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| author | Richard Guenther <rguenther@suse.de> | 2008-04-29 15:59:43 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2008-04-29 15:59:43 +0000 |
| commit | 1447bf0556ad0cb300aabd1b883fedee314b6fca (patch) | |
| tree | c9e456f594c1a551adbd796e105d2374bafd6819 /gcc/fold-const.c | |
| parent | 59e6913ad1743f76ca98421b9b5614caf96a7cf7 (diff) | |
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re PR tree-optimization/15255 ([tree-ssa] a * 2 + a * 2 is not converted to a * 4)
2008-04-29 Richard Guenther <rguenther@suse.de>
PR middle-end/15255
* fold-const.c (fold_binary): Fold (A + A) * C to A * 2*C.
* gcc.dg/fold-plusmult.c: New testcase.
From-SVN: r134798
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index aae2037..b4645ca 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -10154,6 +10154,17 @@ fold_binary (enum tree_code code, tree type, tree op0, tree op1) return fold_build2 (LSHIFT_EXPR, type, op1, TREE_OPERAND (arg0, 1)); + /* (A + A) * C -> A * 2 * C */ + if (TREE_CODE (arg0) == PLUS_EXPR + && TREE_CODE (arg1) == INTEGER_CST + && operand_equal_p (TREE_OPERAND (arg0, 0), + TREE_OPERAND (arg0, 1), 0)) + return fold_build2 (MULT_EXPR, type, + omit_one_operand (type, TREE_OPERAND (arg0, 0), + TREE_OPERAND (arg0, 1)), + fold_build2 (MULT_EXPR, type, + build_int_cst (type, 2) , arg1)); + strict_overflow_p = false; if (TREE_CODE (arg1) == INTEGER_CST && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE, |