Hi!
Great to see this. Just a few comments...
On Thu, Nov 10, 2016 at 02:25:47PM +0000, Kyrill Tkachov wrote:
> +/* Implement TARGET_SHRINK_WRAP_GET_SEPARATE_COMPONENTS. */
> +
> +static sbitmap
> +aarch64_get_separate_components (void)
> +{
> + /* Calls to alloca further extend the stack frame and it can be messy to
> + figure out the location of the stack slots for each register.
> + For now be conservative. */
> + if (cfun->calls_alloca)
> + return NULL;
The generic code already disallows functions with alloca (in
try_shrink_wrapping_separate).
> +static void
> +aarch64_emit_prologue_components (sbitmap components)
> +{
> + rtx ptr_reg = gen_rtx_REG (Pmode, frame_pointer_needed
> + ? HARD_FRAME_POINTER_REGNUM
> + : STACK_POINTER_REGNUM);
> +
> + for (unsigned regno = R0_REGNUM; regno <= V31_REGNUM; regno++)
> + if (bitmap_bit_p (components, regno))
> + {
> + rtx reg = gen_rtx_REG (Pmode, regno);
> + HOST_WIDE_INT offset = cfun->machine->frame.reg_offset[regno];
> + if (!frame_pointer_needed)
> + offset += cfun->machine->frame.frame_size
> + - cfun->machine->frame.hard_fp_offset;
> + rtx addr = plus_constant (Pmode, ptr_reg, offset);
> + rtx mem = gen_frame_mem (Pmode, addr);
> +
> + RTX_FRAME_RELATED_P (emit_move_insn (mem, reg)) = 1;
> + }
> +}
I think you should emit the CFI notes here directly, just like for the
epilogue components.
Segher
