Kill flags are difficult to maintain, and liveness queries are better
handled by live intervals.
Kill flags are reinserted after register allocation by addKillFlags().
llvm-svn: 163334
A value number is a PHI def if and only if it begins at a block
boundary. This can be derived from the def slot, a separate flag is not
necessary.
llvm-svn: 160893
Catch uses of undefined physregs that haven't been added to basic block
live-in lists. Run the verifier to pinpoint the problem.
Also run the verifier when a virtual register use is not jointly
dominated by defs.
llvm-svn: 160207
If a value is defined by a COPY, that instuction can easily and cheaply
be found by getInstructionFromIndex(VNI->def).
This reduces the size of VNInfo from 24 to 16 bytes, and improves
llc compile time by 3%.
llvm-svn: 149763
SplitKit will soon need two copies of these data structures, and the
algorithms will also be useful when LiveIntervalAnalysis becomes
independent of LiveVariables.
llvm-svn: 139572