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| author | Richard Guenther <rguenther@suse.de> | 2006-05-10 10:22:39 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2006-05-10 10:22:39 +0000 |
| commit | a04d8591f266f810cf4681930772982444227b83 (patch) | |
| tree | 2e26bba9ef58b3eadcdafeb6f4d3d820b548704f /gcc | |
| parent | 4db60bd06f820684418d7bb179d6edee80cddb08 (diff) | |
| download | gcc-a04d8591f266f810cf4681930772982444227b83.zip gcc-a04d8591f266f810cf4681930772982444227b83.tar.gz gcc-a04d8591f266f810cf4681930772982444227b83.tar.bz2 | |
re PR middle-end/27302 (Fold does not fold (i < j) == (j > i) to 1)
2006-05-10 Richard Guenther <rguenther@suse.de>
PR tree-optimization/27302
* fold-const.c (operand_equal_p): For two comparisons,
try comparison of one comparison code swapped if that yields
the same code.
* gcc.dg/torture/pr27302.c: New testcase.
From-SVN: r113670
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 7 | ||||
| -rw-r--r-- | gcc/fold-const.c | 16 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr27302.c | 15 |
4 files changed, 43 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 6cd1fcc..c52d9dd 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2006-05-10 Richard Guenther <rguenther@suse.de> + + PR tree-optimization/27302 + * fold-const.c (operand_equal_p): For two comparisons, + try comparison of one comparison code swapped if that yields + the same code. + 2006-05-10 Ben Elliston <bje@au.ibm.com> * tree-pretty-print.c (pretty_print_string): No need to handle diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 26e53c0..030bcb1 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -2489,6 +2489,22 @@ operand_equal_p (tree arg0, tree arg1, unsigned int flags) STRIP_NOPS (arg0); STRIP_NOPS (arg1); + /* In case both args are comparisons but with different comparison + code, try to swap the comparison operands of one arg to produce + a match and compare that variant. */ + if (TREE_CODE (arg0) != TREE_CODE (arg1) + && COMPARISON_CLASS_P (arg0) + && COMPARISON_CLASS_P (arg1)) + { + enum tree_code swap_code = swap_tree_comparison (TREE_CODE (arg1)); + + if (TREE_CODE (arg0) == swap_code) + return operand_equal_p (TREE_OPERAND (arg0, 0), + TREE_OPERAND (arg1, 1), flags) + && operand_equal_p (TREE_OPERAND (arg0, 1), + TREE_OPERAND (arg1, 0), flags); + } + if (TREE_CODE (arg0) != TREE_CODE (arg1) /* This is needed for conversions and for COMPONENT_REF. Might as well play it safe and always test this. */ diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 9eff9f4..7e7c9982 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2006-05-10 Richard Guenther <rguenther@suse.de> + + PR tree-optimization/27302 + * gcc.dg/torture/pr27302.c: New testcase. + 2006-05-09 Dirk Mueller <dmueller@suse.de> Richard Guenther <rguenther@suse.de> diff --git a/gcc/testsuite/gcc.dg/torture/pr27302.c b/gcc/testsuite/gcc.dg/torture/pr27302.c new file mode 100644 index 0000000..0e41fc3 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr27302.c @@ -0,0 +1,15 @@ +/* { dg-do run } */ + +extern void link_error (void); + +void test0 (int a, int b) +{ + if ((a < b) != (b > a)) + link_error (); +} + +int main() +{ + test0 (1, 2); + return 0; +} |