From ec0109fe82032e869880728da5b026a89c64473f Mon Sep 17 00:00:00 2001
From: jakub <jakub@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Mon, 23 May 2011 10:24:47 +0000
Subject: [PATCH] 	PR middle-end/48973
 	* expr.c (expand_expr_real_2) <case LT_EXPR>: If do_store_flag
 	failed and the comparison has a single bit signed type, use
 	constm1_rtx instead of const1_rtx for true value.
 	(do_store_flag): If ops->type is single bit signed type, disable
 	signel bit test optimization and pass -1 instead of 1 as last
 	parameter to emit_store_flag_force.

	* gcc.c-torture/execute/pr48973-1.c: New test.
	* gcc.c-torture/execute/pr48973-2.c: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_6-branch@174063 138bc75d-0d04-0410-961f-82ee72b054a4

index 1de0ce4..9a81754 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -8134,7 +8134,10 @@ expand_expr_real_2 (sepops ops, rtx target, enum machine_mode tmode,
       op1 = gen_label_rtx ();
       jumpifnot_1 (code, treeop0, treeop1, op1, -1);
 
-      emit_move_insn (target, const1_rtx);
+      if (TYPE_PRECISION (type) == 1 && !TYPE_UNSIGNED (type))
+	emit_move_insn (target, constm1_rtx);
+      else
+	emit_move_insn (target, const1_rtx);
 
       emit_label (op1);
       return target;
@@ -10088,7 +10091,8 @@ do_store_flag (sepops ops, rtx target, enum machine_mode mode)
 
   if ((code == NE || code == EQ)
       && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
-      && integer_pow2p (TREE_OPERAND (arg0, 1)))
+      && integer_pow2p (TREE_OPERAND (arg0, 1))
+      && (TYPE_PRECISION (ops->type) != 1 || TYPE_UNSIGNED (ops->type)))
     {
       tree type = lang_hooks.types.type_for_mode (mode, unsignedp);
       return expand_expr (fold_single_bit_test (loc,
@@ -10108,7 +10112,9 @@ do_store_flag (sepops ops, rtx target, enum machine_mode mode)
 
   /* Try a cstore if possible.  */
   return emit_store_flag_force (target, code, op0, op1,
-			        operand_mode, unsignedp, 1);
+				operand_mode, unsignedp,
+				(TYPE_PRECISION (ops->type) == 1
+				 && !TYPE_UNSIGNED (ops->type)) ? -1 : 1);
 }
 
 
new file mode 100644
index 0000000..02688a0
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr48973-1.c
@@ -0,0 +1,20 @@
+/* PR middle-end/48973 */
+
+extern void abort (void);
+struct S { int f : 1; } s;
+int v = -1;
+
+void
+foo (unsigned int x)
+{
+  if (x != -1U)
+    abort ();
+}
+
+int
+main ()
+{
+  s.f = (v & 1) > 0;
+  foo (s.f);
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr48973-2.c b/gcc/testsuite/gcc.c-torture/execute/pr48973-2.c
new file mode 100644
index 0000000..a64d491
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr48973-2.c
@@ -0,0 +1,14 @@
+/* PR middle-end/48973 */
+
+extern void abort (void);
+struct S { int f : 1; } s;
+int v = -1;
+
+int
+main ()
+{
+  s.f = v < 0;
+  if ((unsigned int) s.f != -1U)
+    abort ();
+  return 0;
+}
-- 
1.7.0.4