[Mesa-dev] [PATCH 09/23] i965/vs: Map scalar VS input locations properly; avoid tons of MOVs.
Kenneth Graunke
kenneth at whitecape.org
Wed Sep 30 00:58:13 PDT 2015
Previously, we used nir_lower_io with the scalar type_size function,
which mapped VERT_ATTRIB_* locations to...some numbers. Then, in
fs_visitor::nir_setup_inputs(), we created temporaries indexed by
those numbers, and emitted MOVs from the actual ATTR registers to
those temporaries.
This patch reworks our input lowering to produce NIR lower_input
intrinsics that properly index into the ATTR file, so we can access
it directly.
No changes in shader-db.
Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
src/mesa/drivers/dri/i965/brw_fs_nir.cpp | 71 +++++++++-----------------------
src/mesa/drivers/dri/i965/brw_nir.c | 23 ++++++++++-
2 files changed, 42 insertions(+), 52 deletions(-)
diff --git a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
index 7a965cd..2997e51 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
@@ -58,61 +58,25 @@ fs_visitor::emit_nir_code()
void
fs_visitor::nir_setup_inputs(nir_shader *shader)
{
+ if (stage != MESA_SHADER_FRAGMENT)
+ return;
+
nir_inputs = bld.vgrf(BRW_REGISTER_TYPE_F, shader->num_inputs);
foreach_list_typed(nir_variable, var, node, &shader->inputs) {
- enum brw_reg_type type = brw_type_for_base_type(var->type);
fs_reg input = offset(nir_inputs, bld, var->data.driver_location);
fs_reg reg;
- switch (stage) {
- case MESA_SHADER_VERTEX: {
- /* Our ATTR file is indexed by VERT_ATTRIB_*, which is the value
- * stored in nir_variable::location.
- *
- * However, NIR's load_input intrinsics use a different index - an
- * offset into a single contiguous array containing all inputs.
- * This index corresponds to the nir_variable::driver_location field.
- *
- * So, we need to copy from fs_reg(ATTR, var->location) to
- * offset(nir_inputs, var->data.driver_location).
- */
- const glsl_type *const t = var->type->without_array();
- const unsigned components = t->components();
- const unsigned cols = t->matrix_columns;
- const unsigned elts = t->vector_elements;
- unsigned array_length = var->type->is_array() ? var->type->length : 1;
- for (unsigned i = 0; i < array_length; i++) {
- for (unsigned j = 0; j < cols; j++) {
- for (unsigned k = 0; k < elts; k++) {
- bld.MOV(offset(retype(input, type), bld,
- components * i + elts * j + k),
- offset(fs_reg(ATTR, var->data.location + i, type),
- bld, 4 * j + k));
- }
- }
- }
- break;
- }
- case MESA_SHADER_GEOMETRY:
- case MESA_SHADER_COMPUTE:
- case MESA_SHADER_TESS_CTRL:
- case MESA_SHADER_TESS_EVAL:
- unreachable("fs_visitor not used for these stages yet.");
- break;
- case MESA_SHADER_FRAGMENT:
- if (var->data.location == VARYING_SLOT_POS) {
- reg = *emit_fragcoord_interpolation(var->data.pixel_center_integer,
- var->data.origin_upper_left);
- emit_percomp(bld, fs_inst(BRW_OPCODE_MOV, bld.dispatch_width(),
- input, reg), 0xF);
- } else {
- emit_general_interpolation(input, var->name, var->type,
- (glsl_interp_qualifier) var->data.interpolation,
- var->data.location, var->data.centroid,
- var->data.sample);
- }
- break;
+ if (var->data.location == VARYING_SLOT_POS) {
+ reg = *emit_fragcoord_interpolation(var->data.pixel_center_integer,
+ var->data.origin_upper_left);
+ emit_percomp(bld, fs_inst(BRW_OPCODE_MOV, bld.dispatch_width(),
+ input, reg), 0xF);
+ } else {
+ emit_general_interpolation(input, var->name, var->type,
+ (glsl_interp_qualifier) var->data.interpolation,
+ var->data.location, var->data.centroid,
+ var->data.sample);
}
}
}
@@ -1635,8 +1599,13 @@ fs_visitor::nir_emit_intrinsic(const fs_builder &bld, nir_intrinsic_instr *instr
case nir_intrinsic_load_input: {
unsigned index = 0;
for (unsigned j = 0; j < instr->num_components; j++) {
- fs_reg src = offset(retype(nir_inputs, dest.type), bld,
- instr->const_index[0] + index);
+ fs_reg src;
+ if (stage == MESA_SHADER_VERTEX) {
+ src = offset(fs_reg(ATTR, instr->const_index[0], dest.type), bld, index);
+ } else {
+ src = offset(retype(nir_inputs, dest.type), bld,
+ instr->const_index[0] + index);
+ }
if (has_indirect)
src.reladdr = new(mem_ctx) fs_reg(get_nir_src(instr->src[0]));
index++;
diff --git a/src/mesa/drivers/dri/i965/brw_nir.c b/src/mesa/drivers/dri/i965/brw_nir.c
index 64763e0..56bd3d3 100644
--- a/src/mesa/drivers/dri/i965/brw_nir.c
+++ b/src/mesa/drivers/dri/i965/brw_nir.c
@@ -33,15 +33,36 @@ brw_nir_lower_inputs(nir_shader *nir,
bool is_scalar)
{
switch (nir->stage) {
+ case MESA_SHADER_VERTEX:
+ /* For now, leave the vec4 backend doing the old method. */
+ if (!is_scalar) {
+ nir_assign_var_locations(&nir->inputs, &nir->num_inputs,
+ type_size_vec4);
+ break;
+ }
+
+ /* Start with the location of the variable's base. */
+ foreach_list_typed(nir_variable, var, node, &nir->inputs) {
+ var->data.driver_location = var->data.location;
+ }
+
+ /* Now use nir_lower_io to walk dereference chains. Attribute arrays
+ * are loaded as one vec4 per element (or matrix column), so we use
+ * type_size_vec4 here.
+ */
+ nir_lower_io(nir, nir_var_shader_in, type_size_vec4);
+ break;
case MESA_SHADER_GEOMETRY:
foreach_list_typed(nir_variable, var, node, &nir->inputs) {
var->data.driver_location = var->data.location;
}
break;
- default:
+ case MESA_SHADER_FRAGMENT:
nir_assign_var_locations(&nir->inputs, &nir->num_inputs,
is_scalar ? type_size_scalar : type_size_vec4);
break;
+ default:
+ unreachable("unsupported scalar shader stage");
}
}
--
2.5.3
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