nir: avoid generating conflicting output variables

Because not all vertex outputs can have corresponding fragment inputs
(eg. edgeflags) some logic is needed to correctly generate variables in
a passthough gs.

Before this change some output variables ened up with the same location.

Fixes: d0342e28b3 ("nir: Add helper to create passthrough GS shader")

Acked-by: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/21238>
This commit is contained in:
antonino
2023-02-20 19:26:20 +01:00
committed by Marge Bot
parent ea14579f3d
commit edecb66b01

View File

@@ -49,7 +49,7 @@ nir_create_passthrough_gs(const nir_shader_compiler_options *options,
nir_variable *in_vars[VARYING_SLOT_MAX];
nir_variable *out_vars[VARYING_SLOT_MAX];
unsigned num_vars = 0;
unsigned num_inputs = 0, num_outputs = 0;
/* Create input/output variables. */
nir_foreach_shader_out_variable(var, prev_stage) {
@@ -72,6 +72,15 @@ nir_create_passthrough_gs(const nir_shader_compiler_options *options,
in->data.interpolation = var->data.interpolation;
in->data.compact = var->data.compact;
in_vars[num_inputs++] = in;
nir->num_inputs++;
if (in->data.location == VARYING_SLOT_EDGE)
continue;
if (var->data.location != VARYING_SLOT_POS)
nir->num_outputs++;
if (var->name)
snprintf(name, sizeof(name), "out_%s", var->name);
else
@@ -85,8 +94,7 @@ nir_create_passthrough_gs(const nir_shader_compiler_options *options,
out->data.interpolation = var->data.interpolation;
out->data.compact = var->data.compact;
in_vars[num_vars] = in;
out_vars[num_vars++] = out;
out_vars[num_outputs++] = out;
}
unsigned int start_vert = 0;
@@ -109,11 +117,15 @@ nir_create_passthrough_gs(const nir_shader_compiler_options *options,
for (unsigned i = start_vert; i < end_vert; i += vert_step) {
/* Copy inputs to outputs. */
for (unsigned j = 0; j < num_vars; ++j) {
for (unsigned j = 0, oj = 0; j < num_inputs; ++j) {
if (in_vars[j]->data.location == VARYING_SLOT_EDGE) {
continue;
}
/* no need to use copy_var to save a lower pass */
nir_ssa_def *value = nir_load_array_var_imm(&b, in_vars[j], i);
nir_store_var(&b, out_vars[j], value,
nir_store_var(&b, out_vars[oj], value,
(1u << value->num_components) - 1);
++oj;
}
nir_emit_vertex(&b, 0);
}