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# DP: 2004-09-26 Roger Sayle <roger@eyesopen.com>
# DP:
# DP: PR other/15526
# DP: Backport from mainline
# DP: 2004-05-20 Falk Hueffner <falk@debian.org>
# DP: * libgcc2.c (__mulvsi3): Fix overflow test.
diff -u -r1.170.6.1 -r1.170.6.2
--- gcc/gcc/libgcc2.c 2004/07/17 21:18:47 1.170.6.1
+++ gcc/gcc/libgcc2.c 2004/09/26 20:47:14 1.170.6.2
@@ -130,9 +130,7 @@
{
const DWtype w = (DWtype) a * (DWtype) b;
- if (((a >= 0) == (b >= 0))
- ? (UDWtype) w > (UDWtype) (((DWtype) 1 << (WORD_SIZE - 1)) - 1)
- : (UDWtype) w < (UDWtype) ((DWtype) -1 << (WORD_SIZE - 1)))
+ if ((Wtype) (w >> WORD_SIZE) != (Wtype) w >> (WORD_SIZE - 1))
abort ();
return w;
/cvs/gcc/gcc/gcc/testsuite/gcc.dg/ftrapv-1.c,v --> standard output
revision 1.1.22.1
--- gcc/gcc/testsuite/gcc.dg/ftrapv-1.c
+++ /dev/null 2004-10-15 06:22:06.980596000 +0000
@@ -0,0 +1,25 @@
+/* Copyright (C) 2004 Free Software Foundation.
+
+ PR other/15526
+ Verify correct overflow checking with -ftrapv.
+
+ Written by Falk Hueffner, 20th May 2004. */
+
+/* { dg-do run } */
+/* { dg-options "-ftrapv" } */
+
+__attribute__((noinline)) int
+mulv(int a, int b)
+{
+ return a * b;
+}
+
+int
+main()
+{
+ mulv( 0, 0);
+ mulv( 0, -1);
+ mulv(-1, 0);
+ mulv(-1, -1);
+ return 0;
+}
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