3 files changed, 16 insertions, 2 deletions
diff --git a/src/gallium/drivers/radeonsi/si_shader.c b/src/gallium/drivers/radeonsi/si_shader.c
index 42a3fc6a73b..6788255f62b 100644
--- a/src/gallium/drivers/radeonsi/si_shader.c
+++ b/src/gallium/drivers/radeonsi/si_shader.c
@@ -169,6 +169,7 @@ static int si_store_shader_io_attribs(struct si_shader *shader,
 		assert(i < Elements(shader->input));
 		shader->input[i].name = d->Semantic.Name;
 		shader->input[i].sid = d->Semantic.Index;
+		shader->input[i].index = d->Range.First;
 		shader->input[i].interpolate = d->Interp.Interpolate;
 		shader->input[i].centroid = d->Interp.Centroid;
 		return -1;
@@ -258,7 +259,9 @@ static void declare_input_gs(
 	struct si_shader *shader = &si_shader_ctx->shader->shader;
 
 	si_store_shader_io_attribs(shader, decl);
-	shader->input[input_index].param_offset = shader->nparam++;
+
+	if (decl->Semantic.Name != TGSI_SEMANTIC_PRIMID)
+		shader->input[input_index].param_offset = shader->nparam++;
 }
 
 static LLVMValueRef fetch_input_gs(
@@ -279,6 +282,15 @@ static LLVMValueRef fetch_input_gs(
 	LLVMValueRef args[9];
 	unsigned vtx_offset_param;
 
+	if (swizzle != ~0 &&
+	    shader->input[reg->Register.Index].name == TGSI_SEMANTIC_PRIMID) {
+		if (swizzle == 0)
+			return LLVMGetParam(si_shader_ctx->radeon_bld.main_fn,
+					    SI_PARAM_PRIMITIVE_ID);
+		else
+			return uint->zero;
+	}
+
 	if (!reg->Register.Dimension)
 		return NULL;
 
@@ -1040,6 +1052,7 @@ handle_semantic:
 		case TGSI_SEMANTIC_CLIPVERTEX:
 			si_llvm_emit_clipvertex(bld_base, pos_args, outputs[i].values);
 			continue;
+		case TGSI_SEMANTIC_PRIMID:
 		case TGSI_SEMANTIC_FOG:
 		case TGSI_SEMANTIC_GENERIC:
 			target = V_008DFC_SQ_EXP_PARAM + param_count;
diff --git a/src/gallium/drivers/radeonsi/si_shader.h b/src/gallium/drivers/radeonsi/si_shader.h
index 32999066cc5..d11d34646ac 100644
--- a/src/gallium/drivers/radeonsi/si_shader.h
+++ b/src/gallium/drivers/radeonsi/si_shader.h
@@ -93,6 +93,7 @@ struct si_shader_input {
 	unsigned		name;
 	int			sid;
 	unsigned		param_offset;
+	unsigned		index;
 	unsigned		interpolate;
 	bool			centroid;
 };
diff --git a/src/gallium/drivers/radeonsi/si_state_draw.c b/src/gallium/drivers/radeonsi/si_state_draw.c
index 66b7ef3e046..e770edd7f45 100644
--- a/src/gallium/drivers/radeonsi/si_state_draw.c
+++ b/src/gallium/drivers/radeonsi/si_state_draw.c
@@ -122,7 +122,7 @@ static void si_pipe_shader_gs(struct pipe_context *ctx, struct si_pipe_shader *s
 	si_pm4_set_reg(pm4, R_028A68_VGT_GSVS_RING_OFFSET_3, gsvs_itemsize);
 
 	si_pm4_set_reg(pm4, R_028AAC_VGT_ESGS_RING_ITEMSIZE,
-		       shader->shader.ninput * (16 >> 2));
+		       shader->shader.nparam * (16 >> 2));
 	si_pm4_set_reg(pm4, R_028AB0_VGT_GSVS_RING_ITEMSIZE, gsvs_itemsize);
 
 	si_pm4_set_reg(pm4, R_028B38_VGT_GS_MAX_VERT_OUT, gs_max_vert_out);