AMDGPU: Add skeleton GlobalIsel implementation

Summary:
This adds the necessary target code to be able to run the ir translator.
Lowering function arguments and returns is a nop and there is no support
for RegBankSelect.

Reviewers: arsenm, qcolombet

Subscribers: arsenm, joker.eph, vkalintiris, llvm-commits

Differential Revision: http://reviews.llvm.org/D19077

llvm-svn: 266356

1 files changed, 42 insertions, 0 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUCallLowering.cpp b/llvm/lib/Target/AMDGPU/AMDGPUCallLowering.cpp
new file mode 100644
index 0000000..1a1da8a
--- /dev/null
+++ b/llvm/lib/Target/AMDGPU/AMDGPUCallLowering.cpp
@@ -0,0 +1,42 @@
+//===-- llvm/lib/Target/AMDGPU/AMDGPUCallLowering.cpp - Call lowering ---===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file implements the lowering of LLVM calls to machine code calls for
+/// GlobalISel.
+///
+//===----------------------------------------------------------------------===//
+
+#include "AMDGPUCallLowering.h"
+#include "AMDGPUISelLowering.h"
+
+#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+
+using namespace llvm;
+
+#ifndef LLVM_BUILD_GLOBAL_ISEL
+#error "This shouldn't be built without GISel"
+#endif
+
+AMDGPUCallLowering::AMDGPUCallLowering(const AMDGPUTargetLowering &TLI)
+  : CallLowering(&TLI) {
+}
+
+bool AMDGPUCallLowering::lowerReturn(MachineIRBuilder &MIRBuilder,
+                                        const Value *Val, unsigned VReg) const {
+  return true;
+}
+
+bool AMDGPUCallLowering::lowerFormalArguments(
+    MachineIRBuilder &MIRBuilder, const Function::ArgumentListType &Args,
+    const SmallVectorImpl<unsigned> &VRegs) const {
+  // TODO: Implement once there are generic loads/stores.
+  return true;
+}