Evict a lighter single interference before attempting to split a live range.
commita1d1ec0416f09612b4fa3363dabed26056524cd2
authorJakob Stoklund Olesen <stoklund@2pi.dk>
Wed, 9 Feb 2011 01:14:03 +0000 (9 01:14 +0000)
committerJakob Stoklund Olesen <stoklund@2pi.dk>
Wed, 9 Feb 2011 01:14:03 +0000 (9 01:14 +0000)
tree94eb0449093393b76f1a8f12079c8640c8456f97
parent0be054b63d7413355c9e162a6f84d3130def1478
Evict a lighter single interference before attempting to split a live range.

Registers are not allocated strictly in spill weight order when live range
splitting and spilling has created new shorter intervals with higher spill
weights.

When one of the new heavy intervals conflicts with a single lighter interval,
simply evict the old interval instead of trying to split the heavy one.

The lighter interval is a better candidate for splitting, it has a smaller use
density.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125151 91177308-0d34-0410-b5e6-96231b3b80d8
lib/CodeGen/RegAllocBase.h
lib/CodeGen/RegAllocBasic.cpp
lib/CodeGen/RegAllocGreedy.cpp