Hi!
On Mon, Apr 13, 2020 at 10:11:43AM +0800, luoxhu wrote:
> frame_pointer_needed is set to true in reload pass setup_can_eliminate,
> but regs_ever_live[31] is false, pro_and_epilogue uses it without live
> check causing CPU2006 465.tonto segment fault of loading from invalid
> addresses due to r31 not saved/restored. Thus, add HARD_FRAME_POINTER_REGNUM
> live check with frame_pointer_needed_indeed_p when generating pro_and_epilogue
> instructions.
I see.
Can you instead make a boolean variable "frame_pointer_needed_indeed",
that you set somewhere early in *logue processing? So that we can be
sure that it will not change behind our backs.
> void
> rs6000_emit_prologue_components (sbitmap components)
> {
> rs6000_stack_t *info = rs6000_stack_info ();
> - rtx ptr_reg = gen_rtx_REG (Pmode, frame_pointer_needed
> - ? HARD_FRAME_POINTER_REGNUM
> - : STACK_POINTER_REGNUM);
> + rtx ptr_reg = gen_rtx_REG (Pmode, frame_pointer_needed_indeed_p ()
> + ? HARD_FRAME_POINTER_REGNUM
> + : STACK_POINTER_REGNUM);
Yeah, I got the indent wrong there, thanks for fixing it :-)
These four cases might well be the only four you need to fix here, but
I'll double-check it tomorrow, when I'm awake ;-)
Thanks!
Segher
