diff options
Diffstat (limited to 'src/compiler/nir/nir_lower_system_values.c')
| -rw-r--r-- | src/compiler/nir/nir_lower_system_values.c | 49 |
1 files changed, 48 insertions, 1 deletions
diff --git a/src/compiler/nir/nir_lower_system_values.c b/src/compiler/nir/nir_lower_system_values.c index fbc40573579..08a9e8be44a 100644 --- a/src/compiler/nir/nir_lower_system_values.c +++ b/src/compiler/nir/nir_lower_system_values.c @@ -51,6 +51,45 @@ build_local_group_size(nir_builder *b) return local_size; } +static nir_ssa_def * +build_local_invocation_id(nir_builder *b) +{ + if (b->shader->options->lower_cs_local_id_from_index) { + /* We lower gl_LocalInvocationID from gl_LocalInvocationIndex based + * on this formula: + * + * gl_LocalInvocationID.x = + * gl_LocalInvocationIndex % gl_WorkGroupSize.x; + * gl_LocalInvocationID.y = + * (gl_LocalInvocationIndex / gl_WorkGroupSize.x) % + * gl_WorkGroupSize.y; + * gl_LocalInvocationID.z = + * (gl_LocalInvocationIndex / + * (gl_WorkGroupSize.x * gl_WorkGroupSize.y)) % + * gl_WorkGroupSize.z; + * + * However, the final % gl_WorkGroupSize.z does nothing unless we + * accidentally end up with a gl_LocalInvocationIndex that is too + * large so it can safely be omitted. + */ + nir_ssa_def *local_index = nir_load_local_invocation_index(b); + nir_ssa_def *local_size = build_local_group_size(b); + + nir_ssa_def *id_x, *id_y, *id_z; + id_x = nir_umod(b, local_index, + nir_channel(b, local_size, 0)); + id_y = nir_umod(b, nir_udiv(b, local_index, + nir_channel(b, local_size, 0)), + nir_channel(b, local_size, 1)); + id_z = nir_udiv(b, local_index, + nir_imul(b, nir_channel(b, local_size, 0), + nir_channel(b, local_size, 1))); + return nir_vec3(b, id_x, id_y, id_z); + } else { + return nir_load_local_invocation_id(b); + } +} + static bool convert_block(nir_block *block, nir_builder *b) { @@ -91,7 +130,7 @@ convert_block(nir_block *block, nir_builder *b) */ nir_ssa_def *group_size = build_local_group_size(b); nir_ssa_def *group_id = nir_load_work_group_id(b); - nir_ssa_def *local_id = nir_load_local_invocation_id(b); + nir_ssa_def *local_id = build_local_invocation_id(b); sysval = nir_iadd(b, nir_imul(b, group_id, group_size), local_id); break; @@ -126,6 +165,14 @@ convert_block(nir_block *block, nir_builder *b) break; } + case SYSTEM_VALUE_LOCAL_INVOCATION_ID: + /* If lower_cs_local_id_from_index is true, then we derive the local + * index from the local id. + */ + if (b->shader->options->lower_cs_local_id_from_index) + sysval = build_local_invocation_id(b); + break; + case SYSTEM_VALUE_LOCAL_GROUP_SIZE: { sysval = build_local_group_size(b); break; |