From 95604f98b90d55fb5f1605460393a7e466d4ac13 Mon Sep 17 00:00:00 2001
From: Eric Christopher <echristo@gmail.com>
Date: Thu, 30 Mar 2017 22:34:20 +0000
Subject: [PATCH] getPristineRegs is not accurately considering shrink wrapping
 puts registers not saved in certain blocks. Use explicit getCalleeSavedInfo
 and isLiveIn instead.

This fixes pr32292.

Patch by Tim Shen!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299124 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/AsmParser/LLParser.cpp               | 3 +++
 lib/CodeGen/AggressiveAntiDepBreaker.cpp | 3 ++-
 lib/CodeGen/CriticalAntiDepBreaker.cpp   | 4 +++-
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index ab315dd2c7f..d8f6c1c5146 100644
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -4593,6 +4593,9 @@ bool LLParser::parseConstantValue(Type *Ty, Constant *&C) {
     C = cast<Constant>(V);
     return false;
   }
+  case ValID::t_Null:
+    C = Constant::getNullValue(Ty);
+    return false;
   default:
     return Error(Loc, "expected a constant value");
   }
diff --git a/lib/CodeGen/AggressiveAntiDepBreaker.cpp b/lib/CodeGen/AggressiveAntiDepBreaker.cpp
index a60a43a2ddc..955524c2a67 100644
--- a/lib/CodeGen/AggressiveAntiDepBreaker.cpp
+++ b/lib/CodeGen/AggressiveAntiDepBreaker.cpp
@@ -166,7 +166,8 @@ void AggressiveAntiDepBreaker::StartBlock(MachineBasicBlock *BB) {
   for (const MCPhysReg *I = MF.getRegInfo().getCalleeSavedRegs(); *I;
        ++I) {
     unsigned Reg = *I;
-    if (!IsReturnBlock && !Pristine.test(Reg)) continue;
+    if (!IsReturnBlock && !(Pristine.test(Reg) || BB->isLiveIn(Reg)))
+      continue;
     for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI) {
       unsigned AliasReg = *AI;
       State->UnionGroups(AliasReg, 0);
diff --git a/lib/CodeGen/CriticalAntiDepBreaker.cpp b/lib/CodeGen/CriticalAntiDepBreaker.cpp
index 615d7eb7b4d..e1eeddf0816 100644
--- a/lib/CodeGen/CriticalAntiDepBreaker.cpp
+++ b/lib/CodeGen/CriticalAntiDepBreaker.cpp
@@ -73,7 +73,9 @@ void CriticalAntiDepBreaker::StartBlock(MachineBasicBlock *BB) {
   BitVector Pristine = MFI.getPristineRegs(MF);
   for (const MCPhysReg *I = MF.getRegInfo().getCalleeSavedRegs(); *I;
        ++I) {
-    if (!IsReturnBlock && !Pristine.test(*I)) continue;
+    unsigned Reg = *I;
+    if (!IsReturnBlock && !(Pristine.test(Reg) || BB->isLiveIn(Reg)))
+      continue;
     for (MCRegAliasIterator AI(*I, TRI, true); AI.isValid(); ++AI) {
       unsigned Reg = *AI;
       Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);
-- 
2.11.0