PR other/15526

	* libgcc2.c (__mulvsi3): Fix overflow test.
	* gcc.dg/ftrapv-1.c: New test case.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@82042 138bc75d-0d04-0410-961f-82ee72b054a4

4 files changed, 36 insertions, 3 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 54e328a560e..6cc921fc091 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2004-05-20  Falk Hueffner  <falk@debian.org>
+
+	PR other/15526
+	* libgcc2.c (__mulvsi3): Fix overflow test.
+
 2004-05-19  Andrew Pinski  <pinskia@physics.uc.edu>
 
 	PR c/14171
diff --git a/gcc/libgcc2.c b/gcc/libgcc2.c
index 34171ad9002..8a953ea8b76 100644
--- a/gcc/libgcc2.c
+++ b/gcc/libgcc2.c
@@ -130,9 +130,7 @@ __mulvsi3 (Wtype a, Wtype b)
 {
   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;
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 92437ffdcc2..c716a323162 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2004-05-20  Falk Hueffner  <falk@debian.org>
+
+	PR other/15526
+	* gcc.dg/ftrapv-1.c: New test case.
+
 2004-05-18  Feng Wang  <fengwang@nudt.edu.cn>
 
 	* gfortran.fortran-torture/execute/power.f90: Test constant integers.
diff --git a/gcc/testsuite/gcc.dg/ftrapv-1.c b/gcc/testsuite/gcc.dg/ftrapv-1.c
new file mode 100644
index 00000000000..44eb176b50d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ftrapv-1.c
@@ -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;
+}