freedreno/a6xx: Track location of gl_Position out as we link it

When using xfb and rasterizing, the fragment shader may have fewer
inputs than the vertex shader outputs. We can't rely on gl_Position to
be placed at fs->total_in, but have to instead remember where we add
it in the link map and use that location.

Fixes 100+ tesselation dEQPs under

  dEQP-GLES31.functional.tessellation.primitive_discard.*
  dEQP-GLES31.functional.tessellation.user_defined_io.*

Reviewed-by: Eric Anholt <[email protected]>

3 files changed, 13 insertions, 13 deletions

diff --git a/src/freedreno/registers/a6xx.xml b/src/freedreno/registers/a6xx.xml
index 13c3dcd5a01..30f0fe85093 100644
--- a/src/freedreno/registers/a6xx.xml
+++ b/src/freedreno/registers/a6xx.xml
@@ -2423,7 +2423,7 @@ to upconvert to 32b float internally?
 			hw streamout (rather than stg instructions in shader)
 		</doc>
 		<bitfield name="STRIDE_IN_VPC" low="0" high="7" type="uint"/>
-		<bitfield name="NUMNONPOSVAR" low="8" high="15" type="uint"/>
+		<bitfield name="POSITIONLOC" low="8" high="15" type="uint"/>
 		<!--
 		This seems to be the OUTLOC for the psize output.  It could possibly
 		be the max-OUTLOC position, but it is only set when VS writes psize
@@ -2434,14 +2434,10 @@ to upconvert to 32b float internally?
 
 	<reg32 offset="0x9303" name="VPC_PACK_3">
 		<doc>
-		  domain shader version
-
-			num of varyings plus four for gl_Position (plus one if gl_PointSize)
-			plus # of transform-feedback (streamout) varyings if using the
-			hw streamout (rather than stg instructions in shader)
+			domain shader version of VPC_PACK
 		</doc>
 		<bitfield name="STRIDE_IN_VPC" low="0" high="7" type="uint"/>
-		<bitfield name="NUMNONPOSVAR" low="8" high="15" type="uint"/>
+		<bitfield name="POSITIONLOC" low="8" high="15" type="uint"/>
 		<!--
 		This seems to be the OUTLOC for the psize output.  It could possibly
 		be the max-OUTLOC position, but it is only set when VS writes psize
diff --git a/src/freedreno/vulkan/tu_pipeline.c b/src/freedreno/vulkan/tu_pipeline.c
index 9964020a81f..12661f40082 100644
--- a/src/freedreno/vulkan/tu_pipeline.c
+++ b/src/freedreno/vulkan/tu_pipeline.c
@@ -523,9 +523,11 @@ tu6_emit_vpc(struct tu_cs *cs,
       ir3_find_output_regid(vs, VARYING_SLOT_POS);
    const uint32_t pointsize_regid =
       ir3_find_output_regid(vs, VARYING_SLOT_PSIZ);
-   uint32_t pointsize_loc = 0xff;
-   if (position_regid != regid(63, 0))
+   uint32_t pointsize_loc = 0xff, position_loc = 0xff;
+   if (position_regid != regid(63, 0)) {
+      position_loc = linkage.max_loc;
       ir3_link_add(&linkage, position_regid, 0xf, linkage.max_loc);
+   }
    if (pointsize_regid != regid(63, 0)) {
       pointsize_loc = linkage.max_loc;
       ir3_link_add(&linkage, pointsize_regid, 0x1, linkage.max_loc);
@@ -559,7 +561,7 @@ tu6_emit_vpc(struct tu_cs *cs,
                      0xff00ff00);
 
    tu_cs_emit_pkt4(cs, REG_A6XX_VPC_PACK, 1);
-   tu_cs_emit(cs, A6XX_VPC_PACK_NUMNONPOSVAR(fs->total_in) |
+   tu_cs_emit(cs, A6XX_VPC_PACK_POSITIONLOC(position_loc) |
                      A6XX_VPC_PACK_PSIZELOC(pointsize_loc) |
                      A6XX_VPC_PACK_STRIDE_IN_VPC(linkage.max_loc));
 
diff --git a/src/gallium/drivers/freedreno/a6xx/fd6_program.c b/src/gallium/drivers/freedreno/a6xx/fd6_program.c
index 8931d40a8e2..47ba86353b1 100644
--- a/src/gallium/drivers/freedreno/a6xx/fd6_program.c
+++ b/src/gallium/drivers/freedreno/a6xx/fd6_program.c
@@ -275,7 +275,7 @@ setup_stateobj(struct fd_ringbuffer *ring, struct fd_screen *screen,
 	uint32_t vertex_regid, instance_regid;
 	uint32_t ij_pix_regid, ij_samp_regid, ij_cent_regid, ij_size_regid;
 	enum a3xx_threadsize fssz;
-	uint8_t psize_loc = ~0;
+	uint8_t psize_loc = ~0, pos_loc = ~0;
 	int i, j;
 
 	static const struct ir3_shader_variant dummy_fs = {0};
@@ -393,8 +393,10 @@ setup_stateobj(struct fd_ringbuffer *ring, struct fd_screen *screen,
 	OUT_RING(ring, ~varmask[3]);  /* VPC_VAR[3].DISABLE */
 
 	/* a6xx appends pos/psize to end of the linkage map: */
-	if (VALIDREG(pos_regid))
+	if (VALIDREG(pos_regid)) {
+		pos_loc = l.max_loc;
 		ir3_link_add(&l, pos_regid, 0xf, l.max_loc);
+	}
 
 	if (VALIDREG(psize_regid)) {
 		psize_loc = l.max_loc;
@@ -551,7 +553,7 @@ setup_stateobj(struct fd_ringbuffer *ring, struct fd_screen *screen,
 	}
 
 	OUT_PKT4(ring, REG_A6XX_VPC_PACK, 1);
-	OUT_RING(ring, A6XX_VPC_PACK_NUMNONPOSVAR(fs->total_in) |
+	OUT_RING(ring, A6XX_VPC_PACK_POSITIONLOC(pos_loc) |
 			 A6XX_VPC_PACK_PSIZELOC(psize_loc) |
 			 A6XX_VPC_PACK_STRIDE_IN_VPC(l.max_loc));