From a7f2dff98e68ed8b2ac32f953768c04f26b52bea Mon Sep 17 00:00:00 2001
From: Dan Gohman <gohman@apple.com>
Date: Wed, 20 Aug 2008 00:35:17 +0000
Subject: [PATCH] Fix FastISel to recognize unhandled operands, such as
 constants that aren't available as virtual registers (for now).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55026 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/SelectionDAG/FastISel.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index 996cea0155c..e56747a89c1 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -25,6 +25,10 @@ bool FastISel::SelectBinaryOp(Instruction *I, ISD::NodeType ISDOpcode,
                               DenseMap<const Value*, unsigned> &ValueMap) {
   unsigned Op0 = ValueMap[I->getOperand(0)];
   unsigned Op1 = ValueMap[I->getOperand(1)];
+  if (Op0 == 0 || Op1 == 0)
+    // Unhandled operand. Halt "fast" selection and bail.
+    return false;
+
   MVT VT = MVT::getMVT(I->getType(), /*HandleUnknown=*/true);
   if (VT == MVT::Other || !VT.isSimple())
     // Unhandled type. Halt "fast" selection and bail.
-- 
2.34.1