radeonsi: fix gl_InstanceID with non-zero start_instance

start_instance doesn't affect gl_InstanceID.

There's no piglit test, but it's kinda obvious the code was wrong.

Reviewed-by: Christian König <christian.koenig@amd.com>

diff --git a/src/gallium/drivers/radeonsi/radeonsi_shader.c b/src/gallium/drivers/radeonsi/radeonsi_shader.c
index 80dd773..867a385 100644 (file)
--- a/src/gallium/drivers/radeonsi/radeonsi_shader.c
+++ b/src/gallium/drivers/radeonsi/radeonsi_shader.c
@@ -122,7 +122,7 @@ static LLVMValueRef build_indexed_load(
        return result;
 }
 
-static LLVMValueRef get_instance_index(
+static LLVMValueRef get_instance_index_for_fetch(
        struct radeon_llvm_context * radeon_bld,
        unsigned divisor)
 {
@@ -174,7 +174,7 @@ static void declare_input_vs(
        if (divisor) {
                /* Build index from instance ID, start instance and divisor */
                si_shader_ctx->shader->shader.uses_instanceid = true;
-               buffer_index = get_instance_index(&si_shader_ctx->radeon_bld, divisor);
+               buffer_index = get_instance_index_for_fetch(&si_shader_ctx->radeon_bld, divisor);
        } else {
                /* Load the buffer index, which is always stored in VGPR0
                 * for Vertex Shaders */
@@ -414,7 +414,8 @@ static void declare_system_value(
 
        switch (decl->Semantic.Name) {
        case TGSI_SEMANTIC_INSTANCEID:
-               value = get_instance_index(radeon_bld, 1);
+               value = LLVMGetParam(radeon_bld->main_fn,
+                                    si_shader_ctx->param_instance_id);
                break;
 
        case TGSI_SEMANTIC_VERTEXID: