3 ms·
The x87 ISA does, yes, and they are supported for binary compatibility reasons. However the actual x87 registers are shadowed by the vector registers so you can
by garmaine 8y ago
The x87 ISA does, yes, and they are supported for binary compatibility reasons. However the actual x87 registers are shadowed by the vector registers so you can only use one. Any modern vectorizing compiler uses the vector instructions for FPU arithmetic, even when scalar, with a max precision of 64-bit.
- gpderetta 8y ago>The x87 ISA does, yes, and they are supported for binary compatibility reasons. Well x86-64 is not binary compatible with x86 so that's not the reason. It is mostly for software relying on either the rounding quirks or the extended 80 bit precision I guess. > However the actual x87 registers are shadowed by the vector registers so you can only use one You are confusing with the legacy MMX registers which are deader than the x87 for stack. XMM registers do not shadow the for stack.