From e6798b757acb3a2077c2498e9913fff2f5e4325c Mon Sep 17 00:00:00 2001
From: Dan Gohman <gohman@apple.com>
Date: Wed, 20 Aug 2008 01:17:01 +0000
Subject: [PATCH] Fix FastISel to recognize that the last block in the function
 does not have a fall-through successor.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55033 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/SelectionDAG/FastISel.cpp | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index e56747a89c1..cd6e2a2a313 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -104,11 +104,14 @@ FastISel::SelectInstructions(BasicBlock::iterator Begin, BasicBlock::iterator En
 
       // For now, check for and handle just the most trivial case: an
       // unconditional fall-through branch.
-      if (BI->isUnconditional() &&
-          next(MachineFunction::iterator(MBB))->getBasicBlock() ==
-            BI->getSuccessor(0)) {
-        MBB->addSuccessor(next(MachineFunction::iterator(MBB)));
-        break;
+      if (BI->isUnconditional()) {
+         MachineFunction::iterator NextMBB =
+           next(MachineFunction::iterator(MBB));
+         if (NextMBB != MF->end() &&
+             NextMBB->getBasicBlock() == BI->getSuccessor(0)) {
+          MBB->addSuccessor(NextMBB);
+          break;
+        }
       }
 
       // Something more complicated. Halt "fast" selection and bail.
-- 
2.34.1