On Fri, Dec 16, 2016 at 07:48:01PM +0300, Alexander Monakov wrote:
> Until a recent change, crtl->is_leaf was initialized only during IRA startup.
> On NVPTX, register allocation is not done, so the backend asserts that this
> field is unset, and recomputes it unconditionally.
>
> Now this field can be optionally set via ira_setup_eliminable_regset for
> register-pressure-sensitive optimizations, so the assumption in the backend no
> longer holds. Remove the assert, but avoid recomputing the field if it is
> already set, indicating that the function is known to be leaf.
>
> OK to apply?
>
> Thanks.
> Alexander
>
> PR target/78831
> * config/nvptx/nvptx.c (init_softstack_frame): Remove assert. Compute
> crtl->is_leaf only if unset. Adjust comment.
LGTM, but please give Bernd a few days to chime in.
> diff --git a/gcc/config/nvptx/nvptx.c b/gcc/config/nvptx/nvptx.c
> index 17fe551..b3f025f 100644
> --- a/gcc/config/nvptx/nvptx.c
> +++ b/gcc/config/nvptx/nvptx.c
> @@ -1048,9 +1048,10 @@ init_softstack_frame (FILE *file, unsigned alignment,
> HOST_WIDE_INT size)
> bits, reg_stack, reg_frame, size);
>
> /* Usually 'crtl->is_leaf' is computed during register allocator
> - initialization, which is not done on NVPTX. Compute it now. */
> - gcc_assert (!crtl->is_leaf);
> - crtl->is_leaf = leaf_function_p ();
> + initialization (which is not done on NVPTX) or for pressure-sensitive
> + optimizations. Initialize it here, except if already set. */
> + if (!crtl->is_leaf)
> + crtl->is_leaf = leaf_function_p ();
> if (!crtl->is_leaf)
> fprintf (file, "\t\tst.shared.u%d [%s], %s;\n",
> bits, reg_sspslot, reg_stack);
Jakub
