Fixed bug when open-coded predicate is used in expression position and

the predicate can be tested at compile time.  No longer generates a
useless true (/false) branch that confuses the rgraph stuff.

diff --git a/v8/src/compiler/midend/rtlgen.scm b/v8/src/compiler/midend/rtlgen.scm
index aec1158ba9d7c3396e81908e74a12aa5cce2b589..b48cbaab1dbbc24317dc901ccc41d62b07351164 100644 (file)
--- a/v8/src/compiler/midend/rtlgen.scm
+++ b/v8/src/compiler/midend/rtlgen.scm
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Id: rtlgen.scm,v 1.9 1995/01/28 02:42:01 adams Exp $
+$Id: rtlgen.scm,v 1.10 1995/01/28 17:10:56 adams Exp $
 
 Copyright (c) 1994 Massachusetts Institute of Technology
 
@@ -1595,11 +1595,13 @@ MIT in each case. |#
 \f
 (define (rtlgen/branch/true state)
   (let ((cont (rtlgen/state/expr/target state)))
-    (rtlgen/emit!/1 `(JUMP ,(rtlgen/reference-true-label! cont)))))
+    (rtlgen/emit!/1 `(JUMP ,(rtlgen/reference-true-label! cont))))
+  false)
 
 (define (rtlgen/branch/false state)
   (let ((cont (rtlgen/state/expr/target state)))
-    (rtlgen/emit!/1 `(JUMP ,(rtlgen/reference-false-label! cont)))))
+    (rtlgen/emit!/1 `(JUMP ,(rtlgen/reference-false-label! cont))))
+  false)
 
 (define (rtlgen/branch/likely state predicate)
   (let ((cont (rtlgen/state/expr/target state)))
@@ -2830,21 +2832,34 @@ MIT in each case. |#
                       (internal-error "Unexpected value target" target
                                       (rtlgen/open-coder/rator
                                        open-coder))))))
-      (let ((merge-label (rtlgen/new-name 'MERGE))
-           (true-label  (rtlgen/new-name 'TRUE))
-           (false-label (rtlgen/new-name 'FALSE)))
-       (handler (rtlgen/state/->expr
-                 state
-                 `(PREDICATE ,(list true-label 0) ,(list false-label 0)))
+      (let* ((true-label  (rtlgen/new-name 'TRUE))
+            (false-label (rtlgen/new-name 'FALSE))
+            (tl          (list true-label 0))
+            (fl          (list false-label 0)))
+       (handler (rtlgen/state/->expr  state  `(PREDICATE ,tl ,fl))
                 rands open-coder)
-       (rtlgen/assign!*
-        `((LABEL ,true-label)
-          (ASSIGN ,target* (CONSTANT ,#t))
-          (JUMP ,merge-label)
-          (LABEL ,false-label)
-          (ASSIGN ,target* (CONSTANT ,#f))
-          (LABEL ,merge-label)))
-       target*))))
+       (let ((true-label-taken?   (not (zero? (cadr tl))))
+             (false-label-taken?  (not (zero? (cadr fl)))))
+         (cond ((and true-label-taken? false-label-taken?)
+                (let ((merge-label  (rtlgen/new-name 'MERGE)))
+                  (rtlgen/assign!*
+                   `((LABEL ,true-label)
+                     (ASSIGN ,target* (CONSTANT ,#t))
+                     (JUMP ,merge-label)
+                     (LABEL ,false-label)
+                     (ASSIGN ,target* (CONSTANT ,#f))
+                     (LABEL ,merge-label)))))
+               (true-label-taken?
+                (rtlgen/assign!* `((LABEL ,true-label)
+                                   (ASSIGN ,target* (CONSTANT ,#T)))))
+               (false-label-taken?
+                (rtlgen/assign!* `((LABEL ,false-label)
+                                   (ASSIGN ,target* (CONSTANT ,#F)))))
+               (else
+                (internal-error "Neither branch taken"
+                                (rtlgen/open-coder/rator open-coder)
+                                rands)))))
+      target*)))
 
 (define (rtlgen/value->pred handler)
   (lambda (state rands open-coder)