simplify-rtx.c (simplify_binary_operation): Check for overflow when folding…

simplify-rtx.c (simplify_binary_operation): Check for overflow when folding integer division and modulo operations.

2001-04-04  Diego Novillo  <dnovillo@redhat.com>

	* simplify-rtx.c (simplify_binary_operation): Check for overflow
	when folding integer division and modulo operations.

2001-04-04  Diego Novillo  <dnovillo@redhat.com>

	* gcc.c-torture/compile/20010404-1.c: New test.

From-SVN: r41105

gcc/ChangeLog

+2001-04-04  Diego Novillo  <dnovillo@redhat.com>
+
+	* simplify-rtx.c (simplify_binary_operation): Check for overflow
+	when folding integer division and modulo operations.
+
 2001-04-04  Andrew MacLeod  <amacleod@redhat.com>
 
 	* dwarf2out.c (output_cfi): Add 'for_eh' parameter, use PTR_SIZE 

gcc/simplify-rtx.c

@@ -1407,25 +1407,33 @@ simplify_binary_operation (code, mode, op0, op1)
       break;
 
     case DIV:
-      if (arg1s == 0)
+      if (arg1s == 0
+	  || (arg0s == (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT - 1)
+	      && arg1s == -1))
 	return 0;
       val = arg0s / arg1s;
       break;
 
     case MOD:
-      if (arg1s == 0)
+      if (arg1s == 0
+	  || (arg0s == (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT - 1)
+	      && arg1s == -1))
 	return 0;
       val = arg0s % arg1s;
       break;
 
     case UDIV:
-      if (arg1 == 0)
+      if (arg1 == 0
+	  || (arg0s == (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT - 1)
+	      && arg1s == -1))
 	return 0;
       val = (unsigned HOST_WIDE_INT) arg0 / arg1;
       break;
 
     case UMOD:
-      if (arg1 == 0)
+      if (arg1 == 0
+	  || (arg0s == (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT - 1)
+	      && arg1s == -1))
 	return 0;
       val = (unsigned HOST_WIDE_INT) arg0 % arg1;
       break;

gcc/testsuite/ChangeLog

+2001-04-04  Diego Novillo  <dnovillo@redhat.com>
+
+	* gcc.c-torture/compile/20010404-1.c: New test.
+
 2001-04-04  Jakub Jelinek  <jakub@redhat.com>
 
 	* gcc.c-torture/compile/20010326-1.c: New test.

gcc/testsuite/gcc.c-torture/compile/20010404-1.c

+/* This testcase caused a floating point exception in the compiler when
+   compiled with -O2. The crash occurs when trying to simplify division
+   and modulo operations.  */
+
+#include <limits.h>
+
+extern void bar (int);
+
+void foo ()
+{
+  int a = INT_MIN;
+  int b = -1;
+  bar (a / b);
+  bar (a % b);
+}