[Bug other/67841] error: unable to find a register to spill if all registers are callee-saved

[ubizjak at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67841

--- Comment #7 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to H.J. Lu from comment #6)
> ix86_expand_prologue in i386.c has
> 
>       /* The computation of the size of the re-aligned stack frame means
>          that we must allocate the size of the register save area before
>          performing the actual alignment.  Otherwise we cannot guarantee
>          that there's enough storage above the realignment point.  */
> 
> That is where unaligned SSE load/store in prologue come from.

We can also use this code for interrupt handler.