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| author | Richard Biener <rguenther@suse.de> | 2016-11-04 08:54:42 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2016-11-04 08:54:42 +0000 |
| commit | 964ef24cd591632a38c3e48154de389470df13df (patch) | |
| tree | 1b2211b7c396c888eb15aa2da13e53fad2848ab5 /gcc/tree-ssa-loop-im.c | |
| parent | b07aafb1ace3bf542acf3884bddf014d0d466ef3 (diff) | |
| download | gcc-964ef24cd591632a38c3e48154de389470df13df.zip gcc-964ef24cd591632a38c3e48154de389470df13df.tar.gz gcc-964ef24cd591632a38c3e48154de389470df13df.tar.bz2 | |
re PR tree-optimization/78185 (Wrong branch optimization with -O1 on x86/x86_64)
2016-11-04 Richard Biener <rguenther@suse.de>
PR middle-end/78185
* loop-invariant.c (find_exits): Record entering inner
loops as possibly exiting to handle infinite sub-loops.
* tree-ssa-loop-im.c: Include tree-ssa-loop-niter.h.
(fill_always_executed_in_1): Honor infinite child loops.
* gcc.dg/pr78185.c: New testcase.
From-SVN: r241841
Diffstat (limited to 'gcc/tree-ssa-loop-im.c')
| -rw-r--r-- | gcc/tree-ssa-loop-im.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/gcc/tree-ssa-loop-im.c b/gcc/tree-ssa-loop-im.c index 463db04..0524e57 100644 --- a/gcc/tree-ssa-loop-im.c +++ b/gcc/tree-ssa-loop-im.c @@ -44,6 +44,7 @@ along with GCC; see the file COPYING3. If not see #include "trans-mem.h" #include "gimple-fold.h" #include "tree-scalar-evolution.h" +#include "tree-ssa-loop-niter.h" /* TODO: Support for predicated code motion. I.e. @@ -2369,8 +2370,16 @@ fill_always_executed_in_1 (struct loop *loop, sbitmap contains_call) break; FOR_EACH_EDGE (e, ei, bb->succs) - if (!flow_bb_inside_loop_p (loop, e->dest)) - break; + { + /* If there is an exit from this BB. */ + if (!flow_bb_inside_loop_p (loop, e->dest)) + break; + /* Or we enter a possibly non-finite loop. */ + if (flow_loop_nested_p (bb->loop_father, + e->dest->loop_father) + && ! finite_loop_p (e->dest->loop_father)) + break; + } if (e) break; |