On Tue, Sep 30, 2025 at 01:25:06PM -0400, Jeffrey Walton wrote:
The 80-bit, 128-bit, 256-bit, 512-bit and friends are the size of registers in coprocessors, like the x87 math coprocessor, the SSE coprocessor, the AVX coprocessor, etc.
None of those are coprocessors on amd64; x86 hasn't used math coprocessors since the late 80s. So this is a matter of choosing to ignore parts of the CPU because they don't fit the model. :)