Shorten bail out checks when calling code which can fail.

src/arm/stub-cache-arm.cc

 // Copyright 2006-2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1508 matching lines @@
   __ b(eq, &miss);
 
   // Do the right check and compute the holder register.
   Register reg = CheckPrototypes(object, r0, holder, r1, r3, r4, name, &miss);
   GenerateFastPropertyLoad(masm(), r1, reg, holder, index);
 
   GenerateCallFunction(masm(), object, arguments(), &miss);
 
   // Handle call cache miss.
   __ bind(&miss);
-  Object* obj;
-  { MaybeObject* maybe_obj = GenerateMissBranch();
-    if (!maybe_obj->ToObject(&obj)) return maybe_obj;
-  }
+  MaybeObject* maybe_result = GenerateMissBranch();
+  if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
   return GetCode(FIELD, name);
 }
 
 
 MaybeObject* CallStubCompiler::CompileArrayPushCall(Object* object,
                                                     JSObject* holder,
                                                     JSGlobalPropertyCell* cell,
                                                     JSFunction* function,
@@ skipping 136 matching lines @@
       __ Ret();
     }
     __ bind(&call_builtin);
     __ TailCallExternalReference(ExternalReference(Builtins::c_ArrayPush),
                                  argc + 1,
                                  1);
   }
 
   // Handle call cache miss.
   __ bind(&miss);
-  Object* obj;
-  { MaybeObject* maybe_obj = GenerateMissBranch();
-    if (!maybe_obj->ToObject(&obj)) return maybe_obj;
-  }
+  MaybeObject* maybe_result = GenerateMissBranch();
+  if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
   return GetCode(function);
 }
 
 
 MaybeObject* CallStubCompiler::CompileArrayPopCall(Object* object,
                                                    JSObject* holder,
                                                    JSGlobalPropertyCell* cell,
                                                    JSFunction* function,
@@ skipping 62 matching lines @@
   __ Drop(argc + 1);
   __ Ret();
 
   __ bind(&call_builtin);
   __ TailCallExternalReference(ExternalReference(Builtins::c_ArrayPop),
                                argc + 1,
                                1);
 
   // Handle call cache miss.
   __ bind(&miss);
-  Object* obj;
-  { MaybeObject* maybe_obj = GenerateMissBranch();
-    if (!maybe_obj->ToObject(&obj)) return maybe_obj;
-  }
+  MaybeObject* maybe_result = GenerateMissBranch();
+  if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
   return GetCode(function);
 }
 
 
 MaybeObject* CallStubCompiler::CompileStringCharCodeAtCall(
     Object* object,
     JSObject* holder,
     JSGlobalPropertyCell* cell,
@@ skipping 62 matching lines @@
     __ bind(&index_out_of_range);
     __ LoadRoot(r0, Heap::kNanValueRootIndex);
     __ Drop(argc + 1);
     __ Ret();
   }
 
   __ bind(&miss);
   // Restore function name in r2.
   __ Move(r2, Handle<String>(name));
   __ bind(&name_miss);
-  Object* obj;
-  { MaybeObject* maybe_obj = GenerateMissBranch();
-    if (!maybe_obj->ToObject(&obj)) return maybe_obj;
-  }
+  MaybeObject* maybe_result = GenerateMissBranch();
+  if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
   return GetCode(function);
 }
 
 
 MaybeObject* CallStubCompiler::CompileStringCharAtCall(
     Object* object,
     JSObject* holder,
     JSGlobalPropertyCell* cell,
@@ skipping 64 matching lines @@
     __ bind(&index_out_of_range);
     __ LoadRoot(r0, Heap::kEmptyStringRootIndex);
     __ Drop(argc + 1);
     __ Ret();
   }
 
   __ bind(&miss);
   // Restore function name in r2.
   __ Move(r2, Handle<String>(name));
   __ bind(&name_miss);
-  Object* obj;
-  { MaybeObject* maybe_obj = GenerateMissBranch();
-    if (!maybe_obj->ToObject(&obj)) return maybe_obj;
-  }
+  MaybeObject* maybe_result = GenerateMissBranch();
+  if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
   return GetCode(function);
 }
 
 
 MaybeObject* CallStubCompiler::CompileStringFromCharCodeCall(
     Object* object,
     JSObject* holder,
     JSGlobalPropertyCell* cell,
@@ skipping 52 matching lines @@
   StubRuntimeCallHelper call_helper;
   char_from_code_generator.GenerateSlow(masm(), call_helper);
 
   // Tail call the full function. We do not have to patch the receiver
   // because the function makes no use of it.
   __ bind(&slow);
   __ InvokeFunction(function, arguments(), JUMP_FUNCTION);
 
   __ bind(&miss);
   // r2: function name.
-  Object* obj;
-  { MaybeObject* maybe_obj = GenerateMissBranch();
-    if (!maybe_obj->ToObject(&obj)) return maybe_obj;
-  }
+  MaybeObject* maybe_result = GenerateMissBranch();
+  if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
   return (cell == NULL) ? GetCode(function) : GetCode(NORMAL, name);
 }
 
 
 MaybeObject* CallStubCompiler::CompileMathFloorCall(Object* object,
                                                     JSObject* holder,
                                                     JSGlobalPropertyCell* cell,
                                                     JSFunction* function,
@@ skipping 125 matching lines @@
   // Restore FPCSR and fall to slow case.
   __ vmsr(r3);
 
   __ bind(&slow);
   // Tail call the full function. We do not have to patch the receiver
   // because the function makes no use of it.
   __ InvokeFunction(function, arguments(), JUMP_FUNCTION);
 
   __ bind(&miss);
   // r2: function name.
-  MaybeObject* obj = GenerateMissBranch();
-  if (obj->IsFailure()) return obj;
+  MaybeObject* maybe_result = GenerateMissBranch();
+  if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
   return (cell == NULL) ? GetCode(function) : GetCode(NORMAL, name);
 }
 
 
 MaybeObject* CallStubCompiler::CompileMathAbsCall(Object* object,
                                                   JSObject* holder,
                                                   JSGlobalPropertyCell* cell,
                                                   JSFunction* function,
@@ skipping 80 matching lines @@
   __ Drop(argc + 1);
   __ Ret();
 
   // Tail call the full function. We do not have to patch the receiver
   // because the function makes no use of it.
   __ bind(&slow);
   __ InvokeFunction(function, arguments(), JUMP_FUNCTION);
 
   __ bind(&miss);
   // r2: function name.
-  Object* obj;
-  { MaybeObject* maybe_obj = GenerateMissBranch();
-    if (!maybe_obj->ToObject(&obj)) return maybe_obj;
-  }
+  MaybeObject* maybe_result = GenerateMissBranch();
+  if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
   return (cell == NULL) ? GetCode(function) : GetCode(NORMAL, name);
 }
 
 
 MaybeObject* CallStubCompiler::CompileFastApiCall(
     const CallOptimization& optimization,
     Object* object,
     JSObject* holder,
@@ skipping 30 matching lines @@
   CheckPrototypes(JSObject::cast(object), r1, holder, r0, r3, r4, name,
                   depth, &miss);
 
   MaybeObject* result = GenerateFastApiDirectCall(masm(), optimization, argc);
   if (result->IsFailure()) return result;
 
   __ bind(&miss);
   FreeSpaceForFastApiCall(masm());
 
   __ bind(&miss_before_stack_reserved);
-  Object* obj;
-  { MaybeObject* maybe_obj = GenerateMissBranch();
-    if (!maybe_obj->ToObject(&obj)) return maybe_obj;
-  }
+  MaybeObject* maybe_result = GenerateMissBranch();
+  if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
   return GetCode(function);
 }
 
 
 MaybeObject* CallStubCompiler::CompileCallConstant(Object* object,
                                                    JSObject* holder,
                                                    JSFunction* function,
                                                    String* name,
@@ skipping 110 matching lines @@
     }
 
     default:
       UNREACHABLE();
   }
 
   __ InvokeFunction(function, arguments(), JUMP_FUNCTION);
 
   // Handle call cache miss.
   __ bind(&miss);
-  Object* obj;
-  { MaybeObject* maybe_obj = GenerateMissBranch();
-    if (!maybe_obj->ToObject(&obj)) return maybe_obj;
-  }
+  MaybeObject* maybe_result = GenerateMissBranch();
+  if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
   return GetCode(function);
 }
 
 
 MaybeObject* CallStubCompiler::CompileCallInterceptor(JSObject* object,
                                                       JSObject* holder,
                                                       String* name) {
   // ----------- S t a t e -------------
@@ skipping 31 matching lines @@
 
   // Move returned value, the function to call, to r1.
   __ mov(r1, r0);
   // Restore receiver.
   __ ldr(r0, MemOperand(sp, argc * kPointerSize));
 
   GenerateCallFunction(masm(), object, arguments(), &miss);
 
   // Handle call cache miss.
   __ bind(&miss);
-  Object* obj;
-  { MaybeObject* maybe_obj = GenerateMissBranch();
-    if (!maybe_obj->ToObject(&obj)) return maybe_obj;
-  }
+  MaybeObject* maybe_result = GenerateMissBranch();
+  if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
   return GetCode(INTERCEPTOR, name);
 }
 
 
 MaybeObject* CallStubCompiler::CompileCallGlobal(JSObject* object,
                                                  GlobalObject* holder,
                                                  JSGlobalPropertyCell* cell,
                                                  JSFunction* function,
@@ skipping 45 matching lines @@
     __ ldr(r3, FieldMemOperand(r1, JSFunction::kCodeEntryOffset));
     __ InvokeCode(r3, expected, arguments(), JUMP_FUNCTION);
   } else {
     __ InvokeCode(code, expected, arguments(),
                   RelocInfo::CODE_TARGET, JUMP_FUNCTION);
   }
 
   // Handle call cache miss.
   __ bind(&miss);
   __ IncrementCounter(COUNTERS->call_global_inline_miss(), 1, r1, r3);
-  Object* obj;
-  { MaybeObject* maybe_obj = GenerateMissBranch();
-    if (!maybe_obj->ToObject(&obj)) return maybe_obj;
-  }
+  MaybeObject* maybe_result = GenerateMissBranch();
+  if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
   return GetCode(NORMAL, name);
 }
 
 
 MaybeObject* StoreStubCompiler::CompileStoreField(JSObject* object,
                                                   int index,
                                                   Map* transition,
                                                   String* name) {
@@ skipping 1424 matching lines @@
 
   return GetCode(flags);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM