tree-vrp.c (get_single_symbol): New function.

	* tree-vrp.c (get_single_symbol): New function.
	(build_symbolic_expr): Likewise.
	(symbolic_range_based_on_p): New predicate.
	(extract_range_from_binary_expr_1): Deal with single-symbolic ranges
	for PLUS and MINUS.  Do not drop symbolic ranges at the end.
	(extract_range_from_binary_expr): Try harder for PLUS and MINUS if
	operand is symbolic and based on the other operand.

From-SVN: r215697

gcc/ChangeLog

+2014-09-29  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* tree-vrp.c (get_single_symbol): New function.
+	(build_symbolic_expr): Likewise.
+	(symbolic_range_based_on_p): New predicate.
+	(extract_range_from_binary_expr_1): Deal with single-symbolic ranges
+	for PLUS and MINUS.  Do not drop symbolic ranges at the end.
+	(extract_range_from_binary_expr): Try harder for PLUS and MINUS if
+	operand is symbolic and based on the other operand.
+
 2014-09-29  Chen Gang  <gang.chen.5i5j@gmail.com>
 
 	* config/microblaze/microblaze.md (call_internal1): Use VOID

gcc/testsuite/ChangeLog

+2014-09-29  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gcc.dg/tree-ssa/vrp94.c: New test.
+	* gnat.dg/opt40.adb: Likewise.
+
 2014-09-29  Bill Schmidt  <wschmidt@vnet.linux.ibm.com>
 
 	* gcc.dg/vmx/ops.c: Remove calls to vec_splat, vec_vsplth,

gcc/testsuite/gcc.dg/tree-ssa/vrp94.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+extern void abort (void);
+
+int
+foo1 (int x, int y)
+{
+  int z;
+
+  if (x >= y)
+    return 1;
+
+  z = y - x;
+  if (z <= 0)
+    abort ();
+
+  return z;
+}
+
+unsigned int
+foo2 (unsigned int x, unsigned int y)
+{
+  unsigned int z;
+
+  if (x >= y)
+    return 1;
+
+  z = y - x;
+  if (z == 0)
+    abort ();
+
+  return z;
+}
+
+/* { dg-final { scan-tree-dump-not "abort" "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */

gcc/testsuite/gnat.dg/opt40.adb

+-- { dg-do compile }
+-- { dg-options "-O2 -fdump-tree-optimized" }
+
+pragma Suppress (Overflow_Check);
+
+function Opt40 (X : Integer; Y : Integer) return Positive is
+   Z : Integer;
+begin
+   if X >= Y then
+      return 1;
+   end if;
+   Z := Y - X;
+   return Z;
+end;
+
+-- { dg-final { scan-tree-dump-not "gnat_rcheck" "optimized" } }
+-- { dg-final { cleanup-tree-dump "optimized" } }