On Binary Translation and its Consequences

The PC market is one of the toughest areas for a CPU designer to compete in. Consumers in the PC segment expect high performance across a wide range of applications, and famously expect their devices to reach beyond a constrained, curated set of use cases. Microsoft’s own Surface RT prominently failed more than a decade ago because it could not run the programs that PC users expect to just work on Windows. Recent 64-bit Arm cores from Qualcomm and others are fast enough to satisfy the performance component of the PC equation, but software compatibility presents a tougher roadblock. PC software is traditionally built for x86-64. Getting developers to offer 64-bit Arm (aarch64) versions of their programs is a slow and gradual process. Some programs may never get aarch64 ports because they’re no longer under active development and were only distributed in binary form. Arm’s PC market chances therefore ride on Microsoft’s efforts to ensure x86-64 binaries can run seamlessly on aarch64…