vallium: initial import of the vulkan frontend

[mesa.git] / src / gallium / frontends / vallium / val_lower_input_attachments.c

diff --git a/src/gallium/frontends/vallium/val_lower_input_attachments.c b/src/gallium/frontends/vallium/val_lower_input_attachments.c
new file mode 100644 (file)
index 0000000..a8b8af7
--- /dev/null
+++ b/src/gallium/frontends/vallium/val_lower_input_attachments.c
@@ -0,0 +1,109 @@
+/*
+ * Copyright © 2016 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "nir.h"
+#include "nir_builder.h"
+#include "val_lower_vulkan_resource.h"
+
+static nir_ssa_def *
+load_frag_coord(nir_builder *b)
+{
+   nir_variable *pos =
+      nir_find_variable_with_location(b->shader, nir_var_shader_in,
+                                      VARYING_SLOT_POS);
+   if (pos == NULL) {
+      nir_variable *pos = nir_variable_create(b->shader, nir_var_shader_in,
+                                           glsl_vec4_type(), NULL);
+      pos->data.location = VARYING_SLOT_POS;
+   }
+   /**
+    * From Vulkan spec:
+    *   "The OriginLowerLeft execution mode must not be used; fragment entry
+    *    points must declare OriginUpperLeft."
+    *
+    * So at this point origin_upper_left should be true
+    */
+   assert(b->shader->info.fs.origin_upper_left == true);
+
+   return nir_load_var(b, pos);
+}
+
+static bool
+try_lower_input_load(nir_function_impl *impl, nir_intrinsic_instr *load,
+                     bool use_fragcoord_sysval)
+{
+   nir_deref_instr *deref = nir_src_as_deref(load->src[0]);
+   assert(glsl_type_is_image(deref->type));
+
+   enum glsl_sampler_dim image_dim = glsl_get_sampler_dim(deref->type);
+   if (image_dim != GLSL_SAMPLER_DIM_SUBPASS &&
+       image_dim != GLSL_SAMPLER_DIM_SUBPASS_MS)
+      return false;
+
+   nir_builder b;
+   nir_builder_init(&b, impl);
+   b.cursor = nir_before_instr(&load->instr);
+
+   nir_ssa_def *frag_coord = use_fragcoord_sysval ? nir_load_frag_coord(&b)
+                                                  : load_frag_coord(&b);
+   frag_coord = nir_f2i32(&b, frag_coord);
+   nir_ssa_def *offset = nir_ssa_for_src(&b, load->src[1], 2);
+   nir_ssa_def *pos = nir_iadd(&b, frag_coord, offset);
+
+   nir_ssa_def *layer = nir_imm_int(&b, 0);
+   nir_ssa_def *coord =
+      nir_vec4(&b, nir_channel(&b, pos, 0), nir_channel(&b, pos, 1), layer, layer);
+
+   nir_instr_rewrite_src(&load->instr, &load->src[1], nir_src_for_ssa(coord));
+
+   return true;
+}
+
+bool
+val_lower_input_attachments(nir_shader *shader, bool use_fragcoord_sysval)
+{
+   assert(shader->info.stage == MESA_SHADER_FRAGMENT);
+   bool progress = false;
+
+   nir_foreach_function(function, shader) {
+      if (!function->impl)
+         continue;
+
+      nir_foreach_block(block, function->impl) {
+         nir_foreach_instr_safe(instr, block) {
+            if (instr->type != nir_instr_type_intrinsic)
+               continue;
+
+            nir_intrinsic_instr *load = nir_instr_as_intrinsic(instr);
+
+            if (load->intrinsic != nir_intrinsic_image_deref_load)
+               continue;
+
+            progress |= try_lower_input_load(function->impl, load,
+                                             use_fragcoord_sysval);
+         }
+      }
+   }
+
+   return progress;
+}