The patch is based on a reverted patch: https://reviews.llvm.org/D103597. It was trying to rename registers before alias check, which is not safe and causes miscompiles. This patch does 2 things: 1. Do the renaming with necessary checks passed, including alias check. 2. Rename the register for the instructions between the pairs and combine the second load into the first. By doing so we can just check the renamability between the pairs and avoid scanning unknown amount of instructions before/after the pairs. Necessary refactoring has been made in order to reuse as much code possible with STR renaming.
107 KiB
107 KiB