diff options
| author | Jeff Law <law@redhat.com> | 2004-12-13 13:12:33 -0700 |
|---|---|---|
| committer | Jeff Law <law@gcc.gnu.org> | 2004-12-13 13:12:33 -0700 |
| commit | fe8728354109159d6b79af99eae6e94f2a282027 (patch) | |
| tree | f1f33fd9143d420f1272633b80a8e2b2bf0908f0 /gcc/tree-ssa-dom.c | |
| parent | 143b6bc3190ea8dfb60bdc611c207d0e15be1cdb (diff) | |
| download | gcc-fe8728354109159d6b79af99eae6e94f2a282027.zip gcc-fe8728354109159d6b79af99eae6e94f2a282027.tar.gz gcc-fe8728354109159d6b79af99eae6e94f2a282027.tar.bz2 | |
tree-ssa-dom.c (thread_across_edge): Do not thread jumps if a PHI argument is set from a PHI_RESULT in the same...
* tree-ssa-dom.c (thread_across_edge): Do not thread jumps if a
PHI argument is set from a PHI_RESULT in the same block and the
PHI argument is not the same as the PHI result.
Co-Authored-By: Kazu Hirata <kazu@cs.umass.edu>
From-SVN: r92102
Diffstat (limited to 'gcc/tree-ssa-dom.c')
| -rw-r--r-- | gcc/tree-ssa-dom.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/gcc/tree-ssa-dom.c b/gcc/tree-ssa-dom.c index 3a3bdad..81fdb0e 100644 --- a/gcc/tree-ssa-dom.c +++ b/gcc/tree-ssa-dom.c @@ -550,6 +550,16 @@ thread_across_edge (struct dom_walk_data *walk_data, edge e) { tree src = PHI_ARG_DEF_FROM_EDGE (phi, e); tree dst = PHI_RESULT (phi); + + /* If the desired argument is not the same as this PHI's result + and it is set by a PHI in this block, then we can not thread + through this block. */ + if (src != dst + && TREE_CODE (src) == SSA_NAME + && TREE_CODE (SSA_NAME_DEF_STMT (src)) == PHI_NODE + && bb_for_stmt (SSA_NAME_DEF_STMT (src)) == e->dest) + return; + record_const_or_copy (dst, src); register_new_def (dst, &block_defs_stack); } |