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| author | Joey Ye <joey.ye@arm.com> | 2011-11-21 02:16:12 +0000 |
|---|---|---|
| committer | Joey Ye <jye2@gcc.gnu.org> | 2011-11-21 02:16:12 +0000 |
| commit | e5fe4319e726b2b6baf4a31e42faa446eb6d00b4 (patch) | |
| tree | 34dbbd53c18e02cc659b9d899a46473dc5ba47e8 /gcc/expr.c | |
| parent | 25a96761979b320209f0b513ad364e5d9e5a05d6 (diff) | |
| download | gcc-e5fe4319e726b2b6baf4a31e42faa446eb6d00b4.zip gcc-e5fe4319e726b2b6baf4a31e42faa446eb6d00b4.tar.gz gcc-e5fe4319e726b2b6baf4a31e42faa446eb6d00b4.tar.bz2 | |
expr.c (expand_expr_real_1): Correctly handle strict volatile bitfield loads smaller than mode size.
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.
From-SVN: r181549
Diffstat (limited to 'gcc/expr.c')
| -rw-r--r-- | gcc/expr.c | 11 |
1 files changed, 8 insertions, 3 deletions
@@ -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 |