUM-ACOS (? operand) #f)
   (rtl:make-flonum-2-args
    'FLONUM-ATAN2
    (rtl:make-flonum-1-arg
@@ -280,7 +285,7 @@ MIT in each case. |#
 ;; asin (x) = atan (x / (sqrt (1 - x^2)))
 
 (define-rule add-pre-cse-rewriting-rule!
-  (FLONUM-1-ARG FLONUM-ASIN (register (? operand)))
+  (FLONUM-1-ARG FLONUM-ASIN (? operand) #f)
   (rtl:make-flonum-2-args
    'FLONUM-ATAN2
    operand
@@ -294,6 +299,8 @@ MIT in each case. |#
     false)
    false))
 
+|#
+
 (define (rtl:constant-flonum-test expression predicate)
   (and (rtl:object->float? expression)
        (let ((expression (rtl:object->float-expression expression)))