blob: ab179f3a9d61a5a5a2073ff614b8ab488bfc879d [file] [log] [blame]
// Copyright 2017 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 "src/wasm/local-decl-encoder.h"
#include "src/wasm/leb-helper.h"
namespace v8 {
namespace internal {
namespace wasm {
void LocalDeclEncoder::Prepend(Zone* zone, const byte** start,
const byte** end) const {
size_t size = (*end - *start);
byte* buffer = reinterpret_cast<byte*>(zone->New(Size() + size));
size_t pos = Emit(buffer);
memcpy(buffer + pos, *start, size);
pos += size;
*start = buffer;
*end = buffer + pos;
}
size_t LocalDeclEncoder::Emit(byte* buffer) const {
byte* pos = buffer;
LEBHelper::write_u32v(&pos, static_cast<uint32_t>(local_decls.size()));
for (auto& local_decl : local_decls) {
LEBHelper::write_u32v(&pos, local_decl.first);
*pos = WasmOpcodes::ValueTypeCodeFor(local_decl.second);
++pos;
}
DCHECK_EQ(Size(), pos - buffer);
return static_cast<size_t>(pos - buffer);
}
uint32_t LocalDeclEncoder::AddLocals(uint32_t count, ValueType type) {
uint32_t result =
static_cast<uint32_t>(total + (sig ? sig->parameter_count() : 0));
total += count;
if (local_decls.size() > 0 && local_decls.back().second == type) {
count += local_decls.back().first;
local_decls.pop_back();
}
local_decls.push_back(std::pair<uint32_t, ValueType>(count, type));
return result;
}
size_t LocalDeclEncoder::Size() const {
size_t size = LEBHelper::sizeof_u32v(local_decls.size());
for (auto p : local_decls) size += 1 + LEBHelper::sizeof_u32v(p.first);
return size;
}
} // namespace wasm
} // namespace internal
} // namespace v8