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| author | Richard Biener <rguenther@suse.de> | 2013-01-04 10:45:37 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2013-01-04 10:45:37 +0000 |
| commit | 3068819a3af2da9cdab935d39b952912b1f63325 (patch) | |
| tree | 002d1787e93d0fc5c2e65f699f5d251bbf4f31ad /gcc/fold-const.c | |
| parent | db59befb099fc4d20a2a60f9eaa6b1fb8a9e85c7 (diff) | |
| download | gcc-3068819a3af2da9cdab935d39b952912b1f63325.tar.gz | |
re PR middle-end/55863 (Fails to fold (i + 2) - (i + 1) to 1)
2013-01-04 Richard Biener <rguenther@suse.de>
PR middle-end/55863
* fold-const.c (split_tree): Undo -X - 1 to ~X folding for
reassociation.
* gcc.dg/fold-reassoc-2.c: New testcase.
From-SVN: r194899
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 4f384a75344..7e619d6d1e5 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -821,6 +821,13 @@ split_tree (tree in, enum tree_code code, tree *conp, tree *litp, if (neg_var_p) var = negate_expr (var); } + else if (TREE_CODE (in) == BIT_NOT_EXPR + && code == PLUS_EXPR) + { + /* -X - 1 is folded to ~X, undo that here. */ + *minus_litp = build_one_cst (TREE_TYPE (in)); + var = negate_expr (TREE_OPERAND (in, 0)); + } else if (TREE_CONSTANT (in)) *conp = in; else |