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| author | Zdenek Dvorak <ook@ucw.cz> | 2012-12-12 14:07:19 +0100 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2012-12-12 13:07:19 +0000 |
| commit | d06a01bf68804185394809bfc9754dfe9c522639 (patch) | |
| tree | 21ace6b448063020524310c868dce7d1b8364db5 /gcc/tree-ssa-loop-ivopts.c | |
| parent | 85619b6fc10c230dd34998b4e7b281c573143421 (diff) | |
| download | gcc-d06a01bf68804185394809bfc9754dfe9c522639.zip gcc-d06a01bf68804185394809bfc9754dfe9c522639.tar.gz gcc-d06a01bf68804185394809bfc9754dfe9c522639.tar.bz2 | |
re PR middle-end/55481 (-O2 generates a wrong-code infinite loop in C++Benchmark's simple_types_constant_folding int8 xor test)
2012-12-12 Zdenek Dvorak <ook@ucw.cz>
PR tree-optimization/55481
* tree-ssa-loop-ivopts.c (rewrite_use_nonlinear_expr): Fall
back to general rewriting if we cannot leave an original biv
definition alone.
* gcc.dg/torture/pr55481.c: New testcase.
From-SVN: r194444
Diffstat (limited to 'gcc/tree-ssa-loop-ivopts.c')
| -rw-r--r-- | gcc/tree-ssa-loop-ivopts.c | 42 |
1 files changed, 10 insertions, 32 deletions
diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c index 1e41fa9..c33fc7c 100644 --- a/gcc/tree-ssa-loop-ivopts.c +++ b/gcc/tree-ssa-loop-ivopts.c @@ -6088,35 +6088,24 @@ rewrite_use_nonlinear_expr (struct ivopts_data *data, if (cand->pos == IP_ORIGINAL && cand->incremented_at == use->stmt) { - tree step, ctype, utype; - enum tree_code incr_code = PLUS_EXPR, old_code; + enum tree_code stmt_code; gcc_assert (is_gimple_assign (use->stmt)); gcc_assert (gimple_assign_lhs (use->stmt) == cand->var_after); - step = cand->iv->step; - ctype = TREE_TYPE (step); - utype = TREE_TYPE (cand->var_after); - if (TREE_CODE (step) == NEGATE_EXPR) - { - incr_code = MINUS_EXPR; - step = TREE_OPERAND (step, 0); - } - /* Check whether we may leave the computation unchanged. This is the case only if it does not rely on other computations in the loop -- otherwise, the computation we rely upon may be removed in remove_unused_ivs, thus leading to ICE. */ - old_code = gimple_assign_rhs_code (use->stmt); - if (old_code == PLUS_EXPR - || old_code == MINUS_EXPR - || old_code == POINTER_PLUS_EXPR) + stmt_code = gimple_assign_rhs_code (use->stmt); + if (stmt_code == PLUS_EXPR + || stmt_code == MINUS_EXPR + || stmt_code == POINTER_PLUS_EXPR) { if (gimple_assign_rhs1 (use->stmt) == cand->var_before) op = gimple_assign_rhs2 (use->stmt); - else if (old_code != MINUS_EXPR - && gimple_assign_rhs2 (use->stmt) == cand->var_before) + else if (gimple_assign_rhs2 (use->stmt) == cand->var_before) op = gimple_assign_rhs1 (use->stmt); else op = NULL_TREE; @@ -6124,24 +6113,13 @@ rewrite_use_nonlinear_expr (struct ivopts_data *data, else op = NULL_TREE; - if (op - && (TREE_CODE (op) == INTEGER_CST - || operand_equal_p (op, step, 0))) + if (op && expr_invariant_in_loop_p (data->current_loop, op)) return; - - /* Otherwise, add the necessary computations to express - the iv. */ - op = fold_convert (ctype, cand->var_before); - comp = fold_convert (utype, - build2 (incr_code, ctype, op, - unshare_expr (step))); - } - else - { - comp = get_computation (data->current_loop, use, cand); - gcc_assert (comp != NULL_TREE); } + comp = get_computation (data->current_loop, use, cand); + gcc_assert (comp != NULL_TREE); + switch (gimple_code (use->stmt)) { case GIMPLE_PHI: |