2 Commits

Author	SHA1	Message	Date
Eli Friedman	1478b657c8	Enhanced vzeroupper insertion pass that avoids inserting vzeroupper where it is unnecessary through local analysis. Patch from Bruno Cardoso Lopes, with some additional changes. ... I'm going to wait for any review comments and perform some additional testing before turning this on by default. llvm-svn: 143750	2011-11-04 23:46:11 +00:00
Bruno Cardoso Lopes	8024703a16	Introduce a pass to insert vzeroupper instructions to avoid AVX to ... SSE transition penalty. The pass is enabled through the "x86-use-vzeroupper" llc command line option. This is only the first step (very naive and conservative one) to sketch out the idea, but proper DFA is coming next to allow smarter decisions. Comments and ideas now and in further commits will be very appreciated. llvm-svn: 138317	2011-08-23 01:14:17 +00:00