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2010-12-02 Bernd Schmidt <bernds@codesourcery.com>
Issue #10089
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.
* config/arm/arm.c (arm_option_override): Don't enable
flag_strict_volatile_bitfields if the ABI version is less than 2.
* config/h8300/h8300.c (h8300_option_override): Likewise.
* config/rx/rx.c (rx_option_override): Likewise.
* config/m32c/m32c.c (m32c_option_override): Likewise.
* config/sh/sh.c (sh_option_override): Likewise.
gcc/testsuite/
* gcc.target/arm/volatile-bitfields-4.c: New test.
* c-c++-common/abi-bf.c: New test.
=== modified file 'gcc/config/arm/arm.c'
--- old/gcc/config/arm/arm.c 2010-12-10 15:30:47 +0000
+++ new/gcc/config/arm/arm.c 2010-12-10 15:34:19 +0000
@@ -1934,7 +1934,8 @@
set_param_value ("gcse-unrestricted-cost", 2);
/* ARM EABI defaults to strict volatile bitfields. */
- if (TARGET_AAPCS_BASED && flag_strict_volatile_bitfields < 0)
+ if (TARGET_AAPCS_BASED && flag_strict_volatile_bitfields < 0
+ && abi_version_at_least(2))
flag_strict_volatile_bitfields = 1;
/* Register global variables with the garbage collector. */
=== modified file 'gcc/config/h8300/h8300.c'
--- old/gcc/config/h8300/h8300.c 2010-11-04 12:43:52 +0000
+++ new/gcc/config/h8300/h8300.c 2010-12-10 15:34:19 +0000
@@ -405,7 +405,7 @@
}
/* This target defaults to strict volatile bitfields. */
- if (flag_strict_volatile_bitfields < 0)
+ if (flag_strict_volatile_bitfields < 0 && abi_version_at_least(2))
flag_strict_volatile_bitfields = 1;
}
=== modified file 'gcc/config/m32c/m32c.c'
--- old/gcc/config/m32c/m32c.c 2010-11-04 12:43:52 +0000
+++ new/gcc/config/m32c/m32c.c 2010-12-10 15:34:19 +0000
@@ -430,7 +430,7 @@
flag_ivopts = 0;
/* This target defaults to strict volatile bitfields. */
- if (flag_strict_volatile_bitfields < 0)
+ if (flag_strict_volatile_bitfields < 0 && abi_version_at_least(2))
flag_strict_volatile_bitfields = 1;
}
=== modified file 'gcc/config/rx/rx.c'
--- old/gcc/config/rx/rx.c 2010-11-04 12:43:52 +0000
+++ new/gcc/config/rx/rx.c 2010-12-10 15:34:19 +0000
@@ -2191,7 +2191,7 @@
rx_option_override (void)
{
/* This target defaults to strict volatile bitfields. */
- if (flag_strict_volatile_bitfields < 0)
+ if (flag_strict_volatile_bitfields < 0 && abi_version_at_least(2))
flag_strict_volatile_bitfields = 1;
}
=== modified file 'gcc/config/sh/sh.c'
--- old/gcc/config/sh/sh.c 2010-11-04 12:43:52 +0000
+++ new/gcc/config/sh/sh.c 2010-12-10 15:34:19 +0000
@@ -952,7 +952,7 @@
sh_fix_range (sh_fixed_range_str);
/* This target defaults to strict volatile bitfields. */
- if (flag_strict_volatile_bitfields < 0)
+ if (flag_strict_volatile_bitfields < 0 && abi_version_at_least(2))
flag_strict_volatile_bitfields = 1;
}
=== modified file 'gcc/expr.c'
--- old/gcc/expr.c 2010-11-04 12:43:52 +0000
+++ new/gcc/expr.c 2010-12-10 15:34:19 +0000
@@ -5848,6 +5848,8 @@
|| 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. */
=== modified file 'gcc/stor-layout.c'
--- old/gcc/stor-layout.c 2010-11-26 12:03:32 +0000
+++ new/gcc/stor-layout.c 2010-12-10 15:34:19 +0000
@@ -621,12 +621,13 @@
/* 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);
=== added file 'gcc/testsuite/c-c++-common/abi-bf.c'
--- old/gcc/testsuite/c-c++-common/abi-bf.c 1970-01-01 00:00:00 +0000
+++ new/gcc/testsuite/c-c++-common/abi-bf.c 2010-12-10 15:34:19 +0000
@@ -0,0 +1,3 @@
+/* { dg-warning "incompatible" } */
+/* { dg-do compile } */
+/* { dg-options "-fstrict-volatile-bitfields -fabi-version=1" } */
=== added file 'gcc/testsuite/gcc.target/arm/volatile-bitfields-4.c'
--- old/gcc/testsuite/gcc.target/arm/volatile-bitfields-4.c 1970-01-01 00:00:00 +0000
+++ new/gcc/testsuite/gcc.target/arm/volatile-bitfields-4.c 2010-12-10 15:34:19 +0000
@@ -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;
+}
=== modified file 'gcc/toplev.c'
--- old/gcc/toplev.c 2010-03-31 01:44:10 +0000
+++ new/gcc/toplev.c 2010-12-10 15:34:19 +0000
@@ -1851,6 +1851,13 @@
sorry ("Graphite loop optimizations cannot be used");
#endif
+ if (flag_strict_volatile_bitfields > 0 && !abi_version_at_least (2))
+ {
+ warning (0, "-fstrict-volatile-bitfield 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)
|
