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| author | Richard Guenther <rguenther@suse.de> | 2009-04-02 09:10:53 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2009-04-02 09:10:53 +0000 |
| commit | bf1cbdc6e43e3a62ef6ecac786ac70ecf5851ef6 (patch) | |
| tree | 1a6f6d8f33ade81a49b8870ef8209f8ef2aa991e /gcc/tree-scalar-evolution.c | |
| parent | 4bb7dbf60ef02a1172371a21e44533aa717a533a (diff) | |
| download | gcc-bf1cbdc6e43e3a62ef6ecac786ac70ecf5851ef6.zip gcc-bf1cbdc6e43e3a62ef6ecac786ac70ecf5851ef6.tar.gz gcc-bf1cbdc6e43e3a62ef6ecac786ac70ecf5851ef6.tar.bz2 | |
re PR middle-end/37221 (Missed early loop-unroll optimization - causes 40% degradation on SPU)
2009-04-02 Richard Guenther <rguenther@suse.de>
PR tree-optimization/37221
* tree-flow.h (degenerate_phi_result): Declare.
* tree-ssa-dom.c (degenerate_phi_result): Export.
* tree-scalar-evolution.c (analyze_initial_condition): If
the initial condition is defined by a degenerate PHI node
use the degenerate value.
* gcc.c-torture/compile/20090331-1.c: New testcase.
From-SVN: r145439
Diffstat (limited to 'gcc/tree-scalar-evolution.c')
| -rw-r--r-- | gcc/tree-scalar-evolution.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/gcc/tree-scalar-evolution.c b/gcc/tree-scalar-evolution.c index 8e12c2b..af959b7 100644 --- a/gcc/tree-scalar-evolution.c +++ b/gcc/tree-scalar-evolution.c @@ -1577,6 +1577,20 @@ analyze_initial_condition (gimple loop_phi_node) if (init_cond == chrec_not_analyzed_yet) init_cond = chrec_dont_know; + /* During early loop unrolling we do not have fully constant propagated IL. + Handle degenerate PHIs here to not miss important unrollings. */ + if (TREE_CODE (init_cond) == SSA_NAME) + { + gimple def = SSA_NAME_DEF_STMT (init_cond); + tree res; + if (gimple_code (def) == GIMPLE_PHI + && (res = degenerate_phi_result (def)) != NULL_TREE + /* Only allow invariants here, otherwise we may break + loop-closed SSA form. */ + && is_gimple_min_invariant (res)) + init_cond = res; + } + if (dump_file && (dump_flags & TDF_DETAILS)) { fprintf (dump_file, " (init_cond = "); |