[all-commits] [llvm/llvm-project] bbb297: [InstCombine] Fold PHIs with equal incoming pointers

[Daniil Suchkov via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: bbb29738b58aaf6f6518269abdcf8f64131665a9
      https://github.com/llvm/llvm-project/commit/bbb29738b58aaf6f6518269abdcf8f64131665a9
  Author: Daniil Suchkov <dsuchkov at azul.com>
  Date:   2019-11-13 (Wed, 13 Nov 2019)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineInternal.h
    M llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp
    M llvm/test/Transforms/InstCombine/phi-equal-incoming-pointers.ll

  Log Message:
  -----------
  [InstCombine] Fold PHIs with equal incoming pointers

In case when all incoming values of a PHI are equal pointers, this
transformation inserts a definition of such a pointer right after
definition of the base pointer and replaces with this value both PHI and
all it's incoming pointers. Primary goal of this transformation is
canonicalization of this pattern in order to enable optimizations that
can't handle PHIs. Non-inbounds pointers aren't currently supported.

Reviewers: spatel, RKSimon, lebedev.ri, apilipenko

Reviewed By: apilipenko

Tags: #llvm

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D68128