CPU学习笔记(2)[2]

> to stack space usage, such as embedded systems and operating system kernels,
> may want to reduce the preferred alignment to
> @samp.
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Who has to align the stack for calls to a function - the caller or the
> callee? In other words: Does this mean that the stack has to be
> aligned before calling a function? Or does it have to be aligned when
> entering a function?
>
> Andreas
> --
> Andreas Jaeger
> SuSE Labs aj@suse.de
> private aj@arthur.inka.de
> http://www.suse.de/~aj
I believe the preferred alignment for long double is a 16 byte boundary, and
the stack (and instruction) alignments must be so set before entering a function.
Pentium 4 increases preferred data alignments to 32 bytes in some situations,
as well as increasing the number of situations (SSE2 instructions) where 16 byte
alignment is needed.


从这里可以看到，栈对齐是在调用函数之前就必须保证的：

the stack (and instruction) alignments must be so set before entering a function


相关文档：

X86汇编语言学习手记(1)
CPU学习笔记(1)
Cache Cohernce with Multi-Processor