[all-commits] [llvm/llvm-project] 464b9a: [InstCombine] Transform extelt-trunc -> bitcast-ex...

[Daan Sprenkels via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 464b9aeafe29104a1a8391f43f91835eeca473b3
      https://github.com/llvm/llvm-project/commit/464b9aeafe29104a1a8391f43f91835eeca473b3
  Author: Daan Sprenkels <daan at dsprenkels.com>
  Date:   2020-03-31 (Tue, 31 Mar 2020)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp
    M llvm/test/Transforms/InstCombine/ExtractCast.ll
    M llvm/test/Transforms/InstCombine/trunc-extractelement.ll

  Log Message:
  -----------
  [InstCombine] Transform extelt-trunc -> bitcast-extelt

Canonicalize the case when a scalar extracted from a vector is
truncated.  Transform such cases to bitcast-then-extractelement.
This will enable erasing the truncate operation.

This commit fixes PR45314.

reviewers: spatel

Differential revision: https://reviews.llvm.org/D76983