On Friday, June 29, 2018 5:13:52 PM PDT Jason Ekstrand wrote:
> These are very similar to the related function in nir_lower_io except
> that they don't handle per-vertex or packed things (that could be added,
> in theory) and they take a more detailed size/align function pointer.
> One day, we should consider switching nir_lower_io over to using the
> more detailed size/align functions and then we could make it use these
> helpers instead of having its own.
> ---
> src/compiler/nir/nir_deref.c | 91 ++++++++++++++++++++++++++++++++++++
> src/compiler/nir/nir_deref.h | 6 +++
> 2 files changed, 97 insertions(+)
>
> diff --git a/src/compiler/nir/nir_deref.c b/src/compiler/nir/nir_deref.c
> index 22ecde4ecca..94f91df5a0f 100644
> --- a/src/compiler/nir/nir_deref.c
> +++ b/src/compiler/nir/nir_deref.c
> @@ -120,6 +120,97 @@ nir_deref_instr_has_indirect(nir_deref_instr *instr)
> return false;
> }
>
> +static unsigned
> +type_get_array_stride(const struct glsl_type *elem_type,
> + glsl_type_size_align_func size_align)
> +{
> + unsigned elem_size, elem_align;
> + glsl_get_natural_size_align_bytes(elem_type, &elem_size, &elem_align);
> + return ALIGN_POT(elem_size, elem_align);
> +}
> +
> +static unsigned
> +struct_type_get_field_offset(const struct glsl_type *struct_type,
> + glsl_type_size_align_func size_align,
> + unsigned field_idx)
> +{
> + assert(glsl_type_is_struct(struct_type));
> + unsigned offset = 0;
> + for (unsigned i = 0; i <= field_idx; i++) {
> + unsigned elem_size, elem_align;
> + glsl_get_natural_size_align_bytes(glsl_get_struct_field(struct_type,
> i),
> + &elem_size, &elem_align);
> + offset = ALIGN_POT(offset, elem_align);
> + if (i < field_idx)
> + offset += elem_size;
> + }
> + return offset;
> +}
> +
> +unsigned
> +nir_deref_instr_get_const_offset(nir_deref_instr *deref,
> + glsl_type_size_align_func size_align)
> +{
> + nir_deref_path path;
> + nir_deref_path_init(&path, deref, NULL);
> +
> + assert(path.path[0]->deref_type == nir_deref_type_var);
> + nir_deref_instr **p = &path.path[1];
> +
> + unsigned offset = 0;
> + for (; *p; p++) {
Personally, I'd just write
for (nir_deref_instr **p = &path.path[1]; *p; p++) {
since you don't need it after the loop.
> + if ((*p)->deref_type == nir_deref_type_array) {
> + offset += nir_src_as_const_value((*p)->arr.index)->u32[0] *
> + type_get_array_stride((*p)->type, size_align);
> + } else if ((*p)->deref_type == nir_deref_type_struct) {
> + /* p starts at path[1], so this is safe */
> + nir_deref_instr *parent = *(p - 1);
> + offset += struct_type_get_field_offset(parent->type, size_align,
> + (*p)->strct.index);
> + } else {
> + unreachable("Unsupported deref type");
> + }
> + }
> +
> + nir_deref_path_finish(&path);
> +
> + return offset;
> +}
> +
> +nir_ssa_def *
> +nir_build_deref_offset(nir_builder *b, nir_deref_instr *deref,
> + glsl_type_size_align_func size_align)
> +{
> + nir_deref_path path;
> + nir_deref_path_init(&path, deref, NULL);
> +
> + assert(path.path[0]->deref_type == nir_deref_type_var);
> + nir_deref_instr **p = &path.path[1];
> +
> + nir_ssa_def *offset = nir_imm_int(b, 0);
> + for (; *p; p++) {
Ditto here.
> + if ((*p)->deref_type == nir_deref_type_array) {
> + nir_ssa_def *index = nir_ssa_for_src(b, (*p)->arr.index, 1);
> + nir_ssa_def *stride =
> + nir_imm_int(b, type_get_array_stride((*p)->type, size_align));
> + offset = nir_iadd(b, offset, nir_imul(b, index, stride));
> + } else if ((*p)->deref_type == nir_deref_type_struct) {
> + /* p starts at path[1], so this is safe */
> + nir_deref_instr *parent = *(p - 1);
> + unsigned field_offset =
> + struct_type_get_field_offset(parent->type, size_align,
> + (*p)->strct.index);
> + nir_iadd(b, offset, nir_imm_int(b, field_offset));
> + } else {
> + unreachable("Unsupported deref type");
> + }
> + }
> +
> + nir_deref_path_finish(&path);
> +
> + return offset;
> +}
> +
> bool
> nir_remove_dead_derefs_impl(nir_function_impl *impl)
> {
> diff --git a/src/compiler/nir/nir_deref.h b/src/compiler/nir/nir_deref.h
> index 0980bae7215..6f4141aaf82 100644
> --- a/src/compiler/nir/nir_deref.h
> +++ b/src/compiler/nir/nir_deref.h
> @@ -48,6 +48,12 @@ void nir_deref_path_init(nir_deref_path *path,
> nir_deref_instr *deref, void *mem_ctx);
> void nir_deref_path_finish(nir_deref_path *path);
>
> +unsigned nir_deref_instr_get_const_offset(nir_deref_instr *deref,
> + glsl_type_size_align_func
> size_align);
> +
> +nir_ssa_def *nir_build_deref_offset(nir_builder *b, nir_deref_instr *deref,
> + glsl_type_size_align_func size_align);
> +
> #ifdef __cplusplus
> } /* extern "C" */
> #endif
>
signature.asc
Description: This is a digitally signed message part.
_______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
