https://github.com/tobias-stadler created https://github.com/llvm/llvm-project/pull/102163
Continues the work for disabling fixed-point iteration in the Combiner (#94291). This introduces improved Observer-based heuristics in the GISel Combiner to retry combining defs/uses of modified instructions and for performing sparse dead code elimination. I have experimented a lot with the heuristics and this seems to be the minimal set of heuristics that allows disabling fixed-point iteration for AArch64 CTMark O2 without regressions. Enabling this globally would pass all regression tests for all official targets (apart from small benign diffs), but I have made this fully opt-in for now, because I can't quantify the impact for other targets. For performance numbers see my follow-up patch for AArch64. _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
