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Update wasm2asm to generate "almost asm" if grow_memory is used #1340

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Merged
merged 2 commits into from
Feb 6, 2018
Merged

Update wasm2asm to generate "almost asm" if grow_memory is used #1340

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e60dcb9
Allow wasm2asm to generate "almost asm"
krisselden Dec 19, 2017
9c6cd74
Log reason for "almost asm" to stderr
krisselden Jan 4, 2018
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5 changes: 4 additions & 1 deletion src/asmjs/shared-constants.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -62,6 +62,7 @@ cashew::IString GLOBAL("global"),
I32_TEMP("asm2wasm_i32_temp"),
DEBUGGER("debugger"),
USE_ASM("use asm"),
ALMOST_ASM("almost asm"),
BUFFER("buffer"),
ENV("env"),
INSTRUMENT("instrument"),
Expand All @@ -84,5 +85,7 @@ cashew::IString GLOBAL("global"),
WASM_ROTL32("__wasm_rotl_i32"),
WASM_ROTL64("__wasm_rotl_i64"),
WASM_ROTR32("__wasm_rotr_i32"),
WASM_ROTR64("__wasm_rotr_i64");
WASM_ROTR64("__wasm_rotr_i64"),
WASM_GROW_MEMORY("__wasm_grow_memory"),
WASM_CURRENT_MEMORY("__wasm_current_memory");
}
5 changes: 4 additions & 1 deletion src/asmjs/shared-constants.h
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Expand Up @@ -65,6 +65,7 @@ extern cashew::IString GLOBAL,
I32_TEMP,
DEBUGGER,
USE_ASM,
ALMOST_ASM,
BUFFER,
ENV,
INSTRUMENT,
Expand All @@ -87,7 +88,9 @@ extern cashew::IString GLOBAL,
WASM_ROTL32,
WASM_ROTL64,
WASM_ROTR32,
WASM_ROTR64;
WASM_ROTR64,
WASM_GROW_MEMORY,
WASM_CURRENT_MEMORY;
}

#endif // wasm_asmjs_shared_constants_h
228 changes: 222 additions & 6 deletions src/wasm2asm.h
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Original file line number Diff line number Diff line change
Expand Up @@ -205,11 +205,15 @@ class Wasm2AsmBuilder {
// All our function tables have the same size TODO: optimize?
size_t tableSize;

bool almostASM = false;

void addBasics(Ref ast);
void addImport(Ref ast, Import* import);
void addTables(Ref ast, Module* wasm);
void addExports(Ref ast, Module* wasm);
void addWasmCompatibilityFuncs(Module* wasm);
void setNeedsAlmostASM(const char *reason);
void addMemoryGrowthFuncs(Ref ast);
bool isAssertHandled(Element& e);
Ref makeAssertReturnFunc(SExpressionWasmBuilder& sexpBuilder,
Builder& wasmBuilder,
Expand Down Expand Up @@ -522,11 +526,54 @@ void Wasm2AsmBuilder::addTables(Ref ast, Module* wasm) {
void Wasm2AsmBuilder::addExports(Ref ast, Module* wasm) {
Ref exports = ValueBuilder::makeObject();
for (auto& export_ : wasm->exports) {
ValueBuilder::appendToObject(
exports,
fromName(export_->name),
ValueBuilder::makeName(fromName(export_->value))
);
if (export_->kind == ExternalKind::Function) {
ValueBuilder::appendToObject(
exports,
fromName(export_->name),
ValueBuilder::makeName(fromName(export_->value))
);
}
if (export_->kind == ExternalKind::Memory) {
setNeedsAlmostASM("memory export");
Ref descs = ValueBuilder::makeObject();
Ref growDesc = ValueBuilder::makeObject();
ValueBuilder::appendToObject(
descs,
IString("grow"),
growDesc);
ValueBuilder::appendToObject(
growDesc,
IString("value"),
ValueBuilder::makeName(WASM_GROW_MEMORY));
Ref bufferDesc = ValueBuilder::makeObject();
Ref bufferGetter = ValueBuilder::makeFunction(IString(""));
bufferGetter[3]->push_back(ValueBuilder::makeReturn(
ValueBuilder::makeName(BUFFER)
));
ValueBuilder::appendToObject(
bufferDesc,
IString("get"),
bufferGetter);
ValueBuilder::appendToObject(
descs,
IString("buffer"),
bufferDesc);
Ref memory = ValueBuilder::makeCall(
ValueBuilder::makeDot(ValueBuilder::makeName(IString("Object")), IString("create")),
ValueBuilder::makeDot(ValueBuilder::makeName(IString("Object")), IString("prototype")));
ValueBuilder::appendToCall(
memory,
descs);
ValueBuilder::appendToObject(
exports,
fromName(export_->name),
memory);
}
}
if (almostASM) {
// replace "use asm"
ast[0] = ValueBuilder::makeStatement(ValueBuilder::makeString(ALMOST_ASM));
addMemoryGrowthFuncs(ast);
}
ast->push_back(ValueBuilder::makeStatement(ValueBuilder::makeReturn(exports)));
}
Expand Down Expand Up @@ -1557,7 +1604,18 @@ Ref Wasm2AsmBuilder::processFunctionBody(Function* func, IString result) {
}

Ref visitHost(Host* curr) {
abort();
if (curr->op == HostOp::GrowMemory) {
parent->setNeedsAlmostASM("grow_memory op");
return ValueBuilder::makeCall(WASM_GROW_MEMORY,
makeAsmCoercion(
visit(curr->operands[0], EXPRESSION_RESULT),
wasmToAsmType(curr->operands[0]->type)));
}
if (curr->op == HostOp::CurrentMemory) {
parent->setNeedsAlmostASM("current_memory op");
return ValueBuilder::makeCall(WASM_CURRENT_MEMORY);
}
return ValueBuilder::makeCall(ABORT_FUNC);
}

Ref visitNop(Nop* curr) {
Expand Down Expand Up @@ -1696,6 +1754,164 @@ Ref Wasm2AsmBuilder::makeAssertTrapFunc(SExpressionWasmBuilder& sexpBuilder,
return outerFunc;
}

void Wasm2AsmBuilder::setNeedsAlmostASM(const char *reason) {
if (!almostASM) {
almostASM = true;
std::cerr << "Switching to \"almost asm\" mode, reason: " << reason << std::endl;
}
}

void Wasm2AsmBuilder::addMemoryGrowthFuncs(Ref ast) {
Ref growMemoryFunc = ValueBuilder::makeFunction(WASM_GROW_MEMORY);
ValueBuilder::appendArgumentToFunction(growMemoryFunc, IString("pagesToAdd"));

growMemoryFunc[3]->push_back(
ValueBuilder::makeStatement(
ValueBuilder::makeBinary(
ValueBuilder::makeName(IString("pagesToAdd")), SET,
makeAsmCoercion(
ValueBuilder::makeName(IString("pagesToAdd")),
AsmType::ASM_INT
)
)
)
);

Ref oldPages = ValueBuilder::makeVar();
growMemoryFunc[3]->push_back(oldPages);
ValueBuilder::appendToVar(
oldPages,
IString("oldPages"),
makeAsmCoercion(ValueBuilder::makeCall(WASM_CURRENT_MEMORY), AsmType::ASM_INT));

Ref newPages = ValueBuilder::makeVar();
growMemoryFunc[3]->push_back(newPages);
ValueBuilder::appendToVar(
newPages,
IString("newPages"),
makeAsmCoercion(ValueBuilder::makeBinary(
ValueBuilder::makeName(IString("oldPages")),
PLUS,
ValueBuilder::makeName(IString("pagesToAdd"))
), AsmType::ASM_INT));

Ref block = ValueBuilder::makeBlock();
growMemoryFunc[3]->push_back(ValueBuilder::makeIf(
ValueBuilder::makeBinary(
ValueBuilder::makeBinary(
ValueBuilder::makeName(IString("oldPages")),
LT,
ValueBuilder::makeName(IString("newPages"))
),
IString("&&"),
ValueBuilder::makeBinary(
ValueBuilder::makeName(IString("newPages")),
LT,
ValueBuilder::makeInt(Memory::kMaxSize)
)
), block, NULL));

Ref newBuffer = ValueBuilder::makeVar();
ValueBuilder::appendToBlock(block, newBuffer);
ValueBuilder::appendToVar(
newBuffer,
IString("newBuffer"),
ValueBuilder::makeNew(ValueBuilder::makeCall(
ARRAY_BUFFER,
ValueBuilder::makeCall(
MATH_IMUL,
ValueBuilder::makeName(IString("newPages")),
ValueBuilder::makeInt(Memory::kPageSize)))));

Ref newHEAP8 = ValueBuilder::makeVar();
ValueBuilder::appendToBlock(block, newHEAP8);
ValueBuilder::appendToVar(
newHEAP8,
IString("newHEAP8"),
ValueBuilder::makeNew(
ValueBuilder::makeCall(
ValueBuilder::makeDot(
ValueBuilder::makeName(GLOBAL),
INT8ARRAY
),
ValueBuilder::makeName(IString("newBuffer"))
)
));

ValueBuilder::appendToBlock(block,
ValueBuilder::makeCall(
ValueBuilder::makeDot(
ValueBuilder::makeName(IString("newHEAP8")),
IString("set")
),
ValueBuilder::makeName(HEAP8)
)
);

ValueBuilder::appendToBlock(block,
ValueBuilder::makeBinary(
ValueBuilder::makeName(HEAP8),
SET,
ValueBuilder::makeName(IString("newHEAP8"))
)
);

auto setHeap = [&](IString name, IString view) {
ValueBuilder::appendToBlock(block,
ValueBuilder::makeBinary(
ValueBuilder::makeName(name),
SET,
ValueBuilder::makeNew(
ValueBuilder::makeCall(
ValueBuilder::makeDot(
ValueBuilder::makeName(GLOBAL),
view
),
ValueBuilder::makeName(IString("newBuffer"))
)
)
)
);
};

setHeap(HEAP16, INT16ARRAY);
setHeap(HEAP32, INT32ARRAY);
setHeap(HEAPU8, UINT8ARRAY);
setHeap(HEAPU16, UINT16ARRAY);
setHeap(HEAPU32, UINT32ARRAY);
setHeap(HEAPF32, FLOAT32ARRAY);
setHeap(HEAPF64, FLOAT64ARRAY);

ValueBuilder::appendToBlock(block,
ValueBuilder::makeBinary(
ValueBuilder::makeName(BUFFER),
SET,
ValueBuilder::makeName(IString("newBuffer"))
)
);

growMemoryFunc[3]->push_back(
ValueBuilder::makeReturn(
ValueBuilder::makeName(IString("oldPages"))));

Ref currentMemoryFunc = ValueBuilder::makeFunction(WASM_CURRENT_MEMORY);
currentMemoryFunc[3]->push_back(ValueBuilder::makeReturn(
makeAsmCoercion(
ValueBuilder::makeBinary(
ValueBuilder::makeDot(
ValueBuilder::makeName(BUFFER),
IString("byteLength")
),
DIV,
ValueBuilder::makeInt(Memory::kPageSize)
),
AsmType::ASM_INT
)
));
ast->push_back(growMemoryFunc);
ast->push_back(currentMemoryFunc);
}

bool Wasm2AsmBuilder::isAssertHandled(Element& e) {
return e.isList() && e.size() >= 2 && e[0]->isStr()
&& (e[0]->str() == Name("assert_return") ||
Expand Down
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