[generators] Decouple generator resume from fullcodegen.

src/full-codegen/arm/full-codegen-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_ARM
 
 #include "src/ast/scopes.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 1822 matching lines @@
 
 
 void FullCodeGenerator::VisitYield(Yield* expr) {
   Comment cmnt(masm_, "[ Yield");
   SetExpressionPosition(expr);
 
   // Evaluate yielded value first; the initial iterator definition depends on
   // 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);
   // When we arrive here, the stack top is the resume mode and
   // result_register() holds the input value (the argument given to the
   // respective resume operation).
   __ RecordGeneratorContinuation();
   __ pop(r1);
-  __ cmp(r1, Operand(Smi::FromInt(JSGeneratorObject::RETURN)));
-  __ b(ne, &resume);
-  __ push(result_register());
+  STATIC_ASSERT(JSGeneratorObject::kNext < JSGeneratorObject::kReturn);
+  STATIC_ASSERT(JSGeneratorObject::kThrow > JSGeneratorObject::kReturn);
+  __ cmp(r1, Operand(Smi::FromInt(JSGeneratorObject::kReturn)));
+  __ b(lt, &resume);
+  __ Push(result_register());
+  __ b(gt, &exception);
   EmitCreateIteratorResult(true);
   EmitUnwindAndReturn();
 
+  __ bind(&exception);
+  __ CallRuntime(Runtime::kThrow);
+
   __ bind(&suspend);
   OperandStackDepthIncrement(1);  // Not popped on this path.
   VisitForAccumulatorValue(expr->generator_object());
   DCHECK(continuation.pos() > 0 && Smi::IsValid(continuation.pos()));
   __ mov(r1, Operand(Smi::FromInt(continuation.pos())));
   __ str(r1, FieldMemOperand(r0, JSGeneratorObject::kContinuationOffset));
   __ str(cp, FieldMemOperand(r0, JSGeneratorObject::kContextOffset));
   __ mov(r1, cp);
   __ RecordWriteField(r0, JSGeneratorObject::kContextOffset, r1, r2,
                       kLRHasBeenSaved, kDontSaveFPRegs);
   __ add(r1, fp, Operand(StandardFrameConstants::kExpressionsOffset));
   __ cmp(sp, r1);
   __ b(eq, &post_runtime);
   __ push(r0);  // generator object
   __ CallRuntime(Runtime::kSuspendJSGeneratorObject, 1);
   __ ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
   __ bind(&post_runtime);
   PopOperand(result_register());
   EmitReturnSequence();
 
   __ bind(&resume);
   context()->Plug(result_register());
 }
 
-
-void FullCodeGenerator::EmitGeneratorResume(Expression *generator,
-    Expression *value,
-    JSGeneratorObject::ResumeMode resume_mode) {
-  // The value stays in r0, 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.
-  // r1 will hold the generator object until the activation has been resumed.
-  VisitForStackValue(generator);
-  VisitForAccumulatorValue(value);
-  PopOperand(r1);
-
-  // Store input value into generator object.
-  __ str(result_register(),
-         FieldMemOperand(r1, JSGeneratorObject::kInputOffset));
-  __ mov(r2, result_register());
-  __ RecordWriteField(r1, JSGeneratorObject::kInputOffset, r2, r3,
-                      kLRHasBeenSaved, kDontSaveFPRegs);
-
-  // Load suspended function and context.
-  __ ldr(cp, FieldMemOperand(r1, JSGeneratorObject::kContextOffset));
-  __ ldr(r4, FieldMemOperand(r1, JSGeneratorObject::kFunctionOffset));
-
-  // Load receiver and store as the first argument.
-  __ ldr(r2, FieldMemOperand(r1, JSGeneratorObject::kReceiverOffset));
-  __ push(r2);
-
-  // 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.
-  __ ldr(r3, FieldMemOperand(r4, JSFunction::kSharedFunctionInfoOffset));
-  __ ldr(r3,
-         FieldMemOperand(r3, SharedFunctionInfo::kFormalParameterCountOffset));
-  __ LoadRoot(r2, Heap::kTheHoleValueRootIndex);
-  Label push_argument_holes, push_frame;
-  __ bind(&push_argument_holes);
-  __ sub(r3, r3, Operand(Smi::FromInt(1)), SetCC);
-  __ b(mi, &push_frame);
-  __ push(r2);
-  __ 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);
-  __ bl(&resume_frame);
-  __ jmp(&done);
-  __ bind(&resume_frame);
-  // lr = return address.
-  // fp = caller's frame pointer.
-  // pp = caller's constant pool (if FLAG_enable_embedded_constant_pool),
-  // cp = callee's context,
-  // r4 = callee's JS function.
-  __ PushStandardFrame(r4);
-
-  // Load the operand stack size.
-  __ ldr(r3, FieldMemOperand(r1, JSGeneratorObject::kOperandStackOffset));
-  __ ldr(r3, FieldMemOperand(r3, FixedArray::kLengthOffset));
-  __ SmiUntag(r3);
-
-  // 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;
-    __ cmp(r3, Operand(0));
-    __ b(ne, &slow_resume);
-    __ ldr(r3, FieldMemOperand(r4, JSFunction::kCodeEntryOffset));
-
-    { ConstantPoolUnavailableScope constant_pool_unavailable(masm_);
-      if (FLAG_enable_embedded_constant_pool) {
-        // Load the new code object's constant pool pointer.
-        __ LoadConstantPoolPointerRegisterFromCodeTargetAddress(r3);
-      }
-
-      __ ldr(r2, FieldMemOperand(r1, JSGeneratorObject::kContinuationOffset));
-      __ SmiUntag(r2);
-      __ add(r3, r3, r2);
-      __ mov(r2, Operand(Smi::FromInt(JSGeneratorObject::kGeneratorExecuting)));
-      __ str(r2, FieldMemOperand(r1, JSGeneratorObject::kContinuationOffset));
-      __ Push(Smi::FromInt(resume_mode));  // Consumed in continuation.
-      __ Jump(r3);
-    }
-    __ 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);
-  __ sub(r3, r3, Operand(1), SetCC);
-  __ b(mi, &call_resume);
-  __ push(r2);
-  __ b(&push_operand_holes);
-  __ bind(&call_resume);
-  __ Push(Smi::FromInt(resume_mode));  // Consumed in continuation.
-  DCHECK(!result_register().is(r1));
-  __ Push(r1, 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);
 }
 
 void FullCodeGenerator::PopOperands(Register reg1, Register reg2) {
   OperandStackDepthDecrement(2);
   __ Pop(reg1, reg2);
 }
 
@@ skipping 2157 matching lines @@
   DCHECK(interrupt_address ==
          isolate->builtins()->OnStackReplacement()->entry());
   return ON_STACK_REPLACEMENT;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM