https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113907
--- Comment #57 from Jan Hubicka <hubicka at ucw dot cz> --- > So, we can punt on differences there (that is desirable for backporting and > maybe GCC 14 too), or we could at that point populate an int vector, which > maps Yep, that is what I do. I had bug in that so I am re-running (forgot to check that callers and callee argument count matches and this cuases ICE during LLVM LTO link). It seems these extra checks makes no difference in practice. During bootstrap there are no pairs of functions during bootstrap where we new checks punt on value range difference or jump function difference that would be merged otherwise. Most common case where we could merge but we don't are those triggered by TBAA. > the callee > vector indexes to indexes in the callee vector in the other candidate > function. > If unsuccessful, we just free the vector, if successful, we first walk all the > callees and union stuff in there using that vector. This is the plan for metadata merging. A small complication here is that ICF works by comparing bodies to a leader of equivalence class but this leader is not necessarilly the surviving function body. So if we compared A to L (leader) and B to L and then decided replace A by B, we need to be able to combine the permutations so we know how to map call sites in A to ones in B. The same is true about SSA names and basic blocks. I have patch for that for next stage1.
