Editing Register window (section)

==Criticism==
A drawback of register windows is that context switches require saving a large number of registers to memory. The SPARC implementation always advances the register window by sixteen registers, meaning that when this happens, many of these saved registers will not even contain useful data. Some have criticized the original studies that led to the implementation of register windows, for considering only programs in isolation and ignoring multitasking workloads. <ref>{{Cite web
	| url = https://cseweb.ucsd.edu/~gbournou/CSE131/sparcstack.html
	| title = Understanding stacks and registers in the Sparc architecture(s)
	| last = Magnusson
	| first = Peter
	| date = April 1997
	| website = CSE 131 - Compiler Construction
	| publisher = [[University of San Diego]]
	| access-date = October 24, 2024
	| quote = The drawback is that upon interactions with the system the registers need to be flushed to the stack, necessitating a long sequence of writes to memory of data that is often mostly garbage. Register windows was a bad idea that was caused by simulation studies that considered only programs in isolation, as opposed to multitasking workloads, and by considering compilers with poor optimization.
}}</ref>

Register windows are not the only way to improve register performance. The group at [[Stanford University]] designing the [[Stanford MIPS|MIPS]] saw the Berkeley work and decided that the problem was not a shortage of registers, but poor utilization of the existing ones. They instead invested more time in their [[compiler]]'s [[register allocation]], making sure it wisely used the larger set available in MIPS. This resulted in reduced complexity of the chip, with one half the total number of registers, while offering potentially higher performance in those cases where a single procedure could make use of the larger visible register space. In the end, with modern compilers, MIPS makes better use of its register space even during procedure calls.{{Citation needed|date=December 2008}}