1 files changed, 54 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/AllocationOrder.cpp b/llvm/lib/CodeGen/AllocationOrder.cpp
new file mode 100644
index 0000000000000..c99800659bfd8
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+++ b/llvm/lib/CodeGen/AllocationOrder.cpp
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+//===-- llvm/CodeGen/AllocationOrder.cpp - Allocation Order ---------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// 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 "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/RegisterClassInfo.h"
+#include "llvm/CodeGen/VirtRegMap.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "regalloc"
+
+// Compare VirtRegMap::getRegAllocPref().
+AllocationOrder::AllocationOrder(unsigned VirtReg,
+                                 const VirtRegMap &VRM,
+                                 const RegisterClassInfo &RegClassInfo,
+                                 const LiveRegMatrix *Matrix)
+  : Pos(0), HardHints(false) {
+  const MachineFunction &MF = VRM.getMachineFunction();
+  const TargetRegisterInfo *TRI = &VRM.getTargetRegInfo();
+  Order = RegClassInfo.getOrder(MF.getRegInfo().getRegClass(VirtReg));
+  if (TRI->getRegAllocationHints(VirtReg, Order, Hints, MF, &VRM, Matrix))
+    HardHints = true;
+  rewind();
+
+  LLVM_DEBUG({
+    if (!Hints.empty()) {
+      dbgs() << "hints:";
+      for (unsigned I = 0, E = Hints.size(); I != E; ++I)
+        dbgs() << ' ' << printReg(Hints[I], TRI);
+      dbgs() << '\n';
+    }
+  });
+#ifndef NDEBUG
+  for (unsigned I = 0, E = Hints.size(); I != E; ++I)
+    assert(is_contained(Order, Hints[I]) &&
+           "Target hint is outside allocation order.");
+#endif
+}