[all-commits] [llvm/llvm-project] 5197d2: [SimplifyLibCalls] Move handling of constant char ...

[Martin Sebor via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 5197d2791f908815134ad48d7b966de2d8c47eeb
      https://github.com/llvm/llvm-project/commit/5197d2791f908815134ad48d7b966de2d8c47eeb
  Author: Martin Sebor <msebor at redhat.com>
  Date:   2022-04-04 (Mon, 04 Apr 2022)

  Changed paths:
    M llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp

  Log Message:
  -----------
  [SimplifyLibCalls] Move handling of constant char earlier (NFC)

Handle the simple constant char case before the bitmask optimization.
This will allow extending the code to handle a non-constant size
argument in a followup change.

Split out from https://reviews.llvm.org/D122836.


  Commit: 5ccfd5f6d43069a5bc152b335bc704c6d2584ddc
      https://github.com/llvm/llvm-project/commit/5ccfd5f6d43069a5bc152b335bc704c6d2584ddc
  Author: Martin Sebor <msebor at redhat.com>
  Date:   2022-04-04 (Mon, 04 Apr 2022)

  Changed paths:
    M llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
    M llvm/test/Transforms/InstCombine/memchr-2.ll

  Log Message:
  -----------
  [SimplifyLibCalls] Optimize memchr() with known char+str and unknown length

If both the character and string are known, but the length
potentially isn't, we can optimize the memchr() call to a select
of either the known position of the character or null.

Split off from https://reviews.llvm.org/D122836.


Compare: https://github.com/llvm/llvm-project/compare/d333b382701e...5ccfd5f6d430