Jakob Stoklund Olesen 40d07bbebb Add CoalescerPair helper class. ... Given a copy instruction, CoalescerPair can determine which registers to coalesce in order to eliminate the copy. It deals with all the subreg fun to determine a tuple (DstReg, SrcReg, SubIdx) such that: - SrcReg is a virtual register that will disappear after coalescing. - DstReg is a virtual or physical register whose live range will be extended. - SubIdx is 0 when DstReg is a physical register. - SrcReg can be joined with DstReg:SubIdx. CoalescerPair::isCoalescable() determines if another copy instruction is compatible with the same tuple. This fixes some NEON miscompilations where shuffles are getting coalesced as if they were copies. The CoalescerPair class will replace a lot of the spaghetti logic in JoinCopy later. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105997 91177308-0d34-0410-b5e6-96231b3b80d8		2010-06-15 16:04:21 +00:00
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llvm	Add CoalescerPair helper class.	2010-06-15 16:04:21 +00:00
llvm-c	add some more (void)'s to prototypes for PR6961	2010-04-29 23:27:32 +00:00