Mesa (master): st/mesa: fix transform feedback of unsubscripted gl_ClipDistance array
Marcin Åšlusarz
mslusarz at kemper.freedesktop.org
Wed Jun 20 19:25:23 UTC 2012
Module: Mesa
Branch: master
Commit: 7e63b613a5a067462c450338e0bdce5b5976f6f1
URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=7e63b613a5a067462c450338e0bdce5b5976f6f1
Author: Marcin Slusarz <marcin.slusarz at gmail.com>
Date: Sat Jun 16 20:30:14 2012 +0200
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 642e5b413e0890b2070ba78fde42db381eaf02e5 "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 59be691638200797583bce39a83f641d30d97492
"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.
---
src/mesa/state_tracker/st_extensions.c | 1 +
src/mesa/state_tracker/st_glsl_to_tgsi.cpp | 49 +++-------------------------
2 files changed, 6 insertions(+), 44 deletions(-)
diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
index 17f271f..dacad9b 100644
--- a/src/mesa/state_tracker/st_extensions.c
+++ b/src/mesa/state_tracker/st_extensions.c
@@ -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
diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index 5802b52..b6abe84 100644
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -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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