[PATCH] D128011: [SimplifyLibCalls] Transform memchr(STR, C, N) to chain of ORs

[Nikita Popov via Phabricator via llvm-commits]

nikic added inline comments.


================
Comment at: llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp:1405
+    for (size_t i = 1; i < SortedStr.size(); ++i) {
+        if (SortedStr[i] > SortedStr[i - 1] + 1) {
+            NonContRanges++;
----------------
So, the reason why this checks `>` rather than `!=` is to handle the case where the same char appears in the string multiple times, right? I don't think there is a test for this case right now, could you please add one?


================
Comment at: llvm/test/Transforms/InstCombine/memchr-7.ll:2
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt < %s -passes=instcombine -S | FileCheck %s
 
----------------
Can you please add `-instcombine-infinite-loop-threshold=2` to this test, to make sure this doesn't require multiple iteration to fold.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D128011/new/

https://reviews.llvm.org/D128011