diff options
| author | rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4> | 2009-05-08 12:24:22 +0000 |
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| committer | rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4> | 2009-05-08 12:24:22 +0000 |
| commit | aebe538b0142a61fedcb2731e035f41e968f6cba (patch) | |
| tree | aabbf2fc3c6814aff869e013b040c9d31041d85e /gcc/tree-scalar-evolution.c | |
| parent | e0bd4156d6613e878cafcb23f52d8c3e72d928eb (diff) | |
| download | gcc-aebe538b0142a61fedcb2731e035f41e968f6cba.tar.gz | |
2009-05-08 Richard Guenther <rguenther@suse.de>
PR tree-optimization/40062
* tree-scalar-evolution.c (follow_ssa_edge_in_condition_phi):
Avoid exponential behavior.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@147283 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/tree-scalar-evolution.c')
| -rw-r--r-- | gcc/tree-scalar-evolution.c | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/gcc/tree-scalar-evolution.c b/gcc/tree-scalar-evolution.c index 2d31f9f534c..b3990c6bfe1 100644 --- a/gcc/tree-scalar-evolution.c +++ b/gcc/tree-scalar-evolution.c @@ -1319,11 +1319,7 @@ follow_ssa_edge_in_condition_phi (struct loop *loop, *evolution_of_loop = evolution_of_branch; - /* If the phi node is just a copy, do not increase the limit. */ n = gimple_phi_num_args (condition_phi); - if (n > 1) - limit++; - for (i = 1; i < n; i++) { /* Quickly give up when the evolution of one of the branches is @@ -1331,10 +1327,12 @@ follow_ssa_edge_in_condition_phi (struct loop *loop, if (*evolution_of_loop == chrec_dont_know) return t_true; + /* Increase the limit by the PHI argument number to avoid exponential + time and memory complexity. */ res = follow_ssa_edge_in_condition_phi_branch (i, loop, condition_phi, halting_phi, &evolution_of_branch, - init, limit); + init, limit + i); if (res == t_false || res == t_dont_know) return res; |