From 03dca5e4b6c41e1e7fa4edad3d7ff8d5f6de7008 Mon Sep 17 00:00:00 2001
From: Andrew Trick <atrick@apple.com>
Date: Fri, 21 Jun 2013 18:33:20 +0000
Subject: [PATCH] Handle more cases in LiveRangeEdit::eliminateDeadDefs.

Live intervals for dead physregs may be created during coalescing. We
need to update these in the event that their instruction goes away.

crash.ll is the unit test that catches it when MI sched is enabled on
X86.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184572 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/CodeGen/MachineRegisterInfo.h | 8 ++++----
 lib/CodeGen/LiveRangeEdit.cpp              | 9 +++++++++
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/include/llvm/CodeGen/MachineRegisterInfo.h b/include/llvm/CodeGen/MachineRegisterInfo.h
index 95c1ffdf443..7a6dcd05897 100644
--- a/include/llvm/CodeGen/MachineRegisterInfo.h
+++ b/include/llvm/CodeGen/MachineRegisterInfo.h
@@ -58,10 +58,6 @@ class MachineRegisterInfo {
   /// physical registers.
   MachineOperand **PhysRegUseDefLists;
 
-  const TargetRegisterInfo *getTargetRegisterInfo() const {
-    return TM.getRegisterInfo();
-  }
-
   /// getRegUseDefListHead - Return the head pointer for the register use/def
   /// list for the specified virtual or physical register.
   MachineOperand *&getRegUseDefListHead(unsigned RegNo) {
@@ -116,6 +112,10 @@ public:
   explicit MachineRegisterInfo(const TargetMachine &TM);
   ~MachineRegisterInfo();
 
+  const TargetRegisterInfo *getTargetRegisterInfo() const {
+    return TM.getRegisterInfo();
+  }
+
   //===--------------------------------------------------------------------===//
   // Function State
   //===--------------------------------------------------------------------===//
diff --git a/lib/CodeGen/LiveRangeEdit.cpp b/lib/CodeGen/LiveRangeEdit.cpp
index 0c1d45902fe..d215d0c28a4 100644
--- a/lib/CodeGen/LiveRangeEdit.cpp
+++ b/lib/CodeGen/LiveRangeEdit.cpp
@@ -249,6 +249,15 @@ void LiveRangeEdit::eliminateDeadDef(MachineInstr *MI, ToShrinkSet &ToShrink) {
       // Check if MI reads any unreserved physregs.
       if (Reg && MOI->readsReg() && !MRI.isReserved(Reg))
         ReadsPhysRegs = true;
+      else if (MOI->isDef()) {
+        for (MCRegUnitIterator Units(Reg, MRI.getTargetRegisterInfo());
+             Units.isValid(); ++Units) {
+          if (LiveInterval *LI = LIS.getCachedRegUnit(*Units)) {
+            if (VNInfo *VNI = LI->getVNInfoAt(Idx))
+              LI->removeValNo(VNI);
+          }
+        }
+      }
       continue;
     }
     LiveInterval &LI = LIS.getInterval(Reg);