[llvm] 3942f8e - [DirectX] Add DXILAsmPrinter

[Chris Bieneman via llvm-commits]

Author: Chris Bieneman
Date: 2022-06-17T21:17:17-05:00
New Revision: 3942f8e4762c990184c77b0fe341e151eaf1cc72

URL: https://github.com/llvm/llvm-project/commit/3942f8e4762c990184c77b0fe341e151eaf1cc72
DIFF: https://github.com/llvm/llvm-project/commit/3942f8e4762c990184c77b0fe341e151eaf1cc72.diff

LOG: [DirectX] Add DXILAsmPrinter

The DXILAsmPrinter will just write globals into sections, so the
DXILAsmPrinter only needs support for emitting global variables, and is
otherwise a stub.

Depends on D127147

Differential Revision: https://reviews.llvm.org/D127153

Added: 
    llvm/lib/Target/DirectX/DirectXAsmPrinter.cpp

Modified: 
    llvm/lib/Target/DirectX/CMakeLists.txt

Removed: 
    


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diff  --git a/llvm/lib/Target/DirectX/CMakeLists.txt b/llvm/lib/Target/DirectX/CMakeLists.txt
index 5adb9de8787e..fd56f23d2c1b 100644
--- a/llvm/lib/Target/DirectX/CMakeLists.txt
+++ b/llvm/lib/Target/DirectX/CMakeLists.txt
@@ -12,6 +12,7 @@ tablegen(LLVM DXILOperation.inc -gen-dxil-operation)
 add_public_tablegen_target(DirectXCommonTableGen)
 
 add_llvm_target(DirectXCodeGen
+  DirectXAsmPrinter.cpp
   DirectXInstrInfo.cpp
   DirectXRegisterInfo.cpp
   DirectXSubtarget.cpp

diff  --git a/llvm/lib/Target/DirectX/DirectXAsmPrinter.cpp b/llvm/lib/Target/DirectX/DirectXAsmPrinter.cpp
new file mode 100644
index 000000000000..cea3283f6756
--- /dev/null
+++ b/llvm/lib/Target/DirectX/DirectXAsmPrinter.cpp
@@ -0,0 +1,57 @@
+//===-- DirectXAsmPrinter.cpp - DirectX assembly writer --------*- C++ -*--===//
+//
+// 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 AsmPrinters for the DirectX backend.
+//
+//===----------------------------------------------------------------------===//
+
+#include "TargetInfo/DirectXTargetInfo.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/IR/GlobalVariable.h"
+#include "llvm/IR/Module.h"
+#include "llvm/MC/MCStreamer.h"
+#include "llvm/MC/SectionKind.h"
+#include "llvm/MC/TargetRegistry.h"
+#include "llvm/Target/TargetLoweringObjectFile.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "asm-printer"
+
+namespace {
+
+// The DXILAsmPrinter is mostly a stub because DXIL is just LLVM bitcode which
+// gets embedded into a DXContainer file.
+class DXILAsmPrinter : public AsmPrinter {
+public:
+  explicit DXILAsmPrinter(TargetMachine &TM,
+                          std::unique_ptr<MCStreamer> Streamer)
+      : AsmPrinter(TM, std::move(Streamer)) {}
+
+  StringRef getPassName() const override { return "DXIL Assembly Printer"; }
+  void emitGlobalVariable(const GlobalVariable *GV) override;
+  bool runOnMachineFunction(MachineFunction &MF) override { return false; }
+};
+} // namespace
+
+void DXILAsmPrinter::emitGlobalVariable(const GlobalVariable *GV) {
+  // If there is no initializer or the section is implicit, do nothing
+  if (!GV->hasInitializer() || GV->hasImplicitSection())
+    return;
+  // Skip the LLVM metadata
+  if (GV->getSection() == "llvm.metadata")
+    return;
+  SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
+  MCSection *TheSection = getObjFileLowering().SectionForGlobal(GV, GVKind, TM);
+  OutStreamer->switchSection(TheSection);
+  emitGlobalConstant(GV->getParent()->getDataLayout(), GV->getInitializer());
+}
+
+extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeDirectXAsmPrinter() {
+  RegisterAsmPrinter<DXILAsmPrinter> X(getTheDirectXTarget());
+}