diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 0dc2ec55301..b8636653e47 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2007-03-26  Ian Lance Taylor  <iant@google.com>
+
+	PR tree-optimization/31345
+	* tree-vrp.c (extract_range_from_binary_expr): Turn ranges like
+	[+INF, +INF(OVF)] into VARYING.
+
 2007-03-26  Zack Weinberg  <zackw@panix.com>
 
 	* gengtype-parse.c: New file.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index d9fa3447051..7ba80be07d9 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2007-03-26  Ian Lance Taylor  <iant@google.com>
+
+	PR tree-optimization/31345
+	* gcc.c-torture/compile/pr31345-1.c: New test.
+
 2007-03-26  Brooks Moses  <brooks.moses@codesourcery.com>
 
 	* gfortran.dg/func_derived_4.f90: Fix module cleanup.
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr31345-1.c b/gcc/testsuite/gcc.c-torture/compile/pr31345-1.c
new file mode 100644
index 00000000000..fb4d8034c55
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr31345-1.c
@@ -0,0 +1,24 @@
+/* PR tree-optimization/31345
+   This caused a crash in VRP when dealing with overflow infinities.  */
+
+void
+dpsnaffle (const char *kbuf)
+{
+  int hash, thash, head[2], off;
+    {
+      int _DP_i;
+      (hash) = 19780211;
+        {
+          (hash) = (hash) + (kbuf)[_DP_i];
+        }
+      (hash) = ((hash) * 43321879) & 0x7FFFFFFF;
+    }
+  while (off != 0)
+    {
+      if (hash > thash) {}
+      else if (hash < thash)
+        {
+          off = head[2];
+        }
+    }
+}
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index 262eeb2e37e..3b7358dc032 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -1982,10 +1982,18 @@ extract_range_from_binary_expr (value_range_t *vr, tree expr)
       return;
     }
 
+  /* We punt if:
+     1) [-INF, +INF]
+     2) [-INF, +-INF(OVF)]
+     3) [+-INF(OVF), +INF]
+     4) [+-INF(OVF), +-INF(OVF)]
+     We learn nothing when we have INF and INF(OVF) on both sides.
+     Note that we do accept [-INF, -INF] and [+INF, +INF] without
+     overflow.  */
   if ((min == TYPE_MIN_VALUE (TREE_TYPE (min))
-       || is_negative_overflow_infinity (min))
+       || is_overflow_infinity (min))
       && (max == TYPE_MAX_VALUE (TREE_TYPE (max))
-	  || is_positive_overflow_infinity (max)))
+	  || is_overflow_infinity (max)))
     {
       set_value_range_to_varying (vr);
       return;