diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/emscripten-optimizer/simple_ast.h | 7 | ||||
| -rw-r--r-- | src/wasm2asm.h | 83 |
2 files changed, 58 insertions, 32 deletions
diff --git a/src/emscripten-optimizer/simple_ast.h b/src/emscripten-optimizer/simple_ast.h index 4012ff8f6..4d34713a6 100644 --- a/src/emscripten-optimizer/simple_ast.h +++ b/src/emscripten-optimizer/simple_ast.h @@ -1526,6 +1526,13 @@ public: array[1]->push_back(&makeRawArray(2)->push_back(makeRawString(key)) .push_back(value)); } + + static Ref makeAssign(Ref obj, Ref target, Ref value) { + return &makeRawArray(3)->push_back(makeRawString(ASSIGN)) + .push_back(&arena.alloc()->setBool(true)) + .push_back(target) + .push_back(value); + } }; // Tolerates 0.0 in the input; does not trust a +() to be there. diff --git a/src/wasm2asm.h b/src/wasm2asm.h index 94406813e..538ed9131 100644 --- a/src/wasm2asm.h +++ b/src/wasm2asm.h @@ -39,9 +39,17 @@ public: // creating statements until we reach a statement context. // - // @param receives Whether the context we are in receives a value, or if not, - // then we can drop our return, if we have one. - Ref processExpression(Expression* curr, bool XXX WasmType receives); + // @param result Whether the context we are in receives a value, + // and its type, or if not, then we can drop our return, + // if we have one. + Ref processExpression(Expression* curr, WasmType result); + + // Get a temp var. + IString getTemp(WasmType type); + // Free a temp var. + void freeTemp(IString temp); + // Get and immediately free a temp var. + IString getTempAndFree(WasmType type); }; Ref Wasm2AsmBuilder::processWasm(Module* wasm) { @@ -65,15 +73,16 @@ Ref Wasm2AsmBuilder::processFunction(Function* func) { ret[1] = ValueBuilder::makeRawString(func->name); // arguments XXX // body - ret[3]->push_back(processExpression(func->body, func->result != none)); + ret[3]->push_back(processExpression(func->body, func->result)); // locals, including new temp locals XXX return ret; } Ref Wasm2AsmBuilder::processExpression(Expression* curr) { struct ExpressionProcessor : public WasmVisitor<Ref> { - bool receives; - ExpressionProcessor(bool receives) : receives(receives) {} + Wasm2AsmBuilder* parent; + WasmType result; + ExpressionProcessor(Wasm2AsmBuilder* parent, WasmType result) : parent(parent), result(result) {} // Expressions with control flow turn into a block, which we must // then handle, even if we are an expression. @@ -81,14 +90,22 @@ Ref Wasm2AsmBuilder::processExpression(Expression* curr) { return ast[0] == BLOCK; } + // Looks for a standard assign at the end of a block, which if this + // block returns a value, it will have. + Ref getBlockAssign(Ref ast) { + if (!(ast.size() >= 2 && ast[1].size() > 0)) return Ref(); + Ref last = deStat(ast[1][ast[1].size()-1]); + if (!(last[0] == ASSIGN && last[2][0] == NAME)) return Ref; + return last; + } + // If we replace an expression with a block, and we need to return // a value, it will show up in the last element, as an assign. This // returns it. IString getBlockValue(Ref ast) { - assert(ast.size() >= 2 && ast[1].size() > 0); - Ref last = deStat(ast[1][ast[1].size()-1]); - assert(last[0] == ASSIGN && last[2][0] == NAME); - return last[2][1]->getIString(); + Ref assign = getBlockAssign(ast); + assert(!!assign); + return assign[2][1]->getIString(); } Ref blockify(Ref ast) { @@ -98,10 +115,16 @@ Ref Wasm2AsmBuilder::processExpression(Expression* curr) { return ret; } - Ref blockifyWithValue(Ref ast) { - if (isBlock(ast)) return ast; + Ref blockifyWithResult(Ref ast, IString temp) { + if (isBlock(ast)) { + Ref assign = getBlockAssign(ast); + assert(!!assign); // if a block, must have a value returned + assign[2][1]->setString(temp); // replace existing assign target + return ast; + } + // not a block, so an expression. Just assign to the temp var. Ref ret = ValueBuilder::makeBlock(); - ret[1]->push_back(ast); + ret[1]->push_back(makeAssign(makeName(temp), ast)); return ret; } @@ -111,33 +134,29 @@ Ref Wasm2AsmBuilder::processExpression(Expression* curr) { Ref ret = ValueBuilder::makeBlock(); size_t size = curr->list.size(); for (size_t i = 0; i < size; i++) { - ret[1]->push_back(processExpression(func->body, i < size-1 ? false : receives); + ret[1]->push_back(processExpression(func->body, i < size-1 ? false : result); } return ret; } void visitIf(If *curr) override { - assert(receives ? !!curr->ifFalse : true); // an if without an else cannot be in a receiving context - Ref condition = processExpression(curr->condition, receives); - Ref ifTrue = processExpression(curr->ifTrue, receives); + assert(result ? !!curr->ifFalse : true); // an if without an else cannot be in a receiving context + Ref condition = processExpression(curr->condition, result); + Ref ifTrue = processExpression(curr->ifTrue, result); Ref ifFalse; if (curr->ifFalse) { - ifFalse = processExpression(curr->ifFalse, receives); + ifFalse = processExpression(curr->ifFalse, result); } - if (!isBlock(condition) && !receives) { - return ValueBuilder::makeIf(condition, ifTrue, ifFalse); // simple if + if (result != none) { + IString temp = parent->getTempAndFree(result); + ifTrue = blockifyWithResult(ifTrue, temp); + if (curr->ifFalse) ifFalse = blockifyWithResult(ifFalse, temp); } - if (receives) { - IString parent->getTemp(); - ifTrue = blockifyWithValue(ifTrue); - ifFalse = blockifyWithValue(ifFalse); - } - condition = blockify(blockify); - // just add an if to the block - IString check = getBlockValue(condition); - condition[1]->push_back(ValueBuilder::makeIf(condition, ifTrue, ifFalse)); - return condition; - if (isBlock(condition)) { + if (!isBlock(condition)) { + return ValueBuilder::makeIf(condition, ifTrue, ifFalse); // simple if } + // just add an if to the block + condition[1]->push_back(ValueBuilder::makeIf(getBlockValue(condition), ifTrue, ifFalse)); + return condition; } void visitLoop(Loop *curr) override { } @@ -180,7 +199,7 @@ Ref Wasm2AsmBuilder::processExpression(Expression* curr) { void visitUnreachable(Unreachable *curr) override { } }; - return ExpressionProcessor(state).visit(curr); + return ExpressionProcessor(this, result).visit(curr); } } // namespace wasm |