llvm-project

6b13656f - [BOLT][AArch64] Transform cmpbr ~> cmp + br when inversion not possible (#185731)

[BOLT][AArch64] Transform cmpbr ~> cmp + br when inversion not possible (#185731) When reordering blocks we may have to invert branches. Sometimes this isn't possible for compare-and-branch instructions because the immediate value would overflow/underflow after the adjustment. In such cases I am splitting the instruction into a compare followed by a branch. For this to be legal we should be sure that the condition flags are not being clobbered. Liveness analysis may help here.