Hi!
On Thu, 1 Mar 2018 13:17:01 -0800, Cesar Philippidis <[email protected]>
wrote:
> To reduce the size of the final patch,
> I've separated all of the misc. function and variable renaming into this
> patch.
Yes, please always do such refactoring changes independently of other
functionality changes.
> This patch also introduces a new populate_offload_attrs function.
I'm seeing:
[...]/gcc/config/nvptx/nvptx.c: In function 'void nvptx_reorg()':
[...]/gcc/config/nvptx/nvptx.c:4451:3: warning:
'oa.offload_attrs::vector_length' may be used uninitialized in this function
[-Wmaybe-uninitialized]
if (oa->vector_length == 0)
^
[...]/gcc/config/nvptx/nvptx.c:4516:21: note:
'oa.offload_attrs::vector_length' was declared here
offload_attrs oa;
^
That must be "populate_offload_attrs" inlined into "nvptx_reorg". I
can't tell yet why it complains about "vector_length" only but not about
the others.
For reference:
> --- a/gcc/config/nvptx/nvptx.c
> +++ b/gcc/config/nvptx/nvptx.c
> +/* Offloading function attributes. */
> +
> +struct offload_attrs
> +{
> + unsigned mask;
> + int num_gangs;
> + int num_workers;
> + int vector_length;
> + int max_workers;
> +};
> +static void
> +populate_offload_attrs (offload_attrs *oa)
> +{
> + tree attr = oacc_get_fn_attrib (current_function_decl);
> + tree dims = TREE_VALUE (attr);
> + unsigned ix;
> +
> + oa->mask = 0;
> +
> + for (ix = 0; ix != GOMP_DIM_MAX; ix++, dims = TREE_CHAIN (dims))
> + {
> + tree t = TREE_VALUE (dims);
> + int size = (t == NULL_TREE) ? 0 : TREE_INT_CST_LOW (t);
> + tree allowed = TREE_PURPOSE (dims);
> +
> + if (size != 1 && !(allowed && integer_zerop (allowed)))
> + oa->mask |= GOMP_DIM_MASK (ix);
> +
> + switch (ix)
> + {
> + case GOMP_DIM_GANG:
> + oa->num_gangs = size;
> + break;
> +
> + case GOMP_DIM_WORKER:
> + oa->num_workers = size;
> + break;
> +
> + case GOMP_DIM_VECTOR:
> + oa->vector_length = size;
> + break;
> + }
> + }
> +
> + if (oa->vector_length == 0)
> + {
> + /* FIXME: Need a more graceful way to handle large vector
> + lengths in OpenACC routines. */
> + if (!lookup_attribute ("omp target entrypoint",
> + DECL_ATTRIBUTES (current_function_decl)))
> + oa->vector_length = PTX_WARP_SIZE;
> + else
> + oa->vector_length = PTX_VECTOR_LENGTH;
> + }
> + if (oa->num_workers == 0)
> + oa->max_workers = PTX_CTA_SIZE / oa->vector_length;
> + else
> + oa->max_workers = oa->num_workers;
> +}
> @@ -4435,27 +4513,19 @@ nvptx_reorg (void)
> {
> /* If we determined this mask before RTL expansion, we could
> elide emission of some levels of forks and joins. */
> - unsigned mask = 0;
> - tree dims = TREE_VALUE (attr);
> - unsigned ix;
> + offload_attrs oa;
>
> - for (ix = 0; ix != GOMP_DIM_MAX; ix++, dims = TREE_CHAIN (dims))
> - {
> - int size = TREE_INT_CST_LOW (TREE_VALUE (dims));
> - tree allowed = TREE_PURPOSE (dims);
> + populate_offload_attrs (&oa);
>
> - if (size != 1 && !(allowed && integer_zerop (allowed)))
> - mask |= GOMP_DIM_MASK (ix);
> - }
> /* If there is worker neutering, there must be vector
> neutering. Otherwise the hardware will fail. */
> - gcc_assert (!(mask & GOMP_DIM_MASK (GOMP_DIM_WORKER))
> - || (mask & GOMP_DIM_MASK (GOMP_DIM_VECTOR)));
> + gcc_assert (!(oa.mask & GOMP_DIM_MASK (GOMP_DIM_WORKER))
> + || (oa.mask & GOMP_DIM_MASK (GOMP_DIM_VECTOR)));
>
> /* Discover & process partitioned regions. */
> parallel *pars = nvptx_discover_pars (&bb_insn_map);
> nvptx_process_pars (pars);
> - nvptx_neuter_pars (pars, mask, 0);
> + nvptx_neuter_pars (pars, oa.mask, 0);
> delete pars;
> }
Grüße
Thomas
