diff --git a/llvm/.gitattributes b/llvm/.gitattributes
--- a/llvm/.gitattributes
+++ b/llvm/.gitattributes
@@ -13,7 +13,8 @@
 test/MC/AsmParser/incbin_abcd binary
 test/YAMLParser/spec-09-02.test binary
 
-# This file must have CRLF line endings, therefore git should treat it as
+# These files must have CRLF line endings, therefore git should treat them as
 # binary and not autoconvert line endings (for example, when core.autocrlf is
 # on).
 test/MC/AsmParser/preserve-comments-crlf.s binary
+test/tools/llvm-mca/directives-handle-crlf.s binary
diff --git a/llvm/lib/MC/MCParser/AsmLexer.cpp b/llvm/lib/MC/MCParser/AsmLexer.cpp
--- a/llvm/lib/MC/MCParser/AsmLexer.cpp
+++ b/llvm/lib/MC/MCParser/AsmLexer.cpp
@@ -228,6 +228,7 @@
   int CurChar = getNextChar();
   while (CurChar != '\n' && CurChar != '\r' && CurChar != EOF)
     CurChar = getNextChar();
+  const char *NewlinePtr = CurPtr;
   if (CurChar == '\r' && CurPtr != CurBuf.end() && *CurPtr == '\n')
     ++CurPtr;
 
@@ -235,7 +236,7 @@
   if (CommentConsumer) {
     CommentConsumer->HandleComment(
         SMLoc::getFromPointer(CommentTextStart),
-        StringRef(CommentTextStart, CurPtr - 1 - CommentTextStart));
+        StringRef(CommentTextStart, NewlinePtr - 1 - CommentTextStart));
   }
 
   IsAtStartOfLine = true;
diff --git a/llvm/test/tools/llvm-mca/directives-handle-crlf.s b/llvm/test/tools/llvm-mca/directives-handle-crlf.s
new file mode 100644
--- /dev/null
+++ b/llvm/test/tools/llvm-mca/directives-handle-crlf.s
@@ -0,0 +1,4 @@
+# RUN: llvm-mca -mtriple=x86_64-unknown-unknown %s
+# LLVM-MCA-BEGIN foo
+addl	$42, %eax
+# LLVM-MCA-END