From f67e9bb406bc6b2907f069234c8d002ae52181ed Mon Sep 17 00:00:00 2001
From: Torok Edwin <edwintorok@gmail.com>
Date: Sun, 16 Nov 2008 17:21:25 +0000
Subject: [PATCH] If SI->size() is 0, we are not allowed to dereference
 ->begin(). This fixed PR3078.

llvm-svn: 59416
---
 lib/Transforms/IPO/ArgumentPromotion.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/Transforms/IPO/ArgumentPromotion.cpp b/lib/Transforms/IPO/ArgumentPromotion.cpp
index d66e2c46202..00d06bab154 100644
--- a/lib/Transforms/IPO/ArgumentPromotion.cpp
+++ b/lib/Transforms/IPO/ArgumentPromotion.cpp
@@ -565,9 +565,11 @@ Function *ArgPromotion::DoPromotion(Function *F,
       // Add a parameter to the function for each element passed in.
       for (ScalarizeTable::iterator SI = ArgIndices.begin(),
              E = ArgIndices.end(); SI != E; ++SI) {
+        unsigned num = SI->size();
+        // not allowed to dereference ->begin() if size() is 0
         Params.push_back(GetElementPtrInst::getIndexedType(I->getType(),
-                                                           &*SI->begin(),
-                                                           SI->size()));
+                                                           num ? &*SI->begin(): 0,
+                                                           num));
         assert(Params.back());
       }