Mesa (master): i965/fs: Move remapping of gl_PointSize to the NIR level

[Jason Ekstrand]

Module: Mesa
Branch: master
Commit: e31042ab40442b06a5226de85aa91bf9c652a099
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=e31042ab40442b06a5226de85aa91bf9c652a099

Author: Jason Ekstrand <jason.ekstrand at intel.com>
Date:   Thu May  4 16:33:32 2017 -0700

i965/fs: Move remapping of gl_PointSize to the NIR level

Reviewed-by: Alejandro Piñeiro <apinheiro at igalia.com>
Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>

---

 src/intel/compiler/brw_fs_nir.cpp | 26 +++-----------------------
 src/intel/compiler/brw_nir.c      | 21 ++++++++++++++++++---
 2 files changed, 21 insertions(+), 26 deletions(-)

diff --git a/src/intel/compiler/brw_fs_nir.cpp b/src/intel/compiler/brw_fs_nir.cpp
index 779d74d915..876b1030ec 100644
--- a/src/intel/compiler/brw_fs_nir.cpp
+++ b/src/intel/compiler/brw_fs_nir.cpp
@@ -1914,27 +1914,15 @@ fs_visitor::emit_gs_input_load(const fs_reg &dst,
    nir_const_value *offset_const = nir_src_as_const_value(offset_src);
    const unsigned push_reg_count = gs_prog_data->base.urb_read_length * 8;
 
-   /* Offset 0 is the VUE header, which contains VARYING_SLOT_LAYER [.y],
-    * VARYING_SLOT_VIEWPORT [.z], and VARYING_SLOT_PSIZ [.w].  Only
-    * gl_PointSize is available as a GS input, however, so it must be that.
-    */
-   const bool is_point_size = (base_offset == 0);
-
    /* TODO: figure out push input layout for invocations == 1 */
    if (gs_prog_data->invocations == 1 &&
        offset_const != NULL && vertex_const != NULL &&
        4 * (base_offset + offset_const->u32[0]) < push_reg_count) {
       int imm_offset = (base_offset + offset_const->u32[0]) * 4 +
                        vertex_const->u32[0] * push_reg_count;
-      /* This input was pushed into registers. */
-      if (is_point_size) {
-         /* gl_PointSize comes in .w */
-         bld.MOV(dst, fs_reg(ATTR, imm_offset + 3, dst.type));
-      } else {
-         for (unsigned i = 0; i < num_components; i++) {
-            bld.MOV(offset(dst, bld, i),
-                    fs_reg(ATTR, imm_offset + i + first_component, dst.type));
-         }
+      for (unsigned i = 0; i < num_components; i++) {
+         bld.MOV(offset(dst, bld, i),
+                 fs_reg(ATTR, imm_offset + i + first_component, dst.type));
       }
       return;
    }
@@ -2104,14 +2092,6 @@ fs_visitor::emit_gs_input_load(const fs_reg &dst,
          }
       }
    }
-
-   if (is_point_size) {
-      /* Read the whole VUE header (because of alignment) and read .w. */
-      fs_reg tmp = bld.vgrf(dst.type, 4);
-      inst->dst = tmp;
-      inst->size_written = 4 * REG_SIZE;
-      bld.MOV(dst, offset(tmp, bld, 3));
-   }
 }
 
 fs_reg
diff --git a/src/intel/compiler/brw_nir.c b/src/intel/compiler/brw_nir.c
index 026f6a2bc1..88a7430168 100644
--- a/src/intel/compiler/brw_nir.c
+++ b/src/intel/compiler/brw_nir.c
@@ -365,9 +365,24 @@ brw_nir_lower_vue_inputs(nir_shader *nir, bool is_scalar,
 
             if (intrin->intrinsic == nir_intrinsic_load_input ||
                 intrin->intrinsic == nir_intrinsic_load_per_vertex_input) {
-               int vue_slot = vue_map->varying_to_slot[intrin->const_index[0]];
-               assert(vue_slot != -1);
-               intrin->const_index[0] = vue_slot;
+               /* Offset 0 is the VUE header, which contains
+                * VARYING_SLOT_LAYER [.y], VARYING_SLOT_VIEWPORT [.z], and
+                * VARYING_SLOT_PSIZ [.w].
+                */
+               int varying = nir_intrinsic_base(intrin);
+               int vue_slot;
+               switch (varying) {
+               case VARYING_SLOT_PSIZ:
+                  nir_intrinsic_set_base(intrin, 0);
+                  nir_intrinsic_set_component(intrin, 3);
+                  break;
+
+               default:
+                  vue_slot = vue_map->varying_to_slot[varying];
+                  assert(vue_slot != -1);
+                  nir_intrinsic_set_base(intrin, vue_slot);
+                  break;
+               }
             }
          }
       }