Re: [Mesa-dev] [PATCH 13/25] radeonsi: add VS epilog

[Marek Olšák]

On Tue, Feb 16, 2016 at 5:12 PM, Nicolai Hähnle  wrote:
> On 15.02.2016 18:59, Marek Olšák wrote:
>>
>> From: Marek Olšák 
>>
>> It only exports the primitive ID.
>> Also used by TES when it's compiled as VS.
>>
>> The VS input location of the primitive ID input is v2.
>
>
> So the reason for having two unused outputs/return values of the main VS is
> so that primitive ID can get passed through without any moves? Sounds good,
> but may be worth documenting e.g. where VS_EPILOG_PRIMID_LOC is defined.

Yes, I'll add the comment.

Marek
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Re: [Mesa-dev] [PATCH 13/25] radeonsi: add VS epilog

[Nicolai Hähnle]

On 15.02.2016 18:59, Marek Olšák wrote:

From: Marek Olšák 

It only exports the primitive ID.
Also used by TES when it's compiled as VS.

The VS input location of the primitive ID input is v2.


So the reason for having two unused outputs/return values of the main VS 
is so that primitive ID can get passed through without any moves? Sounds 
good, but may be worth documenting e.g. where VS_EPILOG_PRIMID_LOC is 
defined.


Nicolai


---
  src/gallium/drivers/radeonsi/si_pipe.c   |   2 +-
  src/gallium/drivers/radeonsi/si_pipe.h   |   1 +
  src/gallium/drivers/radeonsi/si_shader.c | 172 +--
  src/gallium/drivers/radeonsi/si_shader.h |   4 +
  4 files changed, 168 insertions(+), 11 deletions(-)

diff --git a/src/gallium/drivers/radeonsi/si_pipe.c 
b/src/gallium/drivers/radeonsi/si_pipe.c
index 7ce9570..2b5ce3a 100644
--- a/src/gallium/drivers/radeonsi/si_pipe.c
+++ b/src/gallium/drivers/radeonsi/si_pipe.c
@@ -539,7 +539,7 @@ static void si_destroy_screen(struct pipe_screen* pscreen)
struct si_screen *sscreen = (struct si_screen *)pscreen;
struct si_shader_part *parts[] = {
sscreen->vs_prologs,
-   /* this will be filled with other shader parts */
+   sscreen->vs_epilogs,
};
unsigned i;

diff --git a/src/gallium/drivers/radeonsi/si_pipe.h 
b/src/gallium/drivers/radeonsi/si_pipe.h
index f4bafc2..8d98779 100644
--- a/src/gallium/drivers/radeonsi/si_pipe.h
+++ b/src/gallium/drivers/radeonsi/si_pipe.h
@@ -90,6 +90,7 @@ struct si_screen {

pipe_mutex  shader_parts_mutex;
struct si_shader_part   *vs_prologs;
+   struct si_shader_part   *vs_epilogs;
  };

  struct si_blend_color {
diff --git a/src/gallium/drivers/radeonsi/si_shader.c 
b/src/gallium/drivers/radeonsi/si_shader.c
index fbb8394..0085c43 100644
--- a/src/gallium/drivers/radeonsi/si_shader.c
+++ b/src/gallium/drivers/radeonsi/si_shader.c
@@ -129,6 +129,7 @@ static void si_init_shader_ctx(struct si_shader_context 
*ctx,
   LLVMTargetMachineRef tm,
   struct tgsi_shader_info *info);

+#define VS_EPILOG_PRIMID_LOC 2

  #define PERSPECTIVE_BASE 0
  #define LINEAR_BASE 9
@@ -2230,16 +2231,26 @@ static void si_llvm_emit_vs_epilogue(struct 
lp_build_tgsi_context *bld_base)
  "");
}

-   /* Export PrimitiveID when PS needs it. */
-   if (si_vs_exports_prim_id(ctx->shader)) {
-   outputs[i].name = TGSI_SEMANTIC_PRIMID;
-   outputs[i].sid = 0;
-   outputs[i].values[0] = bitcast(bld_base, TGSI_TYPE_FLOAT,
-  get_primitive_id(bld_base, 0));
-   outputs[i].values[1] = bld_base->base.undef;
-   outputs[i].values[2] = bld_base->base.undef;
-   outputs[i].values[3] = bld_base->base.undef;
-   i++;
+   if (ctx->is_monolithic) {
+   /* Export PrimitiveID when PS needs it. */
+   if (si_vs_exports_prim_id(ctx->shader)) {
+   outputs[i].name = TGSI_SEMANTIC_PRIMID;
+   outputs[i].sid = 0;
+   outputs[i].values[0] = bitcast(bld_base, 
TGSI_TYPE_FLOAT,
+  
get_primitive_id(bld_base, 0));
+   outputs[i].values[1] = bld_base->base.undef;
+   outputs[i].values[2] = bld_base->base.undef;
+   outputs[i].values[3] = bld_base->base.undef;
+   i++;
+   }
+   } else {
+   /* Return the primitive ID from the LLVM function. */
+   ctx->return_value =
+   LLVMBuildInsertValue(gallivm->builder,
+ctx->return_value,
+bitcast(bld_base, TGSI_TYPE_FLOAT,
+get_primitive_id(bld_base, 
0)),
+VS_EPILOG_PRIMID_LOC, "");
}

si_llvm_export_vs(bld_base, outputs, i);
@@ -3724,6 +3735,11 @@ static void create_function(struct si_shader_context 
*ctx)

for (i = 0; i < shader->selector->info.num_inputs; i++)
params[num_params++] = ctx->i32;
+
+   /* PrimitiveID output. */
+   if (!shader->key.vs.as_es && !shader->key.vs.as_ls)
+   for (i = 0; i <= VS_EPILOG_PRIMID_LOC; i++)
+   returns[num_returns++] = ctx->f32;
}
break;

@@ -3758,6 +3774,11 @@ static void create_function(struct si_shader_context 
*ctx)
params[ctx->param_tes_v = num_params++] = ctx->f32;
params[ctx->param_tes_rel_patch_id =