From: Antia Puentes Date: Sat, 28 Apr 2018 12:09:21 +0000 (+0200) Subject: compiler/nir: Add conditional lowering for gl_BaseVertex X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=0fb204fac14cd2c7cf4a04f4060d4000bf5e3d35;p=mesa.git compiler/nir: Add conditional lowering for gl_BaseVertex Reviewed-by: Jason Ekstrand --- diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h index f8e71d54a50..ec3dbf035c0 100644 --- a/src/compiler/nir/nir.h +++ b/src/compiler/nir/nir.h @@ -1930,6 +1930,12 @@ typedef struct nir_shader_compiler_options { /* Indicates that the driver only has zero-based vertex id */ bool vertex_id_zero_based; + /** + * If enabled, gl_BaseVertex will be lowered as: + * is_indexed_draw (~0/0) & firstvertex + */ + bool lower_base_vertex; + bool lower_cs_local_index_from_id; bool lower_device_index_to_zero; diff --git a/src/compiler/nir/nir_lower_system_values.c b/src/compiler/nir/nir_lower_system_values.c index 47709e9887b..487da042620 100644 --- a/src/compiler/nir/nir_lower_system_values.c +++ b/src/compiler/nir/nir_lower_system_values.c @@ -121,6 +121,21 @@ convert_block(nir_block *block, nir_builder *b) } break; + case SYSTEM_VALUE_BASE_VERTEX: + /** + * From the OpenGL 4.6 (11.1.3.9 Shader Inputs) specification: + * + * "gl_BaseVertex holds the integer value passed to the baseVertex + * parameter to the command that resulted in the current shader + * invocation. In the case where the command has no baseVertex + * parameter, the value of gl_BaseVertex is zero." + */ + if (b->shader->options->lower_base_vertex) + sysval = nir_iand(b, + nir_load_is_indexed_draw(b), + nir_load_first_vertex(b)); + break; + case SYSTEM_VALUE_INSTANCE_INDEX: sysval = nir_iadd(b, nir_load_instance_id(b),