TargetRegisterInfo: Provide a way to check assigned registers in getRegAllocationHints()

Pass a const reference to LiveRegMatrix to getRegAllocationHints()
because some targets can prodive better hints if they can test whether a
physreg has been used for register allocation yet.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242340 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 11 insertions, 7 deletions

diff --git a/lib/CodeGen/AllocationOrder.cpp b/lib/CodeGen/AllocationOrder.cpp
index dc9bcff5612..40451c0d6c1 100644
--- a/lib/CodeGen/AllocationOrder.cpp
+++ b/lib/CodeGen/AllocationOrder.cpp
@@ -29,12 +29,13 @@ using namespace llvm;
 // Compare VirtRegMap::getRegAllocPref().
 AllocationOrder::AllocationOrder(unsigned VirtReg,
                                  const VirtRegMap &VRM,
-                                 const RegisterClassInfo &RegClassInfo)
+                                 const RegisterClassInfo &RegClassInfo,
+                                 const LiveRegMatrix *Matrix)
   : Pos(0) {
   const MachineFunction &MF = VRM.getMachineFunction();
   const TargetRegisterInfo *TRI = &VRM.getTargetRegInfo();
   Order = RegClassInfo.getOrder(MF.getRegInfo().getRegClass(VirtReg));
-  TRI->getRegAllocationHints(VirtReg, Order, Hints, MF, &VRM);
+  TRI->getRegAllocationHints(VirtReg, Order, Hints, MF, &VRM, Matrix);
   rewind();
 
   DEBUG({
diff --git a/lib/CodeGen/AllocationOrder.h b/lib/CodeGen/AllocationOrder.h
index 02b2d9250bc..2aee3a63a2b 100644
--- a/lib/CodeGen/AllocationOrder.h
+++ b/lib/CodeGen/AllocationOrder.h
@@ -24,6 +24,7 @@ namespace llvm {
 
 class RegisterClassInfo;
 class VirtRegMap;
+class LiveRegMatrix;
 
 class LLVM_LIBRARY_VISIBILITY AllocationOrder {
   SmallVector<MCPhysReg, 16> Hints;
@@ -37,7 +38,8 @@ public:
   /// @param RegClassInfo Information about reserved and allocatable registers.
   AllocationOrder(unsigned VirtReg,
                   const VirtRegMap &VRM,
-                  const RegisterClassInfo &RegClassInfo);
+                  const RegisterClassInfo &RegClassInfo,
+                  const LiveRegMatrix *Matrix);
 
   /// Get the allocation order without reordered hints.
   ArrayRef<MCPhysReg> getOrder() const { return Order; }
diff --git a/lib/CodeGen/RegAllocBasic.cpp b/lib/CodeGen/RegAllocBasic.cpp
index 0090332a812..d9660541d92 100644
--- a/lib/CodeGen/RegAllocBasic.cpp
+++ b/lib/CodeGen/RegAllocBasic.cpp
@@ -223,7 +223,7 @@ unsigned RABasic::selectOrSplit(LiveInterval &VirtReg,
   SmallVector<unsigned, 8> PhysRegSpillCands;
 
   // Check for an available register in this class.
-  AllocationOrder Order(VirtReg.reg, *VRM, RegClassInfo);
+  AllocationOrder Order(VirtReg.reg, *VRM, RegClassInfo, Matrix);
   while (unsigned PhysReg = Order.next()) {
     // Check for interference in PhysReg
     switch (Matrix->checkInterference(VirtReg, PhysReg)) {
diff --git a/lib/CodeGen/RegAllocGreedy.cpp b/lib/CodeGen/RegAllocGreedy.cpp
index 7ebcf7f5485..9da86441767 100644
--- a/lib/CodeGen/RegAllocGreedy.cpp
+++ b/lib/CodeGen/RegAllocGreedy.cpp
@@ -637,7 +637,7 @@ unsigned RAGreedy::tryAssign(LiveInterval &VirtReg,
 //===----------------------------------------------------------------------===//
 
 unsigned RAGreedy::canReassign(LiveInterval &VirtReg, unsigned PrevReg) {
-  AllocationOrder Order(VirtReg.reg, *VRM, RegClassInfo);
+  AllocationOrder Order(VirtReg.reg, *VRM, RegClassInfo, Matrix);
   unsigned PhysReg;
   while ((PhysReg = Order.next())) {
     if (PhysReg == PrevReg)
@@ -2450,7 +2450,7 @@ unsigned RAGreedy::selectOrSplitImpl(LiveInterval &VirtReg,
                                      unsigned Depth) {
   unsigned CostPerUseLimit = ~0u;
   // First try assigning a free register.
-  AllocationOrder Order(VirtReg.reg, *VRM, RegClassInfo);
+  AllocationOrder Order(VirtReg.reg, *VRM, RegClassInfo, Matrix);
   if (unsigned PhysReg = tryAssign(VirtReg, Order, NewVRegs)) {
     // When NewVRegs is not empty, we may have made decisions such as evicting
     // a virtual register, go with the earlier decisions and use the physical
diff --git a/lib/CodeGen/TargetRegisterInfo.cpp b/lib/CodeGen/TargetRegisterInfo.cpp
index 61a66b62392..09d3e80e65b 100644
--- a/lib/CodeGen/TargetRegisterInfo.cpp
+++ b/lib/CodeGen/TargetRegisterInfo.cpp
@@ -266,7 +266,8 @@ TargetRegisterInfo::getRegAllocationHints(unsigned VirtReg,
                                           ArrayRef<MCPhysReg> Order,
                                           SmallVectorImpl<MCPhysReg> &Hints,
                                           const MachineFunction &MF,
-                                          const VirtRegMap *VRM) const {
+                                          const VirtRegMap *VRM,
+                                          const LiveRegMatrix *Matrix) const {
   const MachineRegisterInfo &MRI = MF.getRegInfo();
   std::pair<unsigned, unsigned> Hint = MRI.getRegAllocationHint(VirtReg);