nir: Add nir_builder support for individual system value loads.

The previous nir_load_system_value(b, nir_intrinsic_load_whatever), 0) was
rather verbose, when system values should be easy to generate.

The index is left out because only one system value had an index included
in it.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/compiler/nir/nir_builder.h

@@ -465,6 +465,7 @@ nir_copy_var(nir_builder *build, nir_variable *dest, nir_variable *src)
    nir_builder_instr_insert(build, &copy->instr);
 }
 
+/* Generic builder for system values. */
 static inline nir_ssa_def *
 nir_load_system_value(nir_builder *build, nir_intrinsic_op op, int index)
 {
@@ -477,6 +478,20 @@ nir_load_system_value(nir_builder *build, nir_intrinsic_op op, int index)
    return &load->dest.ssa;
 }
 
+/* Generate custom builders for system values. */
+#define INTRINSIC(name, num_srcs, src_components, has_dest, dest_components, \
+                  num_variables, num_indices, idx0, idx1, idx2, flags)
+#define LAST_INTRINSIC(name)
+
+#define DEFINE_SYSTEM_VALUE(name)                                        \
+   static inline nir_ssa_def *                                           \
+   nir_load_##name(nir_builder *build)                                   \
+   {                                                                     \
+      return nir_load_system_value(build, nir_intrinsic_load_##name, 0); \
+   }                                                                     \
+
+#include "nir_intrinsics.h"
+
 static inline nir_ssa_def *
 nir_load_barycentric(nir_builder *build, nir_intrinsic_op op,
                      unsigned interp_mode)

src/compiler/nir/nir_intrinsics.h

@@ -41,7 +41,6 @@
 
 #define ARR(...) { __VA_ARGS__ }
 
-
 INTRINSIC(load_var, 0, ARR(0), true, 0, 1, 0, xx, xx, xx, NIR_INTRINSIC_CAN_ELIMINATE)
 INTRINSIC(store_var, 1, ARR(0), false, 0, 1, 1, WRMASK, xx, xx, 0)
 INTRINSIC(copy_var, 0, ARR(0), false, 0, 2, 0, xx, xx, xx, 0)
@@ -277,7 +276,13 @@ INTRINSIC(shared_atomic_xor, 2, ARR(1, 1), true, 1, 0, 1, BASE, xx, xx, 0)
 INTRINSIC(shared_atomic_exchange, 2, ARR(1, 1), true, 1, 0, 1, BASE, xx, xx, 0)
 INTRINSIC(shared_atomic_comp_swap, 3, ARR(1, 1, 1), true, 1, 0, 1, BASE, xx, xx, 0)
 
+/* Used by nir_builder.h to generate loader helpers for the system values. */
+#ifndef DEFINE_SYSTEM_VALUE
+#define DEFINE_SYSTEM_VALUE(name)
+#endif
+
 #define SYSTEM_VALUE(name, components, num_indices, idx0, idx1, idx2) \
+   DEFINE_SYSTEM_VALUE(name) \
    INTRINSIC(load_##name, 0, ARR(0), true, components, 0, num_indices, \
    idx0, idx1, idx2, \
    NIR_INTRINSIC_CAN_ELIMINATE | NIR_INTRINSIC_CAN_REORDER)
@@ -406,5 +411,6 @@ STORE(shared, 2, 2, BASE, WRMASK, xx, 0)
 
 LAST_INTRINSIC(store_shared)
 
+#undef DEFINE_SYSTEM_VALUE
 #undef INTRINSIC
 #undef LAST_INTRINSIC

src/compiler/nir/nir_lower_system_values.c

@@ -62,10 +62,8 @@ convert_block(nir_block *block, nir_builder *b)
          local_size.u32[1] = b->shader->info.cs.local_size[1];
          local_size.u32[2] = b->shader->info.cs.local_size[2];
 
-         nir_ssa_def *group_id =
+         nir_ssa_def *group_id = nir_load_work_group_id(b);
-            nir_load_system_value(b, nir_intrinsic_load_work_group_id, 0);
+         nir_ssa_def *local_id = nir_load_local_invocation_id(b);
-         nir_ssa_def *local_id =
-            nir_load_system_value(b, nir_intrinsic_load_local_invocation_id, 0);
 
          sysval = nir_iadd(b, nir_imul(b, group_id,
                                        nir_build_imm(b, 3, 32, local_size)),
@@ -87,8 +85,7 @@ convert_block(nir_block *block, nir_builder *b)
           *    gl_WorkGroupSize.y + gl_LocalInvocationID.y *
           *    gl_WorkGroupSize.x + gl_LocalInvocationID.x"
           */
-         nir_ssa_def *local_id =
+         nir_ssa_def *local_id = nir_load_local_invocation_id(b);
-            nir_load_system_value(b, nir_intrinsic_load_local_invocation_id, 0);
 
          nir_ssa_def *size_x = nir_imm_int(b, b->shader->info.cs.local_size[0]);
          nir_ssa_def *size_y = nir_imm_int(b, b->shader->info.cs.local_size[1]);
@@ -104,17 +101,17 @@ convert_block(nir_block *block, nir_builder *b)
       case SYSTEM_VALUE_VERTEX_ID:
          if (b->shader->options->vertex_id_zero_based) {
             sysval = nir_iadd(b,
-               nir_load_system_value(b, nir_intrinsic_load_vertex_id_zero_base, 0),
+                              nir_load_vertex_id_zero_base(b),
-               nir_load_system_value(b, nir_intrinsic_load_base_vertex, 0));
+                              nir_load_base_vertex(b));
          } else {
-            sysval = nir_load_system_value(b, nir_intrinsic_load_vertex_id, 0);
+            sysval = nir_load_vertex_id(b);
          }
          break;
 
       case SYSTEM_VALUE_INSTANCE_INDEX:
          sysval = nir_iadd(b,
-            nir_load_system_value(b, nir_intrinsic_load_instance_id, 0),
+                           nir_load_instance_id(b),
-            nir_load_system_value(b, nir_intrinsic_load_base_instance, 0));
+                           nir_load_base_instance(b));
          break;
 
       default:

src/compiler/nir/nir_lower_two_sided_color.c

@@ -154,9 +154,7 @@ nir_lower_two_sided_color_block(nir_block *block,
        * bcsel(load_system_value(FACE), load_input(COLn), load_input(BFCn))
        */
       b->cursor = nir_before_instr(&intr->instr);
-      nir_ssa_def *face  = nir_load_system_value(b,
+      nir_ssa_def *face  = nir_load_front_face(b);
-                                                 nir_intrinsic_load_front_face,
-                                                 0);
       nir_ssa_def *front = load_input(b, state->colors[idx].front);
       nir_ssa_def *back  = load_input(b, state->colors[idx].back);
       nir_ssa_def *color = nir_bcsel(b, face, front, back);

src/mesa/drivers/dri/i965/blorp_blit.c

@@ -106,7 +106,7 @@ blorp_blit_get_frag_coords(nir_builder *b,
 
    if (key->persample_msaa_dispatch) {
       return nir_vec3(b, nir_channel(b, coord, 0), nir_channel(b, coord, 1),
-         nir_load_system_value(b, nir_intrinsic_load_sample_id, 0));
+                      nir_load_sample_id(b));
    } else {
       return nir_vec2(b, nir_channel(b, coord, 0), nir_channel(b, coord, 1));
    }

src/mesa/drivers/dri/i965/brw_nir_intrinsics.c

@@ -82,8 +82,7 @@ lower_cs_intrinsics_convert_block(struct lower_intrinsics_state *state,
           *       cs_thread_local_id + channel_num;
           */
          nir_ssa_def *thread_local_id = read_thread_local_id(state);
-         nir_ssa_def *channel =
+         nir_ssa_def *channel = nir_load_channel_num(b);
-            nir_load_system_value(b, nir_intrinsic_load_channel_num, 0);
          sysval = nir_iadd(b, channel, thread_local_id);
          break;
       }
@@ -105,8 +104,7 @@ lower_cs_intrinsics_convert_block(struct lower_intrinsics_state *state,
           */
          unsigned *size = nir->info.cs.local_size;
 
-         nir_ssa_def *local_index =
+         nir_ssa_def *local_index = nir_load_local_invocation_index(b);
-            nir_load_system_value(b, nir_intrinsic_load_local_invocation_index, 0);
 
          nir_const_value uvec3;
          uvec3.u32[0] = 1;