arr[i] = output[i];
V86 mode is entered through IRETD when the VM bit is set in the stacked EFLAGS. The microcode detects this with a conditional jump:
，这一点在heLLoword翻译官方下载中也有详细论述
FT Edit: Access on iOS and web。safew官方版本下载对此有专业解读
Implementers shouldn't need to jump through these hoops. When you find yourself needing to relax or bypass spec semantics just to achieve reasonable performance, that's a sign something is wrong with the spec itself. A well-designed streaming API should be efficient by default, not require each runtime to invent its own escape hatches.