[generators] Decouple generator resume from fullcodegen.

src/full-codegen/mips/full-codegen-mips.cc

Index: src/full-codegen/mips/full-codegen-mips.cc
diff --git a/src/full-codegen/mips/full-codegen-mips.cc b/src/full-codegen/mips/full-codegen-mips.cc
index d84678040ed3570855ab95e3970df82961bf9944..99b2355583981ebc099834dbc98aa0ab590f0f59 100644
--- a/src/full-codegen/mips/full-codegen-mips.cc
+++ b/src/full-codegen/mips/full-codegen-mips.cc
@@ -1838,7 +1838,7 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
   // this.  It stays on the stack while we update the iterator.
   VisitForStackValue(expr->expression());
 
-  Label suspend, continuation, post_runtime, resume;
+  Label suspend, continuation, post_runtime, resume, exception;
 
   __ jmp(&suspend);
   __ bind(&continuation);
@@ -1847,11 +1847,16 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
   // respective resume operation).
   __ RecordGeneratorContinuation();
   __ pop(a1);
-  __ Branch(&resume, ne, a1, Operand(Smi::FromInt(JSGeneratorObject::RETURN)));
-  __ push(result_register());
+  __ Branch(&resume, eq, a1, Operand(Smi::FromInt(JSGeneratorObject::kNext)));
+  __ Push(result_register());
+  __ Branch(&exception, eq, a1,
+            Operand(Smi::FromInt(JSGeneratorObject::kThrow)));
   EmitCreateIteratorResult(true);
   EmitUnwindAndReturn();
 
+  __ bind(&exception);
+  __ CallRuntime(Runtime::kThrow);
+
   __ bind(&suspend);
   OperandStackDepthIncrement(1);  // Not popped on this path.
   VisitForAccumulatorValue(expr->generator_object());
@@ -1875,103 +1880,6 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
   context()->Plug(result_register());
 }
 
-
-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 CallRuntime(Runtime::kSuspendJSGeneratorObject) returned it. Or it
-  // is read to throw the value when the resumed generator is already closed.
-  // a1 will hold the generator object until the activation has been resumed.
-  VisitForStackValue(generator);
-  VisitForAccumulatorValue(value);
-  PopOperand(a1);
-
-  // Store input value into generator object.
-  __ sw(result_register(),
-        FieldMemOperand(a1, JSGeneratorObject::kInputOffset));
-  __ mov(a2, result_register());
-  __ RecordWriteField(a1, JSGeneratorObject::kInputOffset, a2, a3,
-                      kRAHasBeenSaved, kDontSaveFPRegs);
-
-  // Load suspended function and context.
-  __ lw(cp, FieldMemOperand(a1, JSGeneratorObject::kContextOffset));
-  __ lw(t0, FieldMemOperand(a1, JSGeneratorObject::kFunctionOffset));
-
-  // Load receiver and store as the first argument.
-  __ lw(a2, FieldMemOperand(a1, JSGeneratorObject::kReceiverOffset));
-  __ push(a2);
-
-  // Push holes for arguments to generator function. Since the parser forced
-  // context allocation for any variables in generators, the actual argument
-  // values have already been copied into the context and these dummy values
-  // will never be used.
-  __ lw(a3, FieldMemOperand(t0, JSFunction::kSharedFunctionInfoOffset));
-  __ lw(a3,
-        FieldMemOperand(a3, SharedFunctionInfo::kFormalParameterCountOffset));
-  __ LoadRoot(a2, Heap::kTheHoleValueRootIndex);
-  Label push_argument_holes, push_frame;
-  __ bind(&push_argument_holes);
-  __ Subu(a3, a3, Operand(Smi::FromInt(1)));
-  __ Branch(&push_frame, lt, a3, Operand(zero_reg));
-  __ push(a2);
-  __ jmp(&push_argument_holes);
-
-  // Enter a new JavaScript frame, and initialize its slots as they were when
-  // the generator was suspended.
-  Label resume_frame, done;
-  __ bind(&push_frame);
-  __ Call(&resume_frame);
-  __ jmp(&done);
-  __ bind(&resume_frame);
-  // ra = return address.
-  // fp = caller's frame pointer.
-  // cp = callee's context,
-  // t0 = callee's JS function.
-  __ PushStandardFrame(t0);
-
-  // 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::NEXT) {
-    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));
-    __ Push(Smi::FromInt(resume_mode));  // Consumed in continuation.
-    __ 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);
-  __ Branch(&push_operand_holes);
-  __ bind(&call_resume);
-  __ Push(Smi::FromInt(resume_mode));  // Consumed in continuation.
-  DCHECK(!result_register().is(a1));
-  __ Push(a1, result_register());
-  __ Push(Smi::FromInt(resume_mode));
-  __ CallRuntime(Runtime::kResumeJSGeneratorObject);
-  // Not reached: the runtime call returns elsewhere.
-  __ stop("not-reached");
-
-  __ bind(&done);
-  context()->Plug(result_register());
-}
-
 void FullCodeGenerator::PushOperands(Register reg1, Register reg2) {
   OperandStackDepthIncrement(2);
   __ Push(reg1, reg2);