Commit Graph

4 Commits

Author SHA1 Message Date
Andrew Trick
c9b1e25493 Enable the new LoopInfo algorithm by default.
The primary advantage is that loop optimizations will be applied in a
stable order. This helps debugging and unit test creation. It is also
a better overall implementation without pathologically bad performance
on deep functions.

On large functions (llvm-stress --size=200000 | opt -loops)
Before: 0.1263s
After:  0.0225s

On deep functions (after tweaking llvm-stress, thanks Nadav):
Before: 0.2281s
After:  0.0227s

See r158790 for more comments.

The loop tree is now consistently generated in forward order, but loop
passes are applied in reverse order over the program. If we have a
loop optimization that prefers forward order, that can easily be
achieved by adding a different type of LoopPassManager.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159183 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-26 04:11:38 +00:00
Chad Rosier
f1eba25303 Reinstate r146578; it doesn't appear to be the cause of some recent execution-
time regressions.  In general, it is beneficial to compile-time.

Original commit message:
Fix for bug #11429: Wrong behaviour for switches. Small improvement for code
size heuristics.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147175 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-22 21:06:36 +00:00
Chad Rosier
5ddb7a0105 Speculatively revert r146578 to determine if it is the cause of a number of
performance regressions (both execution-time and compile-time) on our
nightly testers.

Original commit message:
Fix for bug #11429: Wrong behaviour for switches. Small improvement for code
size heuristics.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147131 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-22 02:40:57 +00:00
Stepan Dyatkovskiy
ac12ef4ad2 Fix for bug #11429: Wrong behaviour for switches. Small improvement for code size heuristics.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146578 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-14 19:19:17 +00:00