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1 //===- subzero/src/WasmTranslator.cpp - WASM to Subzero Translation -------===//
2 //
3 //                        The Subzero Code Generator
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 ///
10 /// \file
11 /// \brief Defines a driver for translating Wasm bitcode into PNaCl bitcode.
12 ///
13 /// The translator uses V8's WebAssembly decoder to handle the binary Wasm
14 /// format but replaces the usual TurboFan builder with a new PNaCl builder.
15 ///
16 //===----------------------------------------------------------------------===//
17 
18 #if ALLOW_WASM
19 
20 #include "WasmTranslator.h"
21 
22 #ifdef __clang__
23 #pragma clang diagnostic push
24 #pragma clang diagnostic ignored "-Wunused-parameter"
25 #pragma clang diagnostic ignored "-Wcovered-switch-default"
26 #endif // __clang__
27 #if defined(__GNUC__) && !defined(__clang__)
28 #pragma GCC diagnostic push
29 #pragma GCC diagnostic ignored "-Wunused-but-set-variable"
30 #endif // defined(__GNUC__) && !defined(__clang__)
31 
32 #include "src/wasm/module-decoder.h"
33 #include "src/wasm/wasm-opcodes.h"
34 #include "src/zone.h"
35 
36 #include "src/bit-vector.h"
37 
38 #include "src/wasm/ast-decoder-impl.h"
39 
40 #ifdef __clang__
41 #pragma clang diagnostic pop
42 #endif // __clang__
43 #if defined(__GNUC__) && !defined(__clang__)
44 #pragma GCC diagnostic pop
45 #endif // defined(__GNUC__) && !defined(__clang__)
46 
47 #include "IceCfgNode.h"
48 #include "IceGlobalInits.h"
49 
50 using namespace std;
51 using namespace Ice;
52 using namespace v8::internal;
53 using namespace v8::internal::wasm;
54 using v8::internal::wasm::DecodeWasmModule;
55 
56 #undef LOG
57 #define LOG(Expr) log([&](Ostream &out) { Expr; })
58 
59 namespace {
60 // 64KB
61 const uint32_t WASM_PAGE_SIZE = 64 << 10;
62 
toStdString(WasmName Name)63 std::string toStdString(WasmName Name) {
64   return std::string(Name.name, Name.length);
65 }
66 
toIceType(wasm::LocalType Type)67 Ice::Type toIceType(wasm::LocalType Type) {
68   switch (Type) {
69   case MachineRepresentation::kNone:
70     llvm::report_fatal_error("kNone type not supported");
71   case MachineRepresentation::kBit:
72     return IceType_i1;
73   case MachineRepresentation::kWord8:
74     return IceType_i8;
75   case MachineRepresentation::kWord16:
76     return IceType_i16;
77   case MachineRepresentation::kWord32:
78     return IceType_i32;
79   case MachineRepresentation::kWord64:
80     return IceType_i64;
81   case MachineRepresentation::kFloat32:
82     return IceType_f32;
83   case MachineRepresentation::kFloat64:
84     return IceType_f64;
85   case MachineRepresentation::kSimd128:
86     llvm::report_fatal_error("ambiguous SIMD type");
87   case MachineRepresentation::kTagged:
88     llvm::report_fatal_error("kTagged type not supported");
89   }
90   llvm::report_fatal_error("unexpected type");
91 }
92 
toIceType(v8::internal::MachineType Type)93 Ice::Type toIceType(v8::internal::MachineType Type) {
94   // TODO (eholk): reorder these based on expected call frequency.
95   if (Type == MachineType::Int32()) {
96     return IceType_i32;
97   }
98   if (Type == MachineType::Uint32()) {
99     return IceType_i32;
100   }
101   if (Type == MachineType::Int8()) {
102     return IceType_i8;
103   }
104   if (Type == MachineType::Uint8()) {
105     return IceType_i8;
106   }
107   if (Type == MachineType::Int16()) {
108     return IceType_i16;
109   }
110   if (Type == MachineType::Uint16()) {
111     return IceType_i16;
112   }
113   if (Type == MachineType::Int64()) {
114     return IceType_i64;
115   }
116   if (Type == MachineType::Uint64()) {
117     return IceType_i64;
118   }
119   if (Type == MachineType::Float32()) {
120     return IceType_f32;
121   }
122   if (Type == MachineType::Float64()) {
123     return IceType_f64;
124   }
125   llvm::report_fatal_error("Unsupported MachineType");
126 }
127 
fnNameFromId(uint32_t Id)128 std::string fnNameFromId(uint32_t Id) {
129   return std::string("fn") + to_string(Id);
130 }
131 
getFunctionName(const WasmModule * Module,uint32_t func_index)132 std::string getFunctionName(const WasmModule *Module, uint32_t func_index) {
133   // Try to find the function name in the export table
134   for (const auto Export : Module->export_table) {
135     if (Export.func_index == func_index) {
136       return "__szwasm_" + toStdString(Module->GetName(Export.name_offset,
137                                                        Export.name_length));
138     }
139   }
140   return fnNameFromId(func_index);
141 }
142 
143 } // end of anonymous namespace
144 
145 /// This class wraps either an Operand or a CfgNode.
146 ///
147 /// Turbofan's sea of nodes representation only has nodes for values, control
148 /// flow, etc. In Subzero these concepts are all separate. This class lets V8's
149 /// Wasm decoder treat Subzero objects as though they are all the same.
150 class OperandNode {
151   static constexpr uintptr_t NODE_FLAG = 1;
152   static constexpr uintptr_t UNDEF_PTR = (uintptr_t)-1;
153 
154   uintptr_t Data = UNDEF_PTR;
155 
156 public:
157   OperandNode() = default;
OperandNode(Operand * Operand)158   explicit OperandNode(Operand *Operand)
159       : Data(reinterpret_cast<uintptr_t>(Operand)) {}
OperandNode(CfgNode * Node)160   explicit OperandNode(CfgNode *Node)
161       : Data(reinterpret_cast<uintptr_t>(Node) | NODE_FLAG) {}
OperandNode(nullptr_t)162   explicit OperandNode(nullptr_t) : Data(UNDEF_PTR) {}
163 
operator Operand*() const164   operator Operand *() const {
165     if (UNDEF_PTR == Data) {
166       return nullptr;
167     }
168     if (!isOperand()) {
169       llvm::report_fatal_error("This OperandNode is not an Operand");
170     }
171     return reinterpret_cast<Operand *>(Data);
172   }
173 
operator CfgNode*() const174   operator CfgNode *() const {
175     if (UNDEF_PTR == Data) {
176       return nullptr;
177     }
178     if (!isCfgNode()) {
179       llvm::report_fatal_error("This OperandNode is not a CfgNode");
180     }
181     return reinterpret_cast<CfgNode *>(Data & ~NODE_FLAG);
182   }
183 
operator bool() const184   explicit operator bool() const { return (Data != UNDEF_PTR) && Data; }
operator ==(const OperandNode & Rhs) const185   bool operator==(const OperandNode &Rhs) const {
186     return (Data == Rhs.Data) ||
187            (UNDEF_PTR == Data && (Rhs.Data == 0 || Rhs.Data == NODE_FLAG)) ||
188            (UNDEF_PTR == Rhs.Data && (Data == 0 || Data == NODE_FLAG));
189   }
operator !=(const OperandNode & Rhs) const190   bool operator!=(const OperandNode &Rhs) const { return !(*this == Rhs); }
191 
isOperand() const192   bool isOperand() const { return (Data != UNDEF_PTR) && !(Data & NODE_FLAG); }
isCfgNode() const193   bool isCfgNode() const { return (Data != UNDEF_PTR) && (Data & NODE_FLAG); }
194 
toOperand() const195   Operand *toOperand() const { return static_cast<Operand *>(*this); }
196 
toCfgNode() const197   CfgNode *toCfgNode() const { return static_cast<CfgNode *>(*this); }
198 };
199 
operator <<(Ostream & Out,const OperandNode & Op)200 Ostream &operator<<(Ostream &Out, const OperandNode &Op) {
201   if (Op.isOperand()) {
202     const auto *Oper = Op.toOperand();
203     Out << "(Operand*)" << Oper;
204     if (Oper) {
205       Out << "::" << Oper->getType();
206     }
207   } else if (Op.isCfgNode()) {
208     Out << "(CfgNode*)" << Op.toCfgNode();
209   } else {
210     Out << "nullptr";
211   }
212   return Out;
213 }
214 
isComparison(wasm::WasmOpcode Opcode)215 bool isComparison(wasm::WasmOpcode Opcode) {
216   switch (Opcode) {
217   case kExprI32Ne:
218   case kExprI64Ne:
219   case kExprI32Eq:
220   case kExprI64Eq:
221   case kExprI32LtS:
222   case kExprI64LtS:
223   case kExprI32LtU:
224   case kExprI64LtU:
225   case kExprI32GeS:
226   case kExprI64GeS:
227   case kExprI32GtS:
228   case kExprI64GtS:
229   case kExprI32GtU:
230   case kExprI64GtU:
231   case kExprF32Eq:
232   case kExprF64Eq:
233   case kExprF32Ne:
234   case kExprF64Ne:
235   case kExprF32Le:
236   case kExprF64Le:
237   case kExprF32Lt:
238   case kExprF64Lt:
239   case kExprF32Ge:
240   case kExprF64Ge:
241   case kExprF32Gt:
242   case kExprF64Gt:
243   case kExprI32LeS:
244   case kExprI64LeS:
245   case kExprI32GeU:
246   case kExprI64GeU:
247   case kExprI32LeU:
248   case kExprI64LeU:
249     return true;
250   default:
251     return false;
252   }
253 }
254 
255 class IceBuilder {
256   using Node = OperandNode;
257   using Variable = Ice::Variable;
258 
259   IceBuilder() = delete;
260   IceBuilder(const IceBuilder &) = delete;
261   IceBuilder &operator=(const IceBuilder &) = delete;
262 
263 public:
IceBuilder(class Cfg * Func)264   explicit IceBuilder(class Cfg *Func)
265       : ControlPtr(nullptr), Func(Func), Ctx(Func->getContext()) {}
266 
267   /// Allocates a buffer of Nodes for use by V8.
Buffer(size_t Count)268   Node *Buffer(size_t Count) {
269     LOG(out << "Buffer(" << Count << ")\n");
270     return Func->allocateArrayOf<Node>(Count);
271   }
272 
Error()273   Node Error() { llvm::report_fatal_error("Error"); }
Start(uint32_t Params)274   Node Start(uint32_t Params) {
275     LOG(out << "Start(" << Params << ") = ");
276     auto *Entry = Func->getEntryNode();
277     assert(Entry);
278     LOG(out << Node(Entry) << "\n");
279 
280     // Load the WasmMemory address to make it available everywhere else in the
281     // function.
282     auto *WasmMemoryPtr =
283         Ctx->getConstantExternSym(Ctx->getGlobalString("WASM_MEMORY"));
284     assert(WasmMemory == nullptr);
285     auto *WasmMemoryV = makeVariable(getPointerType());
286     Entry->appendInst(InstLoad::create(Func, WasmMemoryV, WasmMemoryPtr));
287     WasmMemory = WasmMemoryV;
288 
289     return OperandNode(Entry);
290   }
Param(uint32_t Index,wasm::LocalType Type)291   Node Param(uint32_t Index, wasm::LocalType Type) {
292     LOG(out << "Param(" << Index << ") = ");
293     auto *Arg = makeVariable(toIceType(Type));
294     assert(Index == NextArg);
295     Func->addArg(Arg);
296     ++NextArg;
297     LOG(out << Node(Arg) << "\n");
298     return OperandNode(Arg);
299   }
Loop(CfgNode * Entry)300   Node Loop(CfgNode *Entry) {
301     auto *Loop = Func->makeNode();
302     LOG(out << "Loop(" << Entry << ") = " << Loop << "\n");
303     Entry->appendInst(InstBr::create(Func, Loop));
304     return OperandNode(Loop);
305   }
Terminate(Node Effect,Node Control)306   void Terminate(Node Effect, Node Control) {
307     // TODO(eholk): this is almost certainly wrong
308     LOG(out << "Terminate(" << Effect << ", " << Control << ")"
309             << "\n");
310   }
Merge(uint32_t Count,Node * Controls)311   Node Merge(uint32_t Count, Node *Controls) {
312     LOG(out << "Merge(" << Count);
313     for (uint32_t i = 0; i < Count; ++i) {
314       LOG(out << ", " << Controls[i]);
315     }
316     LOG(out << ") = ");
317 
318     auto *MergedNode = Func->makeNode();
319 
320     for (uint32_t i = 0; i < Count; ++i) {
321       CfgNode *Control = Controls[i];
322       Control->appendInst(InstBr::create(Func, MergedNode));
323     }
324     LOG(out << (OperandNode)MergedNode << "\n");
325     return OperandNode(MergedNode);
326   }
Phi(wasm::LocalType,uint32_t Count,Node * Vals,Node Control)327   Node Phi(wasm::LocalType, uint32_t Count, Node *Vals, Node Control) {
328     LOG(out << "Phi(" << Count << ", " << Control);
329     for (uint32_t i = 0; i < Count; ++i) {
330       LOG(out << ", " << Vals[i]);
331     }
332     LOG(out << ") = ");
333 
334     const auto &InEdges = Control.toCfgNode()->getInEdges();
335     assert(Count == InEdges.size());
336 
337     assert(Count > 0);
338 
339     auto *Dest = makeVariable(Vals[0].toOperand()->getType(), Control);
340 
341     // Multiply by 200 in case more things get added later.
342 
343     // TODO(eholk): find a better way besides multiplying by some arbitrary
344     // constant.
345     auto *Phi = InstPhi::create(Func, Count * 200, Dest);
346     for (uint32_t i = 0; i < Count; ++i) {
347       auto *Op = Vals[i].toOperand();
348       assert(Op);
349       Phi->addArgument(Op, InEdges[i]);
350     }
351     setDefiningInst(Dest, Phi);
352     Control.toCfgNode()->appendInst(Phi);
353     LOG(out << Node(Dest) << "\n");
354     return OperandNode(Dest);
355   }
EffectPhi(uint32_t Count,Node * Effects,Node Control)356   Node EffectPhi(uint32_t Count, Node *Effects, Node Control) {
357     // TODO(eholk): this function is almost certainly wrong.
358     LOG(out << "EffectPhi(" << Count << ", " << Control << "):\n");
359     for (uint32_t i = 0; i < Count; ++i) {
360       LOG(out << "  " << Effects[i] << "\n");
361     }
362     return OperandNode(nullptr);
363   }
Int32Constant(int32_t Value)364   Node Int32Constant(int32_t Value) {
365     LOG(out << "Int32Constant(" << Value << ") = ");
366     auto *Const = Ctx->getConstantInt32(Value);
367     assert(Const);
368     assert(Control());
369     LOG(out << Node(Const) << "\n");
370     return OperandNode(Const);
371   }
Int64Constant(int64_t Value)372   Node Int64Constant(int64_t Value) {
373     LOG(out << "Int64Constant(" << Value << ") = ");
374     auto *Const = Ctx->getConstantInt64(Value);
375     assert(Const);
376     LOG(out << Node(Const) << "\n");
377     return OperandNode(Const);
378   }
Float32Constant(float Value)379   Node Float32Constant(float Value) {
380     LOG(out << "Float32Constant(" << Value << ") = ");
381     auto *Const = Ctx->getConstantFloat(Value);
382     assert(Const);
383     LOG(out << Node(Const) << "\n");
384     return OperandNode(Const);
385   }
Float64Constant(double Value)386   Node Float64Constant(double Value) {
387     LOG(out << "Float64Constant(" << Value << ") = ");
388     auto *Const = Ctx->getConstantDouble(Value);
389     assert(Const);
390     LOG(out << Node(Const) << "\n");
391     return OperandNode(Const);
392   }
Binop(wasm::WasmOpcode Opcode,Node Left,Node Right)393   Node Binop(wasm::WasmOpcode Opcode, Node Left, Node Right) {
394     LOG(out << "Binop(" << WasmOpcodes::OpcodeName(Opcode) << ", " << Left
395             << ", " << Right << ") = ");
396     BooleanVariable *BoolDest = nullptr;
397     Variable *Dest = nullptr;
398     if (isComparison(Opcode)) {
399       BoolDest = makeVariable<BooleanVariable>(IceType_i32);
400       Dest = BoolDest;
401     } else {
402       Dest = makeVariable(Left.toOperand()->getType());
403     }
404     switch (Opcode) {
405     case kExprI32Add:
406     case kExprI64Add:
407       Control()->appendInst(
408           InstArithmetic::create(Func, InstArithmetic::Add, Dest, Left, Right));
409       break;
410     case kExprF32Add:
411     case kExprF64Add:
412       Control()->appendInst(InstArithmetic::create(Func, InstArithmetic::Fadd,
413                                                    Dest, Left, Right));
414       break;
415     case kExprI32Sub:
416     case kExprI64Sub:
417       Control()->appendInst(
418           InstArithmetic::create(Func, InstArithmetic::Sub, Dest, Left, Right));
419       break;
420     case kExprF32Sub:
421     case kExprF64Sub:
422       Control()->appendInst(InstArithmetic::create(Func, InstArithmetic::Fsub,
423                                                    Dest, Left, Right));
424       break;
425     case kExprI32Mul:
426     case kExprI64Mul:
427       Control()->appendInst(
428           InstArithmetic::create(Func, InstArithmetic::Mul, Dest, Left, Right));
429       break;
430     case kExprF32Mul:
431     case kExprF64Mul:
432       Control()->appendInst(InstArithmetic::create(Func, InstArithmetic::Fmul,
433                                                    Dest, Left, Right));
434       break;
435     case kExprI32DivS:
436     case kExprI64DivS:
437       Control()->appendInst(InstArithmetic::create(Func, InstArithmetic::Sdiv,
438                                                    Dest, Left, Right));
439       break;
440     case kExprI32DivU:
441     case kExprI64DivU:
442       Control()->appendInst(InstArithmetic::create(Func, InstArithmetic::Udiv,
443                                                    Dest, Left, Right));
444       break;
445     case kExprF32Div:
446     case kExprF64Div:
447       Control()->appendInst(InstArithmetic::create(Func, InstArithmetic::Fdiv,
448                                                    Dest, Left, Right));
449       break;
450     case kExprI32RemU:
451     case kExprI64RemU:
452       Control()->appendInst(InstArithmetic::create(Func, InstArithmetic::Urem,
453                                                    Dest, Left, Right));
454       break;
455     case kExprI32RemS:
456     case kExprI64RemS:
457       Control()->appendInst(InstArithmetic::create(Func, InstArithmetic::Srem,
458                                                    Dest, Left, Right));
459       break;
460     case kExprI32Ior:
461     case kExprI64Ior:
462       Control()->appendInst(
463           InstArithmetic::create(Func, InstArithmetic::Or, Dest, Left, Right));
464       break;
465     case kExprI32Xor:
466     case kExprI64Xor:
467       Control()->appendInst(
468           InstArithmetic::create(Func, InstArithmetic::Xor, Dest, Left, Right));
469       break;
470     case kExprI32Shl:
471     case kExprI64Shl:
472       Control()->appendInst(
473           InstArithmetic::create(Func, InstArithmetic::Shl, Dest, Left, Right));
474       break;
475     case kExprI32Rol:
476     case kExprI64Rol: {
477       // TODO(eholk): add rotate as an ICE instruction to make it easier to take
478       // advantage of hardware support.
479 
480       const auto DestTy = Left.toOperand()->getType();
481       const SizeT BitCount = typeWidthInBytes(DestTy) * CHAR_BIT;
482 
483       auto *Masked = makeVariable(DestTy);
484       auto *Bottom = makeVariable(DestTy);
485       auto *Top = makeVariable(DestTy);
486       Control()->appendInst(
487           InstArithmetic::create(Func, InstArithmetic::And, Masked, Right,
488                                  Ctx->getConstantInt(DestTy, BitCount - 1)));
489       Control()->appendInst(
490           InstArithmetic::create(Func, InstArithmetic::Shl, Top, Left, Masked));
491       auto *RotShift = makeVariable(DestTy);
492       Control()->appendInst(InstArithmetic::create(
493           Func, InstArithmetic::Sub, RotShift,
494           Ctx->getConstantInt(DestTy, BitCount), Masked));
495       Control()->appendInst(InstArithmetic::create(Func, InstArithmetic::Lshr,
496                                                    Bottom, Left, RotShift));
497       Control()->appendInst(
498           InstArithmetic::create(Func, InstArithmetic::Or, Dest, Top, Bottom));
499       break;
500     }
501     case kExprI32Ror:
502     case kExprI64Ror: {
503       // TODO(eholk): add rotate as an ICE instruction to make it easier to take
504       // advantage of hardware support.
505 
506       const auto DestTy = Left.toOperand()->getType();
507       const SizeT BitCount = typeWidthInBytes(DestTy) * CHAR_BIT;
508 
509       auto *Masked = makeVariable(DestTy);
510       auto *Bottom = makeVariable(DestTy);
511       auto *Top = makeVariable(DestTy);
512       Control()->appendInst(
513           InstArithmetic::create(Func, InstArithmetic::And, Masked, Right,
514                                  Ctx->getConstantInt(DestTy, BitCount - 1)));
515       Control()->appendInst(InstArithmetic::create(Func, InstArithmetic::Lshr,
516                                                    Top, Left, Masked));
517       auto *RotShift = makeVariable(DestTy);
518       Control()->appendInst(InstArithmetic::create(
519           Func, InstArithmetic::Sub, RotShift,
520           Ctx->getConstantInt(DestTy, BitCount), Masked));
521       Control()->appendInst(InstArithmetic::create(Func, InstArithmetic::Shl,
522                                                    Bottom, Left, RotShift));
523       Control()->appendInst(
524           InstArithmetic::create(Func, InstArithmetic::Or, Dest, Top, Bottom));
525       break;
526     }
527     case kExprI32ShrU:
528     case kExprI64ShrU:
529       Control()->appendInst(InstArithmetic::create(Func, InstArithmetic::Lshr,
530                                                    Dest, Left, Right));
531       break;
532     case kExprI32ShrS:
533     case kExprI64ShrS:
534       Control()->appendInst(InstArithmetic::create(Func, InstArithmetic::Ashr,
535                                                    Dest, Left, Right));
536       break;
537     case kExprI32And:
538     case kExprI64And:
539       Control()->appendInst(
540           InstArithmetic::create(Func, InstArithmetic::And, Dest, Left, Right));
541       break;
542     case kExprI32Ne:
543     case kExprI64Ne: {
544       auto *TmpDest = makeVariable(IceType_i1);
545       Control()->appendInst(
546           InstIcmp::create(Func, InstIcmp::Ne, TmpDest, Left, Right));
547       BoolDest->setBoolSource(TmpDest);
548       Control()->appendInst(
549           InstCast::create(Func, InstCast::Zext, Dest, TmpDest));
550       break;
551     }
552     case kExprI32Eq:
553     case kExprI64Eq: {
554       auto *TmpDest = makeVariable(IceType_i1);
555       Control()->appendInst(
556           InstIcmp::create(Func, InstIcmp::Eq, TmpDest, Left, Right));
557       BoolDest->setBoolSource(TmpDest);
558       Control()->appendInst(
559           InstCast::create(Func, InstCast::Zext, Dest, TmpDest));
560       break;
561     }
562     case kExprI32LtS:
563     case kExprI64LtS: {
564       auto *TmpDest = makeVariable(IceType_i1);
565       Control()->appendInst(
566           InstIcmp::create(Func, InstIcmp::Slt, TmpDest, Left, Right));
567       BoolDest->setBoolSource(TmpDest);
568       Control()->appendInst(
569           InstCast::create(Func, InstCast::Zext, Dest, TmpDest));
570       break;
571     }
572     case kExprI32LeS:
573     case kExprI64LeS: {
574       auto *TmpDest = makeVariable(IceType_i1);
575       Control()->appendInst(
576           InstIcmp::create(Func, InstIcmp::Sle, TmpDest, Left, Right));
577       BoolDest->setBoolSource(TmpDest);
578       Control()->appendInst(
579           InstCast::create(Func, InstCast::Zext, Dest, TmpDest));
580       break;
581     }
582     case kExprI32GeU:
583     case kExprI64GeU: {
584       auto *TmpDest = makeVariable(IceType_i1);
585       Control()->appendInst(
586           InstIcmp::create(Func, InstIcmp::Uge, TmpDest, Left, Right));
587       BoolDest->setBoolSource(TmpDest);
588       Control()->appendInst(
589           InstCast::create(Func, InstCast::Zext, Dest, TmpDest));
590       break;
591     }
592     case kExprI32LeU:
593     case kExprI64LeU: {
594       auto *TmpDest = makeVariable(IceType_i1);
595       Control()->appendInst(
596           InstIcmp::create(Func, InstIcmp::Ule, TmpDest, Left, Right));
597       BoolDest->setBoolSource(TmpDest);
598       Control()->appendInst(
599           InstCast::create(Func, InstCast::Zext, Dest, TmpDest));
600       break;
601     }
602     case kExprI32LtU:
603     case kExprI64LtU: {
604       auto *TmpDest = makeVariable(IceType_i1);
605       Control()->appendInst(
606           InstIcmp::create(Func, InstIcmp::Ult, TmpDest, Left, Right));
607       BoolDest->setBoolSource(TmpDest);
608       Control()->appendInst(
609           InstCast::create(Func, InstCast::Zext, Dest, TmpDest));
610       break;
611     }
612     case kExprI32GeS:
613     case kExprI64GeS: {
614       auto *TmpDest = makeVariable(IceType_i1);
615       Control()->appendInst(
616           InstIcmp::create(Func, InstIcmp::Sge, TmpDest, Left, Right));
617       BoolDest->setBoolSource(TmpDest);
618       Control()->appendInst(
619           InstCast::create(Func, InstCast::Zext, Dest, TmpDest));
620       break;
621     }
622     case kExprI32GtS:
623     case kExprI64GtS: {
624       auto *TmpDest = makeVariable(IceType_i1);
625       Control()->appendInst(
626           InstIcmp::create(Func, InstIcmp::Sgt, TmpDest, Left, Right));
627       BoolDest->setBoolSource(TmpDest);
628       Control()->appendInst(
629           InstCast::create(Func, InstCast::Zext, Dest, TmpDest));
630       break;
631     }
632     case kExprI32GtU:
633     case kExprI64GtU: {
634       auto *TmpDest = makeVariable(IceType_i1);
635       Control()->appendInst(
636           InstIcmp::create(Func, InstIcmp::Ugt, TmpDest, Left, Right));
637       BoolDest->setBoolSource(TmpDest);
638       Control()->appendInst(
639           InstCast::create(Func, InstCast::Zext, Dest, TmpDest));
640       break;
641     }
642     case kExprF32Eq:
643     case kExprF64Eq: {
644       auto *TmpDest = makeVariable(IceType_i1);
645       Control()->appendInst(
646           InstFcmp::create(Func, InstFcmp::Ueq, TmpDest, Left, Right));
647       BoolDest->setBoolSource(TmpDest);
648       Control()->appendInst(
649           InstCast::create(Func, InstCast::Zext, Dest, TmpDest));
650       break;
651     }
652     case kExprF32Ne:
653     case kExprF64Ne: {
654       auto *TmpDest = makeVariable(IceType_i1);
655       Control()->appendInst(
656           InstFcmp::create(Func, InstFcmp::Une, TmpDest, Left, Right));
657       BoolDest->setBoolSource(TmpDest);
658       Control()->appendInst(
659           InstCast::create(Func, InstCast::Zext, Dest, TmpDest));
660       break;
661     }
662     case kExprF32Le:
663     case kExprF64Le: {
664       auto *TmpDest = makeVariable(IceType_i1);
665       Control()->appendInst(
666           InstFcmp::create(Func, InstFcmp::Ule, TmpDest, Left, Right));
667       BoolDest->setBoolSource(TmpDest);
668       Control()->appendInst(
669           InstCast::create(Func, InstCast::Zext, Dest, TmpDest));
670       break;
671     }
672     case kExprF32Lt:
673     case kExprF64Lt: {
674       auto *TmpDest = makeVariable(IceType_i1);
675       Control()->appendInst(
676           InstFcmp::create(Func, InstFcmp::Ult, TmpDest, Left, Right));
677       BoolDest->setBoolSource(TmpDest);
678       Control()->appendInst(
679           InstCast::create(Func, InstCast::Zext, Dest, TmpDest));
680       break;
681     }
682     case kExprF32Ge:
683     case kExprF64Ge: {
684       auto *TmpDest = makeVariable(IceType_i1);
685       Control()->appendInst(
686           InstFcmp::create(Func, InstFcmp::Uge, TmpDest, Left, Right));
687       BoolDest->setBoolSource(TmpDest);
688       Control()->appendInst(
689           InstCast::create(Func, InstCast::Zext, Dest, TmpDest));
690       break;
691     }
692     case kExprF32Gt:
693     case kExprF64Gt: {
694       auto *TmpDest = makeVariable(IceType_i1);
695       Control()->appendInst(
696           InstFcmp::create(Func, InstFcmp::Ugt, TmpDest, Left, Right));
697       BoolDest->setBoolSource(TmpDest);
698       Control()->appendInst(
699           InstCast::create(Func, InstCast::Zext, Dest, TmpDest));
700       break;
701     }
702     default:
703       LOG(out << "Unknown binop: " << WasmOpcodes::OpcodeName(Opcode) << "\n");
704       llvm::report_fatal_error("Uncovered or invalid binop.");
705       return OperandNode(nullptr);
706     }
707     LOG(out << Dest << "\n");
708     return OperandNode(Dest);
709   }
Unop(wasm::WasmOpcode Opcode,Node Input)710   Node Unop(wasm::WasmOpcode Opcode, Node Input) {
711     LOG(out << "Unop(" << WasmOpcodes::OpcodeName(Opcode) << ", " << Input
712             << ") = ");
713     Variable *Dest = nullptr;
714     switch (Opcode) {
715     // TODO (eholk): merge these next two cases using getConstantInteger
716     case kExprI32Eqz: {
717       auto *BoolDest = makeVariable<BooleanVariable>(IceType_i32);
718       Dest = BoolDest;
719       auto *Tmp = makeVariable(IceType_i1);
720       Control()->appendInst(InstIcmp::create(Func, InstIcmp::Eq, Tmp, Input,
721                                              Ctx->getConstantInt32(0)));
722       BoolDest->setBoolSource(Tmp);
723       Control()->appendInst(InstCast::create(Func, InstCast::Zext, Dest, Tmp));
724       break;
725     }
726     case kExprI64Eqz: {
727       auto *BoolDest = makeVariable<BooleanVariable>(IceType_i32);
728       Dest = BoolDest;
729       auto *Tmp = makeVariable(IceType_i1);
730       Control()->appendInst(InstIcmp::create(Func, InstIcmp::Eq, Tmp, Input,
731                                              Ctx->getConstantInt64(0)));
732       BoolDest->setBoolSource(Tmp);
733       Control()->appendInst(InstCast::create(Func, InstCast::Zext, Dest, Tmp));
734       break;
735     }
736     case kExprI32Ctz: {
737       Dest = makeVariable(IceType_i32);
738       const auto FnName = Ctx->getGlobalString("llvm.cttz.i32");
739       bool BadInstrinsic = false;
740       const auto *Info = Ctx->getIntrinsicsInfo().find(FnName, BadInstrinsic);
741       assert(!BadInstrinsic);
742       assert(Info);
743 
744       auto *Call = InstIntrinsic::create(
745           Func, 1, Dest, Ctx->getConstantExternSym(FnName), Info->Info);
746       Call->addArg(Input);
747       Control()->appendInst(Call);
748       break;
749     }
750     case kExprF32Neg: {
751       Dest = makeVariable(IceType_f32);
752       Control()->appendInst(InstArithmetic::create(
753           Func, InstArithmetic::Fsub, Dest, Ctx->getConstantFloat(0), Input));
754       break;
755     }
756     case kExprF64Neg: {
757       Dest = makeVariable(IceType_f64);
758       Control()->appendInst(InstArithmetic::create(
759           Func, InstArithmetic::Fsub, Dest, Ctx->getConstantDouble(0), Input));
760       break;
761     }
762     case kExprF32Abs: {
763       Dest = makeVariable(IceType_f32);
764       const auto FnName = Ctx->getGlobalString("llvm.fabs.f32");
765       bool BadInstrinsic = false;
766       const auto *Info = Ctx->getIntrinsicsInfo().find(FnName, BadInstrinsic);
767       assert(!BadInstrinsic);
768       assert(Info);
769 
770       auto *Call = InstIntrinsic::create(
771           Func, 1, Dest, Ctx->getConstantExternSym(FnName), Info->Info);
772       Call->addArg(Input);
773       Control()->appendInst(Call);
774       break;
775     }
776     case kExprF64Abs: {
777       Dest = makeVariable(IceType_f64);
778       const auto FnName = Ctx->getGlobalString("llvm.fabs.f64");
779       bool BadInstrinsic = false;
780       const auto *Info = Ctx->getIntrinsicsInfo().find(FnName, BadInstrinsic);
781       assert(!BadInstrinsic);
782       assert(Info);
783 
784       auto *Call = InstIntrinsic::create(
785           Func, 1, Dest, Ctx->getConstantExternSym(FnName), Info->Info);
786       Call->addArg(Input);
787       Control()->appendInst(Call);
788       break;
789     }
790     case kExprF32Floor: {
791       Dest = makeVariable(IceType_f64);
792       const auto FnName = Ctx->getGlobalString("env$$floor_f");
793       constexpr bool HasTailCall = false;
794 
795       auto *Call = InstCall::create(
796           Func, 1, Dest, Ctx->getConstantExternSym(FnName), HasTailCall);
797       Call->addArg(Input);
798       Control()->appendInst(Call);
799       break;
800     }
801     case kExprF64Floor: {
802       Dest = makeVariable(IceType_f64);
803       const auto FnName = Ctx->getGlobalString("env$$floor_d");
804       constexpr bool HasTailCall = false;
805 
806       auto *Call = InstCall::create(
807           Func, 1, Dest, Ctx->getConstantExternSym(FnName), HasTailCall);
808       Call->addArg(Input);
809       Control()->appendInst(Call);
810       break;
811     }
812     case kExprF32Sqrt: {
813       Dest = makeVariable(IceType_f32);
814       const auto FnName = Ctx->getGlobalString("llvm.sqrt.f32");
815       bool BadInstrinsic = false;
816       const auto *Info = Ctx->getIntrinsicsInfo().find(FnName, BadInstrinsic);
817       assert(!BadInstrinsic);
818       assert(Info);
819 
820       auto *Call = InstIntrinsic::create(
821           Func, 1, Dest, Ctx->getConstantExternSym(FnName), Info->Info);
822       Call->addArg(Input);
823       Control()->appendInst(Call);
824       break;
825     }
826     case kExprF64Sqrt: {
827       Dest = makeVariable(IceType_f64);
828       const auto FnName = Ctx->getGlobalString("llvm.sqrt.f64");
829       bool BadInstrinsic = false;
830       const auto *Info = Ctx->getIntrinsicsInfo().find(FnName, BadInstrinsic);
831       assert(!BadInstrinsic);
832       assert(Info);
833 
834       auto *Call = InstIntrinsic::create(
835           Func, 1, Dest, Ctx->getConstantExternSym(FnName), Info->Info);
836       Call->addArg(Input);
837       Control()->appendInst(Call);
838       break;
839     }
840     case kExprI64UConvertI32:
841       Dest = makeVariable(IceType_i64);
842       Control()->appendInst(
843           InstCast::create(Func, InstCast::Zext, Dest, Input));
844       break;
845     case kExprI64SConvertI32:
846       Dest = makeVariable(IceType_i64);
847       Control()->appendInst(
848           InstCast::create(Func, InstCast::Sext, Dest, Input));
849       break;
850     case kExprI32SConvertF32:
851       Dest = makeVariable(IceType_i32);
852       Control()->appendInst(
853           InstCast::create(Func, InstCast::Fptosi, Dest, Input));
854       break;
855     case kExprI32UConvertF32:
856       Dest = makeVariable(IceType_i32);
857       Control()->appendInst(
858           InstCast::create(Func, InstCast::Fptoui, Dest, Input));
859       break;
860     case kExprI32SConvertF64:
861       Dest = makeVariable(IceType_i32);
862       Control()->appendInst(
863           InstCast::create(Func, InstCast::Fptosi, Dest, Input));
864       break;
865     case kExprI32UConvertF64:
866       Dest = makeVariable(IceType_i32);
867       Control()->appendInst(
868           InstCast::create(Func, InstCast::Fptoui, Dest, Input));
869       break;
870     case kExprI32ReinterpretF32:
871       Dest = makeVariable(IceType_i32);
872       Control()->appendInst(
873           InstCast::create(Func, InstCast::Bitcast, Dest, Input));
874       break;
875     case kExprI64ReinterpretF64:
876       Dest = makeVariable(IceType_i64);
877       Control()->appendInst(
878           InstCast::create(Func, InstCast::Bitcast, Dest, Input));
879       break;
880     case kExprF64ReinterpretI64:
881       Dest = makeVariable(IceType_f64);
882       Control()->appendInst(
883           InstCast::create(Func, InstCast::Bitcast, Dest, Input));
884       break;
885     case kExprI32ConvertI64:
886       Dest = makeVariable(IceType_i32);
887       Control()->appendInst(
888           InstCast::create(Func, InstCast::Trunc, Dest, Input));
889       break;
890     case kExprF64SConvertI32:
891       Dest = makeVariable(IceType_f64);
892       Control()->appendInst(
893           InstCast::create(Func, InstCast::Sitofp, Dest, Input));
894       break;
895     case kExprF64UConvertI32:
896       Dest = makeVariable(IceType_f64);
897       Control()->appendInst(
898           InstCast::create(Func, InstCast::Uitofp, Dest, Input));
899       break;
900     case kExprF64ConvertF32:
901       Dest = makeVariable(IceType_f64);
902       Control()->appendInst(
903           InstCast::create(Func, InstCast::Fpext, Dest, Input));
904       break;
905     case kExprF32SConvertI32:
906       Dest = makeVariable(IceType_f32);
907       Control()->appendInst(
908           InstCast::create(Func, InstCast::Sitofp, Dest, Input));
909       break;
910     case kExprF32UConvertI32:
911       Dest = makeVariable(IceType_f32);
912       Control()->appendInst(
913           InstCast::create(Func, InstCast::Uitofp, Dest, Input));
914       break;
915     case kExprF32ReinterpretI32:
916       Dest = makeVariable(IceType_f32);
917       Control()->appendInst(
918           InstCast::create(Func, InstCast::Bitcast, Dest, Input));
919       break;
920     case kExprF32ConvertF64:
921       Dest = makeVariable(IceType_f32);
922       Control()->appendInst(
923           InstCast::create(Func, InstCast::Fptrunc, Dest, Input));
924       break;
925     default:
926       LOG(out << "Unknown unop: " << WasmOpcodes::OpcodeName(Opcode) << "\n");
927       llvm::report_fatal_error("Uncovered or invalid unop.");
928       return OperandNode(nullptr);
929     }
930     LOG(out << Dest << "\n");
931     return OperandNode(Dest);
932   }
InputCount(CfgNode * Node) const933   uint32_t InputCount(CfgNode *Node) const { return Node->getInEdges().size(); }
IsPhiWithMerge(Node Phi,Node Merge) const934   bool IsPhiWithMerge(Node Phi, Node Merge) const {
935     LOG(out << "IsPhiWithMerge(" << Phi << ", " << Merge << ")"
936             << "\n");
937     if (Phi && Phi.isOperand()) {
938       LOG(out << "  ...is operand"
939               << "\n");
940       if (getDefiningInst(Phi)) {
941         LOG(out << "  ...has defining instruction"
942                 << "\n");
943         LOG(out << getDefNode(Phi) << "\n");
944         LOG(out << "  ..." << (getDefNode(Phi) == Merge) << "\n");
945         return getDefNode(Phi) == Merge;
946       }
947     }
948     return false;
949   }
AppendToMerge(CfgNode * Merge,CfgNode * From) const950   void AppendToMerge(CfgNode *Merge, CfgNode *From) const {
951     From->appendInst(InstBr::create(Func, Merge));
952   }
AppendToPhi(Node Merge,Node Phi,Node From)953   void AppendToPhi(Node Merge, Node Phi, Node From) {
954     LOG(out << "AppendToPhi(" << Merge << ", " << Phi << ", " << From << ")"
955             << "\n");
956     auto *Inst = getDefiningInst(Phi);
957     assert(Inst->getDest()->getType() == From.toOperand()->getType());
958     Inst->addArgument(From, getDefNode(From));
959   }
960 
961   //-----------------------------------------------------------------------
962   // Operations that read and/or write {control} and {effect}.
963   //-----------------------------------------------------------------------
Branch(Node Cond,Node * TrueNode,Node * FalseNode)964   Node Branch(Node Cond, Node *TrueNode, Node *FalseNode) {
965     // true_node and false_node appear to be out parameters.
966     LOG(out << "Branch(" << Cond << ", ");
967 
968     // save control here because true_node appears to alias control.
969     auto *Ctrl = Control();
970 
971     *TrueNode = OperandNode(Func->makeNode());
972     *FalseNode = OperandNode(Func->makeNode());
973 
974     LOG(out << *TrueNode << ", " << *FalseNode << ")"
975             << "\n");
976 
977     auto *CondBool = Cond.toOperand()->asBoolean();
978     if (CondBool == nullptr) {
979       CondBool = makeVariable(IceType_i1);
980       Ctrl->appendInst(InstIcmp::create(Func, InstIcmp::Ne, CondBool, Cond,
981                                         Ctx->getConstantInt32(0)));
982     }
983 
984     Ctrl->appendInst(InstBr::create(Func, CondBool, *TrueNode, *FalseNode));
985     return OperandNode(nullptr);
986   }
987   InstSwitch *CurrentSwitch = nullptr;
988   CfgNode *SwitchNode = nullptr;
989   SizeT SwitchIndex = 0;
Switch(uint32_t Count,Node Key)990   Node Switch(uint32_t Count, Node Key) {
991     LOG(out << "Switch(" << Count << ", " << Key << ")\n");
992 
993     assert(!CurrentSwitch);
994 
995     auto *Default = Func->makeNode();
996     // Count - 1 because the decoder counts the default label but Subzero does
997     // not.
998     CurrentSwitch = InstSwitch::create(Func, Count - 1, Key, Default);
999     SwitchIndex = 0;
1000     SwitchNode = Control();
1001     // We don't actually append the switch to the CfgNode here because not all
1002     // the branches are ready.
1003     return Node(nullptr);
1004   }
IfValue(int32_t Value,Node)1005   Node IfValue(int32_t Value, Node) {
1006     LOG(out << "IfValue(" << Value << ") [Index = " << SwitchIndex << "]\n");
1007     assert(CurrentSwitch);
1008     auto *Target = Func->makeNode();
1009     CurrentSwitch->addBranch(SwitchIndex++, Value, Target);
1010     return Node(Target);
1011   }
IfDefault(Node)1012   Node IfDefault(Node) {
1013     LOG(out << "IfDefault(...) [Index = " << SwitchIndex << "]\n");
1014     assert(CurrentSwitch);
1015     assert(CurrentSwitch->getLabelDefault());
1016     // Now we append the switch, since this should be the last edge.
1017     assert(SwitchIndex == CurrentSwitch->getNumCases());
1018     SwitchNode->appendInst(CurrentSwitch);
1019     SwitchNode = nullptr;
1020     auto Default = Node(CurrentSwitch->getLabelDefault());
1021     CurrentSwitch = nullptr;
1022     return Default;
1023   }
Return(uint32_t Count,Node * Vals)1024   Node Return(uint32_t Count, Node *Vals) {
1025     assert(1 >= Count);
1026     LOG(out << "Return(");
1027     if (Count > 0)
1028       LOG(out << Vals[0]);
1029     LOG(out << ")"
1030             << "\n");
1031     auto *Instr =
1032         1 == Count ? InstRet::create(Func, Vals[0]) : InstRet::create(Func);
1033     Control()->appendInst(Instr);
1034     Control()->setHasReturn();
1035     LOG(out << Node(nullptr) << "\n");
1036     return OperandNode(nullptr);
1037   }
ReturnVoid()1038   Node ReturnVoid() {
1039     LOG(out << "ReturnVoid() = ");
1040     auto *Instr = InstRet::create(Func);
1041     Control()->appendInst(Instr);
1042     Control()->setHasReturn();
1043     LOG(out << Node(nullptr) << "\n");
1044     return OperandNode(nullptr);
1045   }
Unreachable()1046   Node Unreachable() {
1047     LOG(out << "Unreachable() = ");
1048     auto *Instr = InstUnreachable::create(Func);
1049     Control()->appendInst(Instr);
1050     LOG(out << Node(nullptr) << "\n");
1051     return OperandNode(nullptr);
1052   }
1053 
CallDirect(uint32_t Index,Node * Args)1054   Node CallDirect(uint32_t Index, Node *Args) {
1055     LOG(out << "CallDirect(" << Index << ")"
1056             << "\n");
1057     assert(Module->IsValidFunction(Index));
1058     const auto *Module = this->Module->module;
1059     assert(Module);
1060     const auto &Target = Module->functions[Index];
1061     const auto *Sig = Target.sig;
1062     assert(Sig);
1063     const auto NumArgs = Sig->parameter_count();
1064     LOG(out << "  number of args: " << NumArgs << "\n");
1065 
1066     const auto TargetName = getFunctionName(Module, Index);
1067     LOG(out << "  target name: " << TargetName << "\n");
1068 
1069     assert(Sig->return_count() <= 1);
1070 
1071     auto TargetOperand =
1072         Ctx->getConstantSym(0, Ctx->getGlobalString(TargetName));
1073 
1074     auto *Dest = Sig->return_count() > 0
1075                      ? makeVariable(toIceType(Sig->GetReturn()))
1076                      : nullptr;
1077     auto *Call = InstCall::create(Func, NumArgs, Dest, TargetOperand,
1078                                   false /* HasTailCall */);
1079     for (uint32_t i = 0; i < NumArgs; ++i) {
1080       // The builder reserves the first argument for the code object.
1081       LOG(out << "  args[" << i << "] = " << Args[i + 1] << "\n");
1082       Call->addArg(Args[i + 1]);
1083     }
1084 
1085     Control()->appendInst(Call);
1086     LOG(out << "Call Result = " << Node(Dest) << "\n");
1087     return OperandNode(Dest);
1088   }
CallImport(uint32_t Index,Node * Args)1089   Node CallImport(uint32_t Index, Node *Args) {
1090     LOG(out << "CallImport(" << Index << ")"
1091             << "\n");
1092     const auto *Module = this->Module->module;
1093     assert(Module);
1094     const auto *Sig = this->Module->GetImportSignature(Index);
1095     assert(Sig);
1096     const auto NumArgs = Sig->parameter_count();
1097     LOG(out << "  number of args: " << NumArgs << "\n");
1098 
1099     const auto &Target = Module->import_table[Index];
1100     const auto ModuleName = toStdString(
1101         Module->GetName(Target.module_name_offset, Target.module_name_length));
1102     const auto FnName = toStdString(Module->GetName(
1103         Target.function_name_offset, Target.function_name_length));
1104 
1105     const auto TargetName = Ctx->getGlobalString(ModuleName + "$$" + FnName);
1106     LOG(out << "  target name: " << TargetName << "\n");
1107 
1108     assert(Sig->return_count() <= 1);
1109 
1110     auto TargetOperand = Ctx->getConstantExternSym(TargetName);
1111 
1112     auto *Dest = Sig->return_count() > 0
1113                      ? makeVariable(toIceType(Sig->GetReturn()))
1114                      : nullptr;
1115     constexpr bool NoTailCall = false;
1116     auto *Call =
1117         InstCall::create(Func, NumArgs, Dest, TargetOperand, NoTailCall);
1118     for (uint32_t i = 0; i < NumArgs; ++i) {
1119       // The builder reserves the first argument for the code object.
1120       LOG(out << "  args[" << i << "] = " << Args[i + 1] << "\n");
1121       assert(Args[i + 1].toOperand()->getType() == toIceType(Sig->GetParam(i)));
1122       Call->addArg(Args[i + 1]);
1123     }
1124 
1125     Control()->appendInst(Call);
1126     LOG(out << "Call Result = " << Node(Dest) << "\n");
1127     return OperandNode(Dest);
1128   }
CallIndirect(uint32_t SigIndex,Node * Args)1129   Node CallIndirect(uint32_t SigIndex, Node *Args) {
1130     LOG(out << "CallIndirect(" << SigIndex << ")\n");
1131     // TODO(eholk): Compile to something better than a switch.
1132     const auto *Module = this->Module->module;
1133     assert(Module);
1134     const auto &IndirectTable = Module->function_table;
1135 
1136     auto *Abort = getIndirectFailTarget();
1137 
1138     assert(Args[0].toOperand());
1139 
1140     auto *Switch = InstSwitch::create(Func, IndirectTable.size(),
1141                                       Args[0].toOperand(), Abort);
1142     assert(Abort);
1143 
1144     const bool HasReturn = Module->signatures[SigIndex]->return_count() != 0;
1145     const Ice::Type DestTy =
1146         HasReturn ? toIceType(Module->signatures[SigIndex]->GetReturn())
1147                   : IceType_void;
1148 
1149     auto *Dest = HasReturn ? makeVariable(DestTy) : nullptr;
1150 
1151     auto *ExitNode = Func->makeNode();
1152     auto *PhiInst =
1153         HasReturn ? InstPhi::create(Func, IndirectTable.size(), Dest) : nullptr;
1154 
1155     for (uint32_t Index = 0; Index < IndirectTable.size(); ++Index) {
1156       const auto &Target = Module->functions[IndirectTable[Index]];
1157 
1158       if (SigIndex == Target.sig_index) {
1159         auto *CallNode = Func->makeNode();
1160         auto *SavedControl = Control();
1161         *ControlPtr = OperandNode(CallNode);
1162         auto *Tmp = CallDirect(Target.func_index, Args).toOperand();
1163         *ControlPtr = OperandNode(SavedControl);
1164         if (PhiInst) {
1165           PhiInst->addArgument(Tmp, CallNode);
1166         }
1167         CallNode->appendInst(InstBr::create(Func, ExitNode));
1168         Switch->addBranch(Index, Index, CallNode);
1169       } else {
1170         Switch->addBranch(Index, Index, Abort);
1171       }
1172     }
1173 
1174     if (PhiInst) {
1175       ExitNode->appendInst(PhiInst);
1176     }
1177 
1178     Control()->appendInst(Switch);
1179     *ControlPtr = OperandNode(ExitNode);
1180     return OperandNode(Dest);
1181   }
Invert(Node Node)1182   Node Invert(Node Node) {
1183     (void)Node;
1184     llvm::report_fatal_error("Invert");
1185   }
1186 
1187   //-----------------------------------------------------------------------
1188   // Operations that concern the linear memory.
1189   //-----------------------------------------------------------------------
MemSize(uint32_t Offset)1190   Node MemSize(uint32_t Offset) {
1191     (void)Offset;
1192     llvm::report_fatal_error("MemSize");
1193   }
LoadGlobal(uint32_t Index)1194   Node LoadGlobal(uint32_t Index) {
1195     (void)Index;
1196     llvm::report_fatal_error("LoadGlobal");
1197   }
StoreGlobal(uint32_t Index,Node Val)1198   Node StoreGlobal(uint32_t Index, Node Val) {
1199     (void)Index;
1200     (void)Val;
1201     llvm::report_fatal_error("StoreGlobal");
1202   }
1203 
LoadMem(wasm::LocalType Type,MachineType MemType,Node Index,uint32_t Offset)1204   Node LoadMem(wasm::LocalType Type, MachineType MemType, Node Index,
1205                uint32_t Offset) {
1206     LOG(out << "LoadMem." << toIceType(MemType) << "(" << Index << "[" << Offset
1207             << "]) = ");
1208 
1209     auto *RealAddr = sanitizeAddress(Index, Offset);
1210 
1211     auto *LoadResult = makeVariable(toIceType(MemType));
1212     Control()->appendInst(InstLoad::create(Func, LoadResult, RealAddr));
1213 
1214     // and cast, if needed
1215     Variable *Result = nullptr;
1216     if (toIceType(Type) != toIceType(MemType)) {
1217       auto DestType = toIceType(Type);
1218       Result = makeVariable(DestType);
1219       // TODO(eholk): handle signs correctly.
1220       if (isScalarIntegerType(DestType)) {
1221         if (MemType.IsSigned()) {
1222           Control()->appendInst(
1223               InstCast::create(Func, InstCast::Sext, Result, LoadResult));
1224         } else {
1225           Control()->appendInst(
1226               InstCast::create(Func, InstCast::Zext, Result, LoadResult));
1227         }
1228       } else if (isScalarFloatingType(DestType)) {
1229         Control()->appendInst(
1230             InstCast::create(Func, InstCast::Sitofp, Result, LoadResult));
1231       } else {
1232         llvm::report_fatal_error("Unsupported type for memory load");
1233       }
1234     } else {
1235       Result = LoadResult;
1236     }
1237 
1238     LOG(out << Result << "\n");
1239     return OperandNode(Result);
1240   }
StoreMem(MachineType Type,Node Index,uint32_t Offset,Node Val)1241   void StoreMem(MachineType Type, Node Index, uint32_t Offset, Node Val) {
1242     LOG(out << "StoreMem." << toIceType(Type) << "(" << Index << "[" << Offset
1243             << "] = " << Val << ")"
1244             << "\n");
1245 
1246     auto *RealAddr = sanitizeAddress(Index, Offset);
1247 
1248     // cast the value to the right type, if needed
1249     Operand *StoreVal = nullptr;
1250     if (toIceType(Type) != Val.toOperand()->getType()) {
1251       auto *LocalStoreVal = makeVariable(toIceType(Type));
1252       Control()->appendInst(
1253           InstCast::create(Func, InstCast::Trunc, LocalStoreVal, Val));
1254       StoreVal = LocalStoreVal;
1255     } else {
1256       StoreVal = Val;
1257     }
1258 
1259     // then store the memory
1260     Control()->appendInst(InstStore::create(Func, StoreVal, RealAddr));
1261   }
1262 
PrintDebugName(OperandNode Node)1263   static void PrintDebugName(OperandNode Node) {
1264     (void)Node;
1265     llvm::report_fatal_error("PrintDebugName");
1266   }
1267 
Control()1268   CfgNode *Control() {
1269     return ControlPtr ? ControlPtr->toCfgNode() : Func->getEntryNode();
1270   }
Effect()1271   Node Effect() { return *EffectPtr; }
1272 
set_module(wasm::ModuleEnv * Module)1273   void set_module(wasm::ModuleEnv *Module) { this->Module = Module; }
1274 
set_control_ptr(Node * Control)1275   void set_control_ptr(Node *Control) { this->ControlPtr = Control; }
1276 
set_effect_ptr(Node * Effect)1277   void set_effect_ptr(Node *Effect) { this->EffectPtr = Effect; }
1278 
1279 private:
1280   wasm::ModuleEnv *Module;
1281   Node *ControlPtr;
1282   Node *EffectPtr;
1283 
1284   class Cfg *Func;
1285   GlobalContext *Ctx;
1286 
1287   CfgNode *BoundsFailTarget = nullptr;
1288   CfgNode *IndirectFailTarget = nullptr;
1289 
1290   SizeT NextArg = 0;
1291 
1292   CfgUnorderedMap<Operand *, InstPhi *> PhiMap;
1293   CfgUnorderedMap<Operand *, CfgNode *> DefNodeMap;
1294 
1295   Operand *WasmMemory = nullptr;
1296 
getDefiningInst(Operand * Op) const1297   InstPhi *getDefiningInst(Operand *Op) const {
1298     const auto &Iter = PhiMap.find(Op);
1299     if (Iter == PhiMap.end()) {
1300       return nullptr;
1301     }
1302     return Iter->second;
1303   }
1304 
setDefiningInst(Operand * Op,InstPhi * Phi)1305   void setDefiningInst(Operand *Op, InstPhi *Phi) {
1306     LOG(out << "\n== setDefiningInst(" << Op << ", " << Phi << ") ==\n");
1307     PhiMap.emplace(Op, Phi);
1308   }
1309 
makeVariable(Ice::Type Type)1310   template <typename T = Variable> T *makeVariable(Ice::Type Type) {
1311     return makeVariable<T>(Type, Control());
1312   }
1313 
1314   template <typename T = Variable>
makeVariable(Ice::Type Type,CfgNode * DefNode)1315   T *makeVariable(Ice::Type Type, CfgNode *DefNode) {
1316     auto *Var = Func->makeVariable<T>(Type);
1317     DefNodeMap.emplace(Var, DefNode);
1318     return Var;
1319   }
1320 
getDefNode(Operand * Op) const1321   CfgNode *getDefNode(Operand *Op) const {
1322     const auto &Iter = DefNodeMap.find(Op);
1323     if (Iter == DefNodeMap.end()) {
1324       return nullptr;
1325     }
1326     return Iter->second;
1327   }
1328 
getBoundsFailTarget()1329   CfgNode *getBoundsFailTarget() {
1330     if (!BoundsFailTarget) {
1331       // TODO (eholk): Move this node to the end of the CFG, or even better,
1332       // have only one abort block for the whole module.
1333       BoundsFailTarget = Func->makeNode();
1334       BoundsFailTarget->appendInst(InstCall::create(
1335           Func, 0, nullptr,
1336           Ctx->getConstantExternSym(Ctx->getGlobalString("__Sz_bounds_fail")),
1337           false));
1338       BoundsFailTarget->appendInst(InstUnreachable::create(Func));
1339     }
1340 
1341     return BoundsFailTarget;
1342   }
getIndirectFailTarget()1343   CfgNode *getIndirectFailTarget() {
1344     if (!IndirectFailTarget) {
1345       // TODO (eholk): Move this node to the end of the CFG, or even better,
1346       // have only one abort block for the whole module.
1347       IndirectFailTarget = Func->makeNode();
1348       IndirectFailTarget->appendInst(InstCall::create(
1349           Func, 0, nullptr,
1350           Ctx->getConstantExternSym(Ctx->getGlobalString("__Sz_indirect_fail")),
1351           false));
1352       IndirectFailTarget->appendInst(InstUnreachable::create(Func));
1353     }
1354 
1355     return IndirectFailTarget;
1356   }
1357 
getWasmMemory()1358   Operand *getWasmMemory() {
1359     assert(WasmMemory != nullptr);
1360     return WasmMemory;
1361   }
1362 
sanitizeAddress(Operand * Base,uint32_t Offset)1363   Operand *sanitizeAddress(Operand *Base, uint32_t Offset) {
1364     SizeT MemSize = Module->module->min_mem_pages * WASM_PAGE_SIZE;
1365 
1366     bool ConstZeroBase = false;
1367 
1368     // first, add the index and the offset together.
1369     if (auto *ConstBase = llvm::dyn_cast<ConstantInteger32>(Base)) {
1370       uint32_t RealOffset = Offset + ConstBase->getValue();
1371       if (RealOffset >= MemSize) {
1372         // We've proven this will always be an out of bounds access, so insert
1373         // an unconditional trap.
1374         Control()->appendInst(InstUnreachable::create(Func));
1375         // It doesn't matter what we return here, so return something that will
1376         // allow the rest of code generation to happen.
1377         //
1378         // We might be tempted to just abort translation here, but out of bounds
1379         // memory access is a runtime trap, not a compile error.
1380         return Ctx->getConstantZero(getPointerType());
1381       }
1382       Base = Ctx->getConstantInt32(RealOffset);
1383       ConstZeroBase = (0 == RealOffset);
1384     } else if (0 != Offset) {
1385       auto *Addr = makeVariable(Ice::getPointerType());
1386       auto *OffsetConstant = Ctx->getConstantInt32(Offset);
1387       Control()->appendInst(InstArithmetic::create(Func, InstArithmetic::Add,
1388                                                    Addr, Base, OffsetConstant));
1389 
1390       Base = Addr;
1391     }
1392 
1393     // Do the bounds check if enabled
1394     if (getFlags().getWasmBoundsCheck() &&
1395         !llvm::isa<ConstantInteger32>(Base)) {
1396       // TODO (eholk): creating a new basic block on every memory access is
1397       // terrible (see https://goo.gl/Zj7DTr). Try adding a new instruction that
1398       // encapsulates this "abort if false" pattern.
1399       auto *CheckPassed = Func->makeNode();
1400       auto *CheckFailed = getBoundsFailTarget();
1401 
1402       auto *Check = makeVariable(IceType_i1);
1403       Control()->appendInst(InstIcmp::create(Func, InstIcmp::Ult, Check, Base,
1404                                              Ctx->getConstantInt32(MemSize)));
1405       Control()->appendInst(
1406           InstBr::create(Func, Check, CheckPassed, CheckFailed));
1407 
1408       *ControlPtr = OperandNode(CheckPassed);
1409     }
1410 
1411     Ice::Operand *RealAddr = nullptr;
1412     auto MemBase = getWasmMemory();
1413     if (!ConstZeroBase) {
1414       auto RealAddrV = Func->makeVariable(Ice::getPointerType());
1415       Control()->appendInst(InstArithmetic::create(Func, InstArithmetic::Add,
1416                                                    RealAddrV, Base, MemBase));
1417 
1418       RealAddr = RealAddrV;
1419     } else {
1420       RealAddr = MemBase;
1421     }
1422     return RealAddr;
1423   }
1424 
log(F Fn) const1425   template <typename F = std::function<void(Ostream &)>> void log(F Fn) const {
1426     if (BuildDefs::dump() && (getFlags().getVerbose() & IceV_Wasm)) {
1427       Fn(Ctx->getStrDump());
1428       Ctx->getStrDump().flush();
1429     }
1430   }
1431 };
1432 
translateFunction(Zone * Zone,FunctionBody & Body)1433 std::unique_ptr<Cfg> WasmTranslator::translateFunction(Zone *Zone,
1434                                                        FunctionBody &Body) {
1435   OstreamLocker L1(Ctx);
1436   auto Func = Cfg::create(Ctx, getNextSequenceNumber());
1437   TimerMarker T(TimerStack::TT_wasmGenIce, Func.get());
1438   Ice::CfgLocalAllocatorScope L2(Func.get());
1439 
1440   // TODO(eholk): parse the function signature...
1441 
1442   Func->setEntryNode(Func->makeNode());
1443 
1444   IceBuilder Builder(Func.get());
1445   SR_WasmDecoder<OperandNode, IceBuilder> Decoder(Zone, &Builder, Body);
1446 
1447   LOG(out << getFlags().getDefaultGlobalPrefix() << "\n");
1448   Decoder.Decode();
1449 
1450   // We don't always know where the incoming branches are in phi nodes, so this
1451   // function finds them.
1452   Func->fixPhiNodes();
1453 
1454   Func->computeInOutEdges();
1455 
1456   return Func;
1457 }
1458 
1459 constexpr SizeT InitialBufferSize = 16 << 10; // 16KB
1460 
WasmTranslator(GlobalContext * Ctx)1461 WasmTranslator::WasmTranslator(GlobalContext *Ctx)
1462     : Translator(Ctx), Buffer(InitialBufferSize) {}
1463 
translate(const std::string & IRFilename,std::unique_ptr<llvm::DataStreamer> InputStream)1464 void WasmTranslator::translate(
1465     const std::string &IRFilename,
1466     std::unique_ptr<llvm::DataStreamer> InputStream) {
1467   TimerMarker T(TimerStack::TT_wasm, Ctx);
1468 
1469   LOG(out << "Initializing v8/wasm stuff..."
1470           << "\n");
1471   Zone Zone;
1472   ZoneScope _(&Zone);
1473 
1474   SizeT BytesRead = 0;
1475   while (true) {
1476     BytesRead +=
1477         InputStream->GetBytes(&Buffer[BytesRead], Buffer.size() - BytesRead);
1478     LOG(out << "Read " << BytesRead << " bytes"
1479             << "\n");
1480     if (BytesRead < Buffer.size())
1481       break;
1482     Buffer.resize(Buffer.size() * 2);
1483   }
1484 
1485   LOG(out << "Decoding module " << IRFilename << "\n");
1486 
1487   constexpr v8::internal::Isolate *NoIsolate = nullptr;
1488   auto Result = DecodeWasmModule(NoIsolate, &Zone, Buffer.data(),
1489                                  Buffer.data() + BytesRead, false, kWasmOrigin);
1490 
1491   auto Module = Result.val;
1492 
1493   LOG(out << "Module info:"
1494           << "\n");
1495   LOG(out << "  min_mem_pages:           " << Module->min_mem_pages << "\n");
1496   LOG(out << "  max_mem_pages:           " << Module->max_mem_pages << "\n");
1497   LOG(out << "  number of globals:       " << Module->globals.size() << "\n");
1498   LOG(out << "  number of signatures:    " << Module->signatures.size()
1499           << "\n");
1500   LOG(out << "  number of functions:     " << Module->functions.size() << "\n");
1501   LOG(out << "  number of data_segments: " << Module->data_segments.size()
1502           << "\n");
1503   LOG(out << "  function table size:     " << Module->function_table.size()
1504           << "\n");
1505   LOG(out << "  import table size:       " << Module->import_table.size()
1506           << "\n");
1507   LOG(out << "  export table size:       " << Module->export_table.size()
1508           << "\n");
1509 
1510   LOG(out << "\n"
1511           << "Data segment information:"
1512           << "\n");
1513   uint32_t Id = 0;
1514   for (const auto Seg : Module->data_segments) {
1515     LOG(out << Id << ":  (" << Seg.source_offset << ", " << Seg.source_size
1516             << ") => " << Seg.dest_addr);
1517     if (Seg.init) {
1518       LOG(out << " init\n");
1519     } else {
1520       LOG(out << "\n");
1521     }
1522     Id++;
1523   }
1524 
1525   LOG(out << "\n"
1526           << "Import information:"
1527           << "\n");
1528   for (const auto Import : Module->import_table) {
1529     auto ModuleName = toStdString(
1530         Module->GetName(Import.module_name_offset, Import.module_name_length));
1531     auto FnName = toStdString(Module->GetName(Import.function_name_offset,
1532                                               Import.function_name_length));
1533     LOG(out << "  " << Import.sig_index << ": " << ModuleName << "::" << FnName
1534             << "\n");
1535   }
1536 
1537   LOG(out << "\n"
1538           << "Export information:"
1539           << "\n");
1540   for (const auto Export : Module->export_table) {
1541     LOG(out << "  " << Export.func_index << ": "
1542             << toStdString(
1543                    Module->GetName(Export.name_offset, Export.name_length))
1544             << " (" << Export.name_offset << ", " << Export.name_length << ")");
1545     LOG(out << "\n");
1546   }
1547 
1548   LOG(out << "\n"
1549           << "Function information:"
1550           << "\n");
1551   for (const auto F : Module->functions) {
1552     LOG(out << "  " << F.func_index << ": "
1553             << toStdString(Module->GetName(F.name_offset, F.name_length))
1554             << " (" << F.name_offset << ", " << F.name_length << ")");
1555     if (F.exported)
1556       LOG(out << " export");
1557     if (F.external)
1558       LOG(out << " extern");
1559     LOG(out << "\n");
1560   }
1561 
1562   LOG(out << "\n"
1563           << "Indirect table:"
1564           << "\n");
1565   for (uint32_t F : Module->function_table) {
1566     LOG(out << "  " << F << ": " << getFunctionName(Module, F) << "\n");
1567   }
1568 
1569   ModuleEnv ModuleEnv;
1570   ModuleEnv.module = Module;
1571 
1572   FunctionBody Body;
1573   Body.module = &ModuleEnv;
1574 
1575   LOG(out << "Translating " << IRFilename << "\n");
1576 
1577   {
1578     unique_ptr<VariableDeclarationList> Globals =
1579         makeUnique<VariableDeclarationList>();
1580 
1581     // Global variables, etc go here.
1582     auto *WasmMemory = VariableDeclaration::createExternal(Globals.get());
1583     WasmMemory->setName(Ctx->getGlobalString("WASM_DATA_INIT"));
1584 
1585     // Fill in the segments
1586     SizeT WritePtr = 0;
1587     for (const auto Seg : Module->data_segments) {
1588       // fill in gaps with zero.
1589       if (Seg.dest_addr > WritePtr) {
1590         WasmMemory->addInitializer(VariableDeclaration::ZeroInitializer::create(
1591             Globals.get(), Seg.dest_addr - WritePtr));
1592         WritePtr = Seg.dest_addr;
1593       }
1594 
1595       // Add the data
1596       WasmMemory->addInitializer(VariableDeclaration::DataInitializer::create(
1597           Globals.get(),
1598           reinterpret_cast<const char *>(Module->module_start) +
1599               Seg.source_offset,
1600           Seg.source_size));
1601 
1602       WritePtr += Seg.source_size;
1603     }
1604 
1605     // Save the size of the initialized data in a global variable so the runtime
1606     // can use it to determine the initial heap break.
1607     auto *GlobalDataSize = VariableDeclaration::createExternal(Globals.get());
1608     GlobalDataSize->setName(Ctx->getGlobalString("WASM_DATA_SIZE"));
1609     GlobalDataSize->addInitializer(VariableDeclaration::DataInitializer::create(
1610         Globals.get(), reinterpret_cast<const char *>(&WritePtr),
1611         sizeof(WritePtr)));
1612 
1613     // Save the number of pages for the runtime
1614     auto *GlobalNumPages = VariableDeclaration::createExternal(Globals.get());
1615     GlobalNumPages->setName(Ctx->getGlobalString("WASM_NUM_PAGES"));
1616     GlobalNumPages->addInitializer(VariableDeclaration::DataInitializer::create(
1617         Globals.get(), reinterpret_cast<const char *>(&Module->min_mem_pages),
1618         sizeof(Module->min_mem_pages)));
1619 
1620     Globals->push_back(WasmMemory);
1621     Globals->push_back(GlobalDataSize);
1622     Globals->push_back(GlobalNumPages);
1623 
1624     lowerGlobals(std::move(Globals));
1625   }
1626 
1627   // Translate each function.
1628   for (const auto Fn : Module->functions) {
1629     const auto FnName = getFunctionName(Module, Fn.func_index);
1630 
1631     LOG(out << "  " << Fn.func_index << ": " << FnName << "...");
1632 
1633     Body.sig = Fn.sig;
1634     Body.base = Buffer.data();
1635     Body.start = Buffer.data() + Fn.code_start_offset;
1636     Body.end = Buffer.data() + Fn.code_end_offset;
1637 
1638     std::unique_ptr<Cfg> Func = nullptr;
1639     {
1640       TimerMarker T_func(getContext(), FnName);
1641       Func = translateFunction(&Zone, Body);
1642       Func->setFunctionName(Ctx->getGlobalString(FnName));
1643     }
1644     Ctx->optQueueBlockingPush(makeUnique<CfgOptWorkItem>(std::move(Func)));
1645     LOG(out << "done.\n");
1646   }
1647 
1648   return;
1649 }
1650 
1651 #endif // ALLOW_WASM
1652