[Mesa-dev] [PATCH 32/36] glsl: Translate atomic intrinsic functions on shared variables
Iago Toral
itoral at igalia.com
Tue Nov 17 01:38:28 PST 2015
On Tue, 2015-11-17 at 01:35 -0800, Jordan Justen wrote:
> On 2015-11-16 07:27:10, Iago Toral wrote:
> > hOn Sat, 2015-11-14 at 13:44 -0800, Jordan Justen wrote:
> > > When an intrinsic atomic operation is used on a shared variable, we
> > > translate it to a new 'share variable' specific intrinsic function
> > > call.
> > >
> > > For example, add call to __intrinsic_atomic_add when used on a shared
> > > variable will be translated to a call to
> > > __intrinsic_atomic_add_shared.
> > >
> > > Signed-off-by: Jordan Justen <jordan.l.justen at intel.com>
> > > ---
> > > src/glsl/lower_shared_reference.cpp | 151 ++++++++++++++++++++++++++++++++++++
> > > 1 file changed, 151 insertions(+)
> > >
> > > diff --git a/src/glsl/lower_shared_reference.cpp b/src/glsl/lower_shared_reference.cpp
> > > index 810c6b6..7ff2c0c 100644
> > > --- a/src/glsl/lower_shared_reference.cpp
> > > +++ b/src/glsl/lower_shared_reference.cpp
> > > @@ -79,6 +79,10 @@ public:
> > > ir_visitor_status visit_enter(ir_assignment *ir);
> > > void handle_assignment(ir_assignment *ir);
> > >
> > > + ir_call *lower_shared_atomic_intrinsic(ir_call *ir);
> > > + ir_call *check_for_shared_atomic_intrinsic(ir_call *ir);
> > > + ir_visitor_status visit_enter(ir_call *ir);
> > > +
> > > unsigned get_shared_offset(const ir_variable *);
> > >
> > > ir_call *shared_load(const struct glsl_type *type, ir_rvalue *offset);
> > > @@ -337,6 +341,153 @@ lower_shared_reference_visitor::shared_load(const struct glsl_type *type,
> > > return new(mem_ctx) ir_call(sig, deref_result, &call_params);
> > > }
> > >
> > > +/* Lowers the intrinsic call to a new internal intrinsic that swaps the
> > > + * access to the buffer variable in the first parameter by an offset
> > > + * and block index. This involves creating the new internal intrinsic
> > > + * (i.e. the new function signature).
> > > + */
> > > +ir_call *
> > > +lower_shared_reference_visitor::lower_shared_atomic_intrinsic(ir_call *ir)
> > > +{
> > > + /* Shared atomics usually have 2 parameters, the shared variable and an
> > > + * integer argument. The exception is CompSwap, that has an additional
> > > + * integer parameter.
> > > + */
> > > + int param_count = ir->actual_parameters.length();
> > > + assert(param_count == 2 || param_count == 3);
> > > +
> > > + /* First argument must be a scalar integer buffer variable */
> > > + exec_node *param = ir->actual_parameters.get_head();
> > > + ir_instruction *inst = (ir_instruction *) param;
> > > + assert(inst->ir_type == ir_type_dereference_variable ||
> > > + inst->ir_type == ir_type_dereference_array ||
> > > + inst->ir_type == ir_type_dereference_record ||
> > > + inst->ir_type == ir_type_swizzle);
> > > +
> > > + ir_rvalue *deref = (ir_rvalue *) inst;
> > > + assert(deref->type->is_scalar() && deref->type->is_integer());
> > > +
> > > + ir_variable *var = deref->variable_referenced();
> > > + assert(var);
> > > +
> > > + /* Compute the offset to the start if the dereference and the
> > > + * block index
> > > + */
> > > + mem_ctx = ralloc_parent(shader->ir);
> > > +
> > > + ir_rvalue *offset = NULL;
> > > + unsigned const_offset = get_shared_offset(var);
> > > + bool row_major;
> > > + int matrix_columns;
> > > + const glsl_type *iface = var->get_interface_type();
> > > + unsigned packing =
> > > + iface ? iface->interface_packing : GLSL_INTERFACE_PACKING_STD430;
> > > + buffer_access_type = shared_atomic_access;
> > > +
> > > + setup_buffer_access(var, deref,
> > > + &offset, &const_offset,
> > > + &row_major, &matrix_columns, packing);
> > > +
> > > + assert(offset);
> > > + assert(!row_major);
> > > + assert(matrix_columns == 1);
> > > +
> > > + ir_rvalue *deref_offset =
> > > + add(offset, new(mem_ctx) ir_constant(const_offset));
> > > +
> > > + /* Create the new internal function signature that will take a block
> > > + * index and offset instead of a buffer variable
> > > + */
> > > + exec_list sig_params;
> > > + ir_variable *sig_param = new(mem_ctx)
> > > + ir_variable(glsl_type::uint_type, "offset" , ir_var_function_in);
> > > + sig_params.push_tail(sig_param);
> > > +
> > > + const glsl_type *type = deref->type->base_type == GLSL_TYPE_INT ?
> > > + glsl_type::int_type : glsl_type::uint_type;
> > > + sig_param = new(mem_ctx)
> > > + ir_variable(type, "data1", ir_var_function_in);
> > > + sig_params.push_tail(sig_param);
> > > +
> > > + if (param_count == 3) {
> > > + sig_param = new(mem_ctx)
> > > + ir_variable(type, "data2", ir_var_function_in);
> > > + sig_params.push_tail(sig_param);
> > > + }
> > > +
> > > + ir_function_signature *sig =
> > > + new(mem_ctx) ir_function_signature(deref->type,
> > > + compute_shader_enabled);
> > > + assert(sig);
> > > + sig->replace_parameters(&sig_params);
> > > + sig->is_intrinsic = true;
> > > +
> > > + char func_name[64];
> > > + sprintf(func_name, "%s_shared", ir->callee_name());
> > > + ir_function *f = new(mem_ctx) ir_function(func_name);
> > > + f->add_signature(sig);
> > > +
> > > + /* Now, create the call to the internal intrinsic */
> > > + exec_list call_params;
> > > + call_params.push_tail(deref_offset);
> > > + param = ir->actual_parameters.get_head()->get_next();
> > > + ir_rvalue *param_as_rvalue = ((ir_instruction *) param)->as_rvalue();
> > > + call_params.push_tail(param_as_rvalue->clone(mem_ctx, NULL));
> > > + if (param_count == 3) {
> > > + param = param->get_next();
> > > + param_as_rvalue = ((ir_instruction *) param)->as_rvalue();
> > > + call_params.push_tail(param_as_rvalue->clone(mem_ctx, NULL));
> > > + }
> > > + ir_dereference_variable *return_deref =
> > > + ir->return_deref->clone(mem_ctx, NULL);
> > > + return new(mem_ctx) ir_call(sig, return_deref, &call_params);
> >
> > This function is almost identical to the ssbo version. Could we move
> > this to the base class instead? I guess we could pass a is_ssbo flag to
> > it so we can handle the small differences between both implementations.
>
> Yeah, I think we might be able to move more common code into the base
> class. I looked at this case a little, and it seemed like a few parts
> would make it a bit annoying to combine. Would you be okay if we save
> it for later?
Sure, that's fine too.
> -Jordan
>
> >
> > > +}
> > > +
> > > +ir_call *
> > > +lower_shared_reference_visitor::check_for_shared_atomic_intrinsic(ir_call *ir)
> > > +{
> > > + exec_list& params = ir->actual_parameters;
> > > +
> > > + if (params.length() < 2)
> > > + return ir;
> > > +
> > > + ir_rvalue *rvalue =
> > > + ((ir_instruction *) params.get_head())->as_rvalue();
> > > + if (!rvalue)
> > > + return ir;
> > > +
> > > + ir_variable *var = rvalue->variable_referenced();
> > > + if (!var || var->data.mode != ir_var_shader_shared)
> > > + return ir;
> > > +
> > > + const char *callee = ir->callee_name();
> > > + if (!strcmp("__intrinsic_atomic_add", callee) ||
> > > + !strcmp("__intrinsic_atomic_min", callee) ||
> > > + !strcmp("__intrinsic_atomic_max", callee) ||
> > > + !strcmp("__intrinsic_atomic_and", callee) ||
> > > + !strcmp("__intrinsic_atomic_or", callee) ||
> > > + !strcmp("__intrinsic_atomic_xor", callee) ||
> > > + !strcmp("__intrinsic_atomic_exchange", callee) ||
> > > + !strcmp("__intrinsic_atomic_comp_swap", callee)) {
> > > + return lower_shared_atomic_intrinsic(ir);
> > > + }
> > > +
> > > + return ir;
> > > +}
> > > +
> > > +ir_visitor_status
> > > +lower_shared_reference_visitor::visit_enter(ir_call *ir)
> > > +{
> > > + ir_call *new_ir = check_for_shared_atomic_intrinsic(ir);
> > > + if (new_ir != ir) {
> > > + progress = true;
> > > + base_ir->replace_with(new_ir);
> > > + return visit_continue_with_parent;
> > > + }
> > > +
> > > + return rvalue_visit(ir);
> > > +}
> > > +
> > > } /* unnamed namespace */
> > >
> > > void
> >
> >
>
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