From: Kai Tietz <ktietz@redhat.com>
Date: Mon, 20 Feb 2012 22:05:08 +0000 (+0100)
Subject: re PR target/52238 (-mms-bitfields: __attribute__ ((aligned (n))) ignored for struct... 
X-Git-Tag: upstream/12.2.0~77871
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=9954e17f70b8212a51603332d6c15991b7ada434;p=platform%2Fupstream%2Fgcc.git

re PR target/52238 (-mms-bitfields: __attribute__ ((aligned (n))) ignored for struct members)

	PR target/52238
	* stor-layout.c (place_field): Handle desired_align for
	ms-bitfields, too.

	* gcc.dg/bf-ms-layout-3.c: New testcase.

From-SVN: r184409
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b8366f4..c579214 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2012-02-20  Kai Tietz  <ktietz@redhat.com>
+
+	PR target/52238
+	* stor-layout.c (place_field): Handle desired_align for
+	ms-bitfields, too.
+
 2012-02-20  Richard Guenther  <rguenther@suse.de>
 
 	PR tree-optimization/52298
diff --git a/gcc/stor-layout.c b/gcc/stor-layout.c
index 35320c2..a1ac000 100644
--- a/gcc/stor-layout.c
+++ b/gcc/stor-layout.c
@@ -1141,15 +1141,14 @@ place_field (record_layout_info rli, tree field)
     }
 
   /* Does this field automatically have alignment it needs by virtue
-     of the fields that precede it and the record's own alignment?
-     We already align ms_struct fields, so don't re-align them.  */
-  if (known_align < desired_align
-      && !targetm.ms_bitfield_layout_p (rli->t))
+     of the fields that precede it and the record's own alignment?  */
+  if (known_align < desired_align)
     {
       /* No, we need to skip space before this field.
 	 Bump the cumulative size to multiple of field alignment.  */
 
-      if (DECL_SOURCE_LOCATION (field) != BUILTINS_LOCATION)
+      if (!targetm.ms_bitfield_layout_p (rli->t)
+          && DECL_SOURCE_LOCATION (field) != BUILTINS_LOCATION)
 	warning (OPT_Wpadded, "padding struct to align %q+D", field);
 
       /* If the alignment is still within offset_align, just align
@@ -1171,7 +1170,8 @@ place_field (record_layout_info rli, tree field)
 
       if (! TREE_CONSTANT (rli->offset))
 	rli->offset_align = desired_align;
-
+      if (targetm.ms_bitfield_layout_p (rli->t))
+	rli->prev_field = NULL;
     }
 
   /* Handle compatibility with PCC.  Note that if the record has any
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 6632b58..df818af 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2012-02-20  Kai Tietz  <ktietz@redhat.com>
+
+	* gcc.dg/bf-ms-layout-3.c: New testcase.
+
 2012-02-20  Thomas Koenig  <tkoenig@gcc.gnu.org>
 
 	PR testsuite/52229
diff --git a/gcc/testsuite/gcc.dg/bf-ms-layout-3.c b/gcc/testsuite/gcc.dg/bf-ms-layout-3.c
new file mode 100644
index 0000000..9abb9dc
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/bf-ms-layout-3.c
@@ -0,0 +1,51 @@
+/* Test for MS bitfield layout */
+/* { dg-do run { target *-*-interix* *-*-mingw* *-*-cygwin* i?86-*-* x86_64-*-* } } */
+
+extern void abort();
+
+struct s1_t {
+    char a;
+    char b __attribute__ ((aligned (16)));
+} __attribute__ ((ms_struct));
+struct s1_t s1;
+
+struct s2_t {
+  char a;
+  char b;
+} __attribute__ ((ms_struct));
+struct s2_t s2;
+
+struct s3_t {
+  char a : 6;
+  char b __attribute__ ((aligned (16)));
+} __attribute__ ((ms_struct));
+struct s3_t s3;
+
+struct s4_t {
+  char a : 6;
+  char b __attribute__ ((aligned (2)));
+} __attribute__ ((ms_struct));
+struct s4_t s4;
+
+struct s5_t {
+  char a : 6;
+  char b __attribute__ ((aligned (1)));
+} __attribute__ ((ms_struct));
+struct s5_t s5;
+
+__PTRDIFF_TYPE__ offs (const void *a, const void *b)
+{
+  return (__PTRDIFF_TYPE__) ((const char*)a  - (const char*)b);
+}
+
+int main()
+{
+  if (offs (&s1.b, &s1) != 16
+      || offs (&s2.b, &s2) != 1
+      || offs (&s3.b, &s3) != 16
+      || offs (&s4.b, &s4) != 2
+      || offs (&s5.b, &s5) != 1)
+    abort ();
+  return 0;
+}
+