[Bug target/94743] IRQ handler doesn't save scratch VFP registers

[clyon at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94743

--- Comment #9 from Christophe Lyon <clyon at gcc dot gnu.org> ---

> My initial thoughts are along the lines of...
> Only try to save FP registers that this function directly clobbers.
What's the point of saving these if a callee clobbers other registers?

Shouldn't that be something like save-nothing vs save-all-FP-regs if there is a
callee?

Do you mean save direct clobbers only when the handler is a leaf function?

> Provide libgcc routines to save/restore the FP context.
Do you mean such routines should push all FP regs+status regs?

> Or we could say simply:
> interrupt routines should be compiled as if with -mgeneral-regs-only and if
> they want to call some routine that uses FP then they must take it upon
> themselves to save and restore the FP context.