3 Commits

Author	SHA1	Message	Date
Jakob Stoklund Olesen	273f7e4299	Detect and handle COPY in many places. ... This code is transitional, it will soon be possible to eliminate isExtractSubreg, isInsertSubreg, and isMoveInstr in most places. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107547 91177308-0d34-0410-b5e6-96231b3b80d8	2010-07-03 00:04:37 +00:00
Bob Wilson	bf9b221c00	Besides removing phi cycles that reduce to a single value, also remove dead ... phi cycles. Adjust a few tests to keep dead instructions from being optimized away. This (together with my previous change for phi cycles) fixes Apple radar 7627077. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96057 91177308-0d34-0410-b5e6-96231b3b80d8	2010-02-13 00:31:44 +00:00
Bob Wilson	fe61fb1e10	Add a new pass on machine instructions to optimize away PHI cycles that ... reduce down to a single value. InstCombine already does this transformation but DAG legalization may introduce new opportunities. This has turned out to be important for ARM where 64-bit values are split up during type legalization: InstCombine is not able to remove the PHI cycles on the 64-bit values but the separate 32-bit values can be optimized. I measured the compile time impact of this (running llc on 176.gcc) and it was not significant. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95951 91177308-0d34-0410-b5e6-96231b3b80d8	2010-02-12 01:30:21 +00:00