From a02f434c4e3172b1b02292ee8bb063667e4b26a2 Mon Sep 17 00:00:00 2001
From: Varun Gandhi <varun_gandhi@apple.com>
Date: Wed, 26 May 2021 11:28:24 -0700
Subject: [PATCH] Use additional musttail checking only in debug builds.

---
 llvm/lib/IR/Verifier.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index a6cdd65ecf674..4cd3e0027efe3 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -3323,6 +3323,7 @@ cl::init(false), cl::desc("Check that tail calls from swifttailcc functions to"
 
 void Verifier::verifyMustTailCall(CallInst &CI) {
   if (!CI.isMustTailCall()) {
+#ifndef NDEBUG
     if (EnableSwiftTailCCMustTailCheck &&
         CI.getCallingConv() == CallingConv::SwiftTail &&
         CI.getCaller()->getCallingConv() == CallingConv::SwiftTail &&
@@ -3331,6 +3332,7 @@ void Verifier::verifyMustTailCall(CallInst &CI) {
         false, "tail call from swifttail->swiftail should be marked musttail",
         &CI);
     }
+#endif
     return;
   }