rusticl/kernel: add work_dim lowering

No driver implements this in hardware, so let's implement it once in the
frontend.

Signed-off-by: Karol Herbst <kherbst@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19362>

src/gallium/frontends/rusticl/core/kernel.rs

@@ -59,6 +59,7 @@ pub enum InternalKernelArgType {
     InlineSampler((cl_addressing_mode, cl_filter_mode, bool)),
     FormatArray,
     OrderArray,
+    WorkDim,
 }
 
 #[derive(Hash, PartialEq, Eq, Clone)]
@@ -210,6 +211,7 @@ impl InternalKernelArg {
             }
             InternalKernelArgType::FormatArray => bin.push(4),
             InternalKernelArgType::OrderArray => bin.push(5),
+            InternalKernelArgType::WorkDim => bin.push(6),
         }
 
         bin
@@ -231,6 +233,7 @@ impl InternalKernelArg {
             }
             4 => InternalKernelArgType::FormatArray,
             5 => InternalKernelArgType::OrderArray,
+            6 => InternalKernelArgType::WorkDim,
             _ => return None,
         };
 
@@ -521,6 +524,20 @@ fn lower_and_optimize_nir_late(
         );
     }
 
+    if nir.reads_sysval(gl_system_value::SYSTEM_VALUE_WORK_DIM) {
+        res.push(InternalKernelArg {
+            kind: InternalKernelArgType::WorkDim,
+            size: 1,
+            offset: 0,
+        });
+        lower_state.work_dim = nir.add_var(
+            nir_variable_mode::nir_var_uniform,
+            unsafe { glsl_uint8_t_type() },
+            args.len() + res.len() - 1,
+            "work_dim",
+        );
+    }
+
     nir.pass2(
         nir_lower_vars_to_explicit_types,
         nir_variable_mode::nir_var_mem_shared
@@ -901,6 +918,9 @@ impl Kernel {
                     input.extend_from_slice(&cl_prop::<&Vec<u16>>(&tex_orders));
                     input.extend_from_slice(&cl_prop::<&Vec<u16>>(&img_orders));
                 }
+                InternalKernelArgType::WorkDim => {
+                    input.extend_from_slice(&[work_dim as u8; 1]);
+                }
             }
         }
 

src/gallium/frontends/rusticl/rusticl_nir.c

@@ -59,6 +59,9 @@ rusticl_lower_intrinsics_instr(
         return nir_load_var(b, state->const_buf);
     case nir_intrinsic_load_printf_buffer_address:
         return nir_load_var(b, state->printf_buf);
+    case nir_intrinsic_load_work_dim:
+        assert(state->work_dim);
+        return nir_u2u(b, nir_load_var(b, state->work_dim), nir_dest_bit_size(intrins->dest));
     default:
         return NULL;
     }

src/gallium/frontends/rusticl/rusticl_nir.h

@@ -4,6 +4,7 @@ struct rusticl_lower_state {
     nir_variable *printf_buf;
     nir_variable *format_arr;
     nir_variable *order_arr;
+    nir_variable *work_dim;
 };
 
 bool rusticl_lower_intrinsics(nir_shader *nir, struct rusticl_lower_state *state);