forked from OSchip/llvm-project
fc7654a67b
As K has to dominate I, IIUC I's range metadata must be a subset of K's. After Eli's recent clarification to the LangRef, loading a value outside of the range is undefined behavior. Therefore if I's range contains elements outside of K's range and we would load one such value, K would cause undefined behavior. In cases like hoisting/sinking, we still want the most generic range over all code paths to/from the hoist/sink point. As suggested in the patches related to D47339, I will refactor the handling of those scenarios and try to decouple it from this function as follow up, once we switched to a similar handling of metadata in most of combineMetadata. I updated some tests checking mostly the merging of metadata to keep the metadata of to dominating load. The most interesting one is probably test8 in test/Transforms/JumpThreading/thread-loads.ll. It contained a comment about the alias metadata preventing us to eliminate the branch, but it seem like the actual problem currently is that we merge the ranges of both loads and cannot eliminate the icmp afterwards. With this patch, we manage to eliminate the icmp, as the range of the first load excludes 8. Reviewers: efriedma, nlopes, davide Reviewed By: efriedma Differential Revision: https://reviews.llvm.org/D51629 llvm-svn: 345456 |
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| .. | ||
| 2008-11-27-EntryMunge.ll | ||
| 2010-08-26-and.ll | ||
| 2011-04-02-SimplifyDeadBlock.ll | ||
| 2011-04-14-InfLoop.ll | ||
| 2012-07-19-NoSuccessorIndirectBr.ll | ||
| PR33357-lvi-recursion.ll | ||
| PR37745.ll | ||
| and-and-cond.ll | ||
| and-cond.ll | ||
| assume-edge-dom.ll | ||
| assume.ll | ||
| basic.ll | ||
| bb-unreachable-from-entry.ll | ||
| branch-no-const.ll | ||
| combine-metadata.ll | ||
| compare.ll | ||
| conservative-lvi.ll | ||
| crash.ll | ||
| ddt-crash.ll | ||
| ddt-crash2.ll | ||
| ddt-crash3.ll | ||
| ddt-crash4.ll | ||
| degenerate-phi.ll | ||
| fold-not-thread.ll | ||
| guards.ll | ||
| header-succ.ll | ||
| implied-cond.ll | ||
| indirectbr.ll | ||
| induction.ll | ||
| landing-pad.ll | ||
| lvi-load.ll | ||
| lvi-tristate.ll | ||
| no-irreducible-loops.ll | ||
| or-undef.ll | ||
| phi-eq.ll | ||
| phi-known.ll | ||
| pr9331.ll | ||
| pr15851_hang.ll | ||
| pr22086.ll | ||
| pr26096.ll | ||
| pr27840.ll | ||
| pr33605.ll | ||
| pr33917.ll | ||
| pr36133.ll | ||
| range-compare.ll | ||
| removed-use.ll | ||
| select.ll | ||
| static-profile.ll | ||
| thread-cmp.ll | ||
| thread-loads.ll | ||
| threading_prof1.ll | ||
| threading_prof2.ll | ||
| update-edge-weight.ll | ||