Eliminate the IS_PHI_DEF flag and VNInfo::setIsPHIDef().

A value number is a PHI def if and only if it begins at a block
boundary. This can be derived from the def slot, a separate flag is not
necessary.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160893 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/CodeGen/LiveInterval.h b/include/llvm/CodeGen/LiveInterval.h
index 3fe7c8d..b952722 100644 (file)
--- a/include/llvm/CodeGen/LiveInterval.h
+++ b/include/llvm/CodeGen/LiveInterval.h
@@ -43,8 +43,7 @@ namespace llvm {
   private:
     enum {
       HAS_PHI_KILL    = 1,
-      IS_PHI_DEF      = 1 << 1,
-      IS_UNUSED       = 1 << 2
+      IS_UNUSED       = 1 << 1
     };
 
     unsigned char flags;
@@ -96,14 +95,9 @@ namespace llvm {
 
     /// Returns true if this value is defined by a PHI instruction (or was,
     /// PHI instrucions may have been eliminated).
-    bool isPHIDef() const { return flags & IS_PHI_DEF; }
-    /// Set the "phi def" flag on this value.
-    void setIsPHIDef(bool phiDef) {
-      if (phiDef)
-        flags |= IS_PHI_DEF;
-      else
-        flags &= ~IS_PHI_DEF;
-    }
+    /// PHI-defs begin at a block boundary, all other defs begin at register or
+    /// EC slots.
+    bool isPHIDef() const { return def.isBlock(); }
 
     /// Returns true if this value is unused.
     bool isUnused() const { return flags & IS_UNUSED; }

diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index bc0ec15..c58b8d7 100644 (file)
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -290,7 +290,6 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb,
         assert(getInstructionFromIndex(Start) == 0 &&
                "PHI def index points at actual instruction.");
         ValNo = interval.getNextValue(Start, VNInfoAllocator);
-        ValNo->setIsPHIDef(true);
       }
       LiveRange LR(Start, killIdx, ValNo);
       interval.addRange(LR);

diff --git a/lib/CodeGen/LiveRangeCalc.cpp b/lib/CodeGen/LiveRangeCalc.cpp
index 9384075..d828f25 100644 (file)
--- a/lib/CodeGen/LiveRangeCalc.cpp
+++ b/lib/CodeGen/LiveRangeCalc.cpp
@@ -54,8 +54,7 @@ void LiveRangeCalc::createDeadDefs(LiveInterval *LI, unsigned Reg) {
         .getRegSlot(I.getOperand().isEarlyClobber());
 
     // Create the def in LI. This may find an existing def.
-    VNInfo *VNI = LI->createDeadDef(Idx, *Alloc);
-    VNI->setIsPHIDef(MI->isPHI());
+    LI->createDeadDef(Idx, *Alloc);
   }
 }
 
@@ -320,7 +319,6 @@ void LiveRangeCalc::updateSSA() {
         SlotIndex Start, End;
         tie(Start, End) = Indexes->getMBBRange(MBB);
         VNInfo *VNI = I->LI->getNextValue(Start, *Alloc);
-        VNI->setIsPHIDef(true);
         I->Value = VNI;
         // This block is done, we know the final value.
         I->DomNode = 0;

diff --git a/lib/CodeGen/SplitKit.cpp b/lib/CodeGen/SplitKit.cpp
index 9a751c1..98ed2cf 100644 (file)
--- a/lib/CodeGen/SplitKit.cpp
+++ b/lib/CodeGen/SplitKit.cpp
@@ -1047,8 +1047,7 @@ void SplitEditor::finish(SmallVectorImpl<unsigned> *LRMap) {
     if (ParentVNI->isUnused())
       continue;
     unsigned RegIdx = RegAssign.lookup(ParentVNI->def);
-    VNInfo *VNI = defValue(RegIdx, ParentVNI, ParentVNI->def);
-    VNI->setIsPHIDef(ParentVNI->isPHIDef());
+    defValue(RegIdx, ParentVNI, ParentVNI->def);
 
     // Force rematted values to be recomputed everywhere.
     // The new live ranges may be truncated.

diff --git a/lib/CodeGen/StrongPHIElimination.cpp b/lib/CodeGen/StrongPHIElimination.cpp
index c6fdc73..389dc97 100644 (file)
--- a/lib/CodeGen/StrongPHIElimination.cpp
+++ b/lib/CodeGen/StrongPHIElimination.cpp
@@ -744,7 +744,6 @@ void StrongPHIElimination::InsertCopiesForPHI(MachineInstr *PHI,
     SlotIndex PHIIndex = LI->getInstructionIndex(PHI);
     VNInfo *DestVNI = DestLI.getVNInfoAt(PHIIndex.getRegSlot());
     assert(DestVNI);
-    DestVNI->setIsPHIDef(true);
   
     // Prior to PHI elimination, the live ranges of PHIs begin at their defining
     // instruction. After PHI elimination, PHI instructions are replaced by VNs
@@ -777,7 +776,6 @@ void StrongPHIElimination::InsertCopiesForPHI(MachineInstr *PHI,
   SlotIndex DestCopyIndex = LI->getInstructionIndex(CopyInstr);
   VNInfo *CopyVNI = CopyLI.getNextValue(MBBStartIndex,
                                         LI->getVNInfoAllocator());
-  CopyVNI->setIsPHIDef(true);
   CopyLI.addRange(LiveRange(MBBStartIndex,
                             DestCopyIndex.getRegSlot(),
                             CopyVNI));