1 files changed, 15 insertions, 4 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
index 8405ba9..6a6bc19 100644
--- a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -31,6 +31,7 @@
 #include "llvm/IR/Function.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/Module.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -200,12 +201,22 @@ void FunctionLoweringInfo::set(const Function &fn, MachineFunction &mf,
             }
           }
         }
-        // Look for calls to the @llvm.va_start intrinsic. We can omit some
-        // prologue boilerplate for variadic functions that don't examine their
-        // arguments.
         if (const auto *II = dyn_cast<IntrinsicInst>(&I)) {
-          if (II->getIntrinsicID() == Intrinsic::vastart)
+          switch (II->getIntrinsicID()) {
+          case Intrinsic::vastart:
+            // Look for calls to the @llvm.va_start intrinsic. We can omit
+            // some prologue boilerplate for variadic functions that don't
+            // examine their arguments.
             MF->getFrameInfo().setHasVAStart(true);
+            break;
+          case Intrinsic::fake_use:
+            // Look for llvm.fake.uses, so that we can remove loads into fake
+            // uses later if necessary.
+            MF->setHasFakeUses(true);
+            break;
+          default:
+            break;
+          }
         }
 
         // If we have a musttail call in a variadic function, we need to ensure