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| author | Zdenek Dvorak <dvorakz@suse.cz> | 2005-02-06 19:48:58 +0100 |
|---|---|---|
| committer | Zdenek Dvorak <rakdver@gcc.gnu.org> | 2005-02-06 18:48:58 +0000 |
| commit | 3520b7452c46c56f64697dcdad55160cdf947d39 (patch) | |
| tree | 10830e1a2a76f15e0178f61c26c6ab42113944c8 /gcc | |
| parent | b0a168b645d310b6bf2638967562cfab8f89d555 (diff) | |
| download | gcc-3520b7452c46c56f64697dcdad55160cdf947d39.zip gcc-3520b7452c46c56f64697dcdad55160cdf947d39.tar.gz gcc-3520b7452c46c56f64697dcdad55160cdf947d39.tar.bz2 | |
tree-ssa-loop-ivopts.c (rewrite_use_nonlinear_expr): Do not add unnecessary cast to original induction variable increments.
* tree-ssa-loop-ivopts.c (rewrite_use_nonlinear_expr): Do not add
unnecessary cast to original induction variable increments.
From-SVN: r94681
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/tree-ssa-loop-ivopts.c | 27 |
2 files changed, 29 insertions, 3 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 83c0ed5..a498661 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,10 @@ 2005-02-06 Zdenek Dvorak <dvorakz@suse.cz> + * tree-ssa-loop-ivopts.c (rewrite_use_nonlinear_expr): Do not add + unnecessary cast to original induction variable increments. + +2005-02-06 Zdenek Dvorak <dvorakz@suse.cz> + PR tree-optimization/18219 * tree-ssa-loop-ivopts.c (get_computation_at): Produce computations in distributed form. diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c index 05f4a8d..b5f693e 100644 --- a/gcc/tree-ssa-loop-ivopts.c +++ b/gcc/tree-ssa-loop-ivopts.c @@ -4542,11 +4542,32 @@ static void rewrite_use_nonlinear_expr (struct ivopts_data *data, struct iv_use *use, struct iv_cand *cand) { - tree comp = unshare_expr (get_computation (data->current_loop, - use, cand)); + tree comp; tree op, stmts, tgt, ass; block_stmt_iterator bsi, pbsi; - + + /* An important special case -- if we are asked to express value of + the original iv by itself, just exit; there is no need to + introduce a new computation (that might also need casting the + variable to unsigned and back). */ + if (cand->pos == IP_ORIGINAL + && TREE_CODE (use->stmt) == MODIFY_EXPR + && TREE_OPERAND (use->stmt, 0) == cand->var_after) + { + op = TREE_OPERAND (use->stmt, 1); + + /* Be a bit careful. In case variable is expressed in some + complicated way, rewrite it so that we may get rid of this + complicated expression. */ + if ((TREE_CODE (op) == PLUS_EXPR + || TREE_CODE (op) == MINUS_EXPR) + && TREE_OPERAND (op, 0) == cand->var_before + && TREE_CODE (TREE_OPERAND (op, 1)) == INTEGER_CST) + return; + } + + comp = unshare_expr (get_computation (data->current_loop, + use, cand)); switch (TREE_CODE (use->stmt)) { case PHI_NODE: |