Fixed gcc (upstream patch) to not optimize abs() moving negative multipliers inside

17 years ago · d32f7ff958
1 changed files with 62 additions and 0 deletions
--- a/base/gcc/extract_muldiv.patch
+++ b/base/gcc/extract_muldiv.patch
@ -0,0 +1,62 @@
+# --- SDE-COPYRIGHT-NOTE-BEGIN ---
+# This copyright note is auto-generated by ./scripts/Create-CopyPatch.
+# 
+# Filename: package/.../gcc/extract_muldiv.patch
+# Copyright (C) 2007 The OpenSDE Project
+# 
+# More information can be found in the files COPYING and README.
+# 
+# This patch file is dual-licensed. It is available under the license the
+# patched project is licensed under, as long as it is an OpenSource license
+# as defined at http://www.opensource.org/ (e.g. BSD, X11) or under the terms
+# of the GNU General Public License as published by the Free Software
+# Foundation; either version 2 of the License, or (at your option) any later
+# version.
+# --- SDE-COPYRIGHT-NOTE-END ---
+
+Take from http://gcc.gnu.org/ml/gcc-patches/2007-11/msg00948.html
+
+2007-11-17  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/34130
+	* fold-const.c (extract_muldiv_1): Do not move negative
+	constants inside ABS_EXPR.
+
+	* gcc.c-torture/execute/pr34130.c: New testcase.
+
+Index: ./gcc/fold-const.c
+===================================================================
+*** ./gcc/fold-const.c	(revision 130238)
+--- ./gcc/fold-const.c	(working copy)
+*************** extract_muldiv_1 (tree t, tree c, enum t
+*** 6095,6100 ****
+--- 6095,6103 ----
+              }
+            break;
+          }
+       /* If the constant is negative, we cannot simplify this.  */
+       if (tree_int_cst_sgn (c) == -1)
+         break;
+        /* FALLTHROUGH */
+      case NEGATE_EXPR:
+        if ((t1 = extract_muldiv (op0, c, code, wide_type, strict_overflow_p))
+Index: ./gcc/testsuite/gcc.c-torture/execute/pr34130.c
+===================================================================
+*** ./gcc/testsuite/gcc.c-torture/execute/pr34130.c	(revision 0)
+--- ./gcc/testsuite/gcc.c-torture/execute/pr34130.c	(revision 0)
+***************
+*** 0 ****
+--- 1,12 ----
+ extern void abort (void);
+ int foo (int i)
+ {
+   return -2 * __builtin_abs(i - 2);
+ }
+ int main()
+ {
+   if (foo(1) != -2
+       || foo(3) != -2)
+     abort ();
+   return 0;
+ }
+