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| author | Zdenek Dvorak <rakdver@atrey.karlin.mff.cuni.cz> | 2004-02-17 20:51:15 +0100 |
|---|---|---|
| committer | Jeff Law <law@gcc.gnu.org> | 2004-02-17 12:51:15 -0700 |
| commit | 017b3258fa075ff64facea88e200ee6b88bcd602 (patch) | |
| tree | 8a82c181579a38d2a696ed2860af7e1f75ec4e38 | |
| parent | e70e9b0faac98b2f123c0cd1c20da1d54e986738 (diff) | |
| download | gcc-017b3258fa075ff64facea88e200ee6b88bcd602.zip gcc-017b3258fa075ff64facea88e200ee6b88bcd602.tar.gz gcc-017b3258fa075ff64facea88e200ee6b88bcd602.tar.bz2 | |
* cfghooks.c (split_edge): Speed up updating of dominators.
From-SVN: r77973
| -rw-r--r-- | gcc/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/cfghooks.c | 31 |
2 files changed, 32 insertions, 3 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index c099df6..33c5733 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,7 @@ +2004-02-17 Zdenek Dvorak <rakdver@atrey.karlin.mff.cuni.cz> + + * cfghooks.c (split_edge): Speed up updating of dominators. + 2004-02-17 Mark Mitchell <mark@codesourcery.com> PR c++/11326 diff --git a/gcc/cfghooks.c b/gcc/cfghooks.c index ab47181..e256124 100644 --- a/gcc/cfghooks.c +++ b/gcc/cfghooks.c @@ -373,6 +373,7 @@ split_edge (edge e) basic_block ret; gcov_type count = e->count; int freq = EDGE_FREQUENCY (e); + edge f; if (!cfg_hooks->split_edge) internal_error ("%s does not support split_edge.", cfg_hooks->name); @@ -387,9 +388,33 @@ split_edge (edge e) set_immediate_dominator (CDI_DOMINATORS, ret, ret->pred->src); if (dom_computed[CDI_DOMINATORS] >= DOM_NO_FAST_QUERY) - set_immediate_dominator (CDI_DOMINATORS, ret->succ->dest, - recount_dominator (CDI_DOMINATORS, - ret->succ->dest)); + { + /* There are two cases: + + If the immediate dominator of e->dest is not e->src, it + remains unchanged. + + If immediate dominator of e->dest is e->src, it may become + ret, provided that all other predecessors of e->dest are + dominated by e->dest. */ + + if (get_immediate_dominator (CDI_DOMINATORS, ret->succ->dest) + == ret->pred->src) + { + for (f = ret->succ->dest->pred; f; f = f->pred_next) + { + if (f == ret->succ) + continue; + + if (!dominated_by_p (CDI_DOMINATORS, f->src, + ret->succ->dest)) + break; + } + + if (!f) + set_immediate_dominator (CDI_DOMINATORS, ret->succ->dest, ret); + } + }; return ret; } |