1. A computer-implemented method for loading an application in a reduced-thread mode, the method comprising: receiving, by a compiler, an application and an application binary interface (ABI) specification; determining that the application is to be compiled for execution by a processor in a reduced-thread mode; generating a binary by compiling the application according to the ABI specification, the generated binary being configured to be run by the processor in the reduced-thread mode, the processor supporting simultaneous multithreading (SMT), the processor having a first hardware thread with a first architected resource and a second hardware thread with a second architected resource, the first hardware thread being a primary hardware thread and the second hardware thread being a secondary hardware thread, the second hardware thread being associated with the first hardware thread such that the first hardware thread can access the second architected resource; identifying, by an operating system, that the application is to be loaded; determining whether the operating system is in the reduced-thread mode; and loading, in response to determining that the operating system is in the reduced-thread mode, the application.