Commit 7e63b613 authored by Marcin Ślusarz's avatar Marcin Ślusarz

st/mesa: fix transform feedback of unsubscripted gl_ClipDistance array

gl_ClipDistance needs special treatment in form of lowering pass
which transforms gl_ClipDistance representation from float[] to
vec4[]. There are 2 implementations - at glsl linker level (enabled
by LowerClipDistance option) and at glsl_to_tgsi level (enabled
unconditionally for gallium drivers). Second implementation is
incomplete - it does not take into account transform feedback (see
commit 642e5b41 "mesa: Fix transform
feedback of unsubscripted gl_ClipDistance array" for details).

There are 2 possible fixes:
- adding transform feedback support into glsl_to_tgsi version
- ripping gl_ClipDistance support from glsl_to_tgsi and enabling
  gl_ClipDistance lowering on glsl linker side

This patch implements 2nd option. All it does is:
- reverts most of the commit 59be6916
  "st/mesa: add support for gl_ClipDistance"
- changes LowerClipDistance to true

Fixes Piglit tests "EXT_transform_feedback/builtin-varyings
gl_ClipDistance[{2,3,4,5,6,7,8}]-no-subscript" at least on nv50
and evergreen cards.
parent f2f05e50
......@@ -222,6 +222,7 @@ void st_init_limits(struct st_context *st)
options->MaxUnrollIterations = MIN2(screen->get_shader_param(screen, sh, PIPE_SHADER_CAP_MAX_INSTRUCTIONS), 65536);
else
options->MaxUnrollIterations = 255; /* SM3 limit */
options->LowerClipDistance = true;
}
/* PIPE_SHADER_CAP_MAX_INPUTS for the FS specifies the maximum number
......
......@@ -304,7 +304,6 @@ public:
int samplers_used;
bool indirect_addr_temps;
bool indirect_addr_consts;
int num_clip_distances;
int glsl_version;
bool native_integers;
......@@ -2825,7 +2824,6 @@ glsl_to_tgsi_visitor::glsl_to_tgsi_visitor()
samplers_used = 0;
indirect_addr_temps = false;
indirect_addr_consts = false;
num_clip_distances = 0;
glsl_version = 0;
native_integers = false;
mem_ctx = ralloc_context(NULL);
......@@ -4593,17 +4591,9 @@ st_translate_program(
}
for (i = 0; i < numOutputs; i++) {
if (outputSemanticName[i] == TGSI_SEMANTIC_CLIPDIST) {
int mask = ((1 << (program->num_clip_distances - 4*outputSemanticIndex[i])) - 1) & TGSI_WRITEMASK_XYZW;
t->outputs[i] = ureg_DECL_output_masked(ureg,
outputSemanticName[i],
outputSemanticIndex[i],
mask);
} else {
t->outputs[i] = ureg_DECL_output(ureg,
outputSemanticName[i],
outputSemanticIndex[i]);
}
t->outputs[i] = ureg_DECL_output(ureg,
outputSemanticName[i],
outputSemanticIndex[i]);
}
if (passthrough_edgeflags)
emit_edgeflags(t);
......@@ -4759,8 +4749,7 @@ out:
static struct gl_program *
get_mesa_program(struct gl_context *ctx,
struct gl_shader_program *shader_program,
struct gl_shader *shader,
int num_clip_distances)
struct gl_shader *shader)
{
glsl_to_tgsi_visitor* v = new glsl_to_tgsi_visitor();
struct gl_program *prog;
......@@ -4800,7 +4789,6 @@ get_mesa_program(struct gl_context *ctx,
v->options = options;
v->glsl_version = ctx->Const.GLSLVersion;
v->native_integers = ctx->Const.NativeIntegers;
v->num_clip_distances = num_clip_distances;
_mesa_generate_parameters_list_for_uniforms(shader_program, shader,
prog->Parameters);
......@@ -4925,25 +4913,6 @@ get_mesa_program(struct gl_context *ctx,
return prog;
}
/**
* Searches through the IR for a declaration of gl_ClipDistance and returns the
* declared size of the gl_ClipDistance array. Returns 0 if gl_ClipDistance is
* not declared in the IR.
*/
int get_clip_distance_size(exec_list *ir)
{
foreach_iter (exec_list_iterator, iter, *ir) {
ir_instruction *inst = (ir_instruction *)iter.get();
ir_variable *var = inst->as_variable();
if (var == NULL) continue;
if (!strcmp(var->name, "gl_ClipDistance")) {
return var->type->length;
}
}
return 0;
}
extern "C" {
struct gl_shader *
......@@ -4982,7 +4951,6 @@ st_new_shader_program(struct gl_context *ctx, GLuint name)
GLboolean
st_link_shader(struct gl_context *ctx, struct gl_shader_program *prog)
{
int num_clip_distances[MESA_SHADER_TYPES];
assert(prog->LinkStatus);
for (unsigned i = 0; i < MESA_SHADER_TYPES; i++) {
......@@ -4994,11 +4962,6 @@ st_link_shader(struct gl_context *ctx, struct gl_shader_program *prog)
const struct gl_shader_compiler_options *options =
&ctx->ShaderCompilerOptions[_mesa_shader_type_to_index(prog->_LinkedShaders[i]->Type)];
/* We have to determine the length of the gl_ClipDistance array before
* the array is lowered to two vec4s by lower_clip_distance().
*/
num_clip_distances[i] = get_clip_distance_size(ir);
do {
unsigned what_to_lower = MOD_TO_FRACT | DIV_TO_MUL_RCP |
EXP_TO_EXP2 | LOG_TO_LOG2;
......@@ -5020,7 +4983,6 @@ st_link_shader(struct gl_context *ctx, struct gl_shader_program *prog)
|| progress;
progress = lower_quadop_vector(ir, false) || progress;
progress = lower_clip_distance(ir) || progress;
if (options->MaxIfDepth == 0)
progress = lower_discard(ir) || progress;
......@@ -5055,8 +5017,7 @@ st_link_shader(struct gl_context *ctx, struct gl_shader_program *prog)
if (prog->_LinkedShaders[i] == NULL)
continue;
linked_prog = get_mesa_program(ctx, prog, prog->_LinkedShaders[i],
num_clip_distances[i]);
linked_prog = get_mesa_program(ctx, prog, prog->_LinkedShaders[i]);
if (linked_prog) {
static const GLenum targets[] = {
......
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