| Index: src/x64/full-codegen-x64.cc | 
| diff --git a/src/x64/full-codegen-x64.cc b/src/x64/full-codegen-x64.cc | 
| index 1d9b8fffc2ba31442de8df8b9edddc25620ef549..d2775129e40fde3de16ddc5e49174c4e261f6ed5 100644 | 
| --- a/src/x64/full-codegen-x64.cc | 
| +++ b/src/x64/full-codegen-x64.cc | 
| @@ -2658,9 +2658,12 @@ void FullCodeGenerator::EmitRandomHeapNumber(ZoneList<Expression*>* args) { | 
| // The fresh HeapNumber is in rbx, which is callee-save on both x64 ABIs. | 
| __ PrepareCallCFunction(1); | 
| #ifdef _WIN64 | 
| -  __ LoadAddress(rcx, ExternalReference::isolate_address()); | 
| +  __ movq(rcx, ContextOperand(context_register(), Context::GLOBAL_INDEX)); | 
| +  __ movq(rcx, FieldOperand(rcx, GlobalObject::kGlobalContextOffset)); | 
| + | 
| #else | 
| -  __ LoadAddress(rdi, ExternalReference::isolate_address()); | 
| +  __ movq(rdi, ContextOperand(context_register(), Context::GLOBAL_INDEX)); | 
| +  __ movq(rdi, FieldOperand(rdi, GlobalObject::kGlobalContextOffset)); | 
| #endif | 
| __ CallCFunction(ExternalReference::random_uint32_function(isolate()), 1); | 
|  | 
|  |