Jakob Stoklund Olesen aba6559370 Add an MRI::tracksLiveness() flag. ... Late optimization passes like branch folding and tail duplication can transform the machine code in a way that makes it expensive to keep the register liveness information up to date. There is a fuzzy line between register allocation and late scheduling where the liveness information degrades. The MRI::tracksLiveness() flag makes the line clear: While true, liveness information is accurate, and can be used for register scavenging. Once the flag is false, liveness information is not accurate, and can only be used as a hint. Late passes generally don't need the liveness information, but they will sometimes use the register scavenger to help update it. The scavenger enforces strict correctness, and we have to spend a lot of code to update register liveness that may never be used. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153511 91177308-0d34-0410-b5e6-96231b3b80d8		2012-03-27 15:13:58 +00:00
..
llvm	Add an MRI::tracksLiveness() flag.	2012-03-27 15:13:58 +00:00
llvm-c	Add 'undef's to make SWIG happier. Patch by Baozeng Ding.	2012-03-26 22:15:12 +00:00