1 files changed, 79 insertions, 0 deletions
diff --git a/contrib/llvm/lib/CodeGen/AllocationOrder.cpp b/contrib/llvm/lib/CodeGen/AllocationOrder.cpp
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+++ b/contrib/llvm/lib/CodeGen/AllocationOrder.cpp
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+//===-- llvm/CodeGen/AllocationOrder.cpp - Allocation Order ---------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements an allocation order for virtual registers.
+//
+// The preferred allocation order for a virtual register depends on allocation
+// hints and target hooks. The AllocationOrder class encapsulates all of that.
+//
+//===----------------------------------------------------------------------===//
+
+#include "AllocationOrder.h"
+#include "RegisterClassInfo.h"
+#include "VirtRegMap.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+
+using namespace llvm;
+
+// Compare VirtRegMap::getRegAllocPref().
+AllocationOrder::AllocationOrder(unsigned VirtReg,
+                                 const VirtRegMap &VRM,
+                                 const RegisterClassInfo &RegClassInfo)
+  : Begin(0), End(0), Pos(0), RCI(RegClassInfo), OwnedBegin(false) {
+  const TargetRegisterClass *RC = VRM.getRegInfo().getRegClass(VirtReg);
+  std::pair<unsigned, unsigned> HintPair =
+    VRM.getRegInfo().getRegAllocationHint(VirtReg);
+
+  // HintPair.second is a register, phys or virt.
+  Hint = HintPair.second;
+
+  // Translate to physreg, or 0 if not assigned yet.
+  if (TargetRegisterInfo::isVirtualRegister(Hint))
+    Hint = VRM.getPhys(Hint);
+
+  // The first hint pair component indicates a target-specific hint.
+  if (HintPair.first) {
+    const TargetRegisterInfo &TRI = VRM.getTargetRegInfo();
+    // The remaining allocation order may depend on the hint.
+    ArrayRef<unsigned> Order =
+      TRI.getRawAllocationOrder(RC, HintPair.first, Hint,
+                                VRM.getMachineFunction());
+    if (Order.empty())
+      return;
+
+    // Copy the allocation order with reserved registers removed.
+    OwnedBegin = true;
+    unsigned *P = new unsigned[Order.size()];
+    Begin = P;
+    for (unsigned i = 0; i != Order.size(); ++i)
+      if (!RCI.isReserved(Order[i]))
+        *P++ = Order[i];
+    End = P;
+
+    // Target-dependent hints require resolution.
+    Hint = TRI.ResolveRegAllocHint(HintPair.first, Hint,
+                                   VRM.getMachineFunction());
+  } else {
+    // If there is no hint or just a normal hint, use the cached allocation
+    // order from RegisterClassInfo.
+    ArrayRef<unsigned> O = RCI.getOrder(RC);
+    Begin = O.begin();
+    End = O.end();
+  }
+
+  // The hint must be a valid physreg for allocation.
+  if (Hint && (!TargetRegisterInfo::isPhysicalRegister(Hint) ||
+               !RC->contains(Hint) || RCI.isReserved(Hint)))
+    Hint = 0;
+}
+
+AllocationOrder::~AllocationOrder() {
+  if (OwnedBegin)
+    delete [] Begin;
+}