fold-const.c (fold_binary_loc): Preserve side-effects of X - X when simplifying to 0.

2014-10-22  Richard Biener  <rguenther@suse.de>

	* fold-const.c (fold_binary_loc): Preserve side-effects of
	X - X when simplifying to 0.
	* stor-layout.c (finish_bitfield_representative): Strip
	side-effects of evaluating the difference of two DECL_FIELD_OFFSET.

From-SVN: r216575
This commit is contained in:
Richard Biener 2014-10-23 08:25:55 +00:00 committed by Richard Biener
parent a15d2ea8ad
commit 4d885a639e
3 changed files with 10 additions and 1 deletions

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@ -1,3 +1,10 @@
2014-10-23 Richard Biener <rguenther@suse.de>
* fold-const.c (fold_binary_loc): Preserve side-effects of
X - X when simplifying to 0.
* stor-layout.c (finish_bitfield_representative): Strip
side-effects of evaluating the difference of two DECL_FIELD_OFFSET.
2014-10-22 Richard Biener <rguenther@suse.de>
Tobias Burnus <burnus@net-b.de>

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@ -10749,7 +10749,7 @@ fold_binary_loc (location_t loc,
if ((!FLOAT_TYPE_P (type) || !HONOR_NANS (TYPE_MODE (type)))
&& operand_equal_p (arg0, arg1, 0))
return build_zero_cst (type);
return omit_one_operand_loc (loc, type, build_zero_cst (type), arg0);
/* A - B -> A + (-B) if B is easily negatable. */
if (negate_expr_p (arg1)

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@ -1860,6 +1860,8 @@ finish_bitfield_representative (tree repr, tree field)
size = size_diffop (DECL_FIELD_OFFSET (field),
DECL_FIELD_OFFSET (repr));
while (TREE_CODE (size) == COMPOUND_EXPR)
size = TREE_OPERAND (size, 1);
gcc_assert (tree_fits_uhwi_p (size));
bitsize = (tree_to_uhwi (size) * BITS_PER_UNIT
+ tree_to_uhwi (DECL_FIELD_BIT_OFFSET (field))