During its DevSummit developer event, ARM has announced that it will drop support for 32-bit architecture in its CPUs. The change will be applicable from 2022, but the impact on the app ecosystem could be felt a bit earlier.
ARM's VP and GM of Client Business at ARM made this announcement during the keynote event of its DevSummit yesterday. This implies that future smartphones using ARM's 64-bit chips will not support legacy 32-bit apps.
Incidentally, ARM plans to launch pure 64-bit architecture chips in 2022. However, consumer devices may come out a bit later, maybe even in 2023. This is because third-party manufacturers like Qualcomm and Mediatek will need to adopt these new designs.
ARMs motivation to move to pure 64-bit architectures is for enhanced performance and efficiency. 64-bit systems are designed to perform better over legacy 32-bit systems. So far, ARM has been supporting both 32-bit and 64-bit architectures in its chips.
Supporting legacy 32-bit systems increases maintenance work and results in bulkier chips. As confirmed by ARM, from 2022 the Cortex-A cores (the "big" cores in its big.LITTLE architecture) will not support 32-bit architectures.
Incidentally, the LITTLE chips in this big.LITTLE architecture will still support 32-bit systems and code. Though, this means that some of the higher-end chips not using this specific architecture would be purely 64-bit.
ARM's big.LITTLE architecture combines battery-saving and slower processor cores (LITTLE) and comparatively more powerful "big" cores. The idea is to have the LITTLE cores used for daily driving tasks, while the powerful big cores come into play for computing extensive tasks – like gaming.
ARM drops 32-bit architecture support, how does it impact Android?
The impact in the near future on Android is expected to be negligible. Since August 2019, Google has mandated that new apps and app updates should support 64-bit architecture.
Google had introduced support for 64-bit architecture Android, way back in 2014. Apple had followed suit in 2015, and by 2017, Apple had dropped 32-bit support from iOS completely.
It is evident, with ARM dropping support for 32-bit architecture, Apple will not be impacted.
As a matter of fact, Google is pushing app developers towards making Android a pure 64-bit mobile OS as well. However, Google has allowed some existing games to continue receiving 32-bit updates until August 2021.
Though, from next year onwards, 64-bit device users won't find 32-bit apps in the Google Play store. While the impact is not as drastic, Android app developers have enough time to update their legacy 32-bit apps to 64-bit.
With ARM now pushing pure 64-bit cores and CPUs, we will see how Qualcomm responds to its custom Kryo cores.