diff options
| author | rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4> | 2005-08-01 08:52:59 +0000 |
|---|---|---|
| committer | rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4> | 2005-08-01 08:52:59 +0000 |
| commit | 685b24f5babbfea0e9374a5fd393cf9e1c7bcd0d (patch) | |
| tree | 6c454da7c03895efb5f70d5099fddba16413ef4a /gcc/tree-ssa-math-opts.c | |
| parent | c5235c0b315ea8765f6b018a98fee695d60d9469 (diff) | |
| download | gcc-685b24f5babbfea0e9374a5fd393cf9e1c7bcd0d.tar.gz | |
2005-08-01 Richard Guenther <rguenther@suse.de>
PR tree-optimization/23109
* tree-ssa-math-opts.c (execute_cse_reciprocals_1):
If trapping math is in effect, use post-dominator information
to check if we'd in any case reach a trapping point before
doing the reciprocal insertion.
(execute_cse_reciprocals): Compute post-dominators, if necessary.
* tree-ssa-loop-im.c (determine_invariantness_stmt): RDIV
expressions are invariant only if trapping math is not in effect.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@102627 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/tree-ssa-math-opts.c')
| -rw-r--r-- | gcc/tree-ssa-math-opts.c | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/gcc/tree-ssa-math-opts.c b/gcc/tree-ssa-math-opts.c index 9544a6c256c..bff3c1db21a 100644 --- a/gcc/tree-ssa-math-opts.c +++ b/gcc/tree-ssa-math-opts.c @@ -69,6 +69,7 @@ execute_cse_reciprocals_1 (block_stmt_iterator *bsi, tree def, bool phi) imm_use_iterator use_iter; tree t, new_stmt, type; int count = 0; + bool ok = !flag_trapping_math; /* Find uses. */ FOR_EACH_IMM_USE_FAST (use_p, use_iter, def) @@ -77,13 +78,18 @@ execute_cse_reciprocals_1 (block_stmt_iterator *bsi, tree def, bool phi) if (TREE_CODE (use_stmt) == MODIFY_EXPR && TREE_CODE (TREE_OPERAND (use_stmt, 1)) == RDIV_EXPR && TREE_OPERAND (TREE_OPERAND (use_stmt, 1), 1) == def) - { - if (++count == 2) - break; - } + { + ++count; + /* Check if this use post-dominates the insertion point. */ + if (ok || dominated_by_p (CDI_POST_DOMINATORS, bsi->bb, + bb_for_stmt (use_stmt))) + ok = true; + } + if (count >= 2 && ok) + break; } - if (count < 2) + if (count < 2 || !ok) return; /* Make a variable with the replacement and substitute it. */ @@ -116,6 +122,10 @@ static void execute_cse_reciprocals (void) { basic_block bb; + + if (flag_trapping_math) + calculate_dominance_info (CDI_POST_DOMINATORS); + FOR_EACH_BB (bb) { block_stmt_iterator bsi; @@ -143,6 +153,9 @@ execute_cse_reciprocals (void) execute_cse_reciprocals_1 (&bsi, def, false); } } + + if (flag_trapping_math) + free_dominance_info (CDI_POST_DOMINATORS); } struct tree_opt_pass pass_cse_reciprocals = |