[llvm] r257440 - [WebAssembly] Implement a prototype instruction encoder and disassembler.
Dan Gohman via llvm-commits
llvm-commits at lists.llvm.org
Mon Jan 11 19:32:29 PST 2016
Author: djg
Date: Mon Jan 11 21:32:29 2016
New Revision: 257440
URL: http://llvm.org/viewvc/llvm-project?rev=257440&view=rev
Log:
[WebAssembly] Implement a prototype instruction encoder and disassembler.
This is using an extremely simple temporary made-up binary format, not the
official binary format (which isn't defined yet).
Added:
llvm/trunk/lib/Target/WebAssembly/Disassembler/
llvm/trunk/lib/Target/WebAssembly/Disassembler/CMakeLists.txt
llvm/trunk/lib/Target/WebAssembly/Disassembler/LLVMBuild.txt
llvm/trunk/lib/Target/WebAssembly/Disassembler/Makefile
llvm/trunk/lib/Target/WebAssembly/Disassembler/WebAssemblyDisassembler.cpp
Modified:
llvm/trunk/lib/Target/WebAssembly/CMakeLists.txt
llvm/trunk/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCCodeEmitter.cpp
llvm/trunk/lib/Target/WebAssembly/Makefile
Modified: llvm/trunk/lib/Target/WebAssembly/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/CMakeLists.txt?rev=257440&r1=257439&r2=257440&view=diff
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/CMakeLists.txt (original)
+++ llvm/trunk/lib/Target/WebAssembly/CMakeLists.txt Mon Jan 11 21:32:29 2016
@@ -39,6 +39,7 @@ add_llvm_target(WebAssemblyCodeGen
add_dependencies(LLVMWebAssemblyCodeGen intrinsics_gen)
+add_subdirectory(Disassembler)
add_subdirectory(InstPrinter)
add_subdirectory(MCTargetDesc)
add_subdirectory(TargetInfo)
Added: llvm/trunk/lib/Target/WebAssembly/Disassembler/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/Disassembler/CMakeLists.txt?rev=257440&view=auto
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/Disassembler/CMakeLists.txt (added)
+++ llvm/trunk/lib/Target/WebAssembly/Disassembler/CMakeLists.txt Mon Jan 11 21:32:29 2016
@@ -0,0 +1,3 @@
+add_llvm_library(LLVMWebAssemblyDisassembler
+ WebAssemblyDisassembler.cpp
+ )
Added: llvm/trunk/lib/Target/WebAssembly/Disassembler/LLVMBuild.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/Disassembler/LLVMBuild.txt?rev=257440&view=auto
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/Disassembler/LLVMBuild.txt (added)
+++ llvm/trunk/lib/Target/WebAssembly/Disassembler/LLVMBuild.txt Mon Jan 11 21:32:29 2016
@@ -0,0 +1,23 @@
+;===-- ./lib/Target/WebAssembly/Disassembler/LLVMBuild.txt -----*- Conf -*--===;
+;
+; The LLVM Compiler Infrastructure
+;
+; This file is distributed under the University of Illinois Open Source
+; License. See LICENSE.TXT for details.
+;
+;===------------------------------------------------------------------------===;
+;
+; This is an LLVMBuild description file for the components in this subdirectory.
+;
+; For more information on the LLVMBuild system, please see:
+;
+; http://llvm.org/docs/LLVMBuild.html
+;
+;===------------------------------------------------------------------------===;
+
+[component_0]
+type = Library
+name = WebAssemblyDisassembler
+parent = WebAssembly
+required_libraries = MCDisassembler WebAssemblyInfo Support
+add_to_library_groups = WebAssembly
Added: llvm/trunk/lib/Target/WebAssembly/Disassembler/Makefile
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/Disassembler/Makefile?rev=257440&view=auto
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/Disassembler/Makefile (added)
+++ llvm/trunk/lib/Target/WebAssembly/Disassembler/Makefile Mon Jan 11 21:32:29 2016
@@ -0,0 +1,16 @@
+##===-- lib/Target/WebAssembly/Disassembler/Makefile -------*- Makefile -*-===##
+#
+# The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+
+LEVEL = ../../../..
+LIBRARYNAME = LLVMWebAssemblyDisassembler
+
+# Hack: we need to include 'main' target directory to grab private headers
+CPP.Flags += -I$(PROJ_OBJ_DIR)/.. -I$(PROJ_SRC_DIR)/..
+
+include $(LEVEL)/Makefile.common
Added: llvm/trunk/lib/Target/WebAssembly/Disassembler/WebAssemblyDisassembler.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/Disassembler/WebAssemblyDisassembler.cpp?rev=257440&view=auto
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/Disassembler/WebAssemblyDisassembler.cpp (added)
+++ llvm/trunk/lib/Target/WebAssembly/Disassembler/WebAssemblyDisassembler.cpp Mon Jan 11 21:32:29 2016
@@ -0,0 +1,148 @@
+//==- WebAssemblyDisassembler.cpp - Disassembler for WebAssembly -*- C++ -*-==//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// \brief This file is part of the WebAssembly Disassembler.
+///
+/// It contains code to translate the data produced by the decoder into
+/// MCInsts.
+///
+//===----------------------------------------------------------------------===//
+
+#include "WebAssembly.h"
+#include "MCTargetDesc/WebAssemblyMCTargetDesc.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDisassembler.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCInstrInfo.h"
+#include "llvm/MC/MCSubtargetInfo.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/Support/Endian.h"
+#include "llvm/Support/TargetRegistry.h"
+using namespace llvm;
+
+#define DEBUG_TYPE "wasm-disassembler"
+
+namespace {
+class WebAssemblyDisassembler final : public MCDisassembler {
+ std::unique_ptr<const MCInstrInfo> MCII;
+
+ DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
+ ArrayRef<uint8_t> Bytes, uint64_t Address,
+ raw_ostream &VStream,
+ raw_ostream &CStream) const override;
+
+public:
+ WebAssemblyDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx,
+ std::unique_ptr<const MCInstrInfo> MCII)
+ : MCDisassembler(STI, Ctx), MCII(std::move(MCII)) {}
+};
+} // end anonymous namespace
+
+static MCDisassembler *createWebAssemblyDisassembler(const Target &T,
+ const MCSubtargetInfo &STI,
+ MCContext &Ctx) {
+ std::unique_ptr<const MCInstrInfo> MCII(T.createMCInstrInfo());
+ return new WebAssemblyDisassembler(STI, Ctx, std::move(MCII));
+}
+
+extern "C" void LLVMInitializeWebAssemblyDisassembler() {
+ // Register the disassembler for each target.
+ TargetRegistry::RegisterMCDisassembler(TheWebAssemblyTarget32,
+ createWebAssemblyDisassembler);
+ TargetRegistry::RegisterMCDisassembler(TheWebAssemblyTarget64,
+ createWebAssemblyDisassembler);
+}
+
+MCDisassembler::DecodeStatus WebAssemblyDisassembler::getInstruction(
+ MCInst &MI, uint64_t &Size, ArrayRef<uint8_t> Bytes, uint64_t /*Address*/,
+ raw_ostream &OS, raw_ostream &CS) const {
+ Size = 0;
+ uint64_t Pos = 0;
+
+ // Read the opcode.
+ if (Pos + sizeof(uint64_t) > Bytes.size())
+ return MCDisassembler::Fail;
+ uint64_t Opcode = support::endian::read64le(Bytes.data() + Pos);
+ Pos += sizeof(uint64_t);
+
+ if (Opcode >= WebAssembly::INSTRUCTION_LIST_END)
+ return MCDisassembler::Fail;
+
+ MI.setOpcode(Opcode);
+ const MCInstrDesc &Desc = MCII->get(Opcode);
+ unsigned NumFixedOperands = Desc.NumOperands;
+
+ // If it's variadic, read the number of extra operands.
+ unsigned NumExtraOperands = 0;
+ if (Desc.isVariadic()) {
+ if (Pos + sizeof(uint64_t) > Bytes.size())
+ return MCDisassembler::Fail;
+ NumExtraOperands = support::endian::read64le(Bytes.data() + Pos);
+ Pos += sizeof(uint64_t);
+ }
+
+ // Read the fixed operands. These are described by the MCInstrDesc.
+ for (unsigned i = 0; i < NumFixedOperands; ++i) {
+ const MCOperandInfo &Info = Desc.OpInfo[i];
+ switch (Info.OperandType) {
+ case MCOI::OPERAND_IMMEDIATE:
+ case WebAssembly::OPERAND_BASIC_BLOCK: {
+ if (Pos + sizeof(uint64_t) > Bytes.size())
+ return MCDisassembler::Fail;
+ uint64_t Imm = support::endian::read64le(Bytes.data() + Pos);
+ Pos += sizeof(uint64_t);
+ MI.addOperand(MCOperand::createImm(Imm));
+ break;
+ }
+ case MCOI::OPERAND_REGISTER: {
+ if (Pos + sizeof(uint64_t) > Bytes.size())
+ return MCDisassembler::Fail;
+ uint64_t Reg = support::endian::read64le(Bytes.data() + Pos);
+ Pos += sizeof(uint64_t);
+ MI.addOperand(MCOperand::createReg(Reg));
+ break;
+ }
+ case WebAssembly::OPERAND_FPIMM: {
+ // TODO: MC converts all floating point immediate operands to double.
+ // This is fine for numeric values, but may cause NaNs to change bits.
+ if (Pos + sizeof(uint64_t) > Bytes.size())
+ return MCDisassembler::Fail;
+ uint64_t Bits = support::endian::read64le(Bytes.data() + Pos);
+ Pos += sizeof(uint64_t);
+ double Imm;
+ memcpy(&Imm, &Bits, sizeof(Imm));
+ MI.addOperand(MCOperand::createFPImm(Imm));
+ break;
+ }
+ default:
+ llvm_unreachable("unimplemented operand kind");
+ }
+ }
+
+ // Read the extra operands.
+ assert(NumExtraOperands == 0 || Desc.isVariadic());
+ for (unsigned i = 0; i < NumExtraOperands; ++i) {
+ if (Pos + sizeof(uint64_t) > Bytes.size())
+ return MCDisassembler::Fail;
+ if (Desc.TSFlags & WebAssemblyII::VariableOpIsImmediate) {
+ // Decode extra immediate operands.
+ uint64_t Imm = support::endian::read64le(Bytes.data() + Pos);
+ MI.addOperand(MCOperand::createImm(Imm));
+ } else {
+ // Decode extra register operands.
+ uint64_t Reg = support::endian::read64le(Bytes.data() + Pos);
+ MI.addOperand(MCOperand::createReg(Reg));
+ }
+ Pos += sizeof(uint64_t);
+ }
+
+ Size = Pos;
+ return MCDisassembler::Success;
+}
Modified: llvm/trunk/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCCodeEmitter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCCodeEmitter.cpp?rev=257440&r1=257439&r2=257440&view=diff
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCCodeEmitter.cpp (original)
+++ llvm/trunk/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCCodeEmitter.cpp Mon Jan 11 21:32:29 2016
@@ -13,6 +13,7 @@
//===----------------------------------------------------------------------===//
#include "MCTargetDesc/WebAssemblyMCTargetDesc.h"
+#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCFixup.h"
@@ -26,30 +27,26 @@ using namespace llvm;
#define DEBUG_TYPE "mccodeemitter"
+STATISTIC(MCNumEmitted, "Number of MC instructions emitted.");
+STATISTIC(MCNumFixups, "Number of MC fixups created.");
+
namespace {
class WebAssemblyMCCodeEmitter final : public MCCodeEmitter {
-public:
- WebAssemblyMCCodeEmitter(const MCInstrInfo &, MCContext &) {}
+ const MCInstrInfo &MCII;
+ const MCContext &Ctx;
- /// TableGen'erated function for getting the binary encoding for an
- /// instruction.
+ // Implementation generated by tablegen.
uint64_t getBinaryCodeForInstr(const MCInst &MI,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
- /// Return binary encoding of operand. If the machine operand requires
- /// relocation, record the relocation and return zero.
- unsigned getMachineOpValue(const MCInst &MI, const MCOperand &MO,
- SmallVectorImpl<MCFixup> &Fixups,
- const MCSubtargetInfo &STI) const;
-
- uint64_t getMemoryOpValue(const MCInst &MI, unsigned Op,
- SmallVectorImpl<MCFixup> &Fixups,
- const MCSubtargetInfo &STI) const;
-
void encodeInstruction(const MCInst &MI, raw_ostream &OS,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const override;
+
+public:
+ WebAssemblyMCCodeEmitter(const MCInstrInfo &mcii, MCContext &ctx)
+ : MCII(mcii), Ctx(ctx) {}
};
} // end anonymous namespace
@@ -61,16 +58,35 @@ MCCodeEmitter *llvm::createWebAssemblyMC
void WebAssemblyMCCodeEmitter::encodeInstruction(
const MCInst &MI, raw_ostream &OS, SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const {
- assert(false && "FIXME: not implemented yet");
-}
+ // FIXME: This is not the real binary encoding. This is an extremely
+ // over-simplified encoding where we just use uint64_t for everything. This
+ // is a temporary measure.
+ support::endian::Writer<support::little>(OS).write<uint64_t>(MI.getOpcode());
+ const MCInstrDesc &Desc = MCII.get(MI.getOpcode());
+ if (Desc.isVariadic())
+ support::endian::Writer<support::little>(OS).write<uint64_t>(
+ MI.getNumOperands() - Desc.NumOperands);
+ for (unsigned i = 0, e = MI.getNumOperands(); i < e; ++i) {
+ const MCOperand &MO = MI.getOperand(i);
+ if (MO.isReg()) {
+ support::endian::Writer<support::little>(OS).write<uint64_t>(MO.getReg());
+ } else if (MO.isImm()) {
+ support::endian::Writer<support::little>(OS).write<uint64_t>(MO.getImm());
+ } else if (MO.isFPImm()) {
+ support::endian::Writer<support::little>(OS).write<double>(MO.getFPImm());
+ } else if (MO.isExpr()) {
+ support::endian::Writer<support::little>(OS).write<uint64_t>(0);
+ Fixups.push_back(MCFixup::create(
+ (1 + MCII.get(MI.getOpcode()).isVariadic() + i) * sizeof(uint64_t),
+ MO.getExpr(), STI.getTargetTriple().isArch64Bit() ? FK_Data_8 : FK_Data_4,
+ MI.getLoc()));
+ ++MCNumFixups;
+ } else {
+ llvm_unreachable("unexpected operand kind");
+ }
+ }
-// Encode WebAssembly Memory Operand
-uint64_t
-WebAssemblyMCCodeEmitter::getMemoryOpValue(const MCInst &MI, unsigned Op,
- SmallVectorImpl<MCFixup> &Fixups,
- const MCSubtargetInfo &STI) const {
- assert(false && "FIXME: not implemented yet");
- return 0;
+ ++MCNumEmitted; // Keep track of the # of mi's emitted.
}
#include "WebAssemblyGenMCCodeEmitter.inc"
Modified: llvm/trunk/lib/Target/WebAssembly/Makefile
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/Makefile?rev=257440&r1=257439&r2=257440&view=diff
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/Makefile (original)
+++ llvm/trunk/lib/Target/WebAssembly/Makefile Mon Jan 11 21:32:29 2016
@@ -21,6 +21,6 @@ BUILT_SOURCES = \
WebAssemblyGenRegisterInfo.inc \
WebAssemblyGenSubtargetInfo.inc
-DIRS = InstPrinter TargetInfo MCTargetDesc
+DIRS = InstPrinter TargetInfo MCTargetDesc Disassembler
include $(LEVEL)/Makefile.common
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