MIPS: Generators can resume
Port r14415 (d358defa) and r14424 (7b549ce7) Original commit message: The generator object methods "next", "send", and "throw" now include some inline assembly to set up a resumed stack frame. In some common cases, we can just jump back into the frame to resume it. Otherwise the resume code calls out to a runtime to fill in the operand stack, rewind the handlers, and possibly to throw an exception. BUG=v8:2355 TESTS=mjsunit/harmony/generators-iteration Review URL: https://codereview.chromium.org/13864010 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14428 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
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@ -1980,6 +1980,97 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
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}
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void FullCodeGenerator::EmitGeneratorResume(Expression *generator,
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Expression *value,
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JSGeneratorObject::ResumeMode resume_mode) {
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// The value stays in a0, and is ultimately read by the resumed generator, as
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// if the CallRuntime(Runtime::kSuspendJSGeneratorObject) returned it. a1
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// will hold the generator object until the activation has been resumed.
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VisitForStackValue(generator);
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VisitForAccumulatorValue(value);
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__ pop(a1);
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// Check generator state.
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Label wrong_state, done;
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__ lw(a3, FieldMemOperand(a1, JSGeneratorObject::kContinuationOffset));
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STATIC_ASSERT(JSGeneratorObject::kGeneratorExecuting <= 0);
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STATIC_ASSERT(JSGeneratorObject::kGeneratorClosed <= 0);
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__ Branch(&wrong_state, le, a3, Operand(zero_reg));
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// Load suspended function and context.
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__ lw(cp, FieldMemOperand(a1, JSGeneratorObject::kContextOffset));
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__ lw(t0, FieldMemOperand(a1, JSGeneratorObject::kFunctionOffset));
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// Push holes for arguments to generator function.
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__ lw(a3, FieldMemOperand(t0, JSFunction::kSharedFunctionInfoOffset));
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__ lw(a3,
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FieldMemOperand(a3, SharedFunctionInfo::kFormalParameterCountOffset));
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__ LoadRoot(a2, Heap::kTheHoleValueRootIndex);
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Label push_argument_holes;
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__ bind(&push_argument_holes);
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__ push(a2);
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__ Subu(a3, a3, Operand(1));
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__ Branch(&push_argument_holes, ge, a3, Operand(zero_reg));
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// Enter a new JavaScript frame, and initialize its slots as they were when
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// the generator was suspended.
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Label push_frame, resume_frame;
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__ bind(&push_frame);
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__ Call(&resume_frame);
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__ jmp(&done);
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__ bind(&resume_frame);
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__ push(ra); // Return address.
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__ push(fp); // Caller's frame pointer.
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__ mov(fp, sp);
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__ push(cp); // Callee's context.
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__ push(t0); // Callee's JS Function.
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// Load the operand stack size.
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__ lw(a3, FieldMemOperand(a1, JSGeneratorObject::kOperandStackOffset));
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__ lw(a3, FieldMemOperand(a3, FixedArray::kLengthOffset));
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__ SmiUntag(a3);
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// If we are sending a value and there is no operand stack, we can jump back
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// in directly.
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if (resume_mode == JSGeneratorObject::SEND) {
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Label slow_resume;
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__ Branch(&slow_resume, ne, a3, Operand(zero_reg));
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__ lw(a3, FieldMemOperand(t0, JSFunction::kCodeEntryOffset));
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__ lw(a2, FieldMemOperand(a1, JSGeneratorObject::kContinuationOffset));
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__ SmiUntag(a2);
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__ Addu(a3, a3, Operand(a2));
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__ li(a2, Operand(Smi::FromInt(JSGeneratorObject::kGeneratorExecuting)));
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__ sw(a2, FieldMemOperand(a1, JSGeneratorObject::kContinuationOffset));
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__ Jump(a3);
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__ bind(&slow_resume);
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}
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// Otherwise, we push holes for the operand stack and call the runtime to fix
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// up the stack and the handlers.
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Label push_operand_holes, call_resume;
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__ bind(&push_operand_holes);
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__ Subu(a3, a3, Operand(1));
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__ Branch(&call_resume, lt, a3, Operand(zero_reg));
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__ push(a2);
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__ b(&push_operand_holes);
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__ bind(&call_resume);
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__ push(a1);
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__ push(result_register());
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__ Push(Smi::FromInt(resume_mode));
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__ CallRuntime(Runtime::kResumeJSGeneratorObject, 3);
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// Not reached: the runtime call returns elsewhere.
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__ stop("not-reached");
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// Throw error if we attempt to operate on a running generator.
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__ bind(&wrong_state);
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__ push(a1);
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__ CallRuntime(Runtime::kThrowGeneratorStateError, 1);
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__ bind(&done);
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context()->Plug(result_register());
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}
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void FullCodeGenerator::EmitNamedPropertyLoad(Property* prop) {
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SetSourcePosition(prop->position());
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Literal* key = prop->key()->AsLiteral();
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