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/*
* Copyright 2015 WebAssembly Community Group participants
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
//
// asm.js-to-WebAssembly translator. Uses the Emscripten optimizer
// infrastructure.
//
#ifndef wasm_asm2wasm_h
#define wasm_asm2wasm_h
#include "wasm.h"
#include "emscripten-optimizer/optimizer.h"
#include "mixed_arena.h"
#include "shared-constants.h"
#include "asmjs/shared-constants.h"
#include "asm_v_wasm.h"
#include "passes/passes.h"
#include "pass.h"
#include "parsing.h"
#include "ir/bits.h"
#include "ir/branch-utils.h"
#include "ir/literal-utils.h"
#include "ir/trapping.h"
#include "ir/utils.h"
#include "wasm-builder.h"
#include "wasm-emscripten.h"
#include "wasm-module-building.h"
namespace wasm {
using namespace cashew;
// Names
Name I32_CTTZ("i32_cttz"),
I32_CTPOP("i32_ctpop"),
I32_BC2F("i32_bc2f"),
I32_BC2I("i32_bc2i"),
I64("i64"),
I64_CONST("i64_const"),
I64_ADD("i64_add"),
I64_SUB("i64_sub"),
I64_MUL("i64_mul"),
I64_UDIV("i64_udiv"),
I64_SDIV("i64_sdiv"),
I64_UREM("i64_urem"),
I64_SREM("i64_srem"),
I64_AND("i64_and"),
I64_OR("i64_or"),
I64_XOR("i64_xor"),
I64_SHL("i64_shl"),
I64_ASHR("i64_ashr"),
I64_LSHR("i64_lshr"),
I64_EQ("i64_eq"),
I64_NE("i64_ne"),
I64_ULE("i64_ule"),
I64_SLE("i64_sle"),
I64_UGE("i64_uge"),
I64_SGE("i64_sge"),
I64_ULT("i64_ult"),
I64_SLT("i64_slt"),
I64_UGT("i64_ugt"),
I64_SGT("i64_sgt"),
I64_TRUNC("i64_trunc"),
I64_SEXT("i64_sext"),
I64_ZEXT("i64_zext"),
I64_S2F("i64_s2f"),
I64_S2D("i64_s2d"),
I64_U2F("i64_u2f"),
I64_U2D("i64_u2d"),
I64_F2S("i64_f2s"),
I64_D2S("i64_d2s"),
I64_F2U("i64_f2u"),
I64_D2U("i64_d2u"),
I64_BC2D("i64_bc2d"),
I64_BC2I("i64_bc2i"),
I64_CTTZ("i64_cttz"),
I64_CTLZ("i64_ctlz"),
I64_CTPOP("i64_ctpop"),
F32_COPYSIGN("f32_copysign"),
F64_COPYSIGN("f64_copysign"),
LOAD1("load1"),
LOAD2("load2"),
LOAD4("load4"),
LOAD8("load8"),
LOADF("loadf"),
LOADD("loadd"),
STORE1("store1"),
STORE2("store2"),
STORE4("store4"),
STORE8("store8"),
STOREF("storef"),
STORED("stored"),
FTCALL("ftCall_"),
MFTCALL("mftCall_"),
MAX_("max"),
MIN_("min"),
ATOMICS("Atomics"),
ATOMICS_LOAD("load"),
ATOMICS_STORE("store"),
ATOMICS_EXCHANGE("exchange"),
ATOMICS_COMPARE_EXCHANGE("compareExchange"),
ATOMICS_ADD("add"),
ATOMICS_SUB("sub"),
ATOMICS_AND("and"),
ATOMICS_OR("or"),
ATOMICS_XOR("xor"),
I64_ATOMICS_LOAD("i64_atomics_load"),
I64_ATOMICS_STORE("i64_atomics_store"),
I64_ATOMICS_AND("i64_atomics_and"),
I64_ATOMICS_OR("i64_atomics_or"),
I64_ATOMICS_XOR("i64_atomics_xor"),
I64_ATOMICS_ADD("i64_atomics_add"),
I64_ATOMICS_SUB("i64_atomics_sub"),
I64_ATOMICS_EXCHANGE("i64_atomics_exchange"),
I64_ATOMICS_COMPAREEXCHANGE("i64_atomics_compareExchange"),
EMSCRIPTEN_DEBUGINFO("emscripten_debuginfo");
// Utilities
static void abort_on(std::string why, Ref element) {
std::cerr << why << ' ';
element->stringify(std::cerr);
std::cerr << '\n';
abort();
}
static void abort_on(std::string why, IString element) {
std::cerr << why << ' ' << element.str << '\n';
abort();
}
Index indexOr(Index x, Index y) {
return x ? x : y;
}
// useful when we need to see our parent, in an asm.js expression stack
struct AstStackHelper {
static std::vector<Ref> astStack;
AstStackHelper(Ref curr) {
astStack.push_back(curr);
}
~AstStackHelper() {
astStack.pop_back();
}
Ref getParent() {
if (astStack.size() >= 2) {
return astStack[astStack.size()-2];
} else {
return Ref();
}
}
};
std::vector<Ref> AstStackHelper::astStack;
static bool startsWith(const char* string, const char *prefix) {
while (1) {
if (*prefix == 0) return true;
if (*string == 0) return false;
if (*string++ != *prefix++) return false;
}
};
//
// Asm2WasmPreProcessor - does some initial parsing/processing
// of asm.js code.
//
struct Asm2WasmPreProcessor {
bool memoryGrowth = false;
bool debugInfo = false;
std::vector<std::string> debugInfoFileNames;
std::unordered_map<std::string, Index> debugInfoFileIndices;
char* allocatedCopy = nullptr;
~Asm2WasmPreProcessor() {
if (allocatedCopy) free(allocatedCopy);
}
char* process(char* input) {
// emcc --separate-asm modules can look like
//
// Module["asm"] = (function(global, env, buffer) {
// ..
// });
//
// we need to clean that up.
if (*input == 'M') {
size_t num = strlen(input);
while (*input != 'f') {
input++;
num--;
}
char *end = input + num - 1;
while (*end != '}') {
*end = 0;
end--;
}
}
// asm.js memory growth uses a quite elaborate pattern. Instead of parsing and
// matching it, we do a simpler detection on emscripten's asm.js output format
const char* START_FUNCS = "// EMSCRIPTEN_START_FUNCS";
char *marker = strstr(input, START_FUNCS);
if (marker) {
*marker = 0; // look for memory growth code just up to here, as an optimization
}
char *growthSign = strstr(input, "return true;"); // this can only show up in growth code, as normal asm.js lacks "true"
if (growthSign) {
memoryGrowth = true;
// clean out this function, we don't need it. first where it starts
char *growthFuncStart = growthSign;
while (*growthFuncStart != '{') growthFuncStart--; // skip body
while (*growthFuncStart != '(') growthFuncStart--; // skip params
while (*growthFuncStart != ' ') growthFuncStart--; // skip function name
while (*growthFuncStart != 'f') growthFuncStart--; // skip 'function'
assert(strstr(growthFuncStart, "function ") == growthFuncStart);
char *growthFuncEnd = strchr(growthSign, '}');
assert(growthFuncEnd > growthFuncStart + 5);
growthFuncStart[0] = '/';
growthFuncStart[1] = '*';
growthFuncEnd--;
growthFuncEnd[0] = '*';
growthFuncEnd[1] = '/';
}
if (marker) {
*marker = START_FUNCS[0];
}
// handle debug info, if this build wants that.
if (debugInfo) {
// asm.js debug info comments look like
// ..command..; //@line 4 "tests/hello_world.c"
// we convert those into emscripten_debuginfo(file, line)
// calls, where the params are indices into a mapping. then
// the compiler and optimizer can operate on them. after
// that, we can apply the debug info to the wasm node right
// before it - this is guaranteed to be correct without opts,
// and is usually decently accurate with them.
const auto SCALE_FACTOR = 1.25; // an upper bound on how much more space we need as a multiple of the original
const auto ADD_FACTOR = 100; // an upper bound on how much we write for each debug info element itself
auto size = strlen(input);
auto upperBound = Index(size * SCALE_FACTOR) + ADD_FACTOR;
char* copy = allocatedCopy = (char*)malloc(upperBound);
char* end = copy + upperBound;
char* out = copy;
std::string DEBUGINFO_INTRINSIC = EMSCRIPTEN_DEBUGINFO.str;
auto DEBUGINFO_INTRINSIC_SIZE = DEBUGINFO_INTRINSIC.size();
const char* UNKNOWN_FILE = "(unknown)";
bool seenUseAsm = false;
while (input[0]) {
if (out + ADD_FACTOR >= end) {
Fatal() << "error in handling debug info";
}
if (startsWith(input, "//@line")) {
char* linePos = input + 8;
char* lineEnd = strpbrk(input + 8, " \n");
if (!lineEnd) {
// comment goes to end of input
break;
}
input = lineEnd + 1;
std::string file;
if (*lineEnd == ' ') {
// we have a file
char* filePos = strpbrk(input, "\"\n");
if (!filePos) {
// goes to end of input
break;
}
if (*filePos == '"') {
char* fileEnd = strpbrk(filePos + 1, "\"\n");
input = fileEnd + 1;
*fileEnd = 0;
file = filePos + 1;
} else {
file = UNKNOWN_FILE;
input = filePos + 1;
}
} else {
// no file, we found \n
file = UNKNOWN_FILE;
}
*lineEnd = 0;
std::string line = linePos;
auto iter = debugInfoFileIndices.find(file);
if (iter == debugInfoFileIndices.end()) {
Index index = debugInfoFileNames.size();
debugInfoFileNames.push_back(file);
debugInfoFileIndices[file] = index;
}
std::string fileIndex = std::to_string(debugInfoFileIndices[file]);
// write out the intrinsic
strcpy(out, DEBUGINFO_INTRINSIC.c_str());
out += DEBUGINFO_INTRINSIC_SIZE;
*out++ = '(';
strcpy(out, fileIndex.c_str());
out += fileIndex.size();
*out++ = ',';
strcpy(out, line.c_str());
out += line.size();
*out++ = ')';
*out++ = ';';
} else if (!seenUseAsm && (startsWith(input, "asm'") || startsWith(input, "asm\""))) {
// end of "use asm" or "almost asm"
const auto SKIP = 5; // skip the end of "use asm"; (5 chars, a,s,m," or ',;)
seenUseAsm = true;
memcpy(out, input, SKIP);
out += SKIP;
input += SKIP;
// add a fake import for the intrinsic, so the module validates
std::string import = "\n var emscripten_debuginfo = env.emscripten_debuginfo;";
strcpy(out, import.c_str());
out += import.size();
} else {
*out++ = *input++;
}
}
if (out >= end) {
Fatal() << "error in handling debug info";
}
*out = 0;
input = copy;
}
return input;
}
};
static CallImport* checkDebugInfo(Expression* curr) {
if (auto* call = curr->dynCast<CallImport>()) {
if (call->target == EMSCRIPTEN_DEBUGINFO) {
return call;
}
}
return nullptr;
}
// Debug info appears in the ast as calls to the debug intrinsic. These are usually
// after the relevant node. We adjust them to a position that is not dce-able, so that
// they are not trivially removed when optimizing.
struct AdjustDebugInfo : public WalkerPass<PostWalker<AdjustDebugInfo, Visitor<AdjustDebugInfo>>> {
bool isFunctionParallel() override { return true; }
Pass* create() override { return new AdjustDebugInfo(); }
AdjustDebugInfo() {
name = "adjust-debug-info";
}
void visitBlock(Block* curr) {
// look for a debug info call that is unreachable
if (curr->list.size() == 0) return;
auto* back = curr->list.back();
for (Index i = 1; i < curr->list.size(); i++) {
if (checkDebugInfo(curr->list[i]) && !checkDebugInfo(curr->list[i - 1])) {
// swap them
std::swap(curr->list[i - 1], curr->list[i]);
}
}
if (curr->list.back() != back) {
// we changed the last element, update the type
curr->finalize();
}
}
};
//
// Asm2WasmBuilder - converts an asm.js module into WebAssembly
//
class Asm2WasmBuilder {
public:
Module& wasm;
MixedArena &allocator;
Builder builder;
std::unique_ptr<OptimizingIncrementalModuleBuilder> optimizingBuilder;
// globals
struct MappedGlobal {
Type type;
bool import; // if true, this is an import - we should read the value, not just set a zero
IString module, base;
MappedGlobal() : type(none), import(false) {}
MappedGlobal(Type type) : type(type), import(false) {}
MappedGlobal(Type type, bool import, IString module, IString base) : type(type), import(import), module(module), base(base) {}
};
// function table
std::map<IString, int> functionTableStarts; // each asm function table gets a range in the one wasm table, starting at a location
Asm2WasmPreProcessor& preprocessor;
bool debug;
TrapMode trapMode;
TrappingFunctionContainer trappingFunctions;
PassOptions passOptions;
bool legalizeJavaScriptFFI;
bool runOptimizationPasses;
bool wasmOnly;
public:
std::map<IString, MappedGlobal> mappedGlobals;
private:
void allocateGlobal(IString name, Type type) {
assert(mappedGlobals.find(name) == mappedGlobals.end());
mappedGlobals.emplace(name, MappedGlobal(type));
wasm.addGlobal(builder.makeGlobal(
name,
type,
LiteralUtils::makeZero(type, wasm),
Builder::Mutable
));
}
struct View {
unsigned bytes;
bool integer, signed_;
AsmType type;
View() : bytes(0) {}
View(unsigned bytes, bool integer, bool signed_, AsmType type) : bytes(bytes), integer(integer), signed_(signed_), type(type) {}
};
std::map<IString, View> views; // name (e.g. HEAP8) => view info
// Imported names of Math.*
IString Math_imul;
IString Math_clz32;
IString Math_fround;
IString Math_abs;
IString Math_floor;
IString Math_ceil;
IString Math_sqrt;
IString Math_max;
IString Math_min;
// Imported names of Atomics.*
IString Atomics_load;
IString Atomics_store;
IString Atomics_exchange;
IString Atomics_compareExchange;
IString Atomics_add;
IString Atomics_sub;
IString Atomics_and;
IString Atomics_or;
IString Atomics_xor;
IString llvm_cttz_i32;
IString tempDoublePtr; // imported name of tempDoublePtr
// possibly-minified names, detected via their exports
IString udivmoddi4;
IString getTempRet0;
// function types. we fill in this information as we see
// uses, in the first pass
std::map<IString, std::unique_ptr<FunctionType>> importedFunctionTypes;
void noteImportedFunctionCall(Ref ast, Type resultType, CallImport* call) {
assert(ast[0] == CALL && ast[1]->isString());
IString importName = ast[1]->getIString();
auto type = make_unique<FunctionType>();
type->name = IString((std::string("type$") + importName.str).c_str(), false); // TODO: make a list of such types
type->result = resultType;
for (auto* operand : call->operands) {
type->params.push_back(operand->type);
}
// if we already saw this signature, verify it's the same (or else handle that)
if (importedFunctionTypes.find(importName) != importedFunctionTypes.end()) {
FunctionType* previous = importedFunctionTypes[importName].get();
if (*type != *previous) {
// merge it in. we'll add on extra 0 parameters for ones not actually used, and upgrade types to
// double where there is a conflict (which is ok since in JS, double can contain everything
// i32 and f32 can).
for (size_t i = 0; i < type->params.size(); i++) {
if (previous->params.size() > i) {
if (previous->params[i] == none) {
previous->params[i] = type->params[i]; // use a more concrete type
} else if (previous->params[i] != type->params[i]) {
previous->params[i] = f64; // overloaded type, make it a double
}
} else {
previous->params.push_back(type->params[i]); // add a new param
}
}
// we accept none and a concrete type, but two concrete types mean we need to use an f64 to contain anything
if (previous->result == none) {
previous->result = type->result; // use a more concrete type
} else if (previous->result != type->result && type->result != none) {
previous->result = f64; // overloaded return type, make it a double
}
}
} else {
importedFunctionTypes[importName].swap(type);
}
}
Type getResultTypeOfCallUsingParent(Ref parent, AsmData* data) {
auto result = none;
if (!!parent) {
// if the parent is a seq, we cannot be the last element in it (we would have a coercion, which would be
// the parent), so we must be (us, somethingElse), and so our return is void
if (parent[0] != SEQ) {
result = detectWasmType(parent, data);
}
}
return result;
}
FunctionType* getFunctionType(Ref parent, ExpressionList& operands, AsmData* data) {
Type result = getResultTypeOfCallUsingParent(parent, data);
return ensureFunctionType(getSig(result, operands), &wasm);
}
public:
Asm2WasmBuilder(Module& wasm, Asm2WasmPreProcessor& preprocessor, bool debug, TrapMode trapMode, PassOptions passOptions, bool legalizeJavaScriptFFI, bool runOptimizationPasses, bool wasmOnly)
: wasm(wasm),
allocator(wasm.allocator),
builder(wasm),
preprocessor(preprocessor),
debug(debug),
trapMode(trapMode),
trappingFunctions(trapMode, wasm, /* immediate = */ true),
passOptions(passOptions),
legalizeJavaScriptFFI(legalizeJavaScriptFFI),
runOptimizationPasses(runOptimizationPasses),
wasmOnly(wasmOnly) {}
void processAsm(Ref ast);
private:
AsmType detectAsmType(Ref ast, AsmData *data) {
if (ast->isString()) {
IString name = ast->getIString();
if (!data->isLocal(name)) {
// must be global
assert(mappedGlobals.find(name) != mappedGlobals.end());
return wasmToAsmType(mappedGlobals[name].type);
}
} else if (ast->isArray(SUB) && ast[1]->isString()) {
// could be a heap access, use view info
auto view = views.find(ast[1]->getIString());
if (view != views.end()) {
return view->second.type;
}
}
return detectType(ast, data, false, Math_fround, wasmOnly);
}
Type detectWasmType(Ref ast, AsmData *data) {
return asmToWasmType(detectAsmType(ast, data));
}
bool isUnsignedCoercion(Ref ast) {
return detectSign(ast, Math_fround) == ASM_UNSIGNED;
}
bool isParentUnsignedCoercion(Ref parent) {
// parent may not exist, or may be a non-relevant node
if (!!parent && parent->isArray() && parent[0] == BINARY && isUnsignedCoercion(parent)) {
return true;
}
return false;
}
BinaryOp parseAsmBinaryOp(IString op, Ref left, Ref right, Expression* leftWasm, Expression* rightWasm) {
Type leftType = leftWasm->type;
bool isInteger = leftType == Type::i32;
if (op == PLUS) return isInteger ? BinaryOp::AddInt32 : (leftType == f32 ? BinaryOp::AddFloat32 : BinaryOp::AddFloat64);
if (op == MINUS) return isInteger ? BinaryOp::SubInt32 : (leftType == f32 ? BinaryOp::SubFloat32 : BinaryOp::SubFloat64);
if (op == MUL) return isInteger ? BinaryOp::MulInt32 : (leftType == f32 ? BinaryOp::MulFloat32 : BinaryOp::MulFloat64);
if (op == AND) return BinaryOp::AndInt32;
if (op == OR) return BinaryOp::OrInt32;
if (op == XOR) return BinaryOp::XorInt32;
if (op == LSHIFT) return BinaryOp::ShlInt32;
if (op == RSHIFT) return BinaryOp::ShrSInt32;
if (op == TRSHIFT) return BinaryOp::ShrUInt32;
if (op == EQ) return isInteger ? BinaryOp::EqInt32 : (leftType == f32 ? BinaryOp::EqFloat32 : BinaryOp::EqFloat64);
if (op == NE) return isInteger ? BinaryOp::NeInt32 : (leftType == f32 ? BinaryOp::NeFloat32 : BinaryOp::NeFloat64);
bool isUnsigned = isUnsignedCoercion(left) || isUnsignedCoercion(right);
if (op == DIV) {
if (isInteger) {
return isUnsigned ? BinaryOp::DivUInt32 : BinaryOp::DivSInt32;
}
return leftType == f32 ? BinaryOp::DivFloat32 : BinaryOp::DivFloat64;
}
if (op == MOD) {
if (isInteger) {
return isUnsigned ? BinaryOp::RemUInt32 : BinaryOp::RemSInt32;
}
return BinaryOp::RemSInt32; // XXX no floating-point remainder op, this must be handled by the caller
}
if (op == GE) {
if (isInteger) {
return isUnsigned ? BinaryOp::GeUInt32 : BinaryOp::GeSInt32;
}
return leftType == f32 ? BinaryOp::GeFloat32 : BinaryOp::GeFloat64;
}
if (op == GT) {
if (isInteger) {
return isUnsigned ? BinaryOp::GtUInt32 : BinaryOp::GtSInt32;
}
return leftType == f32 ? BinaryOp::GtFloat32 : BinaryOp::GtFloat64;
}
if (op == LE) {
if (isInteger) {
return isUnsigned ? BinaryOp::LeUInt32 : BinaryOp::LeSInt32;
}
return leftType == f32 ? BinaryOp::LeFloat32 : BinaryOp::LeFloat64;
}
if (op == LT) {
if (isInteger) {
return isUnsigned ? BinaryOp::LtUInt32 : BinaryOp::LtSInt32;
}
return leftType == f32 ? BinaryOp::LtFloat32 : BinaryOp::LtFloat64;
}
abort_on("bad wasm binary op", op);
abort(); // avoid warning
}
int32_t bytesToShift(unsigned bytes) {
switch (bytes) {
case 1: return 0;
case 2: return 1;
case 4: return 2;
case 8: return 3;
default: {}
}
abort();
return -1; // avoid warning
}
std::map<unsigned, Ref> tempNums;
Literal checkLiteral(Ref ast, bool rawIsInteger = true) {
if (ast->isNumber()) {
if (rawIsInteger) {
return Literal((int32_t)ast->getInteger());
} else {
return Literal(ast->getNumber());
}
} else if (ast->isArray(UNARY_PREFIX)) {
if (ast[1] == PLUS && ast[2]->isNumber()) {
return Literal((double)ast[2]->getNumber());
}
if (ast[1] == MINUS && ast[2]->isNumber()) {
double num = -ast[2]->getNumber();
if (isSInteger32(num)) return Literal((int32_t)num);
if (isUInteger32(num)) return Literal((uint32_t)num);
assert(false && "expected signed or unsigned int32");
}
if (ast[1] == PLUS && ast[2]->isArray(UNARY_PREFIX) && ast[2][1] == MINUS && ast[2][2]->isNumber()) {
return Literal((double)-ast[2][2]->getNumber());
}
if (ast[1] == MINUS && ast[2]->isArray(UNARY_PREFIX) && ast[2][1] == PLUS && ast[2][2]->isNumber()) {
return Literal((double)-ast[2][2]->getNumber());
}
} else if (wasmOnly && ast->isArray(CALL) && ast[1]->isString() && ast[1] == I64_CONST) {
uint64_t low = ast[2][0]->getNumber();
uint64_t high = ast[2][1]->getNumber();
return Literal(uint64_t(low + (high << 32)));
}
return Literal();
}
Literal getLiteral(Ref ast) {
Literal ret = checkLiteral(ast);
assert(ret.type != none);
return ret;
}
void fixCallType(Expression* call, Type type) {
if (call->is<Call>()) call->cast<Call>()->type = type;
if (call->is<CallImport>()) call->cast<CallImport>()->type = type;
else if (call->is<CallIndirect>()) call->cast<CallIndirect>()->type = type;
}
FunctionType* getBuiltinFunctionType(Name module, Name base, ExpressionList* operands = nullptr) {
if (module == GLOBAL_MATH) {
if (base == ABS) {
assert(operands && operands->size() == 1);
Type type = (*operands)[0]->type;
if (type == i32) return ensureFunctionType("ii", &wasm);
if (type == f32) return ensureFunctionType("ff", &wasm);
if (type == f64) return ensureFunctionType("dd", &wasm);
}
}
return nullptr;
}
// ensure a nameless block
Block* blockify(Expression* expression) {
if (expression->is<Block>() && !expression->cast<Block>()->name.is()) return expression->dynCast<Block>();
auto ret = allocator.alloc<Block>();
ret->list.push_back(expression);
ret->finalize();
return ret;
}
Expression* ensureDouble(Expression* expr) {
return wasm::ensureDouble(expr, allocator);
}
Expression* truncateToInt32(Expression* value) {
if (value->type == i64) return builder.makeUnary(UnaryOp::WrapInt64, value);
// either i32, or a call_import whose type we don't know yet (but would be legalized to i32 anyhow)
return value;
}
Function* processFunction(Ref ast);
};
void Asm2WasmBuilder::processAsm(Ref ast) {
assert(ast[0] == TOPLEVEL);
Ref asmFunction = ast[1][0];
assert(asmFunction[0] == DEFUN);
Ref body = asmFunction[3];
assert(body[0][0] == STRING && (body[0][1]->getIString() == IString("use asm") || body[0][1]->getIString() == IString("almost asm")));
// extra functions that we add, that are not from the compiled code. we need
// to make sure to optimize them normally (OptimizingIncrementalModuleBuilder
// does that on the fly for compiled code)
std::vector<Function*> extraSupportFunctions;
// first, add the memory elements. we do this before the main compile+optimize
// since the optimizer should see the memory
// apply memory growth, if relevant
if (preprocessor.memoryGrowth) {
EmscriptenGlueGenerator generator(wasm);
auto* func = generator.generateMemoryGrowthFunction();
extraSupportFunctions.push_back(func);
wasm.memory.max = Memory::kMaxSize;
}
// import memory
auto memoryImport = make_unique<Import>();
memoryImport->name = MEMORY;
memoryImport->module = ENV;
memoryImport->base = MEMORY;
memoryImport->kind = ExternalKind::Memory;
wasm.memory.exists = true;
wasm.memory.imported = true;
wasm.addImport(memoryImport.release());
// import table
auto tableImport = make_unique<Import>();
tableImport->name = TABLE;
tableImport->module = ENV;
tableImport->base = TABLE;
tableImport->kind = ExternalKind::Table;
wasm.addImport(tableImport.release());
wasm.table.exists = true;
wasm.table.imported = true;
// Import memory offset, if not already there
{
auto* import = new Import;
import->name = Name("memoryBase");
import->module = Name("env");
import->base = Name("memoryBase");
import->kind = ExternalKind::Global;
import->globalType = i32;
wasm.addImport(import);
}
// Import table offset, if not already there
{
auto* import = new Import;
import->name = Name("tableBase");
import->module = Name("env");
import->base = Name("tableBase");
import->kind = ExternalKind::Global;
import->globalType = i32;
wasm.addImport(import);
}
auto addImport = [&](IString name, Ref imported, Type type) {
assert(imported[0] == DOT);
Ref module = imported[1];
IString moduleName;
if (module->isArray(DOT)) {
// we can have (global.Math).floor; skip the 'Math'
assert(module[1]->isString());
if (module[2] == MATH) {
if (imported[2] == IMUL) {
assert(Math_imul.isNull());
Math_imul = name;
return;
} else if (imported[2] == CLZ32) {
assert(Math_clz32.isNull());
Math_clz32 = name;
return;
} else if (imported[2] == FROUND) {
assert(Math_fround.isNull());
Math_fround = name;
return;
} else if (imported[2] == ABS) {
assert(Math_abs.isNull());
Math_abs = name;
return;
} else if (imported[2] == FLOOR) {
assert(Math_floor.isNull());
Math_floor = name;
return;
} else if (imported[2] == CEIL) {
assert(Math_ceil.isNull());
Math_ceil = name;
return;
} else if (imported[2] == SQRT) {
assert(Math_sqrt.isNull());
Math_sqrt = name;
return;
} else if (imported[2] == MAX_) {
assert(Math_max.isNull());
Math_max = name;
return;
} else if (imported[2] == MIN_) {
assert(Math_min.isNull());
Math_min = name;
return;
}
} else if (module[2] == ATOMICS) {
if (imported[2] == ATOMICS_LOAD) {
assert(Atomics_load.isNull());
Atomics_load = name;
return;
} else if (imported[2] == ATOMICS_STORE) {
assert(Atomics_store.isNull());
Atomics_store = name;
return;
} else if (imported[2] == ATOMICS_EXCHANGE) {
assert(Atomics_exchange.isNull());
Atomics_exchange = name;
return;
} else if (imported[2] == ATOMICS_COMPARE_EXCHANGE) {
assert(Atomics_compareExchange.isNull());
Atomics_compareExchange = name;
return;
} else if (imported[2] == ATOMICS_ADD) {
assert(Atomics_add.isNull());
Atomics_add = name;
return;
} else if (imported[2] == ATOMICS_SUB) {
assert(Atomics_sub.isNull());
Atomics_sub = name;
return;
} else if (imported[2] == ATOMICS_AND) {
assert(Atomics_and.isNull());
Atomics_and = name;
return;
} else if (imported[2] == ATOMICS_OR) {
assert(Atomics_or.isNull());
Atomics_or = name;
return;
} else if (imported[2] == ATOMICS_XOR) {
assert(Atomics_xor.isNull());
Atomics_xor = name;
return;
}
}
std::string fullName = module[1]->getCString();
fullName += '.';
fullName += + module[2]->getCString();
moduleName = IString(fullName.c_str(), false);
} else {
assert(module->isString());
moduleName = module->getIString();
if (moduleName == ENV) {
auto base = imported[2]->getIString();
if (base == TEMP_DOUBLE_PTR) {
assert(tempDoublePtr.isNull());
tempDoublePtr = name;
// we don't return here, as we can only optimize out some uses of tDP. So it remains imported
} else if (base == LLVM_CTTZ_I32) {
assert(llvm_cttz_i32.isNull());
llvm_cttz_i32 = name;
return;
}
}
}
auto import = make_unique<Import>();
import->name = name;
import->module = moduleName;
import->base = imported[2]->getIString();
// special-case some asm builtins
if (import->module == GLOBAL && (import->base == NAN_ || import->base == INFINITY_)) {
type = Type::f64;
}
if (type != Type::none) {
// this is a global
import->kind = ExternalKind::Global;
import->globalType = type;
mappedGlobals.emplace(name, type);
// tableBase and memoryBase are used as segment/element offsets, and must be constant;
// otherwise, an asm.js import of a constant is mutable, e.g. STACKTOP
if (name != "tableBase" && name != "memoryBase") {
// we need imported globals to be mutable, but wasm doesn't support that yet, so we must
// import an immutable and create a mutable global initialized to its value
import->name = Name(std::string(import->name.str) + "$asm2wasm$import");
{
wasm.addGlobal(builder.makeGlobal(
name,
type,
builder.makeGetGlobal(import->name, type),
Builder::Mutable
));
}
}
} else {
import->kind = ExternalKind::Function;
}
// we may have already created an import for this manually
if ((name == "tableBase" || name == "memoryBase") &&
(wasm.getImportOrNull(import->base) || wasm.getGlobalOrNull(import->base))) {
return;
}
wasm.addImport(import.release());
};
IString Int8Array, Int16Array, Int32Array, UInt8Array, UInt16Array, UInt32Array, Float32Array, Float64Array;
// set up optimization
if (runOptimizationPasses) {
Index numFunctions = 0;
for (unsigned i = 1; i < body->size(); i++) {
if (body[i][0] == DEFUN) numFunctions++;
}
optimizingBuilder = make_unique<OptimizingIncrementalModuleBuilder>(&wasm, numFunctions, passOptions, [&](PassRunner& passRunner) {
// addPrePasses
if (debug) {
passRunner.setDebug(true);
passRunner.setValidateGlobally(false);
}
// run autodrop first, before optimizations
passRunner.add<AutoDrop>();
if (preprocessor.debugInfo) {
// fix up debug info to better survive optimization
passRunner.add<AdjustDebugInfo>();
}
// optimize relooper label variable usage at the wasm level, where it is easy
passRunner.add("relooper-jump-threading");
}, debug, false /* do not validate globally yet */);
}
// if we see no function tables in the processing below, then the table still exists and has size 0
wasm.table.initial = wasm.table.max = 0;
// first pass - do all global things, aside from function bodies (second pass)
// and function imports and indirect calls (last pass)
for (unsigned i = 1; i < body->size(); i++) {
Ref curr = body[i];
if (curr[0] == VAR) {
// import, global, or table
for (unsigned j = 0; j < curr[1]->size(); j++) {
Ref pair = curr[1][j];
IString name = pair[0]->getIString();
Ref value = pair[1];
if (value->isNumber()) {
// global int
assert(value->getNumber() == 0);
allocateGlobal(name, Type::i32);
} else if (value[0] == BINARY) {
// int import
assert(value[1] == OR && value[3]->isNumber() && value[3]->getNumber() == 0);
Ref import = value[2]; // env.what
addImport(name, import, Type::i32);
} else if (value[0] == UNARY_PREFIX) {
// double import or global
assert(value[1] == PLUS);
Ref import = value[2];
if (import->isNumber()) {
// global
assert(import->getNumber() == 0);
allocateGlobal(name, Type::f64);
} else {
// import
addImport(name, import, Type::f64);
}
} else if (value[0] == CALL) {
assert(value[1]->isString() && value[1] == Math_fround && value[2][0]->isNumber() && value[2][0]->getNumber() == 0);
allocateGlobal(name, Type::f32);
} else if (value[0] == DOT) {
// simple module.base import. can be a view, or a function.
if (value[1]->isString()) {
IString module = value[1]->getIString();
IString base = value[2]->getIString();
if (module == GLOBAL) {
if (base == INT8ARRAY) {
Int8Array = name;
} else if (base == INT16ARRAY) {
Int16Array = name;
} else if (base == INT32ARRAY) {
Int32Array = name;
} else if (base == UINT8ARRAY) {
UInt8Array = name;
} else if (base == UINT16ARRAY) {
UInt16Array = name;
} else if (base == UINT32ARRAY) {
UInt32Array = name;
} else if (base == FLOAT32ARRAY) {
Float32Array = name;
} else if (base == FLOAT64ARRAY) {
Float64Array = name;
}
}
}
// function import
addImport(name, value, Type::none);
} else if (value[0] == NEW) {
// ignore imports of typed arrays, but note the names of the arrays
value = value[1];
assert(value[0] == CALL);
unsigned bytes;
bool integer, signed_;
AsmType asmType;
Ref constructor = value[1];
if (constructor->isArray(DOT)) { // global.*Array
IString heap = constructor[2]->getIString();
if (heap == INT8ARRAY) {
bytes = 1; integer = true; signed_ = true; asmType = ASM_INT;
} else if (heap == INT16ARRAY) {
bytes = 2; integer = true; signed_ = true; asmType = ASM_INT;
} else if (heap == INT32ARRAY) {
bytes = 4; integer = true; signed_ = true; asmType = ASM_INT;
} else if (heap == UINT8ARRAY) {
bytes = 1; integer = true; signed_ = false; asmType = ASM_INT;
} else if (heap == UINT16ARRAY) {
bytes = 2; integer = true; signed_ = false; asmType = ASM_INT;
} else if (heap == UINT32ARRAY) {
bytes = 4; integer = true; signed_ = false; asmType = ASM_INT;
} else if (heap == FLOAT32ARRAY) {
bytes = 4; integer = false; signed_ = true; asmType = ASM_FLOAT;
} else if (heap == FLOAT64ARRAY) {
bytes = 8; integer = false; signed_ = true; asmType = ASM_DOUBLE;
} else {
abort_on("invalid view import", heap);
}
} else { // *ArrayView that was previously imported
assert(constructor->isString());
IString viewName = constructor->getIString();
if (viewName == Int8Array) {
bytes = 1; integer = true; signed_ = true; asmType = ASM_INT;
} else if (viewName == Int16Array) {
bytes = 2; integer = true; signed_ = true; asmType = ASM_INT;
} else if (viewName == Int32Array) {
bytes = 4; integer = true; signed_ = true; asmType = ASM_INT;
} else if (viewName == UInt8Array) {
bytes = 1; integer = true; signed_ = false; asmType = ASM_INT;
} else if (viewName == UInt16Array) {
bytes = 2; integer = true; signed_ = false; asmType = ASM_INT;
} else if (viewName == UInt32Array) {
bytes = 4; integer = true; signed_ = false; asmType = ASM_INT;
} else if (viewName == Float32Array) {
bytes = 4; integer = false; signed_ = true; asmType = ASM_FLOAT;
} else if (viewName == Float64Array) {
bytes = 8; integer = false; signed_ = true; asmType = ASM_DOUBLE;
} else {
abort_on("invalid short view import", viewName);
}
}
assert(views.find(name) == views.end());
views.emplace(name, View(bytes, integer, signed_, asmType));
} else if (value[0] == ARRAY) {
// function table. we merge them into one big table, so e.g. [foo, b1] , [b2, bar] => [foo, b1, b2, bar]
// TODO: when not using aliasing function pointers, we could merge them by noticing that
// index 0 in each table is the null func, and each other index should only have one
// non-null func. However, that breaks down when function pointer casts are emulated.
if (wasm.table.segments.size() == 0) {
wasm.table.segments.emplace_back(builder.makeGetGlobal(Name("tableBase"), i32));
}
auto& segment = wasm.table.segments[0];
functionTableStarts[name] = segment.data.size(); // this table starts here
Ref contents = value[1];
for (unsigned k = 0; k < contents->size(); k++) {
IString curr = contents[k]->getIString();
segment.data.push_back(curr);
}
wasm.table.initial = wasm.table.max = segment.data.size();
} else {
abort_on("invalid var element", pair);
}
}
} else if (curr[0] == RETURN) {
// exports
Ref object = curr[1];
Ref contents = object[1];
std::map<Name, Export*> exported;
for (unsigned k = 0; k < contents->size(); k++) {
Ref pair = contents[k];
IString key = pair[0]->getIString();
if (pair[1]->isString()) {
// exporting a function
IString value = pair[1]->getIString();
if (key == Name("_emscripten_replace_memory")) {
// asm.js memory growth provides this special non-asm function, which we don't need (we use grow_memory)
assert(!wasm.getFunctionOrNull(value));
continue;
} else if (key == UDIVMODDI4) {
udivmoddi4 = value;
} else if (key == GET_TEMP_RET0) {
getTempRet0 = value;
}
if (exported.count(key) > 0) {
// asm.js allows duplicate exports, but not wasm. use the last, like asm.js
exported[key]->value = value;
} else {
auto* export_ = new Export;
export_->name = key;
export_->value = value;
export_->kind = ExternalKind::Function;
wasm.addExport(export_);
exported[key] = export_;
}
} else {
// export a number. create a global and export it
assert(pair[1]->isNumber());
assert(exported.count(key) == 0);
auto value = pair[1]->getInteger();
auto* global = builder.makeGlobal(
key,
i32,
builder.makeConst(Literal(int32_t(value))),
Builder::Immutable
);
wasm.addGlobal(global);
auto* export_ = new Export;
export_->name = key;
export_->value = global->name;
export_->kind = ExternalKind::Global;
wasm.addExport(export_);
exported[key] = export_;
}
}
}
}
// second pass: function bodies
for (unsigned i = 1; i < body->size(); i++) {
Ref curr = body[i];
if (curr[0] == DEFUN) {
// function
auto* func = processFunction(curr);
if (wasm.getFunctionOrNull(func->name)) {
Fatal() << "duplicate function: " << func->name;
}
if (runOptimizationPasses) {
optimizingBuilder->addFunction(func);
} else {
wasm.addFunction(func);
}
}
}
if (runOptimizationPasses) {
optimizingBuilder->finish();
// if we added any helper functions (like non-trapping i32-div, etc.), then those
// have not been optimized (the optimizing builder has just been fed the asm.js
// functions). Optimize those now. Typically there are very few, just do it
// sequentially.
PassRunner passRunner(&wasm, passOptions);
passRunner.addDefaultFunctionOptimizationPasses();
for (auto& pair : trappingFunctions.getFunctions()) {
auto* func = pair.second;
passRunner.runOnFunction(func);
}
for (auto* func : extraSupportFunctions) {
passRunner.runOnFunction(func);
}
}
wasm.debugInfoFileNames = std::move(preprocessor.debugInfoFileNames);
// third pass. first, function imports
std::vector<IString> toErase;
for (auto& import : wasm.imports) {
if (import->kind != ExternalKind::Function) continue;
IString name = import->name;
if (importedFunctionTypes.find(name) != importedFunctionTypes.end()) {
// special math builtins
FunctionType* builtin = getBuiltinFunctionType(import->module, import->base);
if (builtin) {
import->functionType = builtin->name;
continue;
}
import->functionType = ensureFunctionType(getSig(importedFunctionTypes[name].get()), &wasm)->name;
} else if (import->module != ASM2WASM) { // special-case the special module
// never actually used, which means we don't know the function type since the usage tells us, so illegal for it to remain
toErase.push_back(name);
}
}
for (auto curr : toErase) {
wasm.removeImport(curr);
}
// Finalize calls now that everything is known and generated
struct FinalizeCalls : public WalkerPass<PostWalker<FinalizeCalls>> {
bool isFunctionParallel() override { return true; }
Pass* create() override { return new FinalizeCalls(parent); }
Asm2WasmBuilder* parent;
FinalizeCalls(Asm2WasmBuilder* parent) : parent(parent) {
name = "finalize-calls";
}
void notifyAboutWrongOperands(std::string why, Function* calledFunc) {
// use a mutex as this may be shown from multiple threads
static std::mutex mutex;
std::unique_lock<std::mutex> lock(mutex);
static const int MAX_SHOWN = 20;
static std::unique_ptr<std::atomic<int>> numShown;
if (!numShown) {
numShown = make_unique<std::atomic<int>>();
numShown->store(0);
}
if (numShown->load() >= MAX_SHOWN) return;
std::cerr << why << " in call from " << getFunction()->name << " to " << calledFunc->name << " (this is likely due to undefined behavior in C, like defining a function one way and calling it in another, which is important to fix)\n";
(*numShown)++;
if (numShown->load() >= MAX_SHOWN) {
std::cerr << "(" << numShown->load() << " such warnings shown; not showing any more)\n";
}
}
void visitCall(Call* curr) {
auto* calledFunc = getModule()->getFunctionOrNull(curr->target);
if (!calledFunc) {
std::cerr << "invalid call target: " << curr->target << '\n';
WASM_UNREACHABLE();
}
// The result type of the function being called is now known, and can be applied.
auto result = calledFunc->result;
if (curr->type != result) {
curr->type = result;
}
// Handle mismatched numbers of arguments. In clang, if a function is declared one way
// but called in another, it inserts bitcasts to make things work. Those end up
// working since it is "ok" to drop or add parameters in native platforms, even
// though it's undefined behavior. We warn about it here, but tolerate it, if there is
// a simple solution.
if (curr->operands.size() < calledFunc->params.size()) {
notifyAboutWrongOperands("warning: asm2wasm adding operands", calledFunc);
while (curr->operands.size() < calledFunc->params.size()) {
// Add params as necessary, with zeros.
curr->operands.push_back(
LiteralUtils::makeZero(calledFunc->params[curr->operands.size()], *getModule())
);
}
}
if (curr->operands.size() > calledFunc->params.size()) {
notifyAboutWrongOperands("warning: asm2wasm dropping operands", calledFunc);
curr->operands.resize(calledFunc->params.size());
}
// If the types are wrong, validation will fail later anyhow, but add a warning here,
// it may help people.
for (Index i = 0; i < curr->operands.size(); i++) {
auto sent = curr->operands[i]->type;
auto expected = calledFunc->params[i];
if (sent != unreachable && sent != expected) {
notifyAboutWrongOperands("error: asm2wasm seeing an invalid argument type at index " + std::to_string(i) + " (this will not validate)", calledFunc);
}
}
}
void visitCallImport(CallImport* curr) {
// fill out call_import - add extra params as needed, etc. asm tolerates ffi overloading, wasm does not
auto iter = parent->importedFunctionTypes.find(curr->target);
if (iter == parent->importedFunctionTypes.end()) return; // one of our fake imports for callIndirect fixups
auto type = iter->second.get();
for (size_t i = 0; i < type->params.size(); i++) {
if (i >= curr->operands.size()) {
// add a new param
auto val = parent->allocator.alloc<Const>();
val->type = val->value.type = type->params[i];
curr->operands.push_back(val);
} else if (curr->operands[i]->type != type->params[i]) {
// if the param is used, then we have overloading here and the combined type must be f64;
// if this is an unreachable param, then it doesn't matter.
assert(type->params[i] == f64 || curr->operands[i]->type == unreachable);
// overloaded, upgrade to f64
switch (curr->operands[i]->type) {
case i32: curr->operands[i] = parent->builder.makeUnary(ConvertSInt32ToFloat64, curr->operands[i]); break;
case f32: curr->operands[i] = parent->builder.makeUnary(PromoteFloat32, curr->operands[i]); break;
default: {} // f64, unreachable, etc., are all good
}
}
}
Module* wasm = getModule();
auto importResult = wasm->getFunctionType(wasm->getImport(curr->target)->functionType)->result;
if (curr->type != importResult) {
auto old = curr->type;
curr->type = importResult;
if (importResult == f64) {
// we use a JS f64 value which is the most general, and convert to it
switch (old) {
case i32: {
Unary* trunc = parent->builder.makeUnary(TruncSFloat64ToInt32, curr);
replaceCurrent(makeTrappingUnary(trunc, parent->trappingFunctions));
break;
}
case f32: {
replaceCurrent(parent->builder.makeUnary(DemoteFloat64, curr));
break;
}
case none: {
// this function returns a value, but we are not using it, so it must be dropped.
// autodrop will do that for us.
break;
}
default: WASM_UNREACHABLE();
}
} else {
assert(old == none);
// we don't want a return value here, but the import does provide one
// autodrop will do that for us.
}
}
}
void visitCallIndirect(CallIndirect* curr) {
// we already call into target = something + offset, where offset is a callImport with the name of the table. replace that with the table offset
// note that for an ftCall or mftCall, we have no asm.js mask, so have nothing to do here
auto* target = curr->target;
// might be a block with a fallthrough
if (auto* block = target->dynCast<Block>()) {
target = block->list.back();
}
// the something might have been optimized out, leaving only the call
if (auto* call = target->dynCast<CallImport>()) {
auto tableName = call->target;
if (parent->functionTableStarts.find(tableName) == parent->functionTableStarts.end()) return;
curr->target = parent->builder.makeConst(Literal((int32_t)parent->functionTableStarts[tableName]));
return;
}
auto* add = target->dynCast<Binary>();
if (!add) return;
if (add->right->is<CallImport>()) {
auto* offset = add->right->cast<CallImport>();
auto tableName = offset->target;
if (parent->functionTableStarts.find(tableName) == parent->functionTableStarts.end()) return;
add->right = parent->builder.makeConst(Literal((int32_t)parent->functionTableStarts[tableName]));
} else {
auto* offset = add->left->dynCast<CallImport>();
if (!offset) return;
auto tableName = offset->target;
if (parent->functionTableStarts.find(tableName) == parent->functionTableStarts.end()) return;
add->left = parent->builder.makeConst(Literal((int32_t)parent->functionTableStarts[tableName]));
}
}
void visitFunction(Function* curr) {
// changing call types requires we percolate types, and drop stuff.
// we do this in this pass so that we don't look broken between passes
AutoDrop().walkFunctionInModule(curr, getModule());
}
};
// apply debug info, reducing intrinsic calls into annotations on the ast nodes
struct ApplyDebugInfo : public WalkerPass<ExpressionStackWalker<ApplyDebugInfo, UnifiedExpressionVisitor<ApplyDebugInfo>>> {
bool isFunctionParallel() override { return true; }
Pass* create() override { return new ApplyDebugInfo(); }
ApplyDebugInfo() {
name = "apply-debug-info";
}
CallImport* lastDebugInfo = nullptr;
void visitExpression(Expression* curr) {
if (auto* call = checkDebugInfo(curr)) {
lastDebugInfo = call;
replaceCurrent(getModule()->allocator.alloc<Nop>());
} else {
if (lastDebugInfo) {
auto& debugLocations = getFunction()->debugLocations;
uint32_t fileIndex = lastDebugInfo->operands[0]->cast<Const>()->value.geti32();
assert(getModule()->debugInfoFileNames.size() > fileIndex);
uint32_t lineNumber = lastDebugInfo->operands[1]->cast<Const>()->value.geti32();
// look up the stack, apply to the root expression
Index i = expressionStack.size() - 1;
while (1) {
auto* exp = expressionStack[i];
bool parentIsStructure = i > 0 && (expressionStack[i - 1]->is<Block>() ||
expressionStack[i - 1]->is<Loop>() ||
expressionStack[i - 1]->is<If>());
if (i == 0 || parentIsStructure || exp->type == none || exp->type == unreachable) {
if (debugLocations.count(exp) > 0) {
// already present, so look back up
i++;
while (i < expressionStack.size()) {
exp = expressionStack[i];
if (debugLocations.count(exp) == 0) {
debugLocations[exp] = { fileIndex, lineNumber, 0 };
break;
}
i++;
}
} else {
debugLocations[exp] = { fileIndex, lineNumber, 0 };
}
break;
}
i--;
}
lastDebugInfo = nullptr;
}
}
}
};
PassRunner passRunner(&wasm, passOptions);
passRunner.setFeatures(passOptions.features);
if (debug) {
passRunner.setDebug(true);
passRunner.setValidateGlobally(false);
}
// finalizeCalls also does autoDrop, which is crucial for the non-optimizing case,
// so that the output of the first pass is valid
passRunner.add<FinalizeCalls>(this);
if (legalizeJavaScriptFFI) {
passRunner.add("legalize-js-interface");
}
if (runOptimizationPasses) {
// autodrop can add some garbage
passRunner.add("vacuum");
passRunner.add("remove-unused-brs");
passRunner.add("merge-blocks");
passRunner.add("optimize-instructions");
passRunner.add("post-emscripten");
} else {
if (preprocessor.debugInfo) {
// we would have run this before if optimizing, do it now otherwise. must
// precede ApplyDebugInfo
passRunner.add<AdjustDebugInfo>();
}
}
if (preprocessor.debugInfo) {
passRunner.add<ApplyDebugInfo>();
passRunner.add("vacuum"); // FIXME maybe just remove the nops that were debuginfo nodes, if not optimizing?
}
if (runOptimizationPasses) {
// do final global optimizations after all function work is done
// (e.g. duplicate funcs may appear thanks to that work)
passRunner.addDefaultGlobalOptimizationPostPasses();
}
passRunner.run();
// remove the debug info intrinsic
if (preprocessor.debugInfo) {
wasm.removeImport(EMSCRIPTEN_DEBUGINFO);
}
if (udivmoddi4.is() && getTempRet0.is()) {
// generate a wasm-optimized __udivmoddi4 method, which we can do much more efficiently in wasm
// we can only do this if we know getTempRet0 as well since we use it to figure out which minified global is tempRet0
// (getTempRet0 might be an import, if this is a shared module, so we can't optimize that case)
Name tempRet0;
{
Expression* curr = wasm.getFunction(getTempRet0)->body;
if (curr->is<Block>()) curr = curr->cast<Block>()->list.back();
if (curr->is<Return>()) curr = curr->cast<Return>()->value;
auto* get = curr->cast<GetGlobal>();
tempRet0 = get->name;
}
// udivmoddi4 receives xl, xh, yl, yl, r, and
// if r then *r = x % y
// returns x / y
auto* func = wasm.getFunction(udivmoddi4);
assert(!func->type.is());
Builder::clearLocals(func);
Index xl = Builder::addParam(func, "xl", i32),
xh = Builder::addParam(func, "xh", i32),
yl = Builder::addParam(func, "yl", i32),
yh = Builder::addParam(func, "yh", i32),
r = Builder::addParam(func, "r", i32),
x64 = Builder::addVar(func, "x64", i64),
y64 = Builder::addVar(func, "y64", i64);
auto* body = allocator.alloc<Block>();
body->list.push_back(builder.makeSetLocal(x64, I64Utilities::recreateI64(builder, xl, xh)));
body->list.push_back(builder.makeSetLocal(y64, I64Utilities::recreateI64(builder, yl, yh)));
body->list.push_back(
builder.makeIf(
builder.makeGetLocal(r, i32),
builder.makeStore(
8, 0, 8,
builder.makeGetLocal(r, i32),
builder.makeBinary(
RemUInt64,
builder.makeGetLocal(x64, i64),
builder.makeGetLocal(y64, i64)
),
i64
)
)
);
body->list.push_back(
builder.makeSetLocal(
x64,
builder.makeBinary(
DivUInt64,
builder.makeGetLocal(x64, i64),
builder.makeGetLocal(y64, i64)
)
)
);
body->list.push_back(
builder.makeSetGlobal(
tempRet0,
I64Utilities::getI64High(builder, x64)
)
);
body->list.push_back(I64Utilities::getI64Low(builder, x64));
body->finalize();
func->body = body;
}
}
Function* Asm2WasmBuilder::processFunction(Ref ast) {
auto name = ast[1]->getIString();
if (debug) {
std::cout << "asm2wasming func: " << ast[1]->getIString().str << '\n';
}
auto function = new Function;
function->name = name;
Ref params = ast[2];
Ref body = ast[3];
UniqueNameMapper nameMapper;
// given an asm.js label, returns the wasm label for breaks or continues
auto getBreakLabelName = [](IString label) {
return Name(std::string("label$break$") + label.str);
};
auto getContinueLabelName = [](IString label) {
return Name(std::string("label$continue$") + label.str);
};
IStringSet functionVariables; // params or vars
IString parentLabel; // set in LABEL, then read in WHILE/DO/SWITCH
std::vector<IString> breakStack; // where a break will go
std::vector<IString> continueStack; // where a continue will go
AsmData asmData; // need to know var and param types, for asm type detection
for (unsigned i = 0; i < params->size(); i++) {
Ref curr = body[i];
auto* assign = curr->asAssignName();
IString name = assign->target();
AsmType asmType = detectType(assign->value(), nullptr, false, Math_fround, wasmOnly);
Builder::addParam(function, name, asmToWasmType(asmType));
functionVariables.insert(name);
asmData.addParam(name, asmType);
}
unsigned start = params->size();
while (start < body->size() && body[start]->isArray(VAR)) {
Ref curr = body[start];
for (unsigned j = 0; j < curr[1]->size(); j++) {
Ref pair = curr[1][j];
IString name = pair[0]->getIString();
AsmType asmType = detectType(pair[1], nullptr, true, Math_fround, wasmOnly);
Builder::addVar(function, name, asmToWasmType(asmType));
functionVariables.insert(name);
asmData.addVar(name, asmType);
}
start++;
}
bool addedI32Temp = false;
auto ensureI32Temp = [&]() {
if (addedI32Temp) return;
addedI32Temp = true;
Builder::addVar(function, I32_TEMP, i32);
functionVariables.insert(I32_TEMP);
asmData.addVar(I32_TEMP, ASM_INT);
};
bool seenReturn = false; // function->result is updated if we see a return
// processors
std::function<Expression* (Ref, unsigned)> processStatements;
std::function<Expression* (Ref, unsigned)> processUnshifted;
std::function<Expression* (Ref)> process = [&](Ref ast) -> Expression* {
AstStackHelper astStackHelper(ast); // TODO: only create one when we need it?
if (ast->isString()) {
IString name = ast->getIString();
if (functionVariables.has(name)) {
// var in scope
auto ret = allocator.alloc<GetLocal>();
ret->index = function->getLocalIndex(name);
ret->type = asmToWasmType(asmData.getType(name));
return ret;
}
if (name == DEBUGGER) {
CallImport *call = allocator.alloc<CallImport>();
call->target = DEBUGGER;
call->type = none;
static bool addedImport = false;
if (!addedImport) {
addedImport = true;
auto import = new Import; // debugger = asm2wasm.debugger;
import->name = DEBUGGER;
import->module = ASM2WASM;
import->base = DEBUGGER;
import->functionType = ensureFunctionType("v", &wasm)->name;
import->kind = ExternalKind::Function;
wasm.addImport(import);
}
return call;
}
// global var
assert(mappedGlobals.find(name) != mappedGlobals.end() ? true : (std::cerr << name.str << '\n', false));
MappedGlobal& global = mappedGlobals[name];
return builder.makeGetGlobal(name, global.type);
}
if (ast->isNumber()) {
auto ret = allocator.alloc<Const>();
double num = ast->getNumber();
if (isSInteger32(num)) {
ret->value = Literal(int32_t(toSInteger32(num)));
} else if (isUInteger32(num)) {
ret->value = Literal(uint32_t(toUInteger32(num)));
} else {
ret->value = Literal(num);
}
ret->type = ret->value.type;
return ret;
}
if (ast->isAssignName()) {
auto* assign = ast->asAssignName();
IString name = assign->target();
if (functionVariables.has(name)) {
auto ret = allocator.alloc<SetLocal>();
ret->index = function->getLocalIndex(assign->target());
ret->value = process(assign->value());
ret->setTee(false);
ret->finalize();
return ret;
}
// global var
if (mappedGlobals.find(name) == mappedGlobals.end()) {
Fatal() << "error: access of a non-existent global var " << name.str;
}
auto* ret = builder.makeSetGlobal(name, process(assign->value()));
// set_global does not return; if our value is trivially not used, don't emit a load (if nontrivially not used, opts get it later)
auto parent = astStackHelper.getParent();
if (!parent || parent->isArray(BLOCK) || parent->isArray(IF)) return ret;
return builder.makeSequence(ret, builder.makeGetGlobal(name, ret->value->type));
}
if (ast->isAssign()) {
auto* assign = ast->asAssign();
assert(assign->target()->isArray(SUB));
Ref target = assign->target();
assert(target[1]->isString());
IString heap = target[1]->getIString();
assert(views.find(heap) != views.end());
View& view = views[heap];
auto ret = allocator.alloc<Store>();
ret->isAtomic = false;
ret->bytes = view.bytes;
ret->offset = 0;
ret->align = view.bytes;
ret->ptr = processUnshifted(target[2], view.bytes);
ret->value = process(assign->value());
ret->valueType = asmToWasmType(view.type);
ret->finalize();
if (ret->valueType != ret->value->type) {
// in asm.js we have some implicit coercions that we must do explicitly here
if (ret->valueType == f32 && ret->value->type == f64) {
auto conv = allocator.alloc<Unary>();
conv->op = DemoteFloat64;
conv->value = ret->value;
conv->type = Type::f32;
ret->value = conv;
} else if (ret->valueType == f64 && ret->value->type == f32) {
ret->value = ensureDouble(ret->value);
} else {
abort_on("bad sub[] types", ast);
}
}
return ret;
}
IString what = ast[0]->getIString();
if (what == BINARY) {
if ((ast[1] == OR || ast[1] == TRSHIFT) && ast[3]->isNumber() && ast[3]->getNumber() == 0) {
auto ret = process(ast[2]); // just look through the ()|0 or ()>>>0 coercion
fixCallType(ret, i32);
return ret;
}
auto ret = allocator.alloc<Binary>();
ret->left = process(ast[2]);
ret->right = process(ast[3]);
ret->op = parseAsmBinaryOp(ast[1]->getIString(), ast[2], ast[3], ret->left, ret->right);
ret->finalize();
if (ret->op == BinaryOp::RemSInt32 && isFloatType(ret->type)) {
// WebAssembly does not have floating-point remainder, we have to emit a call to a special import of ours
CallImport *call = allocator.alloc<CallImport>();
call->target = F64_REM;
call->operands.push_back(ensureDouble(ret->left));
call->operands.push_back(ensureDouble(ret->right));
call->type = f64;
static bool addedImport = false;
if (!addedImport) {
addedImport = true;
auto import = new Import; // f64-rem = asm2wasm.f64-rem;
import->name = F64_REM;
import->module = ASM2WASM;
import->base = F64_REM;
import->functionType = ensureFunctionType("ddd", &wasm)->name;
import->kind = ExternalKind::Function;
wasm.addImport(import);
}
return call;
}
return makeTrappingBinary(ret, trappingFunctions);
} else if (what == SUB) {
Ref target = ast[1];
assert(target->isString());
IString heap = target->getIString();
assert(views.find(heap) != views.end());
View& view = views[heap];
auto ret = allocator.alloc<Load>();
ret->isAtomic = false;
ret->bytes = view.bytes;
ret->signed_ = view.signed_;
ret->offset = 0;
ret->align = view.bytes;
ret->ptr = processUnshifted(ast[2], view.bytes);
ret->type = getType(view.bytes, !view.integer);
return ret;
} else if (what == UNARY_PREFIX) {
if (ast[1] == PLUS) {
Literal literal = checkLiteral(ast);
if (literal.type != none) {
return builder.makeConst(literal);
}
auto ret = process(ast[2]); // we are a +() coercion
if (ret->type == i32) {
auto conv = allocator.alloc<Unary>();
conv->op = isUnsignedCoercion(ast[2]) ? ConvertUInt32ToFloat64 : ConvertSInt32ToFloat64;
conv->value = ret;
conv->type = Type::f64;
return conv;
}
if (ret->type == f32) {
return ensureDouble(ret);
}
fixCallType(ret, f64);
return ret;
} else if (ast[1] == MINUS) {
if (ast[2]->isNumber() || (ast[2]->isArray(UNARY_PREFIX) && ast[2][1] == PLUS && ast[2][2]->isNumber())) {
auto ret = allocator.alloc<Const>();
ret->value = getLiteral(ast);
ret->type = ret->value.type;
return ret;
}
AsmType asmType = detectAsmType(ast[2], &asmData);
if (asmType == ASM_INT) {
// wasm has no unary negation for int, so do 0-
auto ret = allocator.alloc<Binary>();
ret->op = SubInt32;
ret->left = builder.makeConst(Literal((int32_t)0));
ret->right = process(ast[2]);
ret->type = Type::i32;
return ret;
}
auto ret = allocator.alloc<Unary>();
ret->value = process(ast[2]);
if (asmType == ASM_DOUBLE) {
ret->op = NegFloat64;
ret->type = Type::f64;
} else if (asmType == ASM_FLOAT) {
ret->op = NegFloat32;
ret->type = Type::f32;
} else {
WASM_UNREACHABLE();
}
return ret;
} else if (ast[1] == B_NOT) {
// ~, might be ~~ as a coercion or just a not
if (ast[2]->isArray(UNARY_PREFIX) && ast[2][1] == B_NOT) {
// if we have an unsigned coercion on us, it is an unsigned op
Expression* expr = process(ast[2][2]);
bool isSigned = !isParentUnsignedCoercion(astStackHelper.getParent());
bool isF64 = expr->type == f64;
UnaryOp op;
if (isSigned && isF64) {
op = UnaryOp::TruncSFloat64ToInt32;
} else if (isSigned && !isF64) {
op = UnaryOp::TruncSFloat32ToInt32;
} else if (!isSigned && isF64) {
op = UnaryOp::TruncUFloat64ToInt32;
} else { // !isSigned && !isF64
op = UnaryOp::TruncUFloat32ToInt32;
}
return makeTrappingUnary(builder.makeUnary(op, expr), trappingFunctions);
}
// no bitwise unary not, so do xor with -1
auto ret = allocator.alloc<Binary>();
ret->op = XorInt32;
ret->left = process(ast[2]);
ret->right = builder.makeConst(Literal(int32_t(-1)));
ret->type = Type::i32;
return ret;
} else if (ast[1] == L_NOT) {
auto ret = allocator.alloc<Unary>();
ret->op = EqZInt32;
ret->value = process(ast[2]);
ret->type = i32;
return ret;
}
abort_on("bad unary", ast);
} else if (what == IF) {
auto* condition = process(ast[1]);
auto* ifTrue = process(ast[2]);
return builder.makeIf(truncateToInt32(condition), ifTrue, !!ast[3] ? process(ast[3]) : nullptr);
} else if (what == CALL) {
if (ast[1]->isString()) {
IString name = ast[1]->getIString();
if (name == Math_imul) {
assert(ast[2]->size() == 2);
auto ret = allocator.alloc<Binary>();
ret->op = MulInt32;
ret->left = process(ast[2][0]);
ret->right = process(ast[2][1]);
ret->type = Type::i32;
return ret;
}
if (name == Math_clz32 || name == llvm_cttz_i32) {
assert(ast[2]->size() == 1);
auto ret = allocator.alloc<Unary>();
ret->op = name == Math_clz32 ? ClzInt32 : CtzInt32;
ret->value = process(ast[2][0]);
ret->type = Type::i32;
return ret;
}
if (name == Math_fround) {
assert(ast[2]->size() == 1);
Literal lit = checkLiteral(ast[2][0], false /* raw is float */);
if (lit.type == f64) {
return builder.makeConst(Literal((float)lit.getf64()));
}
auto ret = allocator.alloc<Unary>();
ret->value = process(ast[2][0]);
if (ret->value->type == f64) {
ret->op = DemoteFloat64;
} else if (ret->value->type == i32) {
if (isUnsignedCoercion(ast[2][0])) {
ret->op = ConvertUInt32ToFloat32;
} else {
ret->op = ConvertSInt32ToFloat32;
}
} else if (ret->value->type == f32) {
return ret->value;
} else if (ret->value->type == none) { // call, etc.
ret->value->type = f32;
return ret->value;
} else {
abort_on("confusing fround target", ast[2][0]);
}
ret->type = f32;
return ret;
}
if (name == Math_abs) {
// overloaded on type: i32, f32 or f64
Expression* value = process(ast[2][0]);
if (value->type == i32) {
// No wasm support, so use a temp local
ensureI32Temp();
auto set = allocator.alloc<SetLocal>();
set->index = function->getLocalIndex(I32_TEMP);
set->value = value;
set->setTee(false);
set->finalize();
auto get = [&]() {
auto ret = allocator.alloc<GetLocal>();
ret->index = function->getLocalIndex(I32_TEMP);
ret->type = i32;
return ret;
};
auto isNegative = allocator.alloc<Binary>();
isNegative->op = LtSInt32;
isNegative->left = get();
isNegative->right = builder.makeConst(Literal(0));
isNegative->finalize();
auto block = allocator.alloc<Block>();
block->list.push_back(set);
auto flip = allocator.alloc<Binary>();
flip->op = SubInt32;
flip->left = builder.makeConst(Literal(0));
flip->right = get();
flip->type = i32;
auto select = allocator.alloc<Select>();
select->ifTrue = flip;
select->ifFalse = get();
select->condition = isNegative;
select->type = i32;
block->list.push_back(select);
block->finalize();
return block;
} else if (value->type == f32 || value->type == f64) {
auto ret = allocator.alloc<Unary>();
ret->op = value->type == f32 ? AbsFloat32 : AbsFloat64;
ret->value = value;
ret->type = value->type;
return ret;
} else {
WASM_UNREACHABLE();
}
}
if (name == Math_floor || name == Math_sqrt || name == Math_ceil) {
// overloaded on type: f32 or f64
Expression* value = process(ast[2][0]);
auto ret = allocator.alloc<Unary>();
ret->value = value;
if (value->type == f32) {
ret->op = name == Math_floor ? FloorFloat32 : name == Math_ceil ? CeilFloat32 : SqrtFloat32;
ret->type = value->type;
} else if (value->type == f64) {
ret->op = name == Math_floor ? FloorFloat64 : name == Math_ceil ? CeilFloat64 : SqrtFloat64;
ret->type = value->type;
} else {
Fatal() << "floor/sqrt/ceil only work on float/double in asm.js and wasm";
}
return ret;
}
if (name == Math_max || name == Math_min) {
// overloaded on type: f32 or f64
assert(ast[2]->size() == 2);
auto ret = allocator.alloc<Binary>();
ret->left = process(ast[2][0]);
ret->right = process(ast[2][1]);
if (ret->left->type == f32) {
ret->op = name == Math_max ? MaxFloat32 : MinFloat32;
} else if (ret->left->type == f64) {
ret->op = name == Math_max ? MaxFloat64 : MinFloat64;
} else {
Fatal() << "min/max only work on float/double in asm.js and wasm";
}
ret->type = ret->left->type;
return ret;
}
if (name == Atomics_load ||
name == Atomics_store ||
name == Atomics_exchange ||
name == Atomics_compareExchange ||
name == Atomics_add ||
name == Atomics_sub ||
name == Atomics_and ||
name == Atomics_or ||
name == Atomics_xor) {
// atomic operation
Ref target = ast[2][0];
assert(target->isString());
IString heap = target->getIString();
assert(views.find(heap) != views.end());
View& view = views[heap];
wasm.memory.shared = true;
if (name == Atomics_load) {
Expression* ret = builder.makeAtomicLoad(view.bytes, 0, processUnshifted(ast[2][1], view.bytes), asmToWasmType(view.type));
if (view.signed_) {
// atomic loads are unsigned; add a signing
ret = Bits::makeSignExt(ret, view.bytes, wasm);
}
return ret;
} else if (name == Atomics_store) {
// asm.js stores return the value, wasm does not
auto type = asmToWasmType(view.type);
auto temp = Builder::addVar(function, type);
return builder.makeSequence(
builder.makeAtomicStore(view.bytes, 0, processUnshifted(ast[2][1], view.bytes),
builder.makeTeeLocal(temp, process(ast[2][2])),
type),
builder.makeGetLocal(temp, type)
);
} else if (name == Atomics_exchange) {
return builder.makeAtomicRMW(AtomicRMWOp::Xchg, view.bytes, 0, processUnshifted(ast[2][1], view.bytes), process(ast[2][2]), asmToWasmType(view.type));
} else if (name == Atomics_compareExchange) {
return builder.makeAtomicCmpxchg(view.bytes, 0, processUnshifted(ast[2][1], view.bytes), process(ast[2][2]), process(ast[2][3]), asmToWasmType(view.type));
} else if (name == Atomics_add) {
return builder.makeAtomicRMW(AtomicRMWOp::Add, view.bytes, 0, processUnshifted(ast[2][1], view.bytes), process(ast[2][2]), asmToWasmType(view.type));
} else if (name == Atomics_sub) {
return builder.makeAtomicRMW(AtomicRMWOp::Sub, view.bytes, 0, processUnshifted(ast[2][1], view.bytes), process(ast[2][2]), asmToWasmType(view.type));
} else if (name == Atomics_and) {
return builder.makeAtomicRMW(AtomicRMWOp::And, view.bytes, 0, processUnshifted(ast[2][1], view.bytes), process(ast[2][2]), asmToWasmType(view.type));
} else if (name == Atomics_or) {
return builder.makeAtomicRMW(AtomicRMWOp::Or, view.bytes, 0, processUnshifted(ast[2][1], view.bytes), process(ast[2][2]), asmToWasmType(view.type));
} else if (name == Atomics_xor) {
return builder.makeAtomicRMW(AtomicRMWOp::Xor, view.bytes, 0, processUnshifted(ast[2][1], view.bytes), process(ast[2][2]), asmToWasmType(view.type));
}
WASM_UNREACHABLE();
}
bool tableCall = false;
if (wasmOnly) {
auto num = ast[2]->size();
switch (name.str[0]) {
case 'l': {
auto align = num == 2 ? ast[2][1]->getInteger() : 0;
if (name == LOAD1) return builder.makeLoad(1, true, 0, 1, process(ast[2][0]), i32);
if (name == LOAD2) return builder.makeLoad(2, true, 0, indexOr(align, 2), process(ast[2][0]), i32);
if (name == LOAD4) return builder.makeLoad(4, true, 0, indexOr(align, 4), process(ast[2][0]), i32);
if (name == LOAD8) return builder.makeLoad(8, true, 0, indexOr(align, 8), process(ast[2][0]), i64);
if (name == LOADF) return builder.makeLoad(4, true, 0, indexOr(align, 4), process(ast[2][0]), f32);
if (name == LOADD) return builder.makeLoad(8, true, 0, indexOr(align, 8), process(ast[2][0]), f64);
break;
}
case 's': {
auto align = num == 3 ? ast[2][2]->getInteger() : 0;
if (name == STORE1) return builder.makeStore(1, 0, 1, process(ast[2][0]), process(ast[2][1]), i32);
if (name == STORE2) return builder.makeStore(2, 0, indexOr(align, 2), process(ast[2][0]), process(ast[2][1]), i32);
if (name == STORE4) return builder.makeStore(4, 0, indexOr(align, 4), process(ast[2][0]), process(ast[2][1]), i32);
if (name == STORE8) return builder.makeStore(8, 0, indexOr(align, 8), process(ast[2][0]), process(ast[2][1]), i64);
if (name == STOREF) {
auto* value = process(ast[2][1]);
if (value->type == f64) {
// asm.js allows storing a double to HEAPF32, we must cast here
value = builder.makeUnary(DemoteFloat64, value);
}
return builder.makeStore(4, 0, indexOr(align, 4), process(ast[2][0]), value, f32);
}
if (name == STORED) return builder.makeStore(8, 0, indexOr(align, 8), process(ast[2][0]), process(ast[2][1]), f64);
break;
}
case 'i': {
if (num == 1) {
auto* value = process(ast[2][0]);
if (name == I64) {
// no-op "coercion" / "cast", although we also tolerate i64(0) for constants that fit in i32
if (value->type == i32) {
return builder.makeConst(Literal(int64_t(value->cast<Const>()->value.geti32())));
} else {
fixCallType(value, i64);
return value;
}
}
if (name == I32_CTTZ) return builder.makeUnary(UnaryOp::CtzInt32, value);
if (name == I32_CTPOP) return builder.makeUnary(UnaryOp::PopcntInt32, value);
if (name == I32_BC2F) return builder.makeUnary(UnaryOp::ReinterpretInt32, value);
if (name == I32_BC2I) return builder.makeUnary(UnaryOp::ReinterpretFloat32, value);
if (name == I64_TRUNC) return builder.makeUnary(UnaryOp::WrapInt64, value);
if (name == I64_SEXT) return builder.makeUnary(UnaryOp::ExtendSInt32, value);
if (name == I64_ZEXT) return builder.makeUnary(UnaryOp::ExtendUInt32, value);
if (name == I64_S2F) return builder.makeUnary(UnaryOp::ConvertSInt64ToFloat32, value);
if (name == I64_S2D) return builder.makeUnary(UnaryOp::ConvertSInt64ToFloat64, value);
if (name == I64_U2F) return builder.makeUnary(UnaryOp::ConvertUInt64ToFloat32, value);
if (name == I64_U2D) return builder.makeUnary(UnaryOp::ConvertUInt64ToFloat64, value);
if (name == I64_F2S) {
Unary* conv = builder.makeUnary(UnaryOp::TruncSFloat32ToInt64, value);
return makeTrappingUnary(conv, trappingFunctions);
}
if (name == I64_D2S) {
Unary* conv = builder.makeUnary(UnaryOp::TruncSFloat64ToInt64, value);
return makeTrappingUnary(conv, trappingFunctions);
}
if (name == I64_F2U) {
Unary* conv = builder.makeUnary(UnaryOp::TruncUFloat32ToInt64, value);
return makeTrappingUnary(conv, trappingFunctions);
}
if (name == I64_D2U) {
Unary* conv = builder.makeUnary(UnaryOp::TruncUFloat64ToInt64, value);
return makeTrappingUnary(conv, trappingFunctions);
}
if (name == I64_BC2D) return builder.makeUnary(UnaryOp::ReinterpretInt64, value);
if (name == I64_BC2I) return builder.makeUnary(UnaryOp::ReinterpretFloat64, value);
if (name == I64_CTTZ) return builder.makeUnary(UnaryOp::CtzInt64, value);
if (name == I64_CTLZ) return builder.makeUnary(UnaryOp::ClzInt64, value);
if (name == I64_CTPOP) return builder.makeUnary(UnaryOp::PopcntInt64, value);
if (name == I64_ATOMICS_LOAD) return builder.makeAtomicLoad(8, 0, value, i64);
} else if (num == 2) { // 2 params,binary
if (name == I64_CONST) return builder.makeConst(getLiteral(ast));
auto* left = process(ast[2][0]);
auto* right = process(ast[2][1]);
// maths
if (name == I64_ADD) return builder.makeBinary(BinaryOp::AddInt64, left, right);
if (name == I64_SUB) return builder.makeBinary(BinaryOp::SubInt64, left, right);
if (name == I64_MUL) return builder.makeBinary(BinaryOp::MulInt64, left, right);
if (name == I64_UDIV) {
Binary* div = builder.makeBinary(BinaryOp::DivUInt64, left, right);
return makeTrappingBinary(div, trappingFunctions);
}
if (name == I64_SDIV) {
Binary* div = builder.makeBinary(BinaryOp::DivSInt64, left, right);
return makeTrappingBinary(div, trappingFunctions);
}
if (name == I64_UREM) {
Binary* rem = builder.makeBinary(BinaryOp::RemUInt64, left, right);
return makeTrappingBinary(rem, trappingFunctions);
}
if (name == I64_SREM) {
Binary* rem = builder.makeBinary(BinaryOp::RemSInt64, left, right);
return makeTrappingBinary(rem, trappingFunctions);
}
if (name == I64_AND) return builder.makeBinary(BinaryOp::AndInt64, left, right);
if (name == I64_OR) return builder.makeBinary(BinaryOp::OrInt64, left, right);
if (name == I64_XOR) return builder.makeBinary(BinaryOp::XorInt64, left, right);
if (name == I64_SHL) return builder.makeBinary(BinaryOp::ShlInt64, left, right);
if (name == I64_ASHR) return builder.makeBinary(BinaryOp::ShrSInt64, left, right);
if (name == I64_LSHR) return builder.makeBinary(BinaryOp::ShrUInt64, left, right);
// comps
if (name == I64_EQ) return builder.makeBinary(BinaryOp::EqInt64, left, right);
if (name == I64_NE) return builder.makeBinary(BinaryOp::NeInt64, left, right);
if (name == I64_ULE) return builder.makeBinary(BinaryOp::LeUInt64, left, right);
if (name == I64_SLE) return builder.makeBinary(BinaryOp::LeSInt64, left, right);
if (name == I64_UGE) return builder.makeBinary(BinaryOp::GeUInt64, left, right);
if (name == I64_SGE) return builder.makeBinary(BinaryOp::GeSInt64, left, right);
if (name == I64_ULT) return builder.makeBinary(BinaryOp::LtUInt64, left, right);
if (name == I64_SLT) return builder.makeBinary(BinaryOp::LtSInt64, left, right);
if (name == I64_UGT) return builder.makeBinary(BinaryOp::GtUInt64, left, right);
if (name == I64_SGT) return builder.makeBinary(BinaryOp::GtSInt64, left, right);
// atomics
if (name == I64_ATOMICS_STORE) {
wasm.memory.shared = true;
return builder.makeAtomicStore(8, 0, left, right, i64);
}
if (name == I64_ATOMICS_ADD) {
wasm.memory.shared = true;
return builder.makeAtomicRMW(AtomicRMWOp::Add, 8, 0, left, right, i64);
}
if (name == I64_ATOMICS_SUB) {
wasm.memory.shared = true;
return builder.makeAtomicRMW(AtomicRMWOp::Sub, 8, 0, left, right, i64);
}
if (name == I64_ATOMICS_AND) {
wasm.memory.shared = true;
return builder.makeAtomicRMW(AtomicRMWOp::And, 8, 0, left, right, i64);
}
if (name == I64_ATOMICS_OR) {
wasm.memory.shared = true;
return builder.makeAtomicRMW(AtomicRMWOp::Or, 8, 0, left, right, i64);
}
if (name == I64_ATOMICS_XOR) {
wasm.memory.shared = true;
return builder.makeAtomicRMW(AtomicRMWOp::Xor, 8, 0, left, right, i64);
}
if (name == I64_ATOMICS_EXCHANGE) {
wasm.memory.shared = true;
return builder.makeAtomicRMW(AtomicRMWOp::Xchg, 8, 0, left, right, i64);
}
} else if (num == 3) {
if (name == I64_ATOMICS_COMPAREEXCHANGE) {
wasm.memory.shared = true;
return builder.makeAtomicCmpxchg(8, 0, process(ast[2][0]), process(ast[2][1]), process(ast[2][2]), i64);
}
}
break;
}
case 'f': {
if (name == F32_COPYSIGN) return builder.makeBinary(BinaryOp::CopySignFloat32, process(ast[2][0]), process(ast[2][1]));
if (name == F64_COPYSIGN) return builder.makeBinary(BinaryOp::CopySignFloat64, process(ast[2][0]), process(ast[2][1]));
break;
}
default: {}
}
}
// ftCall_* and mftCall_* represent function table calls, either from the outside, or
// from the inside of the module. when compiling to wasm, we can just convert those
// into table calls
if ((name.str[0] == 'f' && strncmp(name.str, FTCALL.str, 7) == 0) ||
(name.str[0] == 'm' && strncmp(name.str, MFTCALL.str, 8) == 0)) {
tableCall = true;
}
Expression* ret;
ExpressionList* operands;
CallImport* callImport = nullptr;
Index firstOperand = 0;
Ref args = ast[2];
if (tableCall) {
auto specific = allocator.alloc<CallIndirect>();
specific->target = process(args[0]);
firstOperand = 1;
operands = &specific->operands;
ret = specific;
} else if (wasm.getImportOrNull(name)) {
callImport = allocator.alloc<CallImport>();
callImport->target = name;
operands = &callImport->operands;
ret = callImport;
} else {
auto specific = allocator.alloc<Call>();
specific->target = name;
operands = &specific->operands;
ret = specific;
}
for (unsigned i = firstOperand; i < args->size(); i++) {
operands->push_back(process(args[i]));
}
if (tableCall) {
auto specific = ret->dynCast<CallIndirect>();
// note that we could also get the type from the suffix of the name, e.g., mftCall_vi
auto* fullType = getFunctionType(astStackHelper.getParent(), specific->operands, &asmData);
specific->fullType = fullType->name;
specific->type = fullType->result;
}
if (callImport) {
// apply the detected type from the parent
// note that this may not be complete, e.g. we may see f(); but f is an
// import which does return a value, and we use that elsewhere. finalizeCalls
// fixes that up. what we do here is wherever a value is used, we set the right
// value, which is enough to ensure that the wasm ast is valid for such uses.
// this is important as we run the optimizer on functions before we get
// to finalizeCalls (which we can only do once we've read all the functions,
// and we optimize in parallel starting earlier).
callImport->type = getResultTypeOfCallUsingParent(astStackHelper.getParent(), &asmData);
noteImportedFunctionCall(ast, callImport->type, callImport);
}
return ret;
}
// function pointers
auto ret = allocator.alloc<CallIndirect>();
Ref target = ast[1];
assert(target[0] == SUB && target[1]->isString() && target[2][0] == BINARY && target[2][1] == AND && target[2][3]->isNumber()); // FUNCTION_TABLE[(expr) & mask]
ret->target = process(target[2]); // TODO: as an optimization, we could look through the mask
Ref args = ast[2];
for (unsigned i = 0; i < args->size(); i++) {
ret->operands.push_back(process(args[i]));
}
auto* fullType = getFunctionType(astStackHelper.getParent(), ret->operands, &asmData);
ret->fullType = fullType->name;
ret->type = fullType->result;
// we don't know the table offset yet. emit target = target + callImport(tableName), which we fix up later when we know how asm function tables are layed out inside the wasm table.
ret->target = builder.makeBinary(BinaryOp::AddInt32, ret->target, builder.makeCallImport(target[1]->getIString(), {}, i32));
return ret;
} else if (what == RETURN) {
Type type = !!ast[1] ? detectWasmType(ast[1], &asmData) : none;
if (seenReturn) {
assert(function->result == type);
} else {
function->result = type;
}
// wasm has no return, so we just break on the topmost block
auto ret = allocator.alloc<Return>();
ret->value = !!ast[1] ? process(ast[1]) : nullptr;
return ret;
} else if (what == BLOCK) {
Name name;
if (parentLabel.is()) {
name = nameMapper.pushLabelName(getBreakLabelName(parentLabel));
parentLabel = IString();
breakStack.push_back(name);
}
auto ret = processStatements(ast[1], 0);
if (name.is()) {
breakStack.pop_back();
nameMapper.popLabelName(name);
Block* block = ret->dynCast<Block>();
if (block && block->name.isNull()) {
block->name = name;
} else {
block = allocator.alloc<Block>();
block->name = name;
block->list.push_back(ret);
block->finalize();
ret = block;
}
}
return ret;
} else if (what == BREAK) {
auto ret = allocator.alloc<Break>();
assert(breakStack.size() > 0);
ret->name = !!ast[1] ? nameMapper.sourceToUnique(getBreakLabelName(ast[1]->getIString())) : breakStack.back();
return ret;
} else if (what == CONTINUE) {
auto ret = allocator.alloc<Break>();
assert(continueStack.size() > 0);
ret->name = !!ast[1] ? nameMapper.sourceToUnique(getContinueLabelName(ast[1]->getIString())) : continueStack.back();
return ret;
} else if (what == WHILE) {
bool forever = ast[1]->isNumber() && ast[1]->getInteger() == 1;
auto ret = allocator.alloc<Loop>();
IString out, in;
if (!parentLabel.isNull()) {
out = getBreakLabelName(parentLabel);
in = getContinueLabelName(parentLabel);
parentLabel = IString();
} else {
out = "while-out";
in = "while-in";
}
out = nameMapper.pushLabelName(out);
in = nameMapper.pushLabelName(in);
ret->name = in;
breakStack.push_back(out);
continueStack.push_back(in);
if (forever) {
ret->body = process(ast[2]);
} else {
Break *breakOut = allocator.alloc<Break>();
breakOut->name = out;
If *condition = allocator.alloc<If>();
condition->condition = builder.makeUnary(EqZInt32, process(ast[1]));
condition->ifTrue = breakOut;
condition->finalize();
auto body = allocator.alloc<Block>();
body->list.push_back(condition);
body->list.push_back(process(ast[2]));
body->finalize();
ret->body = body;
}
// loops do not automatically loop, add a branch back
Block* block = builder.blockifyWithName(ret->body, out);
auto continuer = allocator.alloc<Break>();
continuer->name = ret->name;
block->list.push_back(continuer);
block->finalize();
ret->body = block;
ret->finalize();
continueStack.pop_back();
breakStack.pop_back();
nameMapper.popLabelName(in);
nameMapper.popLabelName(out);
return ret;
} else if (what == DO) {
if (ast[1]->isNumber() && ast[1]->getNumber() == 0) {
// one-time loop, unless there is a continue
IString stop;
if (!parentLabel.isNull()) {
stop = getBreakLabelName(parentLabel);
parentLabel = IString();
} else {
stop = "do-once";
}
stop = nameMapper.pushLabelName(stop);
Name more = nameMapper.pushLabelName("unlikely-continue");
breakStack.push_back(stop);
continueStack.push_back(more);
auto child = process(ast[2]);
continueStack.pop_back();
breakStack.pop_back();
nameMapper.popLabelName(more);
nameMapper.popLabelName(stop);
// if we never continued, we don't need a loop
BranchUtils::BranchSeeker seeker(more);
seeker.walk(child);
if (seeker.found == 0) {
auto block = allocator.alloc<Block>();
block->list.push_back(child);
if (isConcreteType(child->type)) {
block->list.push_back(builder.makeNop()); // ensure a nop at the end, so the block has guaranteed none type and no values fall through
}
block->name = stop;
block->finalize();
return block;
} else {
auto loop = allocator.alloc<Loop>();
loop->body = child;
loop->name = more;
loop->finalize();
return builder.blockifyWithName(loop, stop);
}
}
// general do-while loop
auto loop = allocator.alloc<Loop>();
IString out, in;
if (!parentLabel.isNull()) {
out = getBreakLabelName(parentLabel);
in = getContinueLabelName(parentLabel);
parentLabel = IString();
} else {
out = "do-out";
in = "do-in";
}
out = nameMapper.pushLabelName(out);
in = nameMapper.pushLabelName(in);
loop->name = in;
breakStack.push_back(out);
continueStack.push_back(in);
loop->body = process(ast[2]);
continueStack.pop_back();
breakStack.pop_back();
nameMapper.popLabelName(in);
nameMapper.popLabelName(out);
Break *continuer = allocator.alloc<Break>();
continuer->name = in;
continuer->condition = process(ast[1]);
continuer->finalize();
Block *block = builder.blockifyWithName(loop->body, out, continuer);
loop->body = block;
loop->finalize();
return loop;
} else if (what == FOR) {
Ref finit = ast[1],
fcond = ast[2],
finc = ast[3],
fbody = ast[4];
auto ret = allocator.alloc<Loop>();
IString out, in;
if (!parentLabel.isNull()) {
out = getBreakLabelName(parentLabel);
in = getContinueLabelName(parentLabel);
parentLabel = IString();
} else {
out = "for-out";
in = "for-in";
}
out = nameMapper.pushLabelName(out);
in = nameMapper.pushLabelName(in);
ret->name = in;
breakStack.push_back(out);
continueStack.push_back(in);
Break *breakOut = allocator.alloc<Break>();
breakOut->name = out;
If *condition = allocator.alloc<If>();
condition->condition = builder.makeUnary(EqZInt32, process(fcond));
condition->ifTrue = breakOut;
condition->finalize();
auto body = allocator.alloc<Block>();
body->list.push_back(condition);
body->list.push_back(process(fbody));
body->list.push_back(process(finc));
body->finalize();
ret->body = body;
// loops do not automatically loop, add a branch back
auto continuer = allocator.alloc<Break>();
continuer->name = ret->name;
Block* block = builder.blockifyWithName(ret->body, out, continuer);
ret->body = block;
ret->finalize();
continueStack.pop_back();
breakStack.pop_back();
nameMapper.popLabelName(in);
nameMapper.popLabelName(out);
Block *outer = allocator.alloc<Block>();
// add an outer block for the init as well
outer->list.push_back(process(finit));
outer->list.push_back(ret);
outer->finalize();
return outer;
} else if (what == LABEL) {
assert(parentLabel.isNull());
parentLabel = ast[1]->getIString();
return process(ast[2]);
} else if (what == CONDITIONAL) {
auto ret = allocator.alloc<If>();
ret->condition = process(ast[1]);
ret->ifTrue = process(ast[2]);
ret->ifFalse = process(ast[3]);
ret->finalize();
return ret;
} else if (what == SEQ) {
// Some (x, y) patterns can be optimized, like bitcasts,
// (HEAP32[tempDoublePtr >> 2] = i, Math_fround(HEAPF32[tempDoublePtr >> 2])); // i32->f32
// (HEAP32[tempDoublePtr >> 2] = i, +HEAPF32[tempDoublePtr >> 2]); // i32->f32, no fround
// (HEAPF32[tempDoublePtr >> 2] = f, HEAP32[tempDoublePtr >> 2] | 0); // f32->i32
if (ast[1]->isAssign()) {
auto* assign = ast[1]->asAssign();
Ref target = assign->target();
if (target->isArray(SUB) && target[1]->isString() && target[2]->isArray(BINARY) && target[2][1] == RSHIFT &&
target[2][2]->isString() && target[2][2] == tempDoublePtr && target[2][3]->isNumber() && target[2][3]->getNumber() == 2) {
// (?[tempDoublePtr >> 2] = ?, ?) so far
auto heap = target[1]->getIString();
if (views.find(heap) != views.end()) {
AsmType writeType = views[heap].type;
AsmType readType = ASM_NONE;
Ref readValue;
if (ast[2]->isArray(BINARY) && ast[2][1] == OR && ast[2][3]->isNumber() && ast[2][3]->getNumber() == 0) {
readType = ASM_INT;
readValue = ast[2][2];
} else if (ast[2]->isArray(UNARY_PREFIX) && ast[2][1] == PLUS) {
readType = ASM_DOUBLE;
readValue = ast[2][2];
} else if (ast[2]->isArray(CALL) && ast[2][1]->isString() && ast[2][1] == Math_fround) {
readType = ASM_FLOAT;
readValue = ast[2][2][0];
}
if (readType != ASM_NONE) {
if (readValue->isArray(SUB) && readValue[1]->isString() && readValue[2]->isArray(BINARY) && readValue[2][1] == RSHIFT &&
readValue[2][2]->isString() && readValue[2][2] == tempDoublePtr && readValue[2][3]->isNumber() && readValue[2][3]->getNumber() == 2) {
// pattern looks right!
Ref writtenValue = assign->value();
if (writeType == ASM_INT && (readType == ASM_FLOAT || readType == ASM_DOUBLE)) {
auto conv = allocator.alloc<Unary>();
conv->op = ReinterpretInt32;
conv->value = process(writtenValue);
conv->type = Type::f32;
if (readType == ASM_DOUBLE) {
return ensureDouble(conv);
}
return conv;
} else if (writeType == ASM_FLOAT && readType == ASM_INT) {
auto conv = allocator.alloc<Unary>();
conv->op = ReinterpretFloat32;
conv->value = process(writtenValue);
if (conv->value->type == f64) {
// this has an implicit f64->f32 in the write to memory
conv->value = builder.makeUnary(DemoteFloat64, conv->value);
}
conv->type = Type::i32;
return conv;
}
}
}
}
}
}
auto ret = allocator.alloc<Block>();
ret->list.push_back(process(ast[1]));
ret->list.push_back(process(ast[2]));
ret->finalize();
return ret;
} else if (what == SWITCH) {
IString name; // for breaking out of the entire switch
if (!parentLabel.isNull()) {
name = getBreakLabelName(parentLabel);
parentLabel = IString();
} else {
name = "switch";
}
name = nameMapper.pushLabelName(name);
breakStack.push_back(name);
auto br = allocator.alloc<Switch>();
br->condition = process(ast[1]);
Ref cases = ast[2];
bool seen = false;
int64_t min = 0; // the lowest index we see; we will offset to it
int64_t max = 0; // the highest, to check if the range is too big
for (unsigned i = 0; i < cases->size(); i++) {
Ref curr = cases[i];
Ref condition = curr[0];
if (!condition->isNull()) {
int64_t index = getLiteral(condition).getInteger();
if (!seen) {
seen = true;
min = index;
max = index;
} else {
if (index < min) min = index;
if (index > max) max = index;
}
}
}
// we can use a switch if it's not too big
auto range = double(max) - double(min); // test using doubles to avoid UB
bool canSwitch = 0 <= range && range < 10240;
auto top = allocator.alloc<Block>();
if (canSwitch) {
// we may need a break for the case where the condition doesn't match
// any of the cases. it should go to the default, if we have one, or
// outside if not
Break* breakWhenNotMatching = nullptr;
if (br->condition->type == i32) {
Binary* offsetor = allocator.alloc<Binary>();
offsetor->op = BinaryOp::SubInt32;
offsetor->left = br->condition;
offsetor->right = builder.makeConst(Literal(int32_t(min)));
offsetor->type = i32;
br->condition = offsetor;
} else {
assert(br->condition->type == i64);
// 64-bit condition. after offsetting it must be in a reasonable range, but the offsetting itself must be 64-bit
Binary* offsetor = allocator.alloc<Binary>();
offsetor->op = BinaryOp::SubInt64;
offsetor->left = br->condition;
offsetor->right = builder.makeConst(Literal(int64_t(min)));
offsetor->type = i64;
// the switch itself can be 32-bit, as the range is in a reasonable range. so after
// offsetting, we need to make sure there are no high bits, then we can just look
// at the lower 32 bits
auto temp = Builder::addVar(function, i64);
auto* block = builder.makeBlock();
block->list.push_back(builder.makeSetLocal(temp, offsetor));
// if high bits, we can break to the default (we'll fill in the name later)
breakWhenNotMatching = builder.makeBreak(Name(), nullptr,
builder.makeUnary(
UnaryOp::WrapInt64,
builder.makeBinary(BinaryOp::ShrUInt64,
builder.makeGetLocal(temp, i64),
builder.makeConst(Literal(int64_t(32)))
)
)
);
block->list.push_back(breakWhenNotMatching);
block->list.push_back(
builder.makeGetLocal(temp, i64)
);
block->finalize();
br->condition = builder.makeUnary(UnaryOp::WrapInt64, block);
}
top->list.push_back(br);
for (unsigned i = 0; i < cases->size(); i++) {
Ref curr = cases[i];
Ref condition = curr[0];
Ref body = curr[1];
auto case_ = processStatements(body, 0);
Name name;
if (condition->isNull()) {
name = br->default_ = nameMapper.pushLabelName("switch-default");
} else {
auto index = getLiteral(condition).getInteger();
assert(index >= min);
index -= min;
assert(index >= 0);
uint64_t index_s = index;
name = nameMapper.pushLabelName("switch-case");
if (br->targets.size() <= index_s) {
br->targets.resize(index_s + 1);
}
br->targets[index_s] = name;
}
auto next = allocator.alloc<Block>();
top->name = name;
next->list.push_back(top);
next->list.push_back(case_);
next->finalize();
top = next;
nameMapper.popLabelName(name);
}
// the outermost block can be branched to to exit the whole switch
top->name = name;
// ensure a default
if (br->default_.isNull()) {
br->default_ = top->name;
}
if (breakWhenNotMatching) {
breakWhenNotMatching->name = br->default_;
}
for (size_t i = 0; i < br->targets.size(); i++) {
if (br->targets[i].isNull()) br->targets[i] = br->default_;
}
} else {
// we can't switch, make an if-chain instead of br_table
auto var = Builder::addVar(function, br->condition->type);
top->list.push_back(builder.makeSetLocal(var, br->condition));
auto* brHolder = top;
If* chain = nullptr;
If* first = nullptr;
for (unsigned i = 0; i < cases->size(); i++) {
Ref curr = cases[i];
Ref condition = curr[0];
Ref body = curr[1];
auto case_ = processStatements(body, 0);
Name name;
if (condition->isNull()) {
name = br->default_ = nameMapper.pushLabelName("switch-default");
} else {
name = nameMapper.pushLabelName("switch-case");
auto* iff = builder.makeIf(
builder.makeBinary(
br->condition->type == i32 ? EqInt32 : EqInt64,
builder.makeGetLocal(var, br->condition->type),
builder.makeConst(getLiteral(condition))
),
builder.makeBreak(name),
chain
);
chain = iff;
if (!first) first = iff;
}
auto next = allocator.alloc<Block>();
top->name = name;
next->list.push_back(top);
next->list.push_back(case_);
top = next;
nameMapper.popLabelName(name);
}
// the outermost block can be branched to to exit the whole switch
top->name = name;
// ensure a default
if (br->default_.isNull()) {
br->default_ = top->name;
}
first->ifFalse = builder.makeBreak(br->default_);
brHolder->list.push_back(chain);
}
breakStack.pop_back();
nameMapper.popLabelName(name);
return top;
}
abort_on("confusing expression", ast);
return (Expression*)nullptr; // avoid warning
};
// given HEAP32[addr >> 2], we need an absolute address, and would like to remove that shift.
// if there is a shift, we can just look through it, etc.
processUnshifted = [&](Ref ptr, unsigned bytes) {
auto shifts = bytesToShift(bytes);
// HEAP?[addr >> ?], or HEAP8[x | 0]
if ((ptr->isArray(BINARY) && ptr[1] == RSHIFT && ptr[3]->isNumber() && ptr[3]->getInteger() == shifts) ||
(bytes == 1 && ptr->isArray(BINARY) && ptr[1] == OR && ptr[3]->isNumber() && ptr[3]->getInteger() == 0)) {
return process(ptr[2]); // look through it
} else if (ptr->isNumber()) {
// constant, apply a shift (e.g. HEAP32[1] is address 4)
unsigned addr = ptr->getInteger();
unsigned shifted = addr << shifts;
return (Expression*)builder.makeConst(Literal(int32_t(shifted)));
}
abort_on("bad processUnshifted", ptr);
return (Expression*)nullptr; // avoid warning
};
processStatements = [&](Ref ast, unsigned from) -> Expression* {
unsigned size = ast->size() - from;
if (size == 0) return allocator.alloc<Nop>();
if (size == 1) return process(ast[from]);
auto block = allocator.alloc<Block>();
for (unsigned i = from; i < ast->size(); i++) {
block->list.push_back(process(ast[i]));
}
block->finalize();
return block;
};
// body
function->body = processStatements(body, start);
// cleanups/checks
assert(breakStack.size() == 0 && continueStack.size() == 0);
assert(parentLabel.isNull());
return function;
}
} // namespace wasm
#endif // wasm_asm2wasm_h