===================================================================
@@ -1330,6 +1330,13 @@
flag_ira_region
= optimize_size || !optimize ? IRA_REGION_ONE : IRA_REGION_MIXED;
+ if (flag_strict_volatile_bitfields > 0 && !abi_version_at_least (2))
+ {
+ warning (0, "-fstrict-volatile-bitfields disabled; "
+ "it is incompatible with ABI versions < 2");
+ flag_strict_volatile_bitfields = 0;
+ }
+
/* Unrolling all loops implies that standard loop unrolling must also
be done. */
if (flag_unroll_all_loops)
===================================================================
@@ -0,0 +1,30 @@
+/* { dg-require-effective-target arm_eabi } */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+/* { dg-final { scan-assembler-times "ldr\[\\t \]+\[^\n\]*,\[\\t \]*\\\[\[^\n\]*\\\]" 2 } } */
+/* { dg-final { scan-assembler-times "str\[\\t \]+\[^\n\]*,\[\\t \]*\\\[\[^\n\]*\\\]" 2 } } */
+/* { dg-final { scan-assembler-not "strb" } } */
+
+struct thing {
+ unsigned a: 8;
+ unsigned b: 8;
+ unsigned c: 8;
+ unsigned d: 8;
+};
+
+struct thing2 {
+ volatile unsigned a: 8;
+ volatile unsigned b: 8;
+ volatile unsigned c: 8;
+ volatile unsigned d: 8;
+};
+
+void test1(volatile struct thing *t)
+{
+ t->a = 5;
+}
+
+void test2(struct thing2 *t)
+{
+ t->a = 5;
+}
===================================================================
@@ -0,0 +1,15 @@
+/* { dg-do run } */
+/* { dg-options "-fstrict-volatile-bitfields" } */
+
+extern void abort(void);
+struct thing {
+ volatile unsigned short a: 8;
+ volatile unsigned short b: 8;
+} t = {1,2};
+
+int main()
+{
+ t.a = 3;
+ if (t.a !=3 || t.b !=2) abort();
+ return 0;
+}
===================================================================
@@ -1,4 +1,4 @@
-// { dg-options "-Wabi -fabi-version=1" }
+// { dg-options "-Wabi -fabi-version=1 -fno-strict-volatile-bitfields" }
struct S { // { dg-warning "ABI" }
char c : 1024; // { dg-warning "width" }
===================================================================
@@ -0,0 +1,3 @@
+/* { dg-warning "incompatible" } */
+/* { dg-do compile } */
+/* { dg-options "-fstrict-volatile-bitfields -fabi-version=1" } */
===================================================================
@@ -6327,6 +6327,8 @@
|| bitpos % GET_MODE_ALIGNMENT (mode))
&& SLOW_UNALIGNED_ACCESS (mode, MEM_ALIGN (target)))
|| (bitpos % BITS_PER_UNIT != 0)))
+ || (bitsize >= 0 && mode != BLKmode
+ && GET_MODE_BITSIZE (mode) > bitsize)
/* If the RHS and field are a constant size and the size of the
RHS isn't the same size as the bitfield, we must use bitfield
operations. */
===================================================================
@@ -622,12 +622,13 @@
/* See if we can use an ordinary integer mode for a bit-field.
Conditions are: a fixed size that is correct for another mode,
occupying a complete byte or bytes on proper boundary,
- and not volatile or not -fstrict-volatile-bitfields. */
+ and not -fstrict-volatile-bitfields. If the latter is set,
+ we unfortunately can't check TREE_THIS_VOLATILE, as a cast
+ may make a volatile object later. */
if (TYPE_SIZE (type) != 0
&& TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST
&& GET_MODE_CLASS (TYPE_MODE (type)) == MODE_INT
- && !(TREE_THIS_VOLATILE (decl)
- && flag_strict_volatile_bitfields > 0))
+ && flag_strict_volatile_bitfields <= 0)
{
enum machine_mode xmode
= mode_for_size_tree (DECL_SIZE (decl), MODE_INT, 1);
Ping, PR middle-end/51200 Tailored from Bernd's, and added target independent test case. Now it is a pure middle-end fix. OK for trunk and 4.6? Bernd Schmidt <bernds_cb1@t-online.de> gcc/ * expr.c (store_field): Avoid a direct store if the mode is larger than the size of the bit field. * stor-layout.c (layout_decl): If flag_strict_volatile_bitfields, treat non-volatile bit fields like volatile ones. * toplev.c (process_options): Disallow combination of -fstrict-volatile-bitfields and ABI versions less than 2. gcc/testsuite/ * gcc.target/arm/volatile-bitfields-4.c: New test. * c-c++-common/abi-bf.c: New test. Joey Ye <joey.ye@arm.com> * gcc.dg/volatile-bitfields-2.c: New test. * g++.dg/abi/bitfield12.C: no-strict-volatile-bitfields.