[PATCH] D83640: [PredicateInfo] Add a common method to interpret predicate as cmp constraint

[Nikita Popov via Phabricator via llvm-commits]

nikic created this revision.
nikic added a reviewer: fhahn.
Herald added subscribers: llvm-commits, hiraditya, Prazek.
Herald added a project: LLVM.

Both users of predicteinfo (NewGVN and SCCP) are interested in getting a cmp constraint on the predicated value. They currently implement separate logic for this. This patch adds a common method for this in PredicateWithCondition (it would be nice to drop the PredicateBase/PredicateWithCondition split ... I saw you had a patch for that).

This enables a missing bit of PredicateInfo handling in SCCP: Now the predicate on the condition itself is also used. For switches it means we know that the switched-on value is the same as the case value. For assumes/branches we know that the condition is true or false.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D83640

Files:
  llvm/include/llvm/Transforms/Utils/PredicateInfo.h
  llvm/lib/Transforms/Scalar/NewGVN.cpp
  llvm/lib/Transforms/Scalar/SCCP.cpp
  llvm/lib/Transforms/Utils/PredicateInfo.cpp
  llvm/test/Transforms/SCCP/predicateinfo-cond.ll

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