[VE] Minimal codegen for empty functions

Summary:
This patch implements minimal VE code generation for empty function bodies (no args, no value return).

Contents

* empty function code generation test.
* Minimal function prologue & epilogue emission
* Instruction formats and instruction definitions as far as required for the empty function prologue & epilogue.
* I64 register class definitions.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D72598

1 files changed, 78 insertions, 0 deletions

diff --git a/llvm/lib/Target/VE/VEAsmPrinter.cpp b/llvm/lib/Target/VE/VEAsmPrinter.cpp
new file mode 100644
index 00000000000..918f2a1acda
--- /dev/null
+++ b/llvm/lib/Target/VE/VEAsmPrinter.cpp
@@ -0,0 +1,78 @@
+//===-- VEAsmPrinter.cpp - VE LLVM assembly writer ------------------------===//
+//
+// 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 contains a printer that converts from our internal representation
+// of machine-dependent LLVM code to GAS-format VE assembly language.
+//
+//===----------------------------------------------------------------------===//
+
+#include "InstPrinter/VEInstPrinter.h"
+#include "MCTargetDesc/VETargetStreamer.h"
+#include "VE.h"
+#include "VEInstrInfo.h"
+#include "VETargetMachine.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/CodeGen/MachineModuleInfoImpls.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
+#include "llvm/IR/Mangler.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCInstBuilder.h"
+#include "llvm/MC/MCStreamer.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace llvm;
+
+#define DEBUG_TYPE "ve-asmprinter"
+
+namespace {
+class VEAsmPrinter : public AsmPrinter {
+  VETargetStreamer &getTargetStreamer() {
+    return static_cast<VETargetStreamer &>(*OutStreamer->getTargetStreamer());
+  }
+
+public:
+  explicit VEAsmPrinter(TargetMachine &TM, std::unique_ptr<MCStreamer> Streamer)
+      : AsmPrinter(TM, std::move(Streamer)) {}
+
+  StringRef getPassName() const override { return "VE Assembly Printer"; }
+
+  void EmitInstruction(const MachineInstr *MI) override;
+
+  static const char *getRegisterName(unsigned RegNo) {
+    return VEInstPrinter::getRegisterName(RegNo);
+  }
+};
+} // end of anonymous namespace
+
+void VEAsmPrinter::EmitInstruction(const MachineInstr *MI) {
+
+  switch (MI->getOpcode()) {
+  default:
+    break;
+  case TargetOpcode::DBG_VALUE:
+    // FIXME: Debug Value.
+    return;
+  }
+  MachineBasicBlock::const_instr_iterator I = MI->getIterator();
+  MachineBasicBlock::const_instr_iterator E = MI->getParent()->instr_end();
+  do {
+    MCInst TmpInst;
+    LowerVEMachineInstrToMCInst(&*I, TmpInst, *this);
+    EmitToStreamer(*OutStreamer, TmpInst);
+  } while ((++I != E) && I->isInsideBundle()); // Delay slot check.
+}
+
+// Force static initialization.
+extern "C" void LLVMInitializeVEAsmPrinter() {
+  RegisterAsmPrinter<VEAsmPrinter> X(getTheVETarget());
+}