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| author | Roger Sayle <roger@eyesopen.com> | 2004-10-09 15:48:24 +0000 |
|---|---|---|
| committer | Roger Sayle <sayle@gcc.gnu.org> | 2004-10-09 15:48:24 +0000 |
| commit | d2e74f6fd5b8dfff688b382b2fcb076f4f87a724 (patch) | |
| tree | 170040c8e28a24edb9414cf344d53a3ab20d0b53 /gcc/fold-const.c | |
| parent | 0d2e6ffef6be51ec2e1fd9f593c26e1e53b23825 (diff) | |
| download | gcc-d2e74f6fd5b8dfff688b382b2fcb076f4f87a724.tar.gz | |
re PR middle-end/17894 (div/compare folding incorrect)
PR middle-end/17894
* fold-const.c (fold_div_compare): When optimizing X/C1 op C2, the
relational comparison operator op needs to be swapped/reversed when
C1 is negative. i.e. X/-10 < 1 becomes X >= -9, not X < -9.
* gcc.c-torture/execute/divcmp-4.c: New test case.
From-SVN: r88818
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 7de102f9870..41feda3ef1e 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -5720,6 +5720,9 @@ fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1) } else { + /* A negative divisor reverses the relational operators. */ + code = swap_tree_comparison (code); + tmp = int_const_binop (PLUS_EXPR, arg01, integer_one_node, 0); switch (tree_int_cst_sgn (arg1)) { |