1 files changed, 69 insertions, 0 deletions
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUMCInstLower.h b/llvm/lib/Target/AMDGPU/AMDGPUMCInstLower.h
new file mode 100644
index 000000000000..0e43b4fe9461
--- /dev/null
+++ b/llvm/lib/Target/AMDGPU/AMDGPUMCInstLower.h
@@ -0,0 +1,69 @@
+//===- AMDGPUMCInstLower.h - Lower AMDGPU MachineInstr to an MCInst -------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+/// \file
+/// Header of lower AMDGPU MachineInstrs to their corresponding MCInst.
+//
+//===----------------------------------------------------------------------===//
+//
+
+#ifndef LLVM_LIB_TARGET_AMDGPU_AMDGPUMCINSTLOWER_H
+#define LLVM_LIB_TARGET_AMDGPU_AMDGPUMCINSTLOWER_H
+
+#include "AMDGPUTargetMachine.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/Support/Casting.h"
+
+namespace llvm {
+class AsmPrinter;
+class MCContext;
+} // namespace llvm
+
+using namespace llvm;
+
+class AMDGPUMCInstLower {
+  MCContext &Ctx;
+  const TargetSubtargetInfo &ST;
+  const AsmPrinter &AP;
+
+public:
+  AMDGPUMCInstLower(MCContext &ctx, const TargetSubtargetInfo &ST,
+                    const AsmPrinter &AP);
+
+  bool lowerOperand(const MachineOperand &MO, MCOperand &MCOp) const;
+
+  /// Lower a MachineInstr to an MCInst
+  void lower(const MachineInstr *MI, MCInst &OutMI) const;
+};
+
+namespace {
+static inline const MCExpr *lowerAddrSpaceCast(const TargetMachine &TM,
+                                               const Constant *CV,
+                                               MCContext &OutContext) {
+  // TargetMachine does not support llvm-style cast. Use C++-style cast.
+  // This is safe since TM is always of type AMDGPUTargetMachine or its
+  // derived class.
+  auto &AT = static_cast<const AMDGPUTargetMachine &>(TM);
+  auto *CE = dyn_cast<ConstantExpr>(CV);
+
+  // Lower null pointers in private and local address space.
+  // Clang generates addrspacecast for null pointers in private and local
+  // address space, which needs to be lowered.
+  if (CE && CE->getOpcode() == Instruction::AddrSpaceCast) {
+    auto Op = CE->getOperand(0);
+    auto SrcAddr = Op->getType()->getPointerAddressSpace();
+    if (Op->isNullValue() && AT.getNullPointerValue(SrcAddr) == 0) {
+      auto DstAddr = CE->getType()->getPointerAddressSpace();
+      return MCConstantExpr::create(AT.getNullPointerValue(DstAddr),
+                                    OutContext);
+    }
+  }
+  return nullptr;
+}
+} // namespace
+#endif // LLVM_LIB_TARGET_AMDGPU_AMDGPUMCINSTLOWER_H