From a48386a2aaad9c294f9794577337e31283138b18 Mon Sep 17 00:00:00 2001
From: Quentin Colombet <qcolombet@apple.com>
Date: Sat, 21 May 2016 01:41:17 +0000
Subject: [PATCH] [RegisterBankInfo] Fix the initialization of the map VT to
 RegBank.

Prior to this patch we could have read uninitialized memory.

llvm-svn: 270303
---
 include/llvm/CodeGen/GlobalISel/RegisterBankInfo.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/llvm/CodeGen/GlobalISel/RegisterBankInfo.h b/include/llvm/CodeGen/GlobalISel/RegisterBankInfo.h
index b640637cdee..8f7042655cb 100644
--- a/include/llvm/CodeGen/GlobalISel/RegisterBankInfo.h
+++ b/include/llvm/CodeGen/GlobalISel/RegisterBankInfo.h
@@ -272,9 +272,12 @@ protected:
   /// \post if Force == true then getRegBankForType(SVT) == &RegBank
   void recordRegBankForType(const RegisterBank &RegBank,
                             MVT::SimpleValueType SVT, bool Force = false) {
-    if (!VTToRegBank)
+    if (!VTToRegBank) {
       VTToRegBank.reset(
           new const RegisterBank *[MVT::SimpleValueType::LAST_VALUETYPE]);
+      std::fill(&VTToRegBank[0],
+                &VTToRegBank[MVT::SimpleValueType::LAST_VALUETYPE], nullptr);
+    }
     assert(SVT < MVT::SimpleValueType::LAST_VALUETYPE && "Out-of-bound access");
     // If we want to override the mapping or the mapping does not exits yet,
     // set the register bank for SVT.