diff options
Diffstat (limited to 'gcc/expr.c')
| -rw-r--r-- | gcc/expr.c | 24 |
1 files changed, 24 insertions, 0 deletions
@@ -4229,6 +4229,13 @@ expand_assignment (tree to, tree from, bool nontemporal) to_rtx = expand_normal (tem); + /* If the bitfield is volatile, we want to access it in the + field's mode, not the computed mode. */ + if (volatilep + && GET_CODE (to_rtx) == MEM + && flag_strict_volatile_bitfields > 0) + to_rtx = adjust_address (to_rtx, mode1, 0); + if (offset != 0) { enum machine_mode address_mode; @@ -5990,6 +5997,12 @@ get_inner_reference (tree exp, HOST_WIDE_INT *pbitsize, mode = DECL_MODE (field); else if (DECL_MODE (field) == BLKmode) blkmode_bitfield = true; + else if (TREE_THIS_VOLATILE (exp) + && flag_strict_volatile_bitfields > 0) + /* Volatile bitfields should be accessed in the mode of the + field's type, not the mode computed based on the bit + size. */ + mode = TYPE_MODE (DECL_BIT_FIELD_TYPE (field)); *punsignedp = DECL_UNSIGNED (field); } @@ -8966,6 +8979,14 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode, || modifier == EXPAND_STACK_PARM) ? modifier : EXPAND_NORMAL); + + /* If the bitfield is volatile, we want to access it in the + field's mode, not the computed mode. */ + if (volatilep + && GET_CODE (op0) == MEM + && flag_strict_volatile_bitfields > 0) + op0 = adjust_address (op0, mode1, 0); + mode2 = CONSTANT_P (op0) ? TYPE_MODE (TREE_TYPE (tem)) : GET_MODE (op0); @@ -9091,6 +9112,9 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode, && GET_MODE_CLASS (mode) != MODE_COMPLEX_FLOAT && modifier != EXPAND_CONST_ADDRESS && modifier != EXPAND_INITIALIZER) + /* If the field is volatile, we always want an aligned + access. */ + || (volatilep && flag_strict_volatile_bitfields > 0) /* If the field isn't aligned enough to fetch as a memref, fetch it as a bit field. */ || (mode1 != BLKmode |