From: Jakub Jelinek <jakub@redhat.com>
Date: Wed, 22 Oct 2008 18:21:55 +0000 (+0200)
Subject: re PR middle-end/37882 (Bitfield miscompilation)
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=972afb58199cd9228dbf974fe0fbd698b430550e;p=gcc.git

re PR middle-end/37882 (Bitfield miscompilation)

	PR middle-end/37882
	* fold-const.c (build_range_type): For 1 .. signed_max
	range call build_nonstandard_inter_type if signed_type_for
	returned a type with bigger precision.

	* gcc.c-torture/execute/pr37882.c: New test.

From-SVN: r141303
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 484e34014c9..f206c700607 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2008-10-22  Jakub Jelinek  <jakub@redhat.com>
+
+	PR middle-end/37882
+	* fold-const.c (build_range_type): For 1 .. signed_max
+	range call build_nonstandard_inter_type if signed_type_for
+	returned a type with bigger precision.
+
 2008-10-22  Richard Guenther  <rguenther@suse.de>
 
 	* tree.def (COMPLEX_TYPE): Constrain element type.
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 605caa812e0..88e70d6d5fa 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -4503,7 +4503,12 @@ build_range_check (tree type, tree exp, int in_p, tree low, tree high)
 	{
 	  if (TYPE_UNSIGNED (etype))
 	    {
-	      etype = signed_type_for (etype);
+	      tree signed_etype = signed_type_for (etype);
+	      if (TYPE_PRECISION (signed_etype) != TYPE_PRECISION (etype))
+		etype
+		  = build_nonstandard_integer_type (TYPE_PRECISION (etype), 0);
+	      else
+		etype = signed_etype;
 	      exp = fold_convert (etype, exp);
 	    }
 	  return fold_build2 (GT_EXPR, type, exp,
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 76fc9db49ac..2db299781f3 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2008-10-22  Jakub Jelinek  <jakub@redhat.com>
+
+	PR middle-end/37882
+	* gcc.c-torture/execute/pr37882.c: New test.
+
 2008-10-22  Manuel López-Ibáñez  <manu@gcc.gnu.org>
 
 	PR c/30949
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr37882.c b/gcc/testsuite/gcc.c-torture/execute/pr37882.c
new file mode 100644
index 00000000000..4a2affa0e58
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr37882.c
@@ -0,0 +1,16 @@
+/* PR middle-end/37882 */
+
+struct S
+{
+  int a : 21;
+  unsigned char b : 3;
+} s;
+
+int
+main ()
+{
+  s.b = 4;
+  if (s.b > 0 && s.b < 4)
+    __builtin_abort ();
+  return 0;
+}