How many XMM registers are available on an x86 processor supporting SSE?
cpu-registers, processor, sse, x86
Solution
The number of XMM registers is fixed in all the processors that support SSE. If the CPU is in 32-bit mode, you can use 8 registers, from `xmm0` to `xmm7`, while if it's in 64-bit mode, you can address 16 registers, starting at `xmm0` up to `xmm15`. This is thanks to using the `REX.W` prefix.
Problem
How to find out the number of XMM registers on a processor which supports SSE? On Intel X5550, for example.