nir/lower_io: Return SSA defs from helpers

I can't find a single place where nir_lower_io is called after going out
of SSA which is the only real reason why you wouldn't do this. Returning
SSA defs is more idiomatic and is required for the next commit.

Reviewed-by: Matt Turner <mattst88@gmail.com>

diff --git a/src/compiler/nir/nir_lower_io.c b/src/compiler/nir/nir_lower_io.c
index 279e6e77b6a67dd107985432382bce8479900383..ee8128f1025b7eb7573d0f95ebcd88ff0271ebf7 100644 (file)
--- a/src/compiler/nir/nir_lower_io.c
+++ b/src/compiler/nir/nir_lower_io.c
@@ -201,12 +201,13 @@ get_io_offset(nir_builder *b, nir_deref_instr *deref,
    return offset;
 }
 
-static nir_intrinsic_instr *
+static nir_ssa_def *
 lower_load(nir_intrinsic_instr *intrin, struct lower_io_state *state,
            nir_ssa_def *vertex_index, nir_variable *var, nir_ssa_def *offset,
            unsigned component, const struct glsl_type *type)
 {
-   const nir_shader *nir = state->builder.shader;
+   nir_builder *b = &state->builder;
+   const nir_shader *nir = b->shader;
    nir_variable_mode mode = var->data.mode;
    nir_ssa_def *barycentric = NULL;
 
@@ -275,14 +276,21 @@ lower_load(nir_intrinsic_instr *intrin, struct lower_io_state *state,
       load->src[0] = nir_src_for_ssa(offset);
    }
 
-   return load;
+   assert(intrin->dest.is_ssa);
+   nir_ssa_dest_init(&load->instr, &load->dest,
+                     intrin->dest.ssa.num_components,
+                     intrin->dest.ssa.bit_size, NULL);
+   nir_builder_instr_insert(b, &load->instr);
+
+   return &load->dest.ssa;
 }
 
-static nir_intrinsic_instr *
+static void
 lower_store(nir_intrinsic_instr *intrin, struct lower_io_state *state,
             nir_ssa_def *vertex_index, nir_variable *var, nir_ssa_def *offset,
             unsigned component, const struct glsl_type *type)
 {
+   nir_builder *b = &state->builder;
    nir_variable_mode mode = var->data.mode;
 
    nir_intrinsic_op op;
@@ -315,13 +323,14 @@ lower_store(nir_intrinsic_instr *intrin, struct lower_io_state *state,
 
    store->src[vertex_index ? 2 : 1] = nir_src_for_ssa(offset);
 
-   return store;
+   nir_builder_instr_insert(b, &store->instr);
 }
 
-static nir_intrinsic_instr *
+static nir_ssa_def *
 lower_atomic(nir_intrinsic_instr *intrin, struct lower_io_state *state,
              nir_variable *var, nir_ssa_def *offset)
 {
+   nir_builder *b = &state->builder;
    assert(var->data.mode == nir_var_mem_shared);
 
    nir_intrinsic_op op;
@@ -358,14 +367,25 @@ lower_atomic(nir_intrinsic_instr *intrin, struct lower_io_state *state,
       nir_src_copy(&atomic->src[i], &intrin->src[i], atomic);
    }
 
-   return atomic;
+   if (nir_intrinsic_infos[op].has_dest) {
+      assert(intrin->dest.is_ssa);
+      assert(nir_intrinsic_infos[intrin->intrinsic].has_dest);
+      nir_ssa_dest_init(&atomic->instr, &atomic->dest,
+                        intrin->dest.ssa.num_components,
+                        intrin->dest.ssa.bit_size, NULL);
+   }
+
+   nir_builder_instr_insert(b, &atomic->instr);
+
+   return nir_intrinsic_infos[op].has_dest ? &atomic->dest.ssa : NULL;
 }
 
-static nir_intrinsic_instr *
+static nir_ssa_def *
 lower_interpolate_at(nir_intrinsic_instr *intrin, struct lower_io_state *state,
                      nir_variable *var, nir_ssa_def *offset, unsigned component,
                      const struct glsl_type *type)
 {
+   nir_builder *b = &state->builder;
    assert(var->data.mode == nir_var_shader_in);
 
    /* Ignore interpolateAt() for flat variables - flat is flat. */
@@ -399,7 +419,7 @@ lower_interpolate_at(nir_intrinsic_instr *intrin, struct lower_io_state *state,
        intrin->intrinsic == nir_intrinsic_interp_deref_at_offset)
       nir_src_copy(&bary_setup->src[0], &intrin->src[1], bary_setup);
 
-   nir_builder_instr_insert(&state->builder, &bary_setup->instr);
+   nir_builder_instr_insert(b, &bary_setup->instr);
 
    nir_intrinsic_instr *load =
       nir_intrinsic_instr_create(state->builder.shader,
@@ -412,7 +432,13 @@ lower_interpolate_at(nir_intrinsic_instr *intrin, struct lower_io_state *state,
    load->src[0] = nir_src_for_ssa(&bary_setup->dest.ssa);
    load->src[1] = nir_src_for_ssa(offset);
 
-   return load;
+   assert(intrin->dest.is_ssa);
+   nir_ssa_dest_init(&load->instr, &load->dest,
+                     intrin->dest.ssa.num_components,
+                     intrin->dest.ssa.bit_size, NULL);
+   nir_builder_instr_insert(b, &load->instr);
+
+   return &load->dest.ssa;
 }
 
 static bool
@@ -489,7 +515,7 @@ nir_lower_io_block(nir_block *block,
                              state->type_size, &component_offset,
                              bindless_type_size);
 
-      nir_intrinsic_instr *replacement;
+      nir_ssa_def *replacement = NULL;
 
       switch (intrin->intrinsic) {
       case nir_intrinsic_load_deref:
@@ -498,8 +524,8 @@ nir_lower_io_block(nir_block *block,
          break;
 
       case nir_intrinsic_store_deref:
-         replacement = lower_store(intrin, state, vertex_index, var, offset,
-                                   component_offset, deref->type);
+         lower_store(intrin, state, vertex_index, var, offset,
+                     component_offset, deref->type);
          break;
 
       case nir_intrinsic_deref_atomic_add:
@@ -532,19 +558,10 @@ nir_lower_io_block(nir_block *block,
          continue;
       }
 
-      if (nir_intrinsic_infos[intrin->intrinsic].has_dest) {
-         if (intrin->dest.is_ssa) {
-            nir_ssa_dest_init(&replacement->instr, &replacement->dest,
-                              intrin->dest.ssa.num_components,
-                              intrin->dest.ssa.bit_size, NULL);
-            nir_ssa_def_rewrite_uses(&intrin->dest.ssa,
-                                     nir_src_for_ssa(&replacement->dest.ssa));
-         } else {
-            nir_dest_copy(&replacement->dest, &intrin->dest, &intrin->instr);
-         }
+      if (replacement) {
+         nir_ssa_def_rewrite_uses(&intrin->dest.ssa,
+                                  nir_src_for_ssa(replacement));
       }
-
-      nir_instr_insert_before(&intrin->instr, &replacement->instr);
       nir_instr_remove(&intrin->instr);
       progress = true;
    }