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| author | Cong Hou <congh@google.com> | 2015-09-18 18:19:40 +0000 |
|---|---|---|
| committer | Cong Hou <congh@google.com> | 2015-09-18 18:19:40 +0000 |
| commit | f9f9ffb98becba3bf72ab121b5f89f4c250b029d (patch) | |
| tree | a662c296d49e983dcca191e117957b592a525018 /llvm/lib/Transforms/Scalar/JumpThreading.cpp | |
| parent | 2b38f33b82d9d0dd9dc566edb532f71c2406886c (diff) | |
| download | bcm5719-llvm-f9f9ffb98becba3bf72ab121b5f89f4c250b029d.tar.gz bcm5719-llvm-f9f9ffb98becba3bf72ab121b5f89f4c250b029d.zip | |
Scaling up values in ARMBaseInstrInfo::isProfitableToIfCvt() before they are scaled by a probability to avoid precision issue.
In ARMBaseInstrInfo::isProfitableToIfCvt(), there is a simple cost model in which the number of cycles is scaled by a probability to estimate the cost. However, when the number of cycles is small (which is usually the case), there is a precision issue after the computation. To avoid this issue, this patch scales those cycles by 1024 (chosen to make the multiplication a litter faster) before they are scaled by the probability. Other variables are also scaled up for the final comparison.
Differential Revision: http://reviews.llvm.org/D12742
llvm-svn: 248018
Diffstat (limited to 'llvm/lib/Transforms/Scalar/JumpThreading.cpp')
0 files changed, 0 insertions, 0 deletions
