[llvm] r330100 - [NFC] ConstantOffsetExtractor::CanTraceInto(): add FIXME: no tests

[Roman Lebedev via llvm-commits]

Author: lebedevri
Date: Sun Apr 15 11:59:27 2018
New Revision: 330100

URL: http://llvm.org/viewvc/llvm-project?rev=330100&view=rev
Log:
[NFC] ConstantOffsetExtractor::CanTraceInto(): add FIXME: no tests

As suggested in https://reviews.llvm.org/D45631#1068338,
looking at haveNoCommonBitsSet() users, and *trying* to
show the change effect elsewhere.

Modified:
    llvm/trunk/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp?rev=330100&r1=330099&r2=330100&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp Sun Apr 15 11:59:27 2018
@@ -497,6 +497,8 @@ bool ConstantOffsetExtractor::CanTraceIn
   Value *LHS = BO->getOperand(0), *RHS = BO->getOperand(1);
   // Do not trace into "or" unless it is equivalent to "add". If LHS and RHS
   // don't have common bits, (LHS | RHS) is equivalent to (LHS + RHS).
+  // FIXME: this does not appear to be covered by any tests
+  //        (with x86/aarch64 backends at least)
   if (BO->getOpcode() == Instruction::Or &&
       !haveNoCommonBitsSet(LHS, RHS, DL, nullptr, BO, DT))
     return false;