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
This commit is contained in:
palfia@homejinni.com 2013-04-24 23:11:48 +00:00
parent 6dc29db655
commit 8ddaa0c1a5

View File

@ -1980,6 +1980,97 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
}
void FullCodeGenerator::EmitGeneratorResume(Expression *generator,
Expression *value,
JSGeneratorObject::ResumeMode resume_mode) {
// The value stays in a0, and is ultimately read by the resumed generator, as
// if the CallRuntime(Runtime::kSuspendJSGeneratorObject) returned it. a1
// will hold the generator object until the activation has been resumed.
VisitForStackValue(generator);
VisitForAccumulatorValue(value);
__ pop(a1);
// Check generator state.
Label wrong_state, done;
__ lw(a3, FieldMemOperand(a1, JSGeneratorObject::kContinuationOffset));
STATIC_ASSERT(JSGeneratorObject::kGeneratorExecuting <= 0);
STATIC_ASSERT(JSGeneratorObject::kGeneratorClosed <= 0);
__ Branch(&wrong_state, le, a3, Operand(zero_reg));
// Load suspended function and context.
__ lw(cp, FieldMemOperand(a1, JSGeneratorObject::kContextOffset));
__ lw(t0, FieldMemOperand(a1, JSGeneratorObject::kFunctionOffset));
// Push holes for arguments to generator function.
__ lw(a3, FieldMemOperand(t0, JSFunction::kSharedFunctionInfoOffset));
__ lw(a3,
FieldMemOperand(a3, SharedFunctionInfo::kFormalParameterCountOffset));
__ LoadRoot(a2, Heap::kTheHoleValueRootIndex);
Label push_argument_holes;
__ bind(&push_argument_holes);
__ push(a2);
__ Subu(a3, a3, Operand(1));
__ Branch(&push_argument_holes, ge, a3, Operand(zero_reg));
// Enter a new JavaScript frame, and initialize its slots as they were when
// the generator was suspended.
Label push_frame, resume_frame;
__ bind(&push_frame);
__ Call(&resume_frame);
__ jmp(&done);
__ bind(&resume_frame);
__ push(ra); // Return address.
__ push(fp); // Caller's frame pointer.
__ mov(fp, sp);
__ push(cp); // Callee's context.
__ push(t0); // Callee's JS Function.
// Load the operand stack size.
__ lw(a3, FieldMemOperand(a1, JSGeneratorObject::kOperandStackOffset));
__ lw(a3, FieldMemOperand(a3, FixedArray::kLengthOffset));
__ SmiUntag(a3);
// If we are sending a value and there is no operand stack, we can jump back
// in directly.
if (resume_mode == JSGeneratorObject::SEND) {
Label slow_resume;
__ Branch(&slow_resume, ne, a3, Operand(zero_reg));
__ lw(a3, FieldMemOperand(t0, JSFunction::kCodeEntryOffset));
__ lw(a2, FieldMemOperand(a1, JSGeneratorObject::kContinuationOffset));
__ SmiUntag(a2);
__ Addu(a3, a3, Operand(a2));
__ li(a2, Operand(Smi::FromInt(JSGeneratorObject::kGeneratorExecuting)));
__ sw(a2, FieldMemOperand(a1, JSGeneratorObject::kContinuationOffset));
__ Jump(a3);
__ bind(&slow_resume);
}
// Otherwise, we push holes for the operand stack and call the runtime to fix
// up the stack and the handlers.
Label push_operand_holes, call_resume;
__ bind(&push_operand_holes);
__ Subu(a3, a3, Operand(1));
__ Branch(&call_resume, lt, a3, Operand(zero_reg));
__ push(a2);
__ b(&push_operand_holes);
__ bind(&call_resume);
__ push(a1);
__ push(result_register());
__ Push(Smi::FromInt(resume_mode));
__ CallRuntime(Runtime::kResumeJSGeneratorObject, 3);
// Not reached: the runtime call returns elsewhere.
__ stop("not-reached");
// Throw error if we attempt to operate on a running generator.
__ bind(&wrong_state);
__ push(a1);
__ CallRuntime(Runtime::kThrowGeneratorStateError, 1);
__ bind(&done);
context()->Plug(result_register());
}
void FullCodeGenerator::EmitNamedPropertyLoad(Property* prop) {
SetSourcePosition(prop->position());
Literal* key = prop->key()->AsLiteral();