[llvm] [AMDGPU][RFC] Combine asm and disasm tests. (PR #90214)

[Matt Arsenault via llvm-commits]

================
@@ -0,0 +1,89 @@
+//===- lib/MC/MCHexStreamer.cpp - Hex Output --------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/MC/MCAsmBackend.h"
+#include "llvm/MC/MCAssembler.h"
+#include "llvm/MC/MCCodeEmitter.h"
+#include "llvm/MC/MCInstPrinter.h"
+#include "llvm/MC/MCObjectWriter.h"
+#include "llvm/MC/MCStreamer.h"
+#include "llvm/MC/TargetRegistry.h"
+
+using namespace llvm;
+
+namespace {
+
+class MCHexStreamer final : public MCStreamer {
+  std::unique_ptr<formatted_raw_ostream> OSOwner;
+  formatted_raw_ostream &OS;
+  std::unique_ptr<MCInstPrinter> InstPrinter;
+  std::unique_ptr<MCAssembler> Assembler;
+
+  raw_null_ostream NullStream;
+
+public:
+  MCHexStreamer(MCContext &Context, std::unique_ptr<formatted_raw_ostream> os,
+                MCInstPrinter *printer, std::unique_ptr<MCCodeEmitter> emitter,
+                std::unique_ptr<MCAsmBackend> asmbackend)
+      : MCStreamer(Context), OSOwner(std::move(os)), OS(*OSOwner),
+        InstPrinter(printer),
+        Assembler(std::make_unique<MCAssembler>(
+            Context, std::move(asmbackend), std::move(emitter),
+            asmbackend ? asmbackend->createObjectWriter(NullStream)
+                       : nullptr)) {
+    assert(InstPrinter);
+  }
+
+  MCAssembler &getAssembler() { return *Assembler; }
+
+  /// @name MCStreamer Interface
+  /// @{
+
+  bool emitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) override {
+    return true;
+  }
+
+  void emitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
+                        Align ByteAlignment) override {}
+
+  void emitZerofill(MCSection *Section, MCSymbol *Symbol = nullptr,
+                    uint64_t Size = 0, Align ByteAlignment = Align(1),
+                    SMLoc Loc = SMLoc()) override {}
+
+  void emitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI) override;
+};
+
+} // end anonymous namespace.
+
+void MCHexStreamer::emitInstruction(const MCInst &Inst,
+                                    const MCSubtargetInfo &STI) {
+  SmallString<256> Code;
+  SmallVector<MCFixup, 4> Fixups;
+  getAssembler().getEmitter().encodeInstruction(Inst, Code, Fixups, STI);
+
+  OS << "[";
+  for (auto [I, B] : enumerate(Code))
+    OS << (I != 0 ? "," : "") << format("0x%02x", B & 0xff);
----------------
arsenm wrote:

Use ListSeparator for the =0 case 

https://github.com/llvm/llvm-project/pull/90214