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| author | Mark Mitchell <mark@codesourcery.com> | 2001-03-19 18:53:04 +0000 |
|---|---|---|
| committer | Mark Mitchell <mmitchel@gcc.gnu.org> | 2001-03-19 18:53:04 +0000 |
| commit | 68e568c28eb6e4d15b06dc23b27168e783ce008c (patch) | |
| tree | b54bc88743a41fe139d4d714ef19b50f51dcb79b /gcc/fold-const.c | |
| parent | d4b6faf649a1b8f5d84e1e1711a8e66476250de3 (diff) | |
| download | gcc-68e568c28eb6e4d15b06dc23b27168e783ce008c.zip gcc-68e568c28eb6e4d15b06dc23b27168e783ce008c.tar.gz gcc-68e568c28eb6e4d15b06dc23b27168e783ce008c.tar.bz2 | |
cse.c (find_comparison_args): Update documentation.
* cse.c (find_comparison_args): Update documentation. Fix
mishandling of COMPARE operations.
* tree.def (ABS_EXPR): Add documentation.
* fold-const.c (fold): Improve folding of ABS_EXPRs.
From-SVN: r40630
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index dda3102..ed98822 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -5275,8 +5275,16 @@ fold (expr) { if (TREE_CODE (arg0) == INTEGER_CST) { - if (! TREE_UNSIGNED (type) - && TREE_INT_CST_HIGH (arg0) < 0) + /* If the value is unsigned, then the absolute value is + the same as the ordinary value. */ + if (TREE_UNSIGNED (type)) + return arg0; + /* Similarly, if the value is non-negative. */ + else if (INT_CST_LT (integer_minus_one_node, arg0)) + return arg0; + /* If the value is negative, then the absolute value is + its negation. */ + else { unsigned HOST_WIDE_INT low; HOST_WIDE_INT high; |