From 1458e0596703f85d6a6a8041c05ad39c297b3190 Mon Sep 17 00:00:00 2001
From: Matthias Braun <matze@braunis.de>
Date: Wed, 21 Jan 2015 18:50:21 +0000
Subject: [PATCH] LiveIntervalAnalysis: Factor out code to update liveness on
 physreg def removal

This cleans up code and is more in line with the general philosophy of
modifying LiveIntervals through LiveIntervalAnalysis instead of changing
them directly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226687 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/CodeGen/LiveIntervalAnalysis.h |  2 ++
 lib/CodeGen/InlineSpiller.cpp               |  9 ++-------
 lib/CodeGen/LiveIntervalAnalysis.cpp        |  8 ++++++++
 lib/CodeGen/LiveRangeEdit.cpp               | 11 ++---------
 lib/CodeGen/RegisterCoalescer.cpp           | 14 +++++---------
 5 files changed, 19 insertions(+), 25 deletions(-)

diff --git a/include/llvm/CodeGen/LiveIntervalAnalysis.h b/include/llvm/CodeGen/LiveIntervalAnalysis.h
index 61c705e04d2..d9708703697 100644
--- a/include/llvm/CodeGen/LiveIntervalAnalysis.h
+++ b/include/llvm/CodeGen/LiveIntervalAnalysis.h
@@ -393,6 +393,8 @@ namespace llvm {
       return RegUnitRanges[Unit];
     }
 
+    void removePhysRegDefAt(unsigned Reg, SlotIndex Pos);
+
   private:
     /// Compute live intervals for all virtual registers.
     void computeVirtRegs();
diff --git a/lib/CodeGen/InlineSpiller.cpp b/lib/CodeGen/InlineSpiller.cpp
index df889f76412..631b42c7348 100644
--- a/lib/CodeGen/InlineSpiller.cpp
+++ b/lib/CodeGen/InlineSpiller.cpp
@@ -1142,13 +1142,8 @@ foldMemoryOperand(ArrayRef<std::pair<MachineInstr*, unsigned> > Ops,
       continue;
     // FoldMI does not define this physreg. Remove the LI segment.
     assert(MO->isDead() && "Cannot fold physreg def");
-    for (MCRegUnitIterator Units(Reg, &TRI); Units.isValid(); ++Units) {
-      if (LiveRange *LR = LIS.getCachedRegUnit(*Units)) {
-        SlotIndex Idx = LIS.getInstructionIndex(MI).getRegSlot();
-        if (VNInfo *VNI = LR->getVNInfoAt(Idx))
-          LR->removeValNo(VNI);
-      }
-    }
+    SlotIndex Idx = LIS.getInstructionIndex(MI).getRegSlot();
+    LIS.removePhysRegDefAt(Reg, Idx);
   }
 
   LIS.ReplaceMachineInstrInMaps(MI, FoldMI);
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index 36aeaa176a2..48daf2ccd06 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -1367,3 +1367,11 @@ LiveIntervals::repairIntervalsInRange(MachineBasicBlock *MBB,
     repairOldRegInRange(Begin, End, endIdx, LI, Reg);
   }
 }
+
+void LiveIntervals::removePhysRegDefAt(unsigned Reg, SlotIndex Pos) {
+  for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units) {
+    if (LiveRange *LR = getCachedRegUnit(*Units))
+      if (VNInfo *VNI = LR->getVNInfoAt(Pos))
+        LR->removeValNo(VNI);
+  }
+}
diff --git a/lib/CodeGen/LiveRangeEdit.cpp b/lib/CodeGen/LiveRangeEdit.cpp
index 47da205df69..c4bfc0e876c 100644
--- a/lib/CodeGen/LiveRangeEdit.cpp
+++ b/lib/CodeGen/LiveRangeEdit.cpp
@@ -256,15 +256,8 @@ 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 (LiveRange *LR = LIS.getCachedRegUnit(*Units)) {
-            if (VNInfo *VNI = LR->getVNInfoAt(Idx))
-              LR->removeValNo(VNI);
-          }
-        }
-      }
+      else if (MOI->isDef())
+        LIS.removePhysRegDefAt(Reg, Idx);
       continue;
     }
     LiveInterval &LI = LIS.getInterval(Reg);
diff --git a/lib/CodeGen/RegisterCoalescer.cpp b/lib/CodeGen/RegisterCoalescer.cpp
index 5eb1721b35c..70d2e0e18ce 100644
--- a/lib/CodeGen/RegisterCoalescer.cpp
+++ b/lib/CodeGen/RegisterCoalescer.cpp
@@ -1463,17 +1463,13 @@ bool RegisterCoalescer::joinReservedPhysReg(CoalescerPair &CP) {
 
     // We're going to remove the copy which defines a physical reserved
     // register, so remove its valno, etc.
+    DEBUG(dbgs() << "\t\tRemoving phys reg def of " << DstReg << " at "
+          << CopyRegIdx << "\n");
+
+    LIS->removePhysRegDefAt(DstReg, CopyRegIdx);
+    // Create a new dead def at the new def location.
     for (MCRegUnitIterator UI(DstReg, TRI); UI.isValid(); ++UI) {
       LiveRange &LR = LIS->getRegUnit(*UI);
-      VNInfo *OrigRegVNI = LR.getVNInfoAt(CopyRegIdx);
-      if (!OrigRegVNI)
-        continue;
-
-      DEBUG(dbgs() << "\t\tRemoving: " << CopyRegIdx << " from " << LR << "\n");
-      LR.removeSegment(CopyRegIdx, CopyRegIdx.getDeadSlot());
-      LR.removeValNo(OrigRegVNI);
-
-      // Create a new dead def at the new def location.
       LR.createDeadDef(DestRegIdx, LIS->getVNInfoAllocator());
     }
   }