[PATCH] D95260: [Local] Don't DCE calls that may not return

[Nikita Popov via Phabricator via llvm-commits]

nikic created this revision.
nikic added reviewers: jdoerfert, fhahn.
Herald added subscribers: lxfind, okura, kuter.
nikic requested review of this revision.
Herald added a reviewer: sstefan1.
Herald added subscribers: llvm-commits, bbn, sstefan1.
Herald added a reviewer: baziotis.
Herald added a project: LLVM.

Calls that aren't willreturn should not be eliminated, as this may remove an infinite loop.

This patch is a slightly more conservative variation on D94106 <https://reviews.llvm.org/D94106> which assumes that intrinsics are willreturn, as most target intrinsics have not been properly annotated yet, and we don't want to break DCE for them.

In conjunction with the recently implemented willreturn inference, I hope this is conservative enough to land before LLVM 12 branches.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D95260

Files:
  lib/Transforms/Utils/Local.cpp
  test/Transforms/Attributor/ArgumentPromotion/fp80.ll
  test/Transforms/Attributor/align.ll
  test/Transforms/Attributor/nocapture-1.ll
  test/Transforms/Attributor/nocapture-2.ll
  test/Transforms/Attributor/nonnull.ll
  test/Transforms/Attributor/norecurse.ll
  test/Transforms/Attributor/range.ll
  test/Transforms/Attributor/readattrs.ll
  test/Transforms/BDCE/basic.ll
  test/Transforms/CodeGenPrepare/X86/delete-assume-dead-code.ll
  test/Transforms/Coroutines/coro-split-00.ll
  test/Transforms/Coroutines/coro-split-hidden.ll
  test/Transforms/Coroutines/no-suspend.ll
  test/Transforms/InstCombine/nothrow.ll
  test/Transforms/InstSimplify/ConstProp/calls-math-finite.ll
  test/Transforms/InstSimplify/ConstProp/calls.ll
  test/Transforms/InstSimplify/ConstProp/math-1.ll
  test/Transforms/InstSimplify/ConstProp/math-2.ll
  test/Transforms/InstSimplify/ConstProp/rint.ll
  test/Transforms/InstSimplify/ConstProp/round.ll
  test/Transforms/InstSimplify/ConstProp/trunc.ll
  test/Transforms/InstSimplify/remove-dead-call.ll
  test/Transforms/InstSimplify/returned.ll
  test/Transforms/NewGVN/eliminate-callsite-inline.ll
  test/Transforms/OpenMP/parallel_deletion.ll
  test/Transforms/Reassociate/erase_inst_made_change.ll

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