diff options
| author | jye2 <jye2@138bc75d-0d04-0410-961f-82ee72b054a4> | 2011-11-21 02:16:12 +0000 |
|---|---|---|
| committer | jye2 <jye2@138bc75d-0d04-0410-961f-82ee72b054a4> | 2011-11-21 02:16:12 +0000 |
| commit | 16459f3b012163d83d6ce99b9b4e9f5b56906616 (patch) | |
| tree | 34dbbd53c18e02cc659b9d899a46473dc5ba47e8 | |
| parent | 14fdc4a0b800960d3b71a0fb320c0c7bfe4d134a (diff) | |
2011-11-20 Joey Ye <joey.ye@arm.com>
* expr.c (expand_expr_real_1): Correctly handle strict volatile
bitfield loads smaller than mode size.
testsuite:
* gcc.dg/volatile-bitfields-1.c: New.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@181549 138bc75d-0d04-0410-961f-82ee72b054a4
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/expr.c | 11 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/volatile-bitfields-1.c | 23 |
4 files changed, 40 insertions, 3 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 6a14c5419ce..590dba822e2 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2011-11-20 Joey Ye <joey.ye@arm.com> + + * expr.c (expand_expr_real_1): Correctly handle strict volatile + bitfield loads smaller than mode size. + 2011-11-20 Richard Henderson <rth@redhat.com> * config/mips/mips.c (mips_init_libfuncs): Call init_sync_libfuncs. diff --git a/gcc/expr.c b/gcc/expr.c index 84cfe5c23ee..8d3a0f671a8 100644 --- a/gcc/expr.c +++ b/gcc/expr.c @@ -9740,11 +9740,16 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode, && modifier != EXPAND_CONST_ADDRESS && modifier != EXPAND_INITIALIZER) /* If the field is volatile, we always want an aligned - access. Only do this if the access is not already naturally + access. Do this in following two situations: + 1. the access is not already naturally aligned, otherwise "normal" (non-bitfield) volatile fields - become non-addressable. */ + become non-addressable. + 2. the bitsize is narrower than the access size. Need + to extract bitfields from the access. */ || (volatilep && flag_strict_volatile_bitfields > 0 - && (bitpos % GET_MODE_ALIGNMENT (mode) != 0)) + && (bitpos % GET_MODE_ALIGNMENT (mode) != 0 + || (mode1 != BLKmode + && bitsize < GET_MODE_SIZE (mode1) * BITS_PER_UNIT))) /* If the field isn't aligned enough to fetch as a memref, fetch it as a bit field. */ || (mode1 != BLKmode diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 58a3ff0aaf6..5c1fb0077d6 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2011-11-20 Joey Ye <joey.ye@arm.com> + + * gcc.dg/volatile-bitfields-1.c: New. + 2011-11-20 Jason Merrill <jason@redhat.com> PR c++/48322 diff --git a/gcc/testsuite/gcc.dg/volatile-bitfields-1.c b/gcc/testsuite/gcc.dg/volatile-bitfields-1.c new file mode 100644 index 00000000000..6adda27fea4 --- /dev/null +++ b/gcc/testsuite/gcc.dg/volatile-bitfields-1.c @@ -0,0 +1,23 @@ +/* { dg-options "-fstrict-volatile-bitfields" } */ +/* { dg-do run } */ + +extern int puts(const char *); +extern void abort(void) __attribute__((noreturn)); + +typedef struct { + volatile unsigned short a:8, b:8; +} BitStruct; + +BitStruct bits = {1, 2}; + +void check(int i, int j) +{ + if (i != 1 || j != 2) puts("FAIL"), abort(); +} + +int main () +{ + check(bits.a, bits.b); + + return 0; +} |