On Sun, Apr 8, 2018 at 7:21 AM, Rob Clark <robdcl...@gmail.com> wrote:
> On Tue, Apr 3, 2018 at 2:32 PM, Jason Ekstrand <ja...@jlekstrand.net> wrote:
>> ---
>> src/compiler/nir/nir_builder.h | 106
>> +++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 106 insertions(+)
>>
>> diff --git a/src/compiler/nir/nir_builder.h b/src/compiler/nir/nir_builder.h
>> index 8f7ddf1..69c7261 100644
>> --- a/src/compiler/nir/nir_builder.h
>> +++ b/src/compiler/nir/nir_builder.h
>> @@ -525,6 +525,112 @@ nir_ssa_for_alu_src(nir_builder *build, nir_alu_instr
>> *instr, unsigned srcn)
>> return nir_imov_alu(build, *src, num_components);
>> }
>>
>> +static inline nir_deref_instr *
>> +nir_build_deref_var(nir_builder *build, nir_variable *var)
>> +{
>> + nir_deref_instr *deref =
>> + nir_deref_instr_create(build->shader, nir_deref_type_var);
>> +
>> + deref->mode = var->data.mode;
>> + deref->type = var->type;
>> + deref->var = var;
>> +
>> + nir_ssa_dest_init(&deref->instr, &deref->dest, 1, 32, NULL);
>> +
>> + nir_builder_instr_insert(build, &deref->instr);
>> +
>> + return deref;
>> +}
>> +
>> +static inline nir_deref_instr *
>> +nir_build_deref_array(nir_builder *build, nir_deref_instr *parent,
>> + nir_ssa_def *index)
>> +{
>> + assert(glsl_type_is_array(parent->type) ||
>> + glsl_type_is_matrix(parent->type) ||
>> + glsl_type_is_vector(parent->type));
>> +
>> + nir_deref_instr *deref =
>> + nir_deref_instr_create(build->shader, nir_deref_type_array);
>> +
>> + deref->mode = parent->mode;
>> + deref->type = glsl_get_array_element(parent->type);
>> + deref->parent = nir_src_for_ssa(&parent->dest.ssa);
>> + deref->arr.index = nir_src_for_ssa(index);
>> +
>> + nir_ssa_dest_init(&deref->instr, &deref->dest,
>> + parent->dest.ssa.num_components,
>> + parent->dest.ssa.bit_size, NULL);
>> +
>> + nir_builder_instr_insert(build, &deref->instr);
>> +
>> + return deref;
>> +}
>> +
>> +static inline nir_deref_instr *
>> +nir_build_deref_array_wildcard(nir_builder *build, nir_deref_instr *parent)
>> +{
>> + assert(glsl_type_is_array(parent->type) ||
>> + glsl_type_is_matrix(parent->type));
>> +
>> + nir_deref_instr *deref =
>> + nir_deref_instr_create(build->shader, nir_deref_type_array_wildcard);
>> +
>> + deref->mode = parent->mode;
>> + deref->type = glsl_get_array_element(parent->type);
>> + deref->parent = nir_src_for_ssa(&parent->dest.ssa);
>> +
>> + nir_ssa_dest_init(&deref->instr, &deref->dest,
>> + parent->dest.ssa.num_components,
>> + parent->dest.ssa.bit_size, NULL);
>> +
>> + nir_builder_instr_insert(build, &deref->instr);
>> +
>> + return deref;
>> +}
>> +
>> +static inline nir_deref_instr *
>> +nir_build_deref_struct(nir_builder *build, nir_deref_instr *parent,
>> + unsigned index)
>> +{
>> + assert(glsl_type_is_struct(parent->type));
>> +
>> + nir_deref_instr *deref =
>> + nir_deref_instr_create(build->shader, nir_deref_type_struct);
>> +
>> + deref->mode = parent->mode;
>> + deref->type = glsl_get_struct_field(parent->type, index);
>> + deref->parent = nir_src_for_ssa(&parent->dest.ssa);
>> + deref->strct.index = index;
>> +
>> + nir_ssa_dest_init(&deref->instr, &deref->dest,
>> + parent->dest.ssa.num_components,
>> + parent->dest.ssa.bit_size, NULL);
>> +
>> + nir_builder_instr_insert(build, &deref->instr);
>> +
>> + return deref;
>> +}
>> +
>> +static inline nir_deref_instr *
>> +nir_build_deref_cast(nir_builder *build, nir_ssa_def *parent,
>> + nir_variable_mode mode, const struct glsl_type *type)
>
> so a couple small differences between deref_cast and what I had in
> mind for deref_ptr:
>
> 1) deref_ptr took two ssa src's, one is the input pointer (a vec2),
> and the 2nd an array idx (which can be zero), which matches the
> 'Element' parameter in the Op*PtrAccessChain instructions. Ie. a ptr
> is dereferenced as ptrval[Element].foo.bar (where ptr->foo.bar or
> (*ptr).foo.bar is just a nice way to write ptr[0].foo.bar)
>
> 2) not sure nir_variable_mode makes sense with pointers.. well maybe
> we need to add some nir_variable_mode values to differentiate between
> global/local/const memory spaces (I couldn't think of a good name for
> global since nir_var_global is already taken but has a different
> meaning). But in any case, the variable mode comes from the pointer
> value itself.
>
> Other random thought, I don't think we should allow a deref_cast (if
> that is what we use for pointers) to have a src instruction that is a
> deref instruction. We probably instead want an intrinsic that
> evaluates to the address of a deref chain. So something like:
>
> ptr2 = &ptr1->foo;
> ptr2++;
> result_val = ptr2->bar;
>
> becomes something like:
>
> vec1 64 ssa_0 = ... ptr1 address ...
> vec1 64 ssa_1 = ... ptr1 address space, ie. global/shared/const ...
> vec2 64 ssa_2 = vec2 ssa_0, ssa_1
> vec1 32 ssa_3 = deref_cast (struct.SomeStruct *)&ssa_2[0]
> vec1 32 ssa_4 = deref_struct () &ssa_3->foo
> vec2 64 ssa_5 = intrinsic address_deref (ssa_4) ()
or maybe "address_from_deref" would be a better name for this intrinsic..
> vec1 32 ssa_6 = deref_cast (struct.OtherStruct *)&ssa_5[1]
> vec2 64 ssa_7 = intrinsic address_deref (ssa_6) ()
> vec1 32 ssa_8 = deref_cast (struct.OtherStruct *)&ssa_7[0]
> vec1 32 ssa_9 = deref_struct () &ssa_8->bar
> vec1 32 ssa_10 = intrinsic load_deref (ssa_9) () /* load 'result_val' */
>
> BR,
> -R
>
>
>> +{
>> + nir_deref_instr *deref =
>> + nir_deref_instr_create(build->shader, nir_deref_type_cast);
>> +
>> + deref->mode = mode;
>> + deref->type = type;
>> + deref->parent = nir_src_for_ssa(parent);
>> +
>> + nir_ssa_dest_init(&deref->instr, &deref->dest,
>> + parent->num_components, parent->bit_size, NULL);
>> +
>> + nir_builder_instr_insert(build, &deref->instr);
>> +
>> + return deref;
>> +}
>> +
>> static inline nir_ssa_def *
>> nir_load_var(nir_builder *build, nir_variable *var)
>> {
>> --
>> 2.5.0.400.gff86faf
>>
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