2014-06-16 Richard Biener <rguenther@suse.de>

	PR tree-optimization/61482
	* tree-vrp.c (adjust_range_with_scev): Avoid setting of
	[-INF(OVF), +INF(OVF)] range.

	* g++.dg/torture/pr61482.C: New testcase.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@211709 138bc75d-0d04-0410-961f-82ee72b054a4

4 files changed, 52 insertions, 17 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 244d354955d..786ed0cc832 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2014-06-16  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/61482
+	* tree-vrp.c (adjust_range_with_scev): Avoid setting of
+	[-INF(OVF), +INF(OVF)] range.
+
 2014-06-16  Ganesh Gopalasubramanian <Ganesh.Gopalasubramanian@amd.com>
 
 	* config/i386/i386.c (ix86_expand_sse2_mulvxdi3): Issue
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index b417245646a..d6a3dd3c7e0 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2014-06-16  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/61482
+	* g++.dg/torture/pr61482.C: New testcase.
+
 2014-06-16 Ganesh Gopalasubramanian  <Ganesh.Gopalasubramanian@amd.com>
 
 	* gcc.target/i386/xop-imul64-vector.c: Remove the check for
diff --git a/gcc/testsuite/g++.dg/torture/pr61482.C b/gcc/testsuite/g++.dg/torture/pr61482.C
new file mode 100644
index 00000000000..1e186cc5ed6
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr61482.C
@@ -0,0 +1,29 @@
+// { dg-do compile }
+
+class A
+{
+public:
+    int m_fn1 ();
+};
+class B
+{
+  void m_fn2 (const int &p1);
+  A mThebesLayerDataStack;
+};
+int b, c;
+void B::m_fn2 (const int &p1)
+{
+  if (c && b)
+    {
+      int i;
+      i = mThebesLayerDataStack.m_fn1 ();
+      for (; i >= 0;)
+	{
+	  ++i;
+	  break;
+	}
+      --i;
+      for (; i >= 0; --i)
+	mThebesLayerDataStack.m_fn1 ();
+    }
+}
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index 428e622a217..b657546a3d7 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -3892,15 +3892,6 @@ adjust_range_with_scev (value_range_t *vr, struct loop *loop,
 	max = init;
       else
 	min = init;
-
-      /* If we would create an invalid range, then just assume we
-	 know absolutely nothing.  This may be over-conservative,
-	 but it's clearly safe, and should happen only in unreachable
-         parts of code, or for invalid programs.  */
-      if (compare_values (min, max) == 1)
-	return;
-
-      set_value_range (vr, VR_RANGE, min, max, vr->equiv);
     }
   else if (vr->type == VR_RANGE)
     {
@@ -3933,16 +3924,20 @@ adjust_range_with_scev (value_range_t *vr, struct loop *loop,
 	      || compare_values (tmax, max) == -1)
 	    max = tmax;
 	}
+    }
+  else
+    return;
 
-      /* If we just created an invalid range with the minimum
-	 greater than the maximum, we fail conservatively.
-	 This should happen only in unreachable
-	 parts of code, or for invalid programs.  */
-      if (compare_values (min, max) == 1)
-	return;
+  /* If we just created an invalid range with the minimum
+     greater than the maximum, we fail conservatively.
+     This should happen only in unreachable
+     parts of code, or for invalid programs.  */
+  if (compare_values (min, max) == 1
+      || (is_negative_overflow_infinity (min)
+	  && is_positive_overflow_infinity (max)))
+    return;
 
-      set_value_range (vr, VR_RANGE, min, max, vr->equiv);
-    }
+  set_value_range (vr, VR_RANGE, min, max, vr->equiv);
 }