Improve uninit_analysis::collect_phi_def_edges
Commit Message
This avoids expanding an edge to those of a PHI def if it is not
may-undefined, reducing the number of compute_control_dep_chain calls.
Bootstrap and regtest in progress on x86_64-unknown-linux-gnu.
* gimple-predicate-analysis.cc
(uninit_analysis::collect_phi_def_edges): Only expand a
PHI def edge when it is possibly undefined.
---
gcc/gimple-predicate-analysis.cc | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
@@ -605,11 +605,7 @@ uninit_analysis::collect_phi_def_edges (gphi *phi, basic_block cd_root,
{
gimple *def = SSA_NAME_DEF_STMT (opnd);
- if (gimple_code (def) == GIMPLE_PHI
- && dominated_by_p (CDI_DOMINATORS, gimple_bb (def), cd_root))
- collect_phi_def_edges (as_a<gphi *> (def), cd_root, edges,
- visited);
- else if (!m_eval (opnd))
+ if (!m_eval (opnd))
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
@@ -622,6 +618,10 @@ uninit_analysis::collect_phi_def_edges (gphi *phi, basic_block cd_root,
}
edges->safe_push (opnd_edge);
}
+ else if (gimple_code (def) == GIMPLE_PHI
+ && dominated_by_p (CDI_DOMINATORS, gimple_bb (def), cd_root))
+ collect_phi_def_edges (as_a<gphi *> (def), cd_root, edges,
+ visited);
}
else
{