PPC: First version of the new generators implementation.

src/ppc/builtins-ppc.cc

 // Copyright 2014 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_PPC
 
 #include "src/codegen.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 763 matching lines @@
     __ SmiUntag(r6, SetRC);
     __ beq(&done_loop, cr0);
 #endif
     __ mtctr(r6);
     __ bind(&loop);
     __ push(ip);
     __ bdnz(&loop);
     __ bind(&done_loop);
   }
 
-  // Enter a new JavaScript frame, and initialize its slots as they were when
-  // the generator was suspended.
-  FrameScope scope(masm, StackFrame::MANUAL);
-  __ PushStandardFrame(r7);
+  // Dispatch on the kind of generator object.
+  Label old_generator;
+  __ LoadP(r6, FieldMemOperand(r7, JSFunction::kSharedFunctionInfoOffset));
+  __ LoadP(r6, FieldMemOperand(r6, SharedFunctionInfo::kFunctionDataOffset));
+  __ CompareObjectType(r6, r6, r6, BYTECODE_ARRAY_TYPE);
+  __ bne(&old_generator);
 
-  // Restore the operand stack.
-  __ LoadP(r3, FieldMemOperand(r4, JSGeneratorObject::kOperandStackOffset));
-  __ LoadP(r6, FieldMemOperand(r3, FixedArray::kLengthOffset));
-  __ addi(r3, r3,
-          Operand(FixedArray::kHeaderSize - kHeapObjectTag - kPointerSize));
+  // New-style (ignition/turbofan) generator object
   {
-    Label loop, done_loop;
-    __ SmiUntag(r6, SetRC);
-    __ beq(&done_loop, cr0);
-    __ mtctr(r6);
-    __ bind(&loop);
-    __ LoadPU(ip, MemOperand(r3, kPointerSize));
-    __ Push(ip);
-    __ bdnz(&loop);
-    __ bind(&done_loop);
+    __ LoadP(r3, FieldMemOperand(r7, JSFunction::kSharedFunctionInfoOffset));
+    __ LoadP(r3,

[MTBrandyberry, 2016/04/18 18:08:55]

The formal parameter count is an integer value.  See above for proper load and
untag sequence.

Bonus points:  I'm not sure why we'd want to reload this value since we've done
it above and the loop doesn't trash the value as it does on ARM.  It seems like
we should just stash it in a register that survives until this section.

+         FieldMemOperand(r3, SharedFunctionInfo::kFormalParameterCountOffset));
+    __ SmiUntag(r3);
+    // We abuse new.target both to indicate that this is a resume call and to
+    // pass in the generator object.  In ordinary calls, new.target is always
+    // undefined because generator functions are non-constructable.
+    __ mr(r6, r4);
+    __ mr(r4, r7);
+    __ LoadP(r8, FieldMemOperand(r4, JSFunction::kCodeEntryOffset));
+    __ Jump(r5);

[MTBrandyberry, 2016/04/18 18:08:54]

When calling a javascript object entry, we need to call via the ip register for
proper constant pool addressibility.  Load into ip and use the JumpToJSEntry
macro.

   }
 
-  // Reset operand stack so we don't leak.
-  __ LoadRoot(ip, Heap::kEmptyFixedArrayRootIndex);
-  __ StoreP(ip, FieldMemOperand(r4, JSGeneratorObject::kOperandStackOffset),
-            r0);
+  // Old-style (full-codegen) generator object
+  __ bind(&old_generator);
+  {
+    // Enter a new JavaScript frame, and initialize its slots as they were when
+    // the generator was suspended.
+    FrameScope scope(masm, StackFrame::MANUAL);
+    __ PushStandardFrame(r7);
 
-  // Resume the generator function at the continuation.
-  __ LoadP(r6, FieldMemOperand(r7, JSFunction::kSharedFunctionInfoOffset));
-  __ LoadP(r6, FieldMemOperand(r6, SharedFunctionInfo::kCodeOffset));
-  __ addi(r6, r6, Operand(Code::kHeaderSize - kHeapObjectTag));
-  {
-    ConstantPoolUnavailableScope constant_pool_unavailable(masm);
-    if (FLAG_enable_embedded_constant_pool) {
-      __ LoadConstantPoolPointerRegisterFromCodeTargetAddress(r6);
+    // Restore the operand stack.
+    __ LoadP(r3, FieldMemOperand(r4, JSGeneratorObject::kOperandStackOffset));
+    __ LoadP(r6, FieldMemOperand(r3, FixedArray::kLengthOffset));
+    __ addi(r3, r3,
+            Operand(FixedArray::kHeaderSize - kHeapObjectTag - kPointerSize));
+    {
+      Label loop, done_loop;
+      __ SmiUntag(r6, SetRC);
+      __ beq(&done_loop, cr0);
+      __ mtctr(r6);
+      __ bind(&loop);
+      __ LoadPU(ip, MemOperand(r3, kPointerSize));
+      __ Push(ip);
+      __ bdnz(&loop);
+      __ bind(&done_loop);
     }
-    __ LoadP(r5, FieldMemOperand(r4, JSGeneratorObject::kContinuationOffset));
-    __ SmiUntag(r5);
-    __ add(r6, r6, r5);
-    __ LoadSmiLiteral(r5, Smi::FromInt(JSGeneratorObject::kGeneratorExecuting));
-    __ StoreP(r5, FieldMemOperand(r4, JSGeneratorObject::kContinuationOffset),
+
+    // Reset operand stack so we don't leak.
+    __ LoadRoot(ip, Heap::kEmptyFixedArrayRootIndex);
+    __ StoreP(ip, FieldMemOperand(r4, JSGeneratorObject::kOperandStackOffset),
               r0);
-    __ mr(r3, r4);  // Continuation expects generator object in r3.
-    __ Jump(r6);
+
+    // Resume the generator function at the continuation.
+    __ LoadP(r6, FieldMemOperand(r7, JSFunction::kSharedFunctionInfoOffset));
+    __ LoadP(r6, FieldMemOperand(r6, SharedFunctionInfo::kCodeOffset));
+    __ addi(r6, r6, Operand(Code::kHeaderSize - kHeapObjectTag));
+    {
+      ConstantPoolUnavailableScope constant_pool_unavailable(masm);
+      if (FLAG_enable_embedded_constant_pool) {
+        __ LoadConstantPoolPointerRegisterFromCodeTargetAddress(r6);
+      }
+      __ LoadP(r5, FieldMemOperand(r4, JSGeneratorObject::kContinuationOffset));
+      __ SmiUntag(r5);
+      __ add(r6, r6, r5);
+      __ LoadSmiLiteral(r5,
+                        Smi::FromInt(JSGeneratorObject::kGeneratorExecuting));
+      __ StoreP(r5, FieldMemOperand(r4, JSGeneratorObject::kContinuationOffset),
+                r0);
+      __ mr(r3, r4);  // Continuation expects generator object in r3.
+      __ Jump(r6);
+    }
   }
 }
 
 void Builtins::Generate_ConstructedNonConstructable(MacroAssembler* masm) {
   FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
   __ push(r4);
   __ CallRuntime(Runtime::kThrowConstructedNonConstructable);
 }
 
 
@@ skipping 2005 matching lines @@
     __ bkpt(0);
   }
 }
 
 
 #undef __
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_PPC