Arnold Schwaighofer 6fad756c74 swifterror: Don't compute swifterror vregs during instruction selection ... The code used llvm basic block predecessors to decided where to insert phi nodes. Instruction selection can and will liberally insert new machine basic block predecessors. There is not a guaranteed one-to-one mapping from pred. llvm basic blocks and machine basic blocks. Therefore the current approach does not work as it assumes we can mark predecessor machine basic block as needing a copy, and needs to know the set of all predecessor machine basic blocks to decide when to insert phis. Instead of computing the swifterror vregs as we select instructions, propagate them at the end of instruction selection when the MBB CFG is complete. When an instruction needs a swifterror vreg and we don't know the value yet, generate a new vreg and remember this "upward exposed" use, and reconcile this at the end of instruction selection. This will only happen if the target supports promoting swifterror parameters to registers and the swifterror attribute is used. rdar://28300923 llvm-svn: 283617		2016-10-07 22:06:55 +00:00
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llvm	swifterror: Don't compute swifterror vregs during instruction selection	2016-10-07 22:06:55 +00:00
llvm-c	[C API] Add LLVMConstExactUDiv and LLVMBuildExactUDiv functions.	2016-10-04 23:32:42 +00:00