r600g: fix up vs export handling

Certain attributes (position, psize, etc.) don't
count as params; they are handled separately by the hw.
However, the VS is required to export at least one param
and r600_shader_from_tgsi() takes care of adding a dummy
export if there is none.  Make sure the VS param export
count in the SPI properly accounts for this.

Note: This is a candidate for the 7.11 branch.

Signed-off-by: Alex Deucher <[email protected]>

4 files changed, 27 insertions, 4 deletions

diff --git a/src/gallium/drivers/r600/evergreen_state.c b/src/gallium/drivers/r600/evergreen_state.c
index 152c5cf13a0..bc6039dd40c 100644
--- a/src/gallium/drivers/r600/evergreen_state.c
+++ b/src/gallium/drivers/r600/evergreen_state.c
@@ -2298,7 +2298,7 @@ void evergreen_pipe_shader_vs(struct pipe_context *ctx, struct r600_pipe_shader
 	struct r600_pipe_state *rstate = &shader->rstate;
 	struct r600_shader *rshader = &shader->shader;
 	unsigned spi_vs_out_id[10];
-	unsigned i, tmp;
+	unsigned i, tmp, nparams;
 
 	/* clear previous register */
 	rstate->nregs = 0;
@@ -2317,9 +2317,17 @@ void evergreen_pipe_shader_vs(struct pipe_context *ctx, struct r600_pipe_shader
 					spi_vs_out_id[i], 0xFFFFFFFF, NULL);
 	}
 
+	/* Certain attributes (position, psize, etc.) don't count as params.
+	 * VS is required to export at least one param and r600_shader_from_tgsi()
+	 * takes care of adding a dummy export.
+	 */
+	nparams = rshader->noutput - rshader->npos;
+	if (nparams < 1)
+		nparams = 1;
+
 	r600_pipe_state_add_reg(rstate,
 			R_0286C4_SPI_VS_OUT_CONFIG,
-			S_0286C4_VS_EXPORT_COUNT(rshader->noutput - 1),
+			S_0286C4_VS_EXPORT_COUNT(nparams - 1),
 			0xFFFFFFFF, NULL);
 	r600_pipe_state_add_reg(rstate,
 			R_028860_SQ_PGM_RESOURCES_VS,
diff --git a/src/gallium/drivers/r600/r600_shader.c b/src/gallium/drivers/r600/r600_shader.c
index 494f9370597..fc56656f55d 100644
--- a/src/gallium/drivers/r600/r600_shader.c
+++ b/src/gallium/drivers/r600/r600_shader.c
@@ -332,6 +332,12 @@ static int tgsi_declaration(struct r600_shader_ctx *ctx)
 		ctx->shader->output[i].sid = d->Semantic.Index;
 		ctx->shader->output[i].gpr = ctx->file_offset[TGSI_FILE_OUTPUT] + i;
 		ctx->shader->output[i].interpolate = d->Declaration.Interpolate;
+		if (ctx->type == TGSI_PROCESSOR_VERTEX) {
+			/* these don't count as vertex param exports */
+			if ((ctx->shader->output[i].name == TGSI_SEMANTIC_POSITION) ||
+			    (ctx->shader->output[i].name == TGSI_SEMANTIC_PSIZE))
+				ctx->shader->npos++;
+		}
 		break;
 	case TGSI_FILE_CONSTANT:
 	case TGSI_FILE_TEMPORARY:
diff --git a/src/gallium/drivers/r600/r600_shader.h b/src/gallium/drivers/r600/r600_shader.h
index 3ba84bd8907..600c3e2f540 100644
--- a/src/gallium/drivers/r600/r600_shader.h
+++ b/src/gallium/drivers/r600/r600_shader.h
@@ -40,6 +40,7 @@ struct r600_shader {
 	struct r600_bc		bc;
 	unsigned		ninput;
 	unsigned		noutput;
+	unsigned		npos;
 	unsigned		nlds;
 	struct r600_shader_io	input[32];
 	struct r600_shader_io	output[32];
diff --git a/src/gallium/drivers/r600/r600_state.c b/src/gallium/drivers/r600/r600_state.c
index 294c400caa1..1350a1cf565 100644
--- a/src/gallium/drivers/r600/r600_state.c
+++ b/src/gallium/drivers/r600/r600_state.c
@@ -2062,7 +2062,7 @@ void r600_pipe_shader_vs(struct pipe_context *ctx, struct r600_pipe_shader *shad
 	struct r600_pipe_state *rstate = &shader->rstate;
 	struct r600_shader *rshader = &shader->shader;
 	unsigned spi_vs_out_id[10];
-	unsigned i, tmp;
+	unsigned i, tmp, nparams;
 
 	/* clear previous register */
 	rstate->nregs = 0;
@@ -2084,9 +2084,17 @@ void r600_pipe_shader_vs(struct pipe_context *ctx, struct r600_pipe_shader *shad
 					spi_vs_out_id[i], 0xFFFFFFFF, NULL);
 	}
 
+	/* Certain attributes (position, psize, etc.) don't count as params.
+	 * VS is required to export at least one param and r600_shader_from_tgsi()
+	 * takes care of adding a dummy export.
+	 */
+	nparams = rshader->noutput - rshader->npos;
+	if (nparams < 1)
+		nparams = 1;
+
 	r600_pipe_state_add_reg(rstate,
 			R_0286C4_SPI_VS_OUT_CONFIG,
-			S_0286C4_VS_EXPORT_COUNT(rshader->noutput - 1),
+			S_0286C4_VS_EXPORT_COUNT(nparams - 1),
 			0xFFFFFFFF, NULL);
 	r600_pipe_state_add_reg(rstate,
 			R_028868_SQ_PGM_RESOURCES_VS,