vendor/llvm/llvm-trunk-r366426

1 files changed, 23 insertions, 9 deletions

diff --git a/include/llvm/Analysis/LazyCallGraph.h b/include/llvm/Analysis/LazyCallGraph.h
index d1ec6a9dcc55..2d83929211e2 100644
--- a/include/llvm/Analysis/LazyCallGraph.h
+++ b/include/llvm/Analysis/LazyCallGraph.h
@@ -1,9 +1,8 @@
 //===- LazyCallGraph.h - Analysis of a Module's call graph ------*- C++ -*-===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 /// \file
@@ -39,6 +38,7 @@
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/PointerIntPair.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallVector.h"
@@ -1083,12 +1083,26 @@ public:
         continue;
       }
 
+      // The blockaddress constant expression is a weird special case, we can't
+      // generically walk its operands the way we do for all other constants.
       if (BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
-        // The blockaddress constant expression is a weird special case, we
-        // can't generically walk its operands the way we do for all other
-        // constants.
-        if (Visited.insert(BA->getFunction()).second)
-          Worklist.push_back(BA->getFunction());
+        // If we've already visited the function referred to by the block
+        // address, we don't need to revisit it.
+        if (Visited.count(BA->getFunction()))
+          continue;
+
+        // If all of the blockaddress' users are instructions within the
+        // referred to function, we don't need to insert a cycle.
+        if (llvm::all_of(BA->users(), [&](User *U) {
+              if (Instruction *I = dyn_cast<Instruction>(U))
+                return I->getFunction() == BA->getFunction();
+              return false;
+            }))
+          continue;
+
+        // Otherwise we should go visit the referred to function.
+        Visited.insert(BA->getFunction());
+        Worklist.push_back(BA->getFunction());
         continue;
       }