Single instruction, multiple data: Difference between revisions

Content deleted Content added
touchups in lede
Disadvantages: ARM LDM / STM
Tags: Mobile edit Mobile web edit Advanced mobile edit
Line 50:
An order of magnitude increase in code size is not uncommon, when compared to equivalent scalar or equivalent vector code, and an order of magnitude ''or greater'' effectiveness (work done per instruction) is achievable with Vector ISAs.<ref>{{cite web |last1=Patterson |first1=David |last2=Waterman |first2=Andrew |title=SIMD Instructions Considered Harmful |url=https://www.sigarch.org/simd-instructions-considered-harmful/ |website=SIGARCH |date=18 September 2017}}</ref>
 
ARM's [[Scalable Vector Extension]] takes another approach, known in [[Flynn's taxonomy#Single instruction stream, multiple data streams (SIMD)|Flynn's Taxonomy]] as "Associative Processing", more commonly known today as [[Predication (computer architecture)#SIMD, SIMT and vector predication|"Predicated" (masked)]] SIMD. This approach is not as compact as [[Vector processing]] but is still far better than non-predicated SIMD. Detailed comparative examples are given in the [[Vector processor#Vector instruction example|Vector processing]] page. In addition, all versions of the ARM architecture have offered Load and Store multiple instructions, to Load or Store a block of data from a continuous block of memory, into a range or non-continuous set of registers.
 
==Chronology==