Tweak MachineLICM heuristics for cheap instructions.
authorJakob Stoklund Olesen <stoklund@2pi.dk>
Wed, 11 Apr 2012 00:00:28 +0000 (00:00 +0000)
committerJakob Stoklund Olesen <stoklund@2pi.dk>
Wed, 11 Apr 2012 00:00:28 +0000 (00:00 +0000)
commit71fbed45d9f4e2e886afc7f22c058087e7872dc6
tree8ea5a94ca7edf97b66525c94c1dd6fc7fef52e75
parent8b560b8c485992dbd62ee31aaff5ac25b5549bd6
Tweak MachineLICM heuristics for cheap instructions.

Allow cheap instructions to be hoisted if they are register pressure
neutral or better. This happens if the instruction is the last loop use
of another virtual register.

Only expensive instructions are allowed to increase loop register
pressure.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154455 91177308-0d34-0410-b5e6-96231b3b80d8
lib/CodeGen/MachineLICM.cpp