Commit Graph

4 Commits

Author SHA1 Message Date
Quentin Colombet 5084e44d71 [ARM] Make sure we do not dereference the end iterator when accessing debug
information.
Although the problem was always here, it would only be exposed when
shrink-wrapping is enable.

rdar://problem/23110493

llvm-svn: 250352
2015-10-15 00:41:26 +00:00
Quentin Colombet b4c6886215 [ShrinkWrap] Refactor the handling of infinite loop in the analysis.
- Strenghten the logic to be sure we hoist the restore point out of the current
  loop. (The fixes a bug with infinite loop, added as part of the patch.)
- Walk over the exit blocks of the current loop to conver to the desired restore
  point in one iteration of the update loop.

llvm-svn: 247958
2015-09-17 23:21:34 +00:00
Kit Barton a7bf96ab5c Fix possible infinite loop in shrink wrapping when searching for save/restore
points.

There is an infinite loop that can occur in Shrink Wrapping while searching 
for the Save/Restore points. 

Part of this search checks whether the save/restore points are located in
different loop nests and if so, uses the (post) dominator trees to find the
immediate (post) dominator blocks. However, if the current block does not have
any immediate (post) dominators then this search will result in an infinite
loop. This can occur in code containing an infinite loop.

The modification checks whether the immediate (post) dominator is different from
the current save/restore block. If it is not, then the search terminates and the
current location is not considered as a valid save/restore point for shrink wrapping.

Phabricator: http://reviews.llvm.org/D11607
llvm-svn: 244247
2015-08-06 19:01:57 +00:00
Quentin Colombet 48b772007f [ARM] Make the frame lowering code ready for shrink-wrapping.
Shrink-wrapping can now be tested on ARM with -enable-shrink-wrap.

Related to <rdar://problem/20821730>

llvm-svn: 242908
2015-07-22 16:34:37 +00:00