Skip to content
Commit bd0f1079 authored by Benjamin Kramer's avatar Benjamin Kramer
Browse files

BlockFrequency: Saturate at 1 instead of 0 when multiplying a frequency with a branch probability.

Zero is used by BlockFrequencyInfo as a special "don't know" value. It also
causes a sink for frequencies as you can't ever get off a zero frequency with
more multiplies.

This recovers a 10% regression on MultiSource/Benchmarks/7zip. A zero frequency
was propagated into an inner loop causing excessive spilling.

PR16402.

llvm-svn: 184584
parent f0401181
Loading
Loading
Loading
Loading
0% Loading or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment