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| author | Richard Biener <rguenther@suse.de> | 2014-07-14 13:52:38 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2014-07-14 13:52:38 +0000 |
| commit | 236aff7251d50001f8526b04e5c39004490ec3cd (patch) | |
| tree | a374a741ef36dbc1083375dcefa23a616169e834 /gcc/tree-ssa-copy.c | |
| parent | 72602c6cb4707198b2f965d26c2e5009f52d6e96 (diff) | |
| download | gcc-236aff7251d50001f8526b04e5c39004490ec3cd.zip gcc-236aff7251d50001f8526b04e5c39004490ec3cd.tar.gz gcc-236aff7251d50001f8526b04e5c39004490ec3cd.tar.bz2 | |
re PR c/61779 (gcc -Og fails with impossible constraint on legal C code)
2014-07-14 Richard Biener <rguenther@suse.de>
PR tree-optimization/61779
* tree-ssa-copy.c (copy_prop_visit_cond_stmt): Always try
simplifying a condition.
* gcc.dg/tree-ssa/ssa-copyprop-2.c: New testcase.
From-SVN: r212521
Diffstat (limited to 'gcc/tree-ssa-copy.c')
| -rw-r--r-- | gcc/tree-ssa-copy.c | 46 |
1 files changed, 17 insertions, 29 deletions
diff --git a/gcc/tree-ssa-copy.c b/gcc/tree-ssa-copy.c index b8df7a8..06d98df 100644 --- a/gcc/tree-ssa-copy.c +++ b/gcc/tree-ssa-copy.c @@ -237,38 +237,26 @@ copy_prop_visit_cond_stmt (gimple stmt, edge *taken_edge_p) enum ssa_prop_result retval = SSA_PROP_VARYING; location_t loc = gimple_location (stmt); - tree op0 = gimple_cond_lhs (stmt); - tree op1 = gimple_cond_rhs (stmt); + tree op0 = valueize_val (gimple_cond_lhs (stmt)); + tree op1 = valueize_val (gimple_cond_rhs (stmt)); - /* The only conditionals that we may be able to compute statically - are predicates involving two SSA_NAMEs. */ - if (TREE_CODE (op0) == SSA_NAME && TREE_CODE (op1) == SSA_NAME) + /* See if we can determine the predicate's value. */ + if (dump_file && (dump_flags & TDF_DETAILS)) { - op0 = valueize_val (op0); - op1 = valueize_val (op1); - - /* See if we can determine the predicate's value. */ - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "Trying to determine truth value of "); - fprintf (dump_file, "predicate "); - print_gimple_stmt (dump_file, stmt, 0, 0); - } + fprintf (dump_file, "Trying to determine truth value of "); + fprintf (dump_file, "predicate "); + print_gimple_stmt (dump_file, stmt, 0, 0); + } - /* We can fold COND and get a useful result only when we have - the same SSA_NAME on both sides of a comparison operator. */ - if (op0 == op1) - { - tree folded_cond = fold_binary_loc (loc, gimple_cond_code (stmt), - boolean_type_node, op0, op1); - if (folded_cond) - { - basic_block bb = gimple_bb (stmt); - *taken_edge_p = find_taken_edge (bb, folded_cond); - if (*taken_edge_p) - retval = SSA_PROP_INTERESTING; - } - } + /* Fold COND and see whether we get a useful result. */ + tree folded_cond = fold_binary_loc (loc, gimple_cond_code (stmt), + boolean_type_node, op0, op1); + if (folded_cond) + { + basic_block bb = gimple_bb (stmt); + *taken_edge_p = find_taken_edge (bb, folded_cond); + if (*taken_edge_p) + retval = SSA_PROP_INTERESTING; } if (dump_file && (dump_flags & TDF_DETAILS) && *taken_edge_p) |