blob: b262e06e55e72dd0dbf67d57aee56fd6ff40c624 [file] [log] [blame]
//=- WebAssemblyInstPrinter.cpp - WebAssembly assembly instruction printing -=//
//
// 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
//
//===----------------------------------------------------------------------===//
///
/// \file
/// Print MCInst instructions to wasm format.
///
//===----------------------------------------------------------------------===//
#include "MCTargetDesc/WebAssemblyInstPrinter.h"
#include "MCTargetDesc/WebAssemblyMCTargetDesc.h"
#include "WebAssembly.h"
#include "WebAssemblyMachineFunctionInfo.h"
#include "WebAssemblyUtilities.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/CodeGen/TargetRegisterInfo.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCInstrInfo.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/FormattedStream.h"
using namespace llvm;
#define DEBUG_TYPE "asm-printer"
#include "WebAssemblyGenAsmWriter.inc"
WebAssemblyInstPrinter::WebAssemblyInstPrinter(const MCAsmInfo &MAI,
const MCInstrInfo &MII,
const MCRegisterInfo &MRI)
: MCInstPrinter(MAI, MII, MRI) {}
void WebAssemblyInstPrinter::printRegName(raw_ostream &OS,
unsigned RegNo) const {
assert(RegNo != WebAssemblyFunctionInfo::UnusedReg);
// Note that there's an implicit local.get/local.set here!
OS << "$" << RegNo;
}
void WebAssemblyInstPrinter::printInst(const MCInst *MI, uint64_t Address,
StringRef Annot,
const MCSubtargetInfo &STI,
raw_ostream &OS) {
// Print the instruction (this uses the AsmStrings from the .td files).
printInstruction(MI, Address, OS);
// Print any additional variadic operands.
const MCInstrDesc &Desc = MII.get(MI->getOpcode());
if (Desc.isVariadic()) {
if (Desc.getNumOperands() == 0 && MI->getNumOperands() > 0)
OS << "\t";
for (auto I = Desc.getNumOperands(), E = MI->getNumOperands(); I < E; ++I) {
// FIXME: For CALL_INDIRECT_VOID, don't print a leading comma, because
// we have an extra flags operand which is not currently printed, for
// compatiblity reasons.
if (I != 0 && ((MI->getOpcode() != WebAssembly::CALL_INDIRECT_VOID &&
MI->getOpcode() != WebAssembly::CALL_INDIRECT_VOID_S) ||
I != Desc.getNumOperands()))
OS << ", ";
printOperand(MI, I, OS);
}
}
// Print any added annotation.
printAnnotation(OS, Annot);
if (CommentStream) {
// Observe any effects on the control flow stack, for use in annotating
// control flow label references.
unsigned Opc = MI->getOpcode();
switch (Opc) {
default:
break;
case WebAssembly::LOOP:
case WebAssembly::LOOP_S:
printAnnotation(OS, "label" + utostr(ControlFlowCounter) + ':');
ControlFlowStack.push_back(std::make_pair(ControlFlowCounter++, true));
break;
case WebAssembly::BLOCK:
case WebAssembly::BLOCK_S:
ControlFlowStack.push_back(std::make_pair(ControlFlowCounter++, false));
break;
case WebAssembly::TRY:
case WebAssembly::TRY_S:
ControlFlowStack.push_back(std::make_pair(ControlFlowCounter++, false));
EHPadStack.push_back(EHPadStackCounter++);
LastSeenEHInst = TRY;
break;
case WebAssembly::END_LOOP:
case WebAssembly::END_LOOP_S:
if (ControlFlowStack.empty()) {
printAnnotation(OS, "End marker mismatch!");
} else {
ControlFlowStack.pop_back();
}
break;
case WebAssembly::END_BLOCK:
case WebAssembly::END_BLOCK_S:
if (ControlFlowStack.empty()) {
printAnnotation(OS, "End marker mismatch!");
} else {
printAnnotation(
OS, "label" + utostr(ControlFlowStack.pop_back_val().first) + ':');
}
break;
case WebAssembly::END_TRY:
case WebAssembly::END_TRY_S:
if (ControlFlowStack.empty()) {
printAnnotation(OS, "End marker mismatch!");
} else {
printAnnotation(
OS, "label" + utostr(ControlFlowStack.pop_back_val().first) + ':');
LastSeenEHInst = END_TRY;
}
break;
case WebAssembly::CATCH:
case WebAssembly::CATCH_S:
if (EHPadStack.empty()) {
printAnnotation(OS, "try-catch mismatch!");
} else {
printAnnotation(OS, "catch" + utostr(EHPadStack.pop_back_val()) + ':');
}
break;
}
// Annotate any control flow label references.
// rethrow instruction does not take any depth argument and rethrows to the
// nearest enclosing catch scope, if any. If there's no enclosing catch
// scope, it throws up to the caller.
if (Opc == WebAssembly::RETHROW || Opc == WebAssembly::RETHROW_S) {
if (EHPadStack.empty()) {
printAnnotation(OS, "to caller");
} else {
printAnnotation(OS, "down to catch" + utostr(EHPadStack.back()));
}
} else {
unsigned NumFixedOperands = Desc.NumOperands;
SmallSet<uint64_t, 8> Printed;
for (unsigned I = 0, E = MI->getNumOperands(); I < E; ++I) {
// See if this operand denotes a basic block target.
if (I < NumFixedOperands) {
// A non-variable_ops operand, check its type.
if (Desc.OpInfo[I].OperandType != WebAssembly::OPERAND_BASIC_BLOCK)
continue;
} else {
// A variable_ops operand, which currently can be immediates (used in
// br_table) which are basic block targets, or for call instructions
// when using -wasm-keep-registers (in which case they are registers,
// and should not be processed).
if (!MI->getOperand(I).isImm())
continue;
}
uint64_t Depth = MI->getOperand(I).getImm();
if (!Printed.insert(Depth).second)
continue;
if (Depth >= ControlFlowStack.size()) {
printAnnotation(OS, "Invalid depth argument!");
} else {
const auto &Pair = ControlFlowStack.rbegin()[Depth];
printAnnotation(OS, utostr(Depth) + ": " +
(Pair.second ? "up" : "down") + " to label" +
utostr(Pair.first));
}
}
}
}
}
static std::string toString(const APFloat &FP) {
// Print NaNs with custom payloads specially.
if (FP.isNaN() && !FP.bitwiseIsEqual(APFloat::getQNaN(FP.getSemantics())) &&
!FP.bitwiseIsEqual(
APFloat::getQNaN(FP.getSemantics(), /*Negative=*/true))) {
APInt AI = FP.bitcastToAPInt();
return std::string(AI.isNegative() ? "-" : "") + "nan:0x" +
utohexstr(AI.getZExtValue() &
(AI.getBitWidth() == 32 ? INT64_C(0x007fffff)
: INT64_C(0x000fffffffffffff)),
/*LowerCase=*/true);
}
// Use C99's hexadecimal floating-point representation.
static const size_t BufBytes = 128;
char Buf[BufBytes];
auto Written = FP.convertToHexString(
Buf, /*HexDigits=*/0, /*UpperCase=*/false, APFloat::rmNearestTiesToEven);
(void)Written;
assert(Written != 0);
assert(Written < BufBytes);
return Buf;
}
void WebAssemblyInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
raw_ostream &O) {
const MCOperand &Op = MI->getOperand(OpNo);
if (Op.isReg()) {
unsigned WAReg = Op.getReg();
if (int(WAReg) >= 0)
printRegName(O, WAReg);
else if (OpNo >= MII.get(MI->getOpcode()).getNumDefs())
O << "$pop" << WebAssemblyFunctionInfo::getWARegStackId(WAReg);
else if (WAReg != WebAssemblyFunctionInfo::UnusedReg)
O << "$push" << WebAssemblyFunctionInfo::getWARegStackId(WAReg);
else
O << "$drop";
// Add a '=' suffix if this is a def.
if (OpNo < MII.get(MI->getOpcode()).getNumDefs())
O << '=';
} else if (Op.isImm()) {
O << Op.getImm();
} else if (Op.isFPImm()) {
const MCInstrDesc &Desc = MII.get(MI->getOpcode());
const MCOperandInfo &Info = Desc.OpInfo[OpNo];
if (Info.OperandType == WebAssembly::OPERAND_F32IMM) {
// TODO: MC converts all floating point immediate operands to double.
// This is fine for numeric values, but may cause NaNs to change bits.
O << ::toString(APFloat(float(Op.getFPImm())));
} else {
assert(Info.OperandType == WebAssembly::OPERAND_F64IMM);
O << ::toString(APFloat(Op.getFPImm()));
}
} else {
assert(Op.isExpr() && "unknown operand kind in printOperand");
// call_indirect instructions have a TYPEINDEX operand that we print
// as a signature here, such that the assembler can recover this
// information.
auto SRE = static_cast<const MCSymbolRefExpr *>(Op.getExpr());
if (SRE->getKind() == MCSymbolRefExpr::VK_WASM_TYPEINDEX) {
auto &Sym = static_cast<const MCSymbolWasm &>(SRE->getSymbol());
O << WebAssembly::signatureToString(Sym.getSignature());
} else {
Op.getExpr()->print(O, &MAI);
}
}
}
void WebAssemblyInstPrinter::printBrList(const MCInst *MI, unsigned OpNo,
raw_ostream &O) {
O << "{";
for (unsigned I = OpNo, E = MI->getNumOperands(); I != E; ++I) {
if (I != OpNo)
O << ", ";
O << MI->getOperand(I).getImm();
}
O << "}";
}
void WebAssemblyInstPrinter::printWebAssemblyP2AlignOperand(const MCInst *MI,
unsigned OpNo,
raw_ostream &O) {
int64_t Imm = MI->getOperand(OpNo).getImm();
if (Imm == WebAssembly::GetDefaultP2Align(MI->getOpcode()))
return;
O << ":p2align=" << Imm;
}
void WebAssemblyInstPrinter::printWebAssemblySignatureOperand(const MCInst *MI,
unsigned OpNo,
raw_ostream &O) {
const MCOperand &Op = MI->getOperand(OpNo);
if (Op.isImm()) {
auto Imm = static_cast<unsigned>(Op.getImm());
if (Imm != wasm::WASM_TYPE_NORESULT)
O << WebAssembly::anyTypeToString(Imm);
} else {
auto Expr = cast<MCSymbolRefExpr>(Op.getExpr());
auto *Sym = cast<MCSymbolWasm>(&Expr->getSymbol());
if (Sym->getSignature()) {
O << WebAssembly::signatureToString(Sym->getSignature());
} else {
// Disassembler does not currently produce a signature
O << "unknown_type";
}
}
}
// We have various enums representing a subset of these types, use this
// function to convert any of them to text.
const char *WebAssembly::anyTypeToString(unsigned Ty) {
switch (Ty) {
case wasm::WASM_TYPE_I32:
return "i32";
case wasm::WASM_TYPE_I64:
return "i64";
case wasm::WASM_TYPE_F32:
return "f32";
case wasm::WASM_TYPE_F64:
return "f64";
case wasm::WASM_TYPE_V128:
return "v128";
case wasm::WASM_TYPE_FUNCREF:
return "funcref";
case wasm::WASM_TYPE_FUNC:
return "func";
case wasm::WASM_TYPE_EXNREF:
return "exnref";
case wasm::WASM_TYPE_NORESULT:
return "void";
default:
return "invalid_type";
}
}
const char *WebAssembly::typeToString(wasm::ValType Ty) {
return anyTypeToString(static_cast<unsigned>(Ty));
}
std::string WebAssembly::typeListToString(ArrayRef<wasm::ValType> List) {
std::string S;
for (auto &Ty : List) {
if (&Ty != &List[0]) S += ", ";
S += WebAssembly::typeToString(Ty);
}
return S;
}
std::string WebAssembly::signatureToString(const wasm::WasmSignature *Sig) {
std::string S("(");
S += typeListToString(Sig->Params);
S += ") -> (";
S += typeListToString(Sig->Returns);
S += ")";
return S;
}