Commit Graph

3 Commits

Author SHA1 Message Date
Justin Bogner 0fb7ed5726 LoopUnroll: Use the optsize threshold for minsize as well
Currently we're unrolling loops more in minsize than in optsize, which
means -Oz will have a larger code size than -Os. That doesn't make any
sense.

This resolves the FIXME about this in LoopUnrollPass and extends the
optsize test to make sure we use the smaller threshold for minsize as
well.

llvm-svn: 257402
2016-01-11 22:39:43 +00:00
Hal Finkel 38dd590861 [LoopUnroll] Fix the partial unrolling threshold for small loop sizes
When we compute the size of a loop, we include the branch on the backedge and
the comparison feeding the conditional branch. Under normal circumstances,
these don't get replicated with the rest of the loop body when we unroll. This
led to the somewhat surprising behavior that really small loops would not get
unrolled enough -- they could be unrolled more and the resulting loop would be
below the threshold, because we were assuming they'd take
(LoopSize * UnrollingFactor) instructions after unrolling, instead of
(((LoopSize-2) * UnrollingFactor)+2) instructions. This fixes that computation.

llvm-svn: 225565
2015-01-10 00:30:55 +00:00
Hongbin Zheng e1fd20172b Add testcase for r154007, when a function has the optsize attribute,
the loop should be unrolled according the value of OptSizeUnrollThreshold.

llvm-svn: 154014
2012-04-04 13:24:40 +00:00