From 9abd8e8b634af19867783e19c17b2ee7bf1d35d4 Mon Sep 17 00:00:00 2001
From: Jakub Jelinek <jakub@redhat.com>
Date: Sat, 17 Nov 2012 23:00:32 +0100
Subject: [PATCH] re PR tree-optimization/55236
 (gcc.c-torture/execute/pr22493-1.c FAILs with -fPIC)

	PR tree-optimization/55236
	* fold-const.c (make_range_step) <case NEGATE_EXPR>: For -fwrapv
	and signed ARG0_TYPE, force low and high to be non-NULL.

	* gcc.dg/pr55236.c: New test.

From-SVN: r193591
---
 gcc/ChangeLog                  |  6 ++++++
 gcc/fold-const.c               | 11 +++++++++++
 gcc/testsuite/ChangeLog        |  3 +++
 gcc/testsuite/gcc.dg/pr55236.c | 31 +++++++++++++++++++++++++++++++
 4 files changed, 51 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/pr55236.c

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index eb01532c656..935e3c0f908 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2012-11-17  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/55236
+	* fold-const.c (make_range_step) <case NEGATE_EXPR>: For -fwrapv
+	and signed ARG0_TYPE, force low and high to be non-NULL.
+
 2012-11-17  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* common.opt (static-libasan): New option.
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 2e908648451..56e0554737e 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -3880,6 +3880,17 @@ make_range_step (location_t loc, enum tree_code code, tree arg0, tree arg1,
       return arg0;
 
     case NEGATE_EXPR:
+      /* If flag_wrapv and ARG0_TYPE is signed, make sure
+	 low and high are non-NULL, then normalize will DTRT.  */
+      if (!TYPE_UNSIGNED (arg0_type)
+	  && !TYPE_OVERFLOW_UNDEFINED (arg0_type))
+	{
+	  if (low == NULL_TREE)
+	    low = TYPE_MIN_VALUE (arg0_type);
+	  if (high == NULL_TREE)
+	    high = TYPE_MAX_VALUE (arg0_type);
+	}
+
       /* (-x) IN [a,b] -> x in [-b, -a]  */
       n_low = range_binop (MINUS_EXPR, exp_type,
 			   build_int_cst (exp_type, 0),
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 955546e5a6e..245b6ef2a9e 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2012-11-17  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/55236
+	* gcc.dg/pr55236.c: New test.
+
 	PR testsuite/55188
 	* gcc.dg/pr19105.c: Accept also optimizing
 	-[2, 2] and -[3, 3] and -[4, 4] range tests together.
diff --git a/gcc/testsuite/gcc.dg/pr55236.c b/gcc/testsuite/gcc.dg/pr55236.c
new file mode 100644
index 00000000000..dc66c04c327
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr55236.c
@@ -0,0 +1,31 @@
+/* PR tree-optimization/55236 */
+/* { dg-do run } */
+/* { dg-options "-O2 -fwrapv" } */
+
+extern void abort ();
+
+__attribute__((noinline, noclone)) void
+foo (int i)
+{
+  if (i > 0)
+    abort ();
+  i = -i;
+  if (i < 0)
+    return;
+  abort ();
+}
+
+__attribute__((noinline, noclone)) void
+bar (int i)
+{
+  if (i > 0 || (-i) >= 0)
+    abort ();
+}
+
+int
+main ()
+{
+  foo (-__INT_MAX__ - 1);
+  bar (-__INT_MAX__ - 1);
+  return 0;
+}
-- 
2.30.2