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android / platform / external / v8 / a24543157ae2cdd25da43e20f4e48a07481e6ceb / . / src / wasm / wasm-interpreter.cc
blob: f32b5e617b360fb8d144d00a18b913d12059454d [file] [log] [blame]
// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <type_traits>
#include "src/wasm/wasm-interpreter.h"
#include "src/conversions.h"
#include "src/objects-inl.h"
#include "src/utils.h"
#include "src/wasm/decoder.h"
#include "src/wasm/function-body-decoder-impl.h"
#include "src/wasm/function-body-decoder.h"
#include "src/wasm/wasm-external-refs.h"
#include "src/wasm/wasm-limits.h"
#include "src/wasm/wasm-module.h"
#include "src/zone/accounting-allocator.h"
#include "src/zone/zone-containers.h"
namespace v8 {
namespace internal {
namespace wasm {
#if DEBUG
#define TRACE(...) \
do { \
if (FLAG_trace_wasm_interpreter) PrintF(__VA_ARGS__); \
} while (false)
#else
#define TRACE(...)
#endif
#define FOREACH_INTERNAL_OPCODE(V) V(Breakpoint, 0xFF)
#define FOREACH_SIMPLE_BINOP(V) \
V(I32Add, uint32_t, +) \
V(I32Sub, uint32_t, -) \
V(I32Mul, uint32_t, *) \
V(I32And, uint32_t, &) \
V(I32Ior, uint32_t, |) \
V(I32Xor, uint32_t, ^) \
V(I32Eq, uint32_t, ==) \
V(I32Ne, uint32_t, !=) \
V(I32LtU, uint32_t, <) \
V(I32LeU, uint32_t, <=) \
V(I32GtU, uint32_t, >) \
V(I32GeU, uint32_t, >=) \
V(I32LtS, int32_t, <) \
V(I32LeS, int32_t, <=) \
V(I32GtS, int32_t, >) \
V(I32GeS, int32_t, >=) \
V(I64Add, uint64_t, +) \
V(I64Sub, uint64_t, -) \
V(I64Mul, uint64_t, *) \
V(I64And, uint64_t, &) \
V(I64Ior, uint64_t, |) \
V(I64Xor, uint64_t, ^) \
V(I64Eq, uint64_t, ==) \
V(I64Ne, uint64_t, !=) \
V(I64LtU, uint64_t, <) \
V(I64LeU, uint64_t, <=) \
V(I64GtU, uint64_t, >) \
V(I64GeU, uint64_t, >=) \
V(I64LtS, int64_t, <) \
V(I64LeS, int64_t, <=) \
V(I64GtS, int64_t, >) \
V(I64GeS, int64_t, >=) \
V(F32Add, float, +) \
V(F32Sub, float, -) \
V(F32Eq, float, ==) \
V(F32Ne, float, !=) \
V(F32Lt, float, <) \
V(F32Le, float, <=) \
V(F32Gt, float, >) \
V(F32Ge, float, >=) \
V(F64Add, double, +) \
V(F64Sub, double, -) \
V(F64Eq, double, ==) \
V(F64Ne, double, !=) \
V(F64Lt, double, <) \
V(F64Le, double, <=) \
V(F64Gt, double, >) \
V(F64Ge, double, >=) \
V(F32Mul, float, *) \
V(F64Mul, double, *) \
V(F32Div, float, /) \
V(F64Div, double, /)
#define FOREACH_OTHER_BINOP(V) \
V(I32DivS, int32_t) \
V(I32DivU, uint32_t) \
V(I32RemS, int32_t) \
V(I32RemU, uint32_t) \
V(I32Shl, uint32_t) \
V(I32ShrU, uint32_t) \
V(I32ShrS, int32_t) \
V(I64DivS, int64_t) \
V(I64DivU, uint64_t) \
V(I64RemS, int64_t) \
V(I64RemU, uint64_t) \
V(I64Shl, uint64_t) \
V(I64ShrU, uint64_t) \
V(I64ShrS, int64_t) \
V(I32Ror, int32_t) \
V(I32Rol, int32_t) \
V(I64Ror, int64_t) \
V(I64Rol, int64_t) \
V(F32Min, float) \
V(F32Max, float) \
V(F64Min, double) \
V(F64Max, double) \
V(I32AsmjsDivS, int32_t) \
V(I32AsmjsDivU, uint32_t) \
V(I32AsmjsRemS, int32_t) \
V(I32AsmjsRemU, uint32_t)
#define FOREACH_OTHER_UNOP(V) \
V(I32Clz, uint32_t) \
V(I32Ctz, uint32_t) \
V(I32Popcnt, uint32_t) \
V(I32Eqz, uint32_t) \
V(I64Clz, uint64_t) \
V(I64Ctz, uint64_t) \
V(I64Popcnt, uint64_t) \
V(I64Eqz, uint64_t) \
V(F32Abs, float) \
V(F32Neg, float) \
V(F32Ceil, float) \
V(F32Floor, float) \
V(F32Trunc, float) \
V(F32NearestInt, float) \
V(F64Abs, double) \
V(F64Neg, double) \
V(F64Ceil, double) \
V(F64Floor, double) \
V(F64Trunc, double) \
V(F64NearestInt, double) \
V(I32SConvertF32, float) \
V(I32SConvertF64, double) \
V(I32UConvertF32, float) \
V(I32UConvertF64, double) \
V(I32ConvertI64, int64_t) \
V(I64SConvertF32, float) \
V(I64SConvertF64, double) \
V(I64UConvertF32, float) \
V(I64UConvertF64, double) \
V(I64SConvertI32, int32_t) \
V(I64UConvertI32, uint32_t) \
V(F32SConvertI32, int32_t) \
V(F32UConvertI32, uint32_t) \
V(F32SConvertI64, int64_t) \
V(F32UConvertI64, uint64_t) \
V(F32ConvertF64, double) \
V(F32ReinterpretI32, int32_t) \
V(F64SConvertI32, int32_t) \
V(F64UConvertI32, uint32_t) \
V(F64SConvertI64, int64_t) \
V(F64UConvertI64, uint64_t) \
V(F64ConvertF32, float) \
V(F64ReinterpretI64, int64_t) \
V(I32AsmjsSConvertF32, float) \
V(I32AsmjsUConvertF32, float) \
V(I32AsmjsSConvertF64, double) \
V(I32AsmjsUConvertF64, double) \
V(F32Sqrt, float) \
V(F64Sqrt, double)
static inline int32_t ExecuteI32DivS(int32_t a, int32_t b, TrapReason* trap) {
if (b == 0) {
*trap = kTrapDivByZero;
return 0;
}
if (b == -1 && a == std::numeric_limits<int32_t>::min()) {
*trap = kTrapDivUnrepresentable;
return 0;
}
return a / b;
}
static inline uint32_t ExecuteI32DivU(uint32_t a, uint32_t b,
TrapReason* trap) {
if (b == 0) {
*trap = kTrapDivByZero;
return 0;
}
return a / b;
}
static inline int32_t ExecuteI32RemS(int32_t a, int32_t b, TrapReason* trap) {
if (b == 0) {
*trap = kTrapRemByZero;
return 0;
}
if (b == -1) return 0;
return a % b;
}
static inline uint32_t ExecuteI32RemU(uint32_t a, uint32_t b,
TrapReason* trap) {
if (b == 0) {
*trap = kTrapRemByZero;
return 0;
}
return a % b;
}
static inline uint32_t ExecuteI32Shl(uint32_t a, uint32_t b, TrapReason* trap) {
return a << (b & 0x1f);
}
static inline uint32_t ExecuteI32ShrU(uint32_t a, uint32_t b,
TrapReason* trap) {
return a >> (b & 0x1f);
}
static inline int32_t ExecuteI32ShrS(int32_t a, int32_t b, TrapReason* trap) {
return a >> (b & 0x1f);
}
static inline int64_t ExecuteI64DivS(int64_t a, int64_t b, TrapReason* trap) {
if (b == 0) {
*trap = kTrapDivByZero;
return 0;
}
if (b == -1 && a == std::numeric_limits<int64_t>::min()) {
*trap = kTrapDivUnrepresentable;
return 0;
}
return a / b;
}
static inline uint64_t ExecuteI64DivU(uint64_t a, uint64_t b,
TrapReason* trap) {
if (b == 0) {
*trap = kTrapDivByZero;
return 0;
}
return a / b;
}
static inline int64_t ExecuteI64RemS(int64_t a, int64_t b, TrapReason* trap) {
if (b == 0) {
*trap = kTrapRemByZero;
return 0;
}
if (b == -1) return 0;
return a % b;
}
static inline uint64_t ExecuteI64RemU(uint64_t a, uint64_t b,
TrapReason* trap) {
if (b == 0) {
*trap = kTrapRemByZero;
return 0;
}
return a % b;
}
static inline uint64_t ExecuteI64Shl(uint64_t a, uint64_t b, TrapReason* trap) {
return a << (b & 0x3f);
}
static inline uint64_t ExecuteI64ShrU(uint64_t a, uint64_t b,
TrapReason* trap) {
return a >> (b & 0x3f);
}
static inline int64_t ExecuteI64ShrS(int64_t a, int64_t b, TrapReason* trap) {
return a >> (b & 0x3f);
}
static inline uint32_t ExecuteI32Ror(uint32_t a, uint32_t b, TrapReason* trap) {
uint32_t shift = (b & 0x1f);
return (a >> shift) | (a << (32 - shift));
}
static inline uint32_t ExecuteI32Rol(uint32_t a, uint32_t b, TrapReason* trap) {
uint32_t shift = (b & 0x1f);
return (a << shift) | (a >> (32 - shift));
}
static inline uint64_t ExecuteI64Ror(uint64_t a, uint64_t b, TrapReason* trap) {
uint32_t shift = (b & 0x3f);
return (a >> shift) | (a << (64 - shift));
}
static inline uint64_t ExecuteI64Rol(uint64_t a, uint64_t b, TrapReason* trap) {
uint32_t shift = (b & 0x3f);
return (a << shift) | (a >> (64 - shift));
}
static inline float ExecuteF32Min(float a, float b, TrapReason* trap) {
return JSMin(a, b);
}
static inline float ExecuteF32Max(float a, float b, TrapReason* trap) {
return JSMax(a, b);
}
static inline float ExecuteF32CopySign(float a, float b, TrapReason* trap) {
return copysignf(a, b);
}
static inline double ExecuteF64Min(double a, double b, TrapReason* trap) {
return JSMin(a, b);
}
static inline double ExecuteF64Max(double a, double b, TrapReason* trap) {
return JSMax(a, b);
}
static inline double ExecuteF64CopySign(double a, double b, TrapReason* trap) {
return copysign(a, b);
}
static inline int32_t ExecuteI32AsmjsDivS(int32_t a, int32_t b,
TrapReason* trap) {
if (b == 0) return 0;
if (b == -1 && a == std::numeric_limits<int32_t>::min()) {
return std::numeric_limits<int32_t>::min();
}
return a / b;
}
static inline uint32_t ExecuteI32AsmjsDivU(uint32_t a, uint32_t b,
TrapReason* trap) {
if (b == 0) return 0;
return a / b;
}
static inline int32_t ExecuteI32AsmjsRemS(int32_t a, int32_t b,
TrapReason* trap) {
if (b == 0) return 0;
if (b == -1) return 0;
return a % b;
}
static inline uint32_t ExecuteI32AsmjsRemU(uint32_t a, uint32_t b,
TrapReason* trap) {
if (b == 0) return 0;
return a % b;
}
static inline int32_t ExecuteI32AsmjsSConvertF32(float a, TrapReason* trap) {
return DoubleToInt32(a);
}
static inline uint32_t ExecuteI32AsmjsUConvertF32(float a, TrapReason* trap) {
return DoubleToUint32(a);
}
static inline int32_t ExecuteI32AsmjsSConvertF64(double a, TrapReason* trap) {
return DoubleToInt32(a);
}
static inline uint32_t ExecuteI32AsmjsUConvertF64(double a, TrapReason* trap) {
return DoubleToUint32(a);
}
static int32_t ExecuteI32Clz(uint32_t val, TrapReason* trap) {
return base::bits::CountLeadingZeros32(val);
}
static uint32_t ExecuteI32Ctz(uint32_t val, TrapReason* trap) {
return base::bits::CountTrailingZeros32(val);
}
static uint32_t ExecuteI32Popcnt(uint32_t val, TrapReason* trap) {
return word32_popcnt_wrapper(&val);
}
static inline uint32_t ExecuteI32Eqz(uint32_t val, TrapReason* trap) {
return val == 0 ? 1 : 0;
}
static int64_t ExecuteI64Clz(uint64_t val, TrapReason* trap) {
return base::bits::CountLeadingZeros64(val);
}
static inline uint64_t ExecuteI64Ctz(uint64_t val, TrapReason* trap) {
return base::bits::CountTrailingZeros64(val);
}
static inline int64_t ExecuteI64Popcnt(uint64_t val, TrapReason* trap) {
return word64_popcnt_wrapper(&val);
}
static inline int32_t ExecuteI64Eqz(uint64_t val, TrapReason* trap) {
return val == 0 ? 1 : 0;
}
static inline float ExecuteF32Abs(float a, TrapReason* trap) {
return bit_cast<float>(bit_cast<uint32_t>(a) & 0x7fffffff);
}
static inline float ExecuteF32Neg(float a, TrapReason* trap) {
return bit_cast<float>(bit_cast<uint32_t>(a) ^ 0x80000000);
}
static inline float ExecuteF32Ceil(float a, TrapReason* trap) {
return ceilf(a);
}
static inline float ExecuteF32Floor(float a, TrapReason* trap) {
return floorf(a);
}
static inline float ExecuteF32Trunc(float a, TrapReason* trap) {
return truncf(a);
}
static inline float ExecuteF32NearestInt(float a, TrapReason* trap) {
return nearbyintf(a);
}
static inline float ExecuteF32Sqrt(float a, TrapReason* trap) {
float result = sqrtf(a);
return result;
}
static inline double ExecuteF64Abs(double a, TrapReason* trap) {
return bit_cast<double>(bit_cast<uint64_t>(a) & 0x7fffffffffffffff);
}
static inline double ExecuteF64Neg(double a, TrapReason* trap) {
return bit_cast<double>(bit_cast<uint64_t>(a) ^ 0x8000000000000000);
}
static inline double ExecuteF64Ceil(double a, TrapReason* trap) {
return ceil(a);
}
static inline double ExecuteF64Floor(double a, TrapReason* trap) {
return floor(a);
}
static inline double ExecuteF64Trunc(double a, TrapReason* trap) {
return trunc(a);
}
static inline double ExecuteF64NearestInt(double a, TrapReason* trap) {
return nearbyint(a);
}
static inline double ExecuteF64Sqrt(double a, TrapReason* trap) {
return sqrt(a);
}
static int32_t ExecuteI32SConvertF32(float a, TrapReason* trap) {
// The upper bound is (INT32_MAX + 1), which is the lowest float-representable
// number above INT32_MAX which cannot be represented as int32.
float upper_bound = 2147483648.0f;
// We use INT32_MIN as a lower bound because (INT32_MIN - 1) is not
// representable as float, and no number between (INT32_MIN - 1) and INT32_MIN
// is.
float lower_bound = static_cast<float>(INT32_MIN);
if (a < upper_bound && a >= lower_bound) {
return static_cast<int32_t>(a);
}
*trap = kTrapFloatUnrepresentable;
return 0;
}
static int32_t ExecuteI32SConvertF64(double a, TrapReason* trap) {
// The upper bound is (INT32_MAX + 1), which is the lowest double-
// representable number above INT32_MAX which cannot be represented as int32.
double upper_bound = 2147483648.0;
// The lower bound is (INT32_MIN - 1), which is the greatest double-
// representable number below INT32_MIN which cannot be represented as int32.
double lower_bound = -2147483649.0;
if (a < upper_bound && a > lower_bound) {
return static_cast<int32_t>(a);
}
*trap = kTrapFloatUnrepresentable;
return 0;
}
static uint32_t ExecuteI32UConvertF32(float a, TrapReason* trap) {
// The upper bound is (UINT32_MAX + 1), which is the lowest
// float-representable number above UINT32_MAX which cannot be represented as
// uint32.
double upper_bound = 4294967296.0f;
double lower_bound = -1.0f;
if (a < upper_bound && a > lower_bound) {
return static_cast<uint32_t>(a);
}
*trap = kTrapFloatUnrepresentable;
return 0;
}
static uint32_t ExecuteI32UConvertF64(double a, TrapReason* trap) {
// The upper bound is (UINT32_MAX + 1), which is the lowest
// double-representable number above UINT32_MAX which cannot be represented as
// uint32.
double upper_bound = 4294967296.0;
double lower_bound = -1.0;
if (a < upper_bound && a > lower_bound) {
return static_cast<uint32_t>(a);
}
*trap = kTrapFloatUnrepresentable;
return 0;
}
static inline uint32_t ExecuteI32ConvertI64(int64_t a, TrapReason* trap) {
return static_cast<uint32_t>(a & 0xFFFFFFFF);
}
static int64_t ExecuteI64SConvertF32(float a, TrapReason* trap) {
int64_t output;
if (!float32_to_int64_wrapper(&a, &output)) {
*trap = kTrapFloatUnrepresentable;
}
return output;
}
static int64_t ExecuteI64SConvertF64(double a, TrapReason* trap) {
int64_t output;
if (!float64_to_int64_wrapper(&a, &output)) {
*trap = kTrapFloatUnrepresentable;
}
return output;
}
static uint64_t ExecuteI64UConvertF32(float a, TrapReason* trap) {
uint64_t output;
if (!float32_to_uint64_wrapper(&a, &output)) {
*trap = kTrapFloatUnrepresentable;
}
return output;
}
static uint64_t ExecuteI64UConvertF64(double a, TrapReason* trap) {
uint64_t output;
if (!float64_to_uint64_wrapper(&a, &output)) {
*trap = kTrapFloatUnrepresentable;
}
return output;
}
static inline int64_t ExecuteI64SConvertI32(int32_t a, TrapReason* trap) {
return static_cast<int64_t>(a);
}
static inline int64_t ExecuteI64UConvertI32(uint32_t a, TrapReason* trap) {
return static_cast<uint64_t>(a);
}
static inline float ExecuteF32SConvertI32(int32_t a, TrapReason* trap) {
return static_cast<float>(a);
}
static inline float ExecuteF32UConvertI32(uint32_t a, TrapReason* trap) {
return static_cast<float>(a);
}
static inline float ExecuteF32SConvertI64(int64_t a, TrapReason* trap) {
float output;
int64_to_float32_wrapper(&a, &output);
return output;
}
static inline float ExecuteF32UConvertI64(uint64_t a, TrapReason* trap) {
float output;
uint64_to_float32_wrapper(&a, &output);
return output;
}
static inline float ExecuteF32ConvertF64(double a, TrapReason* trap) {
return static_cast<float>(a);
}
static inline float ExecuteF32ReinterpretI32(int32_t a, TrapReason* trap) {
return bit_cast<float>(a);
}
static inline double ExecuteF64SConvertI32(int32_t a, TrapReason* trap) {
return static_cast<double>(a);
}
static inline double ExecuteF64UConvertI32(uint32_t a, TrapReason* trap) {
return static_cast<double>(a);
}
static inline double ExecuteF64SConvertI64(int64_t a, TrapReason* trap) {
double output;
int64_to_float64_wrapper(&a, &output);
return output;
}
static inline double ExecuteF64UConvertI64(uint64_t a, TrapReason* trap) {
double output;
uint64_to_float64_wrapper(&a, &output);
return output;
}
static inline double ExecuteF64ConvertF32(float a, TrapReason* trap) {
return static_cast<double>(a);
}
static inline double ExecuteF64ReinterpretI64(int64_t a, TrapReason* trap) {
return bit_cast<double>(a);
}
static inline int32_t ExecuteI32ReinterpretF32(WasmVal a) {
return a.to_unchecked<int32_t>();
}
static inline int64_t ExecuteI64ReinterpretF64(WasmVal a) {
return a.to_unchecked<int64_t>();
}
static inline int32_t ExecuteGrowMemory(uint32_t delta_pages,
WasmInstance* instance) {
// TODO(ahaas): Move memory allocation to wasm-module.cc for better
// encapsulation.
if (delta_pages > FLAG_wasm_max_mem_pages ||
delta_pages > instance->module->max_mem_pages) {
return -1;
}
uint32_t old_size = instance->mem_size;
uint32_t new_size;
byte* new_mem_start;
if (instance->mem_size == 0) {
// TODO(gdeepti): Fix bounds check to take into account size of memtype.
new_size = delta_pages * wasm::WasmModule::kPageSize;
new_mem_start = static_cast<byte*>(calloc(new_size, sizeof(byte)));
if (!new_mem_start) {
return -1;
}
} else {
DCHECK_NOT_NULL(instance->mem_start);
new_size = old_size + delta_pages * wasm::WasmModule::kPageSize;
if (new_size / wasm::WasmModule::kPageSize > FLAG_wasm_max_mem_pages ||
new_size / wasm::WasmModule::kPageSize >
instance->module->max_mem_pages) {
return -1;
}
new_mem_start = static_cast<byte*>(realloc(instance->mem_start, new_size));
if (!new_mem_start) {
return -1;
}
// Zero initializing uninitialized memory from realloc
memset(new_mem_start + old_size, 0, new_size - old_size);
}
instance->mem_start = new_mem_start;
instance->mem_size = new_size;
return static_cast<int32_t>(old_size / WasmModule::kPageSize);
}
enum InternalOpcode {
#define DECL_INTERNAL_ENUM(name, value) kInternal##name = value,
FOREACH_INTERNAL_OPCODE(DECL_INTERNAL_ENUM)
#undef DECL_INTERNAL_ENUM
};
static const char* OpcodeName(uint32_t val) {
switch (val) {
#define DECL_INTERNAL_CASE(name, value) \
case kInternal##name: \
return "Internal" #name;
FOREACH_INTERNAL_OPCODE(DECL_INTERNAL_CASE)
#undef DECL_INTERNAL_CASE
}
return WasmOpcodes::OpcodeName(static_cast<WasmOpcode>(val));
}
static const int kRunSteps = 1000;
// A helper class to compute the control transfers for each bytecode offset.
// Control transfers allow Br, BrIf, BrTable, If, Else, and End bytecodes to
// be directly executed without the need to dynamically track blocks.
class ControlTransfers : public ZoneObject {
public:
ControlTransferMap map_;
ControlTransfers(Zone* zone, BodyLocalDecls* locals, const byte* start,
const byte* end)
: map_(zone) {
// Represents a control flow label.
struct CLabel : public ZoneObject {
const byte* target;
ZoneVector<const byte*> refs;
explicit CLabel(Zone* zone) : target(nullptr), refs(zone) {}
// Bind this label to the given PC.
void Bind(ControlTransferMap* map, const byte* start, const byte* pc) {
DCHECK_NULL(target);
target = pc;
for (auto from_pc : refs) {
auto pcdiff = static_cast<pcdiff_t>(target - from_pc);
size_t offset = static_cast<size_t>(from_pc - start);
(*map)[offset] = pcdiff;
}
}
// Reference this label from the given location.
void Ref(ControlTransferMap* map, const byte* start,
const byte* from_pc) {
if (target) {
// Target being bound before a reference means this is a loop.
DCHECK_EQ(kExprLoop, *target);
auto pcdiff = static_cast<pcdiff_t>(target - from_pc);
size_t offset = static_cast<size_t>(from_pc - start);
(*map)[offset] = pcdiff;
} else {
refs.push_back(from_pc);
}
}
};
// An entry in the control stack.
struct Control {
const byte* pc;
CLabel* end_label;
CLabel* else_label;
void Ref(ControlTransferMap* map, const byte* start,
const byte* from_pc) {
end_label->Ref(map, start, from_pc);
}
};
// Compute the ControlTransfer map.
// This algorithm maintains a stack of control constructs similar to the
// AST decoder. The {control_stack} allows matching {br,br_if,br_table}
// bytecodes with their target, as well as determining whether the current
// bytecodes are within the true or false block of an else.
std::vector<Control> control_stack;
CLabel* func_label = new (zone) CLabel(zone);
control_stack.push_back({start, func_label, nullptr});
for (BytecodeIterator i(start, end, locals); i.has_next(); i.next()) {
WasmOpcode opcode = i.current();
TRACE("@%u: control %s\n", i.pc_offset(),
WasmOpcodes::OpcodeName(opcode));
switch (opcode) {
case kExprBlock: {
TRACE("control @%u: Block\n", i.pc_offset());
CLabel* label = new (zone) CLabel(zone);
control_stack.push_back({i.pc(), label, nullptr});
break;
}
case kExprLoop: {
TRACE("control @%u: Loop\n", i.pc_offset());
CLabel* label = new (zone) CLabel(zone);
control_stack.push_back({i.pc(), label, nullptr});
label->Bind(&map_, start, i.pc());
break;
}
case kExprIf: {
TRACE("control @%u: If\n", i.pc_offset());
CLabel* end_label = new (zone) CLabel(zone);
CLabel* else_label = new (zone) CLabel(zone);
control_stack.push_back({i.pc(), end_label, else_label});
else_label->Ref(&map_, start, i.pc());
break;
}
case kExprElse: {
Control* c = &control_stack.back();
TRACE("control @%u: Else\n", i.pc_offset());
c->end_label->Ref(&map_, start, i.pc());
DCHECK_NOT_NULL(c->else_label);
c->else_label->Bind(&map_, start, i.pc() + 1);
c->else_label = nullptr;
break;
}
case kExprEnd: {
Control* c = &control_stack.back();
TRACE("control @%u: End\n", i.pc_offset());
if (c->end_label->target) {
// only loops have bound labels.
DCHECK_EQ(kExprLoop, *c->pc);
} else {
if (c->else_label) c->else_label->Bind(&map_, start, i.pc());
c->end_label->Bind(&map_, start, i.pc() + 1);
}
control_stack.pop_back();
break;
}
case kExprBr: {
BreakDepthOperand operand(&i, i.pc());
TRACE("control @%u: Br[depth=%u]\n", i.pc_offset(), operand.depth);
Control* c = &control_stack[control_stack.size() - operand.depth - 1];
c->Ref(&map_, start, i.pc());
break;
}
case kExprBrIf: {
BreakDepthOperand operand(&i, i.pc());
TRACE("control @%u: BrIf[depth=%u]\n", i.pc_offset(), operand.depth);
Control* c = &control_stack[control_stack.size() - operand.depth - 1];
c->Ref(&map_, start, i.pc());
break;
}
case kExprBrTable: {
BranchTableOperand operand(&i, i.pc());
BranchTableIterator iterator(&i, operand);
TRACE("control @%u: BrTable[count=%u]\n", i.pc_offset(),
operand.table_count);
while (iterator.has_next()) {
uint32_t j = iterator.cur_index();
uint32_t target = iterator.next();
Control* c = &control_stack[control_stack.size() - target - 1];
c->Ref(&map_, start, i.pc() + j);
}
break;
}
default: {
break;
}
}
}
if (!func_label->target) func_label->Bind(&map_, start, end);
}
pcdiff_t Lookup(pc_t from) {
auto result = map_.find(from);
if (result == map_.end()) {
V8_Fatal(__FILE__, __LINE__, "no control target for pc %zu", from);
}
return result->second;
}
};
// Code and metadata needed to execute a function.
struct InterpreterCode {
const WasmFunction* function; // wasm function
BodyLocalDecls locals; // local declarations
const byte* orig_start; // start of original code
const byte* orig_end; // end of original code
byte* start; // start of (maybe altered) code
byte* end; // end of (maybe altered) code
ControlTransfers* targets; // helper for control flow.
const byte* at(pc_t pc) { return start + pc; }
};
// The main storage for interpreter code. It maps {WasmFunction} to the
// metadata needed to execute each function.
class CodeMap {
public:
Zone* zone_;
const WasmModule* module_;
ZoneVector<InterpreterCode> interpreter_code_;
CodeMap(const WasmModule* module, const uint8_t* module_start, Zone* zone)
: zone_(zone), module_(module), interpreter_code_(zone) {
if (module == nullptr) return;
for (size_t i = 0; i < module->functions.size(); ++i) {
const WasmFunction* function = &module->functions[i];
const byte* code_start = module_start + function->code_start_offset;
const byte* code_end = module_start + function->code_end_offset;
AddFunction(function, code_start, code_end);
}
}
InterpreterCode* FindCode(const WasmFunction* function) {
if (function->func_index < interpreter_code_.size()) {
InterpreterCode* code = &interpreter_code_[function->func_index];
DCHECK_EQ(function, code->function);
return Preprocess(code);
}
return nullptr;
}
InterpreterCode* GetCode(uint32_t function_index) {
CHECK_LT(function_index, interpreter_code_.size());
return Preprocess(&interpreter_code_[function_index]);
}
InterpreterCode* GetIndirectCode(uint32_t table_index, uint32_t entry_index) {
if (table_index >= module_->function_tables.size()) return nullptr;
const WasmIndirectFunctionTable* table =
&module_->function_tables[table_index];
if (entry_index >= table->values.size()) return nullptr;
uint32_t index = table->values[entry_index];
if (index >= interpreter_code_.size()) return nullptr;
return GetCode(index);
}
InterpreterCode* Preprocess(InterpreterCode* code) {
if (code->targets == nullptr && code->start) {
// Compute the control targets map and the local declarations.
CHECK(DecodeLocalDecls(&code->locals, code->start, code->end));
code->targets = new (zone_) ControlTransfers(
zone_, &code->locals, code->orig_start, code->orig_end);
}
return code;
}
int AddFunction(const WasmFunction* function, const byte* code_start,
const byte* code_end) {
InterpreterCode code = {
function, BodyLocalDecls(zone_), code_start,
code_end, const_cast<byte*>(code_start), const_cast<byte*>(code_end),
nullptr};
DCHECK_EQ(interpreter_code_.size(), function->func_index);
interpreter_code_.push_back(code);
return static_cast<int>(interpreter_code_.size()) - 1;
}
bool SetFunctionCode(const WasmFunction* function, const byte* start,
const byte* end) {
InterpreterCode* code = FindCode(function);
if (code == nullptr) return false;
code->targets = nullptr;
code->orig_start = start;
code->orig_end = end;
code->start = const_cast<byte*>(start);
code->end = const_cast<byte*>(end);
Preprocess(code);
return true;
}
};
namespace {
// Responsible for executing code directly.
class ThreadImpl {
public:
ThreadImpl(Zone* zone, CodeMap* codemap, WasmInstance* instance)
: codemap_(codemap),
instance_(instance),
stack_(zone),
frames_(zone),
blocks_(zone) {}
//==========================================================================
// Implementation of public interface for WasmInterpreter::Thread.
//==========================================================================
WasmInterpreter::State state() { return state_; }
void PushFrame(const WasmFunction* function, WasmVal* args) {
InterpreterCode* code = codemap()->FindCode(function);
CHECK_NOT_NULL(code);
++num_interpreted_calls_;
frames_.push_back({code, 0, 0, stack_.size()});
for (size_t i = 0; i < function->sig->parameter_count(); ++i) {
stack_.push_back(args[i]);
}
frames_.back().ret_pc = InitLocals(code);
blocks_.push_back(
{0, stack_.size(), frames_.size(),
static_cast<uint32_t>(code->function->sig->return_count())});
TRACE(" => PushFrame(#%u @%zu)\n", code->function->func_index,
frames_.back().ret_pc);
}
WasmInterpreter::State Run() {
do {
TRACE(" => Run()\n");
if (state_ == WasmInterpreter::STOPPED ||
state_ == WasmInterpreter::PAUSED) {
state_ = WasmInterpreter::RUNNING;
Execute(frames_.back().code, frames_.back().ret_pc, kRunSteps);
}
} while (state_ == WasmInterpreter::STOPPED);
return state_;
}
WasmInterpreter::State Step() {
TRACE(" => Step()\n");
if (state_ == WasmInterpreter::STOPPED ||
state_ == WasmInterpreter::PAUSED) {
state_ = WasmInterpreter::RUNNING;
Execute(frames_.back().code, frames_.back().ret_pc, 1);
}
return state_;
}
void Pause() { UNIMPLEMENTED(); }
void Reset() {
TRACE("----- RESET -----\n");
stack_.clear();
frames_.clear();
state_ = WasmInterpreter::STOPPED;
trap_reason_ = kTrapCount;
possible_nondeterminism_ = false;
}
int GetFrameCount() {
DCHECK_GE(kMaxInt, frames_.size());
return static_cast<int>(frames_.size());
}
template <typename FrameCons>
InterpretedFrame GetMutableFrame(int index, FrameCons frame_cons) {
DCHECK_LE(0, index);
DCHECK_GT(frames_.size(), index);
Frame* frame = &frames_[index];
DCHECK_GE(kMaxInt, frame->ret_pc);
DCHECK_GE(kMaxInt, frame->sp);
DCHECK_GE(kMaxInt, frame->llimit());
return frame_cons(frame->code->function, static_cast<int>(frame->ret_pc),
static_cast<int>(frame->sp),
static_cast<int>(frame->llimit()));
}
WasmVal GetReturnValue(int index) {
if (state_ == WasmInterpreter::TRAPPED) return WasmVal(0xdeadbeef);
CHECK_EQ(WasmInterpreter::FINISHED, state_);
CHECK_LT(static_cast<size_t>(index), stack_.size());
return stack_[index];
}
pc_t GetBreakpointPc() { return break_pc_; }
bool PossibleNondeterminism() { return possible_nondeterminism_; }
uint64_t NumInterpretedCalls() { return num_interpreted_calls_; }
void AddBreakFlags(uint8_t flags) { break_flags_ |= flags; }
void ClearBreakFlags() { break_flags_ = WasmInterpreter::BreakFlag::None; }
private:
// Entries on the stack of functions being evaluated.
struct Frame {
InterpreterCode* code;
pc_t call_pc;
pc_t ret_pc;
sp_t sp;
// Limit of parameters.
sp_t plimit() { return sp + code->function->sig->parameter_count(); }
// Limit of locals.
sp_t llimit() { return plimit() + code->locals.type_list.size(); }
};
struct Block {
pc_t pc;
sp_t sp;
size_t fp;
unsigned arity;
};
CodeMap* codemap_;
WasmInstance* instance_;
ZoneVector<WasmVal> stack_;
ZoneVector<Frame> frames_;
ZoneVector<Block> blocks_;
WasmInterpreter::State state_ = WasmInterpreter::STOPPED;
pc_t break_pc_ = kInvalidPc;
TrapReason trap_reason_ = kTrapCount;
bool possible_nondeterminism_ = false;
uint8_t break_flags_ = 0; // a combination of WasmInterpreter::BreakFlag
uint64_t num_interpreted_calls_ = 0;
CodeMap* codemap() { return codemap_; }
WasmInstance* instance() { return instance_; }
const WasmModule* module() { return instance_->module; }
void DoTrap(TrapReason trap, pc_t pc) {
state_ = WasmInterpreter::TRAPPED;
trap_reason_ = trap;
CommitPc(pc);
}
// Push a frame with arguments already on the stack.
void PushFrame(InterpreterCode* code, pc_t call_pc, pc_t ret_pc) {
CHECK_NOT_NULL(code);
DCHECK(!frames_.empty());
++num_interpreted_calls_;
frames_.back().call_pc = call_pc;
frames_.back().ret_pc = ret_pc;
size_t arity = code->function->sig->parameter_count();
DCHECK_GE(stack_.size(), arity);
// The parameters will overlap the arguments already on the stack.
frames_.push_back({code, 0, 0, stack_.size() - arity});
blocks_.push_back(
{0, stack_.size(), frames_.size(),
static_cast<uint32_t>(code->function->sig->return_count())});
frames_.back().ret_pc = InitLocals(code);
TRACE(" => push func#%u @%zu\n", code->function->func_index,
frames_.back().ret_pc);
}
pc_t InitLocals(InterpreterCode* code) {
for (auto p : code->locals.type_list) {
WasmVal val;
switch (p) {
case kWasmI32:
val = WasmVal(static_cast<int32_t>(0));
break;
case kWasmI64:
val = WasmVal(static_cast<int64_t>(0));
break;
case kWasmF32:
val = WasmVal(static_cast<float>(0));
break;
case kWasmF64:
val = WasmVal(static_cast<double>(0));
break;
default:
UNREACHABLE();
break;
}
stack_.push_back(val);
}
return code->locals.encoded_size;
}
void CommitPc(pc_t pc) {
if (!frames_.empty()) {
frames_.back().ret_pc = pc;
}
}
bool SkipBreakpoint(InterpreterCode* code, pc_t pc) {
if (pc == break_pc_) {
// Skip the previously hit breakpoint when resuming.
break_pc_ = kInvalidPc;
return true;
}
return false;
}
int LookupTarget(InterpreterCode* code, pc_t pc) {
return static_cast<int>(code->targets->Lookup(pc));
}
int DoBreak(InterpreterCode* code, pc_t pc, size_t depth) {
size_t bp = blocks_.size() - depth - 1;
Block* target = &blocks_[bp];
DoStackTransfer(target->sp, target->arity);
blocks_.resize(bp);
return LookupTarget(code, pc);
}
bool DoReturn(InterpreterCode** code, pc_t* pc, pc_t* limit, size_t arity) {
DCHECK_GT(frames_.size(), 0);
// Pop all blocks for this frame.
while (!blocks_.empty() && blocks_.back().fp == frames_.size()) {
blocks_.pop_back();
}
sp_t dest = frames_.back().sp;
frames_.pop_back();
if (frames_.size() == 0) {
// A return from the last frame terminates the execution.
state_ = WasmInterpreter::FINISHED;
DoStackTransfer(0, arity);
TRACE(" => finish\n");
return false;
} else {
// Return to caller frame.
Frame* top = &frames_.back();
*code = top->code;
*pc = top->ret_pc;
*limit = top->code->end - top->code->start;
TRACE(" => pop func#%u @%zu\n", (*code)->function->func_index, *pc);
DoStackTransfer(dest, arity);
return true;
}
}
void DoCall(InterpreterCode* target, pc_t* pc, pc_t ret_pc, pc_t* limit) {
PushFrame(target, *pc, ret_pc);
*pc = frames_.back().ret_pc;
*limit = target->end - target->start;
}
// Copies {arity} values on the top of the stack down the stack to {dest},
// dropping the values in-between.
void DoStackTransfer(sp_t dest, size_t arity) {
// before: |---------------| pop_count | arity |
// ^ 0 ^ dest ^ stack_.size()
//
// after: |---------------| arity |
// ^ 0 ^ stack_.size()
DCHECK_LE(dest, stack_.size());
DCHECK_LE(dest + arity, stack_.size());
size_t pop_count = stack_.size() - dest - arity;
for (size_t i = 0; i < arity; i++) {
stack_[dest + i] = stack_[dest + pop_count + i];
}
stack_.resize(stack_.size() - pop_count);
}
template <typename ctype, typename mtype>
bool ExecuteLoad(Decoder* decoder, InterpreterCode* code, pc_t pc, int& len) {
MemoryAccessOperand operand(decoder, code->at(pc), sizeof(ctype));
uint32_t index = Pop().to<uint32_t>();
size_t effective_mem_size = instance()->mem_size - sizeof(mtype);
if (operand.offset > effective_mem_size ||
index > (effective_mem_size - operand.offset)) {
DoTrap(kTrapMemOutOfBounds, pc);
return false;
}
byte* addr = instance()->mem_start + operand.offset + index;
WasmVal result(static_cast<ctype>(ReadLittleEndianValue<mtype>(addr)));
Push(pc, result);
len = 1 + operand.length;
return true;
}
template <typename ctype, typename mtype>
bool ExecuteStore(Decoder* decoder, InterpreterCode* code, pc_t pc,
int& len) {
MemoryAccessOperand operand(decoder, code->at(pc), sizeof(ctype));
WasmVal val = Pop();
uint32_t index = Pop().to<uint32_t>();
size_t effective_mem_size = instance()->mem_size - sizeof(mtype);
if (operand.offset > effective_mem_size ||
index > (effective_mem_size - operand.offset)) {
DoTrap(kTrapMemOutOfBounds, pc);
return false;
}
byte* addr = instance()->mem_start + operand.offset + index;
WriteLittleEndianValue<mtype>(addr, static_cast<mtype>(val.to<ctype>()));
len = 1 + operand.length;
if (std::is_same<float, ctype>::value) {
possible_nondeterminism_ |= std::isnan(val.to<float>());
} else if (std::is_same<double, ctype>::value) {
possible_nondeterminism_ |= std::isnan(val.to<double>());
}
return true;
}
void Execute(InterpreterCode* code, pc_t pc, int max) {
Decoder decoder(code->start, code->end);
pc_t limit = code->end - code->start;
while (--max >= 0) {
#define PAUSE_IF_BREAK_FLAG(flag) \
if (V8_UNLIKELY(break_flags_ & WasmInterpreter::BreakFlag::flag)) max = 0;
DCHECK_GT(limit, pc);
const char* skip = " ";
int len = 1;
byte opcode = code->start[pc];
byte orig = opcode;
if (V8_UNLIKELY(opcode == kInternalBreakpoint)) {
orig = code->orig_start[pc];
if (SkipBreakpoint(code, pc)) {
// skip breakpoint by switching on original code.
skip = "[skip] ";
} else {
TRACE("@%-3zu: [break] %-24s:", pc,
WasmOpcodes::OpcodeName(static_cast<WasmOpcode>(orig)));
TraceValueStack();
TRACE("\n");
break;
}
}
USE(skip);
TRACE("@%-3zu: %s%-24s:", pc, skip,
WasmOpcodes::OpcodeName(static_cast<WasmOpcode>(orig)));
TraceValueStack();
TRACE("\n");
switch (orig) {
case kExprNop:
break;
case kExprBlock: {
BlockTypeOperand operand(&decoder, code->at(pc));
blocks_.push_back({pc, stack_.size(), frames_.size(), operand.arity});
len = 1 + operand.length;
break;
}
case kExprLoop: {
BlockTypeOperand operand(&decoder, code->at(pc));
blocks_.push_back({pc, stack_.size(), frames_.size(), 0});
len = 1 + operand.length;
break;
}
case kExprIf: {
BlockTypeOperand operand(&decoder, code->at(pc));
WasmVal cond = Pop();
bool is_true = cond.to<uint32_t>() != 0;
blocks_.push_back({pc, stack_.size(), frames_.size(), operand.arity});
if (is_true) {
// fall through to the true block.
len = 1 + operand.length;
TRACE(" true => fallthrough\n");
} else {
len = LookupTarget(code, pc);
TRACE(" false => @%zu\n", pc + len);
}
break;
}
case kExprElse: {
blocks_.pop_back();
len = LookupTarget(code, pc);
TRACE(" end => @%zu\n", pc + len);
break;
}
case kExprSelect: {
WasmVal cond = Pop();
WasmVal fval = Pop();
WasmVal tval = Pop();
Push(pc, cond.to<int32_t>() != 0 ? tval : fval);
break;
}
case kExprBr: {
BreakDepthOperand operand(&decoder, code->at(pc));
len = DoBreak(code, pc, operand.depth);
TRACE(" br => @%zu\n", pc + len);
break;
}
case kExprBrIf: {
BreakDepthOperand operand(&decoder, code->at(pc));
WasmVal cond = Pop();
bool is_true = cond.to<uint32_t>() != 0;
if (is_true) {
len = DoBreak(code, pc, operand.depth);
TRACE(" br_if => @%zu\n", pc + len);
} else {
TRACE(" false => fallthrough\n");
len = 1 + operand.length;
}
break;
}
case kExprBrTable: {
BranchTableOperand operand(&decoder, code->at(pc));
BranchTableIterator iterator(&decoder, operand);
uint32_t key = Pop().to<uint32_t>();
uint32_t depth = 0;
if (key >= operand.table_count) key = operand.table_count;
for (uint32_t i = 0; i <= key; i++) {
DCHECK(iterator.has_next());
depth = iterator.next();
}
len = key + DoBreak(code, pc + key, static_cast<size_t>(depth));
TRACE(" br[%u] => @%zu\n", key, pc + key + len);
break;
}
case kExprReturn: {
size_t arity = code->function->sig->return_count();
if (!DoReturn(&code, &pc, &limit, arity)) return;
decoder.Reset(code->start, code->end);
PAUSE_IF_BREAK_FLAG(AfterReturn);
continue;
}
case kExprUnreachable: {
DoTrap(kTrapUnreachable, pc);
return CommitPc(pc);
}
case kExprEnd: {
blocks_.pop_back();
break;
}
case kExprI32Const: {
ImmI32Operand operand(&decoder, code->at(pc));
Push(pc, WasmVal(operand.value));
len = 1 + operand.length;
break;
}
case kExprI64Const: {
ImmI64Operand operand(&decoder, code->at(pc));
Push(pc, WasmVal(operand.value));
len = 1 + operand.length;
break;
}
case kExprF32Const: {
ImmF32Operand operand(&decoder, code->at(pc));
Push(pc, WasmVal(operand.value));
len = 1 + operand.length;
break;
}
case kExprF64Const: {
ImmF64Operand operand(&decoder, code->at(pc));
Push(pc, WasmVal(operand.value));
len = 1 + operand.length;
break;
}
case kExprGetLocal: {
LocalIndexOperand operand(&decoder, code->at(pc));
Push(pc, stack_[frames_.back().sp + operand.index]);
len = 1 + operand.length;
break;
}
case kExprSetLocal: {
LocalIndexOperand operand(&decoder, code->at(pc));
WasmVal val = Pop();
stack_[frames_.back().sp + operand.index] = val;
len = 1 + operand.length;
break;
}
case kExprTeeLocal: {
LocalIndexOperand operand(&decoder, code->at(pc));
WasmVal val = Pop();
stack_[frames_.back().sp + operand.index] = val;
Push(pc, val);
len = 1 + operand.length;
break;
}
case kExprDrop: {
Pop();
break;
}
case kExprCallFunction: {
CallFunctionOperand operand(&decoder, code->at(pc));
InterpreterCode* target = codemap()->GetCode(operand.index);
DoCall(target, &pc, pc + 1 + operand.length, &limit);
code = target;
decoder.Reset(code->start, code->end);
PAUSE_IF_BREAK_FLAG(AfterCall);
continue;
}
case kExprCallIndirect: {
CallIndirectOperand operand(&decoder, code->at(pc));
uint32_t entry_index = Pop().to<uint32_t>();
// Assume only one table for now.
DCHECK_LE(module()->function_tables.size(), 1u);
InterpreterCode* target = codemap()->GetIndirectCode(0, entry_index);
if (target == nullptr) {
return DoTrap(kTrapFuncInvalid, pc);
} else if (target->function->sig_index != operand.index) {
// If not an exact match, we have to do a canonical check.
// TODO(titzer): make this faster with some kind of caching?
const WasmIndirectFunctionTable* table =
&module()->function_tables[0];
int function_key = table->map.Find(target->function->sig);
if (function_key < 0 ||
(function_key !=
table->map.Find(module()->signatures[operand.index]))) {
return DoTrap(kTrapFuncSigMismatch, pc);
}
}
DoCall(target, &pc, pc + 1 + operand.length, &limit);
code = target;
decoder.Reset(code->start, code->end);
PAUSE_IF_BREAK_FLAG(AfterCall);
continue;
}
case kExprGetGlobal: {
GlobalIndexOperand operand(&decoder, code->at(pc));
const WasmGlobal* global = &module()->globals[operand.index];
byte* ptr = instance()->globals_start + global->offset;
ValueType type = global->type;
WasmVal val;
if (type == kWasmI32) {
val = WasmVal(*reinterpret_cast<int32_t*>(ptr));
} else if (type == kWasmI64) {
val = WasmVal(*reinterpret_cast<int64_t*>(ptr));
} else if (type == kWasmF32) {
val = WasmVal(*reinterpret_cast<float*>(ptr));
} else if (type == kWasmF64) {
val = WasmVal(*reinterpret_cast<double*>(ptr));
} else {
UNREACHABLE();
}
Push(pc, val);
len = 1 + operand.length;
break;
}
case kExprSetGlobal: {
GlobalIndexOperand operand(&decoder, code->at(pc));
const WasmGlobal* global = &module()->globals[operand.index];
byte* ptr = instance()->globals_start + global->offset;
ValueType type = global->type;
WasmVal val = Pop();
if (type == kWasmI32) {
*reinterpret_cast<int32_t*>(ptr) = val.to<int32_t>();
} else if (type == kWasmI64) {
*reinterpret_cast<int64_t*>(ptr) = val.to<int64_t>();
} else if (type == kWasmF32) {
*reinterpret_cast<float*>(ptr) = val.to<float>();
} else if (type == kWasmF64) {
*reinterpret_cast<double*>(ptr) = val.to<double>();
} else {
UNREACHABLE();
}
len = 1 + operand.length;
break;
}
#define LOAD_CASE(name, ctype, mtype) \
case kExpr##name: { \
if (!ExecuteLoad<ctype, mtype>(&decoder, code, pc, len)) return; \
break; \
}
LOAD_CASE(I32LoadMem8S, int32_t, int8_t);
LOAD_CASE(I32LoadMem8U, int32_t, uint8_t);
LOAD_CASE(I32LoadMem16S, int32_t, int16_t);
LOAD_CASE(I32LoadMem16U, int32_t, uint16_t);
LOAD_CASE(I64LoadMem8S, int64_t, int8_t);
LOAD_CASE(I64LoadMem8U, int64_t, uint8_t);
LOAD_CASE(I64LoadMem16S, int64_t, int16_t);
LOAD_CASE(I64LoadMem16U, int64_t, uint16_t);
LOAD_CASE(I64LoadMem32S, int64_t, int32_t);
LOAD_CASE(I64LoadMem32U, int64_t, uint32_t);
LOAD_CASE(I32LoadMem, int32_t, int32_t);
LOAD_CASE(I64LoadMem, int64_t, int64_t);
LOAD_CASE(F32LoadMem, float, float);
LOAD_CASE(F64LoadMem, double, double);
#undef LOAD_CASE
#define STORE_CASE(name, ctype, mtype) \
case kExpr##name: { \
if (!ExecuteStore<ctype, mtype>(&decoder, code, pc, len)) return; \
break; \
}
STORE_CASE(I32StoreMem8, int32_t, int8_t);
STORE_CASE(I32StoreMem16, int32_t, int16_t);
STORE_CASE(I64StoreMem8, int64_t, int8_t);
STORE_CASE(I64StoreMem16, int64_t, int16_t);
STORE_CASE(I64StoreMem32, int64_t, int32_t);
STORE_CASE(I32StoreMem, int32_t, int32_t);
STORE_CASE(I64StoreMem, int64_t, int64_t);
STORE_CASE(F32StoreMem, float, float);
STORE_CASE(F64StoreMem, double, double);
#undef STORE_CASE
#define ASMJS_LOAD_CASE(name, ctype, mtype, defval) \
case kExpr##name: { \
uint32_t index = Pop().to<uint32_t>(); \
ctype result; \
if (index >= (instance()->mem_size - sizeof(mtype))) { \
result = defval; \
} else { \
byte* addr = instance()->mem_start + index; \
/* TODO(titzer): alignment for asmjs load mem? */ \
result = static_cast<ctype>(*reinterpret_cast<mtype*>(addr)); \
} \
Push(pc, WasmVal(result)); \
break; \
}
ASMJS_LOAD_CASE(I32AsmjsLoadMem8S, int32_t, int8_t, 0);
ASMJS_LOAD_CASE(I32AsmjsLoadMem8U, int32_t, uint8_t, 0);
ASMJS_LOAD_CASE(I32AsmjsLoadMem16S, int32_t, int16_t, 0);
ASMJS_LOAD_CASE(I32AsmjsLoadMem16U, int32_t, uint16_t, 0);
ASMJS_LOAD_CASE(I32AsmjsLoadMem, int32_t, int32_t, 0);
ASMJS_LOAD_CASE(F32AsmjsLoadMem, float, float,
std::numeric_limits<float>::quiet_NaN());
ASMJS_LOAD_CASE(F64AsmjsLoadMem, double, double,
std::numeric_limits<double>::quiet_NaN());
#undef ASMJS_LOAD_CASE
#define ASMJS_STORE_CASE(name, ctype, mtype) \
case kExpr##name: { \
WasmVal val = Pop(); \
uint32_t index = Pop().to<uint32_t>(); \
if (index < (instance()->mem_size - sizeof(mtype))) { \
byte* addr = instance()->mem_start + index; \
/* TODO(titzer): alignment for asmjs store mem? */ \
*(reinterpret_cast<mtype*>(addr)) = static_cast<mtype>(val.to<ctype>()); \
} \
Push(pc, val); \
break; \
}
ASMJS_STORE_CASE(I32AsmjsStoreMem8, int32_t, int8_t);
ASMJS_STORE_CASE(I32AsmjsStoreMem16, int32_t, int16_t);
ASMJS_STORE_CASE(I32AsmjsStoreMem, int32_t, int32_t);
ASMJS_STORE_CASE(F32AsmjsStoreMem, float, float);
ASMJS_STORE_CASE(F64AsmjsStoreMem, double, double);
#undef ASMJS_STORE_CASE
case kExprGrowMemory: {
MemoryIndexOperand operand(&decoder, code->at(pc));
uint32_t delta_pages = Pop().to<uint32_t>();
Push(pc, WasmVal(ExecuteGrowMemory(delta_pages, instance())));
len = 1 + operand.length;
break;
}
case kExprMemorySize: {
MemoryIndexOperand operand(&decoder, code->at(pc));
Push(pc, WasmVal(static_cast<uint32_t>(instance()->mem_size /
WasmModule::kPageSize)));
len = 1 + operand.length;
break;
}
// We need to treat kExprI32ReinterpretF32 and kExprI64ReinterpretF64
// specially to guarantee that the quiet bit of a NaN is preserved on
// ia32 by the reinterpret casts.
case kExprI32ReinterpretF32: {
WasmVal val = Pop();
WasmVal result(ExecuteI32ReinterpretF32(val));
Push(pc, result);
possible_nondeterminism_ |= std::isnan(val.to<float>());
break;
}
case kExprI64ReinterpretF64: {
WasmVal val = Pop();
WasmVal result(ExecuteI64ReinterpretF64(val));
Push(pc, result);
possible_nondeterminism_ |= std::isnan(val.to<double>());
break;
}
#define EXECUTE_SIMPLE_BINOP(name, ctype, op) \
case kExpr##name: { \
WasmVal rval = Pop(); \
WasmVal lval = Pop(); \
WasmVal result(lval.to<ctype>() op rval.to<ctype>()); \
Push(pc, result); \
break; \
}
FOREACH_SIMPLE_BINOP(EXECUTE_SIMPLE_BINOP)
#undef EXECUTE_SIMPLE_BINOP
#define EXECUTE_OTHER_BINOP(name, ctype) \
case kExpr##name: { \
TrapReason trap = kTrapCount; \
volatile ctype rval = Pop().to<ctype>(); \
volatile ctype lval = Pop().to<ctype>(); \
WasmVal result(Execute##name(lval, rval, &trap)); \
if (trap != kTrapCount) return DoTrap(trap, pc); \
Push(pc, result); \
break; \
}
FOREACH_OTHER_BINOP(EXECUTE_OTHER_BINOP)
#undef EXECUTE_OTHER_BINOP
case kExprF32CopySign: {
// Handle kExprF32CopySign separately because it may introduce
// observable non-determinism.
TrapReason trap = kTrapCount;
volatile float rval = Pop().to<float>();
volatile float lval = Pop().to<float>();
WasmVal result(ExecuteF32CopySign(lval, rval, &trap));
Push(pc, result);
possible_nondeterminism_ |= std::isnan(rval);
break;
}
case kExprF64CopySign: {
// Handle kExprF32CopySign separately because it may introduce
// observable non-determinism.
TrapReason trap = kTrapCount;
volatile double rval = Pop().to<double>();
volatile double lval = Pop().to<double>();
WasmVal result(ExecuteF64CopySign(lval, rval, &trap));
Push(pc, result);
possible_nondeterminism_ |= std::isnan(rval);
break;
}
#define EXECUTE_OTHER_UNOP(name, ctype) \
case kExpr##name: { \
TrapReason trap = kTrapCount; \
volatile ctype val = Pop().to<ctype>(); \
WasmVal result(Execute##name(val, &trap)); \
if (trap != kTrapCount) return DoTrap(trap, pc); \
Push(pc, result); \
break; \
}
FOREACH_OTHER_UNOP(EXECUTE_OTHER_UNOP)
#undef EXECUTE_OTHER_UNOP
default:
V8_Fatal(__FILE__, __LINE__, "Unknown or unimplemented opcode #%d:%s",
code->start[pc], OpcodeName(code->start[pc]));
UNREACHABLE();
}
pc += len;
if (pc == limit) {
// Fell off end of code; do an implicit return.
TRACE("@%-3zu: ImplicitReturn\n", pc);
if (!DoReturn(&code, &pc, &limit, code->function->sig->return_count()))
return;
decoder.Reset(code->start, code->end);
PAUSE_IF_BREAK_FLAG(AfterReturn);
}
}
// Set break_pc_, even though we might have stopped because max was reached.
// We don't want to stop after executing zero instructions next time.
break_pc_ = pc;
state_ = WasmInterpreter::PAUSED;
CommitPc(pc);
}
WasmVal Pop() {
DCHECK_GT(stack_.size(), 0);
DCHECK_GT(frames_.size(), 0);
DCHECK_GT(stack_.size(), frames_.back().llimit()); // can't pop into locals
WasmVal val = stack_.back();
stack_.pop_back();
return val;
}
void PopN(int n) {
DCHECK_GE(stack_.size(), n);
DCHECK_GT(frames_.size(), 0);
size_t nsize = stack_.size() - n;
DCHECK_GE(nsize, frames_.back().llimit()); // can't pop into locals
stack_.resize(nsize);
}
WasmVal PopArity(size_t arity) {
if (arity == 0) return WasmVal();
CHECK_EQ(1, arity);
return Pop();
}
void Push(pc_t pc, WasmVal val) {
// TODO(titzer): store PC as well?
if (val.type != kWasmStmt) stack_.push_back(val);
}
void TraceStack(const char* phase, pc_t pc) {
if (FLAG_trace_wasm_interpreter) {
PrintF("%s @%zu", phase, pc);
UNIMPLEMENTED();
PrintF("\n");
}
}
void TraceValueStack() {
#ifdef DEBUG
Frame* top = frames_.size() > 0 ? &frames_.back() : nullptr;
sp_t sp = top ? top->sp : 0;
sp_t plimit = top ? top->plimit() : 0;
sp_t llimit = top ? top->llimit() : 0;
if (FLAG_trace_wasm_interpreter) {
for (size_t i = sp; i < stack_.size(); ++i) {
if (i < plimit)
PrintF(" p%zu:", i);
else if (i < llimit)
PrintF(" l%zu:", i);
else
PrintF(" s%zu:", i);
WasmVal val = stack_[i];
switch (val.type) {
case kWasmI32:
PrintF("i32:%d", val.to<int32_t>());
break;
case kWasmI64:
PrintF("i64:%" PRId64 "", val.to<int64_t>());
break;
case kWasmF32:
PrintF("f32:%f", val.to<float>());
break;
case kWasmF64:
PrintF("f64:%lf", val.to<double>());
break;
case kWasmStmt:
PrintF("void");
break;
default:
UNREACHABLE();
break;
}
}
}
#endif // DEBUG
}
};
// Converters between WasmInterpreter::Thread and WasmInterpreter::ThreadImpl.
// Thread* is the public interface, without knowledge of the object layout.
// This cast is potentially risky, but as long as we always cast it back before
// accessing any data, it should be fine. UBSan is not complaining.
WasmInterpreter::Thread* ToThread(ThreadImpl* impl) {
return reinterpret_cast<WasmInterpreter::Thread*>(impl);
}
static ThreadImpl* ToImpl(WasmInterpreter::Thread* thread) {
return reinterpret_cast<ThreadImpl*>(thread);
}
} // namespace
//============================================================================
// Implementation of the pimpl idiom for WasmInterpreter::Thread.
// Instead of placing a pointer to the ThreadImpl inside of the Thread object,
// we just reinterpret_cast them. ThreadImpls are only allocated inside this
// translation unit anyway.
//============================================================================
WasmInterpreter::State WasmInterpreter::Thread::state() {
return ToImpl(this)->state();
}
void WasmInterpreter::Thread::PushFrame(const WasmFunction* function,
WasmVal* args) {
return ToImpl(this)->PushFrame(function, args);
}
WasmInterpreter::State WasmInterpreter::Thread::Run() {
return ToImpl(this)->Run();
}
WasmInterpreter::State WasmInterpreter::Thread::Step() {
return ToImpl(this)->Step();
}
void WasmInterpreter::Thread::Pause() { return ToImpl(this)->Pause(); }
void WasmInterpreter::Thread::Reset() { return ToImpl(this)->Reset(); }
pc_t WasmInterpreter::Thread::GetBreakpointPc() {
return ToImpl(this)->GetBreakpointPc();
}
int WasmInterpreter::Thread::GetFrameCount() {
return ToImpl(this)->GetFrameCount();
}
const InterpretedFrame WasmInterpreter::Thread::GetFrame(int index) {
return GetMutableFrame(index);
}
InterpretedFrame WasmInterpreter::Thread::GetMutableFrame(int index) {
// We have access to the constructor of InterpretedFrame, but ThreadImpl has
// not. So pass it as a lambda (should all get inlined).
auto frame_cons = [](const WasmFunction* function, int pc, int fp, int sp) {
return InterpretedFrame(function, pc, fp, sp);
};
return ToImpl(this)->GetMutableFrame(index, frame_cons);
}
WasmVal WasmInterpreter::Thread::GetReturnValue(int index) {
return ToImpl(this)->GetReturnValue(index);
}
bool WasmInterpreter::Thread::PossibleNondeterminism() {
return ToImpl(this)->PossibleNondeterminism();
}
uint64_t WasmInterpreter::Thread::NumInterpretedCalls() {
return ToImpl(this)->NumInterpretedCalls();
}
void WasmInterpreter::Thread::AddBreakFlags(uint8_t flags) {
ToImpl(this)->AddBreakFlags(flags);
}
void WasmInterpreter::Thread::ClearBreakFlags() {
ToImpl(this)->ClearBreakFlags();
}
//============================================================================
// The implementation details of the interpreter.
//============================================================================
class WasmInterpreterInternals : public ZoneObject {
public:
WasmInstance* instance_;
// Create a copy of the module bytes for the interpreter, since the passed
// pointer might be invalidated after constructing the interpreter.
const ZoneVector<uint8_t> module_bytes_;
CodeMap codemap_;
ZoneVector<ThreadImpl> threads_;
WasmInterpreterInternals(Zone* zone, const ModuleBytesEnv& env)
: instance_(env.module_env.instance),
module_bytes_(env.wire_bytes.start(), env.wire_bytes.end(), zone),
codemap_(
env.module_env.instance ? env.module_env.instance->module : nullptr,
module_bytes_.data(), zone),
threads_(zone) {
threads_.emplace_back(zone, &codemap_, env.module_env.instance);
}
void Delete() { threads_.clear(); }
};
//============================================================================
// Implementation of the public interface of the interpreter.
//============================================================================
WasmInterpreter::WasmInterpreter(const ModuleBytesEnv& env,
AccountingAllocator* allocator)
: zone_(allocator, ZONE_NAME),
internals_(new (&zone_) WasmInterpreterInternals(&zone_, env)) {}
WasmInterpreter::~WasmInterpreter() { internals_->Delete(); }
void WasmInterpreter::Run() { internals_->threads_[0].Run(); }
void WasmInterpreter::Pause() { internals_->threads_[0].Pause(); }
bool WasmInterpreter::SetBreakpoint(const WasmFunction* function, pc_t pc,
bool enabled) {
InterpreterCode* code = internals_->codemap_.FindCode(function);
if (!code) return false;
size_t size = static_cast<size_t>(code->end - code->start);
// Check bounds for {pc}.
if (pc < code->locals.encoded_size || pc >= size) return false;
// Make a copy of the code before enabling a breakpoint.
if (enabled && code->orig_start == code->start) {
code->start = reinterpret_cast<byte*>(zone_.New(size));
memcpy(code->start, code->orig_start, size);
code->end = code->start + size;
}
bool prev = code->start[pc] == kInternalBreakpoint;
if (enabled) {
code->start[pc] = kInternalBreakpoint;
} else {
code->start[pc] = code->orig_start[pc];
}
return prev;
}
bool WasmInterpreter::GetBreakpoint(const WasmFunction* function, pc_t pc) {
InterpreterCode* code = internals_->codemap_.FindCode(function);
if (!code) return false;
size_t size = static_cast<size_t>(code->end - code->start);
// Check bounds for {pc}.
if (pc < code->locals.encoded_size || pc >= size) return false;
// Check if a breakpoint is present at that place in the code.
return code->start[pc] == kInternalBreakpoint;
}
bool WasmInterpreter::SetTracing(const WasmFunction* function, bool enabled) {
UNIMPLEMENTED();
return false;
}
int WasmInterpreter::GetThreadCount() {
return 1; // only one thread for now.
}
WasmInterpreter::Thread* WasmInterpreter::GetThread(int id) {
CHECK_EQ(0, id); // only one thread for now.
return ToThread(&internals_->threads_[id]);
}
size_t WasmInterpreter::GetMemorySize() {
return internals_->instance_->mem_size;
}
WasmVal WasmInterpreter::ReadMemory(size_t offset) {
UNIMPLEMENTED();
return WasmVal();
}
void WasmInterpreter::WriteMemory(size_t offset, WasmVal val) {
UNIMPLEMENTED();
}
int WasmInterpreter::AddFunctionForTesting(const WasmFunction* function) {
return internals_->codemap_.AddFunction(function, nullptr, nullptr);
}
bool WasmInterpreter::SetFunctionCodeForTesting(const WasmFunction* function,
const byte* start,
const byte* end) {
return internals_->codemap_.SetFunctionCode(function, start, end);
}
ControlTransferMap WasmInterpreter::ComputeControlTransfersForTesting(
Zone* zone, const byte* start, const byte* end) {
ControlTransfers targets(zone, nullptr, start, end);
return targets.map_;
}
//============================================================================
// Implementation of the frame inspection interface.
//============================================================================
int InterpretedFrame::GetParameterCount() const {
USE(fp_);
USE(sp_);
// TODO(clemensh): Return the correct number of parameters.
return 0;
}
WasmVal InterpretedFrame::GetLocalVal(int index) const {
CHECK_GE(index, 0);
UNIMPLEMENTED();
WasmVal none;
none.type = kWasmStmt;
return none;
}
WasmVal InterpretedFrame::GetExprVal(int pc) const {
UNIMPLEMENTED();
WasmVal none;
none.type = kWasmStmt;
return none;
}
void InterpretedFrame::SetLocalVal(int index, WasmVal val) { UNIMPLEMENTED(); }
void InterpretedFrame::SetExprVal(int pc, WasmVal val) { UNIMPLEMENTED(); }
} // namespace wasm
} // namespace internal
} // namespace v8