re PR bootstrap/61583 (stage2 and stage3 compare failure due to value range loss)

gcc/
	PR bootstrap/61583
	* tree-vrp.c (remove_range_assertions): Do not set is_unreachable
	to zero on debug statements.
gcc/testsuite/
	* gcc.dg/pr61583.c: New.

From-SVN: r211897

gcc/ChangeLog

+2014-06-23  Alan Modra  <amodra@gmail.com>
+
+	PR bootstrap/61583
+	* tree-vrp.c (remove_range_assertions): Do not set is_unreachable
+	to zero on debug statements.
+
 2014-06-19  Alan Lawrence  <alan.lawrence@arm.com>
 
 	PR target/60825

gcc/testsuite/ChangeLog

+2014-06-23  Alan Modra  <amodra@gmail.com>
+
+	* gcc.dg/pr61583.c: New.
+
 2014-06-19  Alan Lawrence  <alan.lawrence@arm.com>
 
 	* g++.dg/abi/mangle-neon-aarch64.C (f22, f23): New tests of

gcc/testsuite/gcc.dg/pr61583.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fcompare-debug" } */
+
+void
+f1 (int n, int b)
+{
+  extern void f2 (int);
+  int j;
+
+  if (b)
+    n = 1;
+
+  if (n < 1)
+    __builtin_unreachable ();
+
+  for (j = 0; j < n; j++)
+    f2 (j);
+}

gcc/tree-vrp.c

@@ -6523,8 +6523,9 @@ remove_range_assertions (void)
 	  }
 	else
 	  {
-	    gsi_next (&si);
+	    if (!is_gimple_debug (gsi_stmt (si)))
 	      is_unreachable = 0;
+	    gsi_next (&si);
 	  }
       }
 }