diff options
| -rw-r--r-- | lib/Transforms/Scalar/LoopUnswitch.cpp | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/lib/Transforms/Scalar/LoopUnswitch.cpp b/lib/Transforms/Scalar/LoopUnswitch.cpp index 945803f0af..b3003845d4 100644 --- a/lib/Transforms/Scalar/LoopUnswitch.cpp +++ b/lib/Transforms/Scalar/LoopUnswitch.cpp @@ -333,11 +333,11 @@ unsigned LoopUnswitch::getLoopUnswitchCost(Loop *L, Value *LIC) { if (IsTrivialUnswitchCondition(L, LIC)) return 0; - // If the loop is really large (over twice our threshold) don't even consider - // unswitching it. This will produce a really large loop with lots of empty - // blocks. - if (L->getBlocks().size() > 2*Threshold) - return 2*Threshold; + // FIXME: This is really overly conservative. However, more liberal + // estimations have thus far resulted in excessive unswitching, which is bad + // both in compile time and in code size. This should be replaced once + // someone figures out how a good estimation. + return L->getBlocks().size(); unsigned Cost = 0; // FIXME: this is brain dead. It should take into consideration code |