[ADT] Normalize empty triple components

LLVM triple normalization is handling "unknown" and empty components
differently; for example given "x86_64-unknown-linux-gnu" and
"x86_64-linux-gnu" which should be equivalent, triple normalization
returns "x86_64-unknown-linux-gnu" and "x86_64--linux-gnu". autoconf's
config.sub returns "x86_64-unknown-linux-gnu" for both
"x86_64-linux-gnu" and "x86_64-unknown-linux-gnu". This changes the
triple normalization to behave the same way, replacing empty triple
components with "unknown".

This addresses PR37129.

Differential Revision: https://reviews.llvm.org/D50219

llvm-svn: 339294

1 files changed, 0 insertions, 1 deletions

diff --git a/llvm/tools/llvm-mca/llvm-mca.cpp b/llvm/tools/llvm-mca/llvm-mca.cpp
index 897ff232a36..5b91f4a8e4d 100644
--- a/llvm/tools/llvm-mca/llvm-mca.cpp
+++ b/llvm/tools/llvm-mca/llvm-mca.cpp
@@ -180,7 +180,6 @@ static cl::opt<bool>
 namespace {
 
 const Target *getTarget(const char *ProgName) {
-  TripleName = Triple::normalize(TripleName);
   if (TripleName.empty())
     TripleName = Triple::normalize(sys::getDefaultTargetTriple());
   Triple TheTriple(TripleName);