From 206876e2dabf2a1b4d1f72879afaf2419d6d9afd Mon Sep 17 00:00:00 2001
From: Nick Lewycky <nicholas@mxc.ca>
Date: Thu, 28 May 2009 04:08:10 +0000
Subject: [PATCH] Use Operands.data() instead of &Operands[0] where Operands is
 a potentially empty SmallVector.

llvm-svn: 72512
---
 llvm/lib/Transforms/Scalar/SCCP.cpp                    |  2 +-
 .../Transforms/SCCP/2009-05-27-VectorOperandZero.ll    | 10 ++++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)
 create mode 100644 llvm/test/Transforms/SCCP/2009-05-27-VectorOperandZero.ll

diff --git a/llvm/lib/Transforms/Scalar/SCCP.cpp b/llvm/lib/Transforms/Scalar/SCCP.cpp
index d2a70ea9d001..d73519c04e35 100644
--- a/llvm/lib/Transforms/Scalar/SCCP.cpp
+++ b/llvm/lib/Transforms/Scalar/SCCP.cpp
@@ -1196,7 +1196,7 @@ CallOverdefined:
      
       // If we can constant fold this, mark the result of the call as a
       // constant.
-      if (Constant *C = ConstantFoldCall(F, &Operands[0], Operands.size())) {
+      if (Constant *C = ConstantFoldCall(F, Operands.data(), Operands.size())) {
         markConstant(I, C);
         return;
       }
diff --git a/llvm/test/Transforms/SCCP/2009-05-27-VectorOperandZero.ll b/llvm/test/Transforms/SCCP/2009-05-27-VectorOperandZero.ll
new file mode 100644
index 000000000000..480aca0d1acf
--- /dev/null
+++ b/llvm/test/Transforms/SCCP/2009-05-27-VectorOperandZero.ll
@@ -0,0 +1,10 @@
+; RUN: llvm-as < %s | opt -sccp -disable-output
+; PR4277
+
+define i32 @main() nounwind {
+entry:
+	%0 = tail call signext i8 (...)* @sin() nounwind
+	ret i32 0
+}
+
+declare signext i8 @sin(...)