From 264b1a34445efe12411a8c5256216e9686d1d7e2 Mon Sep 17 00:00:00 2001
From: Quentin Colombet <qcolombet@apple.com>
Date: Mon, 7 Mar 2016 21:22:09 +0000
Subject: [PATCH] [MachineRegisterInfo] Get rid of the global-isel ifdefs. One
 additional pointer is not a big deal size-wise and it makes the code much
 nicer!

llvm-svn: 262856
---
 include/llvm/CodeGen/MachineRegisterInfo.h | 15 ++++++++++-----
 lib/CodeGen/MachineRegisterInfo.cpp        |  9 +++------
 2 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/include/llvm/CodeGen/MachineRegisterInfo.h b/include/llvm/CodeGen/MachineRegisterInfo.h
index 65fb1be8c83..ab29c4849ef 100644
--- a/include/llvm/CodeGen/MachineRegisterInfo.h
+++ b/include/llvm/CodeGen/MachineRegisterInfo.h
@@ -105,10 +105,17 @@ private:
   /// started.
   BitVector ReservedRegs;
 
-#ifdef LLVM_BUILD_GLOBAL_ISEL
+  typedef DenseMap<unsigned, unsigned> VRegToSizeMap;
   /// Map generic virtual registers to their actual size.
-  DenseMap<unsigned, unsigned> VRegToSize;
-#endif
+  mutable std::unique_ptr<VRegToSizeMap> VRegToSize;
+
+  /// Accessor for VRegToSize. This accessor should only be used
+  /// by global-isel related work.
+  VRegToSizeMap &getVRegToSize() const {
+    if (!VRegToSize)
+      VRegToSize.reset(new VRegToSizeMap);
+    return *VRegToSize.get();
+  }
 
   /// Keep track of the physical registers that are live in to the function.
   /// Live in values are typically arguments in registers.  LiveIn values are
@@ -592,7 +599,6 @@ public:
   ///
   unsigned createVirtualRegister(const TargetRegisterClass *RegClass);
 
-#ifdef LLVM_BUILD_GLOBAL_ISEL
   /// Get the size of \p VReg or 0 if VReg is not a generic
   /// (target independent) virtual register.
   unsigned getSize(unsigned VReg) const;
@@ -600,7 +606,6 @@ public:
   /// Create and return a new generic virtual register with a size of \p Size.
   /// \pre Size > 0.
   unsigned createGenericVirtualRegister(unsigned Size);
-#endif
 
   /// getNumVirtRegs - Return the number of virtual registers created.
   ///
diff --git a/lib/CodeGen/MachineRegisterInfo.cpp b/lib/CodeGen/MachineRegisterInfo.cpp
index 313c259a547..2b81f6b2015 100644
--- a/lib/CodeGen/MachineRegisterInfo.cpp
+++ b/lib/CodeGen/MachineRegisterInfo.cpp
@@ -103,12 +103,10 @@ MachineRegisterInfo::createVirtualRegister(const TargetRegisterClass *RegClass){
   return Reg;
 }
 
-#ifdef LLVM_BUILD_GLOBAL_ISEL
 unsigned
 MachineRegisterInfo::getSize(unsigned VReg) const {
-  DenseMap<unsigned, unsigned>::const_iterator SizeIt =
-    VRegToSize.find(VReg);
-  return SizeIt != VRegToSize.end()? SizeIt->second: 0;
+  VRegToSizeMap::const_iterator SizeIt = getVRegToSize().find(VReg);
+  return SizeIt != getVRegToSize().end() ? SizeIt->second : 0;
 }
 
 unsigned
@@ -120,13 +118,12 @@ MachineRegisterInfo::createGenericVirtualRegister(unsigned Size) {
   VRegInfo.grow(Reg);
   // FIXME: Should we use a dummy register class?
   VRegInfo[Reg].first = nullptr;
-  VRegToSize[Reg] = Size;
+  getVRegToSize()[Reg] = Size;
   RegAllocHints.grow(Reg);
   if (TheDelegate)
     TheDelegate->MRI_NoteNewVirtualRegister(Reg);
   return Reg;
 }
-#endif // LLVM_BUILD_GLOBAL_ISEL
 
 /// clearVirtRegs - Remove all virtual registers (after physreg assignment).
 void MachineRegisterInfo::clearVirtRegs() {