From 34729256e8058d4106706e9feb2dfad7893502d1 Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Sun, 14 Oct 2007 10:08:34 +0000
Subject: When coalescing an EXTRACT_SUBREG and the dst register is a physical
 register, the source register will be coalesced to the super register of the
 LHS. Properly merge in the live ranges of the resulting coalesced interval
 that were part of the original source interval to the live interval of the
 super-register.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42961 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/SimpleRegisterCoalescing.cpp | 52 +++++++++++++++++---------------
 1 file changed, 27 insertions(+), 25 deletions(-)

(limited to 'lib/CodeGen/SimpleRegisterCoalescing.cpp')

diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index 67e829efee..5323cb29a8 100644
--- a/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -421,14 +421,16 @@ bool SimpleRegisterCoalescing::JoinCopy(MachineInstr *CopyMI,
     // cl = EXTRACT_SUBREG reg1024, 1
     // then create and update the actual physical register allocated to RHS.
     if (RealDstReg) {
-      unsigned CopyIdx = li_->getInstructionIndex(CopyMI);
-      VNInfo *DstValNo =
-        ResDstInt->getLiveRangeContaining(li_->getUseIndex(CopyIdx))->valno;
       LiveInterval &RealDstInt = li_->getOrCreateInterval(RealDstReg);
-      VNInfo *ValNo = RealDstInt.getNextValue(DstValNo->def, DstValNo->reg,
-                                              li_->getVNInfoAllocator());
-      RealDstInt.addKills(ValNo, DstValNo->kills);
-      RealDstInt.MergeValueInAsValue(*ResDstInt, DstValNo, ValNo);
+      for (unsigned i = 0, e = ResSrcInt->getNumValNums(); i != e; ++i) {
+        const VNInfo *SrcValNo = ResSrcInt->getValNumInfo(i);
+        const VNInfo *DstValNo =
+          ResDstInt->FindLiveRangeContaining(SrcValNo->def)->valno;
+        VNInfo *ValNo = RealDstInt.getNextValue(DstValNo->def, DstValNo->reg,
+                                                li_->getVNInfoAllocator());
+        RealDstInt.addKills(ValNo, DstValNo->kills);
+        RealDstInt.MergeValueInAsValue(*ResDstInt, DstValNo, ValNo);
+      }
       repDstReg = RealDstReg;
     }
 
@@ -879,32 +881,32 @@ bool SimpleRegisterCoalescing::JoinIntervals(LiveInterval &LHS,
     }
   }
 
+  // Update kill info. Some live ranges are extended due to copy coalescing.
+  for (DenseMap<VNInfo*, VNInfo*>::iterator I = LHSValsDefinedFromRHS.begin(),
+         E = LHSValsDefinedFromRHS.end(); I != E; ++I) {
+    VNInfo *VNI = I->first;
+    unsigned LHSValID = LHSValNoAssignments[VNI->id];
+    LiveInterval::removeKill(NewVNInfo[LHSValID], VNI->def);
+    RHS.addKills(NewVNInfo[LHSValID], VNI->kills);
+  }
+
+  // Update kill info. Some live ranges are extended due to copy coalescing.
+  for (DenseMap<VNInfo*, VNInfo*>::iterator I = RHSValsDefinedFromLHS.begin(),
+         E = RHSValsDefinedFromLHS.end(); I != E; ++I) {
+    VNInfo *VNI = I->first;
+    unsigned RHSValID = RHSValNoAssignments[VNI->id];
+    LiveInterval::removeKill(NewVNInfo[RHSValID], VNI->def);
+    LHS.addKills(NewVNInfo[RHSValID], VNI->kills);
+  }
+
   // If we get here, we know that we can coalesce the live ranges.  Ask the
   // intervals to coalesce themselves now.
   if ((RHS.ranges.size() > LHS.ranges.size() &&
       MRegisterInfo::isVirtualRegister(LHS.reg)) ||
       MRegisterInfo::isPhysicalRegister(RHS.reg)) {
-    // Update kill info. Some live ranges are extended due to copy coalescing.
-    for (DenseMap<VNInfo*, VNInfo*>::iterator I = LHSValsDefinedFromRHS.begin(),
-           E = LHSValsDefinedFromRHS.end(); I != E; ++I) {
-      VNInfo *VNI = I->first;
-      unsigned LHSValID = LHSValNoAssignments[VNI->id];
-      LiveInterval::removeKill(NewVNInfo[LHSValID], VNI->def);
-      RHS.addKills(NewVNInfo[LHSValID], VNI->kills);
-    }
-
     RHS.join(LHS, &RHSValNoAssignments[0], &LHSValNoAssignments[0], NewVNInfo);
     Swapped = true;
   } else {
-    // Update kill info. Some live ranges are extended due to copy coalescing.
-    for (DenseMap<VNInfo*, VNInfo*>::iterator I = RHSValsDefinedFromLHS.begin(),
-           E = RHSValsDefinedFromLHS.end(); I != E; ++I) {
-      VNInfo *VNI = I->first;
-      unsigned RHSValID = RHSValNoAssignments[VNI->id];
-      LiveInterval::removeKill(NewVNInfo[RHSValID], VNI->def);
-      LHS.addKills(NewVNInfo[RHSValID], VNI->kills);
-    }
-
     LHS.join(RHS, &LHSValNoAssignments[0], &RHSValNoAssignments[0], NewVNInfo);
     Swapped = false;
   }
-- 
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