Avoid copies of std::strings and APInt/APFloats where we only read from it

As suggested by clang-tidy's performance-unnecessary-copy-initialization.
This can easily hit lifetime issues, so I audited every change and ran the
tests under asan, which came back clean.

llvm-svn: 272126

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/Scalar/GuardWidening.cpp b/llvm/lib/Transforms/Scalar/GuardWidening.cpp
index 18ce986c3da..ee31dfa5f0d 100644
--- a/llvm/lib/Transforms/Scalar/GuardWidening.cpp
+++ b/llvm/lib/Transforms/Scalar/GuardWidening.cpp
@@ -599,7 +599,7 @@ bool GuardWideningImpl::combineRangeChecks(
       return false;
 
     APInt MaxDiff = MaxOffset->getValue() - MinOffset->getValue();
-    APInt HighOffset = MaxOffset->getValue();
+    const APInt &HighOffset = MaxOffset->getValue();
     auto OffsetOK = [&](const GuardWideningImpl::RangeCheck &RC) {
       return (HighOffset - RC.getOffsetValue()).ult(MaxDiff);
     };