If a SPIR-V module contains for example both a geometry and a compute
shader, when processing the geometry shader its vertices out, input
primitive and output primitive attributes would get overwritten by the
value of the WorkgroupSize.
```
; SPIR-V
; Version: 1.5
; Generator: Khronos; 17
; Bound: 12
; Schema: 0
OpCapability Geometry
OpCapability Shader
%1 = OpExtInstImport "GLSL.std.450"
OpMemoryModel Logical GLSL450
OpEntryPoint Geometry %main "main"
OpEntryPoint GLCompute %main_0 "main"
OpExecutionMode %main InputPoints
OpExecutionMode %main Invocations 1
OpExecutionMode %main OutputTriangleStrip
OpExecutionMode %main OutputVertices 4
OpExecutionMode %main_0 LocalSize 1 1 1
OpSource GLSL 460
OpSource GLSL 460
OpName %main "main"
OpName %main_0 "main"
OpModuleProcessed "Linked by SPIR-V Tools Linker"
OpDecorate %gl_WorkGroupSize BuiltIn WorkgroupSize
%void = OpTypeVoid
%6 = OpTypeFunction %void
%uint = OpTypeInt 32 0
%v3uint = OpTypeVector %uint 3
%uint_1 = OpConstant %uint 1
%gl_WorkGroupSize = OpConstantComposite %v3uint %uint_1 %uint_1 %uint_1
%main = OpFunction %void None %6
%10 = OpLabel
OpReturn
OpFunctionEnd
%main_0 = OpFunction %void None %6
%11 = OpLabel
OpReturn
OpFunctionEnd
```
Running spirv_to_nir on the SPIR-V sample above and for the geometry
entry point would say that (among others):
* vertices out: 1
* input primitive: LINES
* output primitive: LINES
By removing any reference to `%gl_WorkGroupSize`, the output would
change to (among others):
* vertices out: 4
* input primitive: POINTS
* output primitive: TRIANGLE_STRIP
Fixes:
7d862ef5302 ("spirv: Rework handling of spec constant workgroup size built-ins")
v2:
* Move the check from inside `handle_workgroup_size_decoration_cb()` to
its caller (Caio Marcelo de Oliveira Filho )
* Add an assert on the shader stage before using
`workgroup_size_builtin` (Caio Marcelo de Oliveira Filho )
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Signed-off-by: Pierre Moreau <dev@pmoreau.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9418>
}
/* Now that we have the value, update the workgroup size if needed */
- vtn_foreach_decoration(b, val, handle_workgroup_size_decoration_cb, NULL);
+ if (b->entry_point_stage == MESA_SHADER_COMPUTE ||
+ b->entry_point_stage == MESA_SHADER_KERNEL)
+ vtn_foreach_decoration(b, val, handle_workgroup_size_decoration_cb,
+ NULL);
}
static void
vtn_handle_execution_mode_id, NULL);
if (b->workgroup_size_builtin) {
+ vtn_assert(stage == MESA_SHADER_COMPUTE || stage == MESA_SHADER_KERNEL);
vtn_assert(b->workgroup_size_builtin->type->type ==
glsl_vector_type(GLSL_TYPE_UINT, 3));