intel/fs: Update location of Render Target Array Index for gen12
[mesa.git] / src / compiler / glsl / builtin_variables.cpp
index d20fc4a816cc694417c0a866469175efaafb87e6..c9fdac84666b7843b7389ec3575c5a3292ce8795 100644 (file)
  * DEALINGS IN THE SOFTWARE.
  */
 
+
+/**
+ * Building this file with MinGW g++ 7.3 or 7.4 with:
+ *   scons platform=windows toolchain=crossmingw machine=x86 build=profile
+ * triggers an internal compiler error.
+ * Overriding the optimization level to -O1 works around the issue.
+ * MinGW 5.3.1 does not seem to have the bug, neither does 8.3.  So for now
+ * we're simply testing for version 7.x here.
+ */
+#if defined(__MINGW32__) && __GNUC__ == 7
+#warning "disabling optimizations for this file to work around compiler bug in MinGW gcc 7.x"
+#pragma GCC optimize("O1")
+#endif
+
+
 #include "ir.h"
 #include "ir_builder.h"
 #include "linker.h"
 #include "glsl_parser_extras.h"
 #include "glsl_symbol_table.h"
-#include "main/core.h"
+#include "main/mtypes.h"
 #include "main/uniforms.h"
 #include "program/prog_statevars.h"
 #include "program/prog_instruction.h"
+#include "builtin_functions.h"
 
 using namespace ir_builder;
 
@@ -84,9 +100,9 @@ static const struct gl_builtin_uniform_element gl_LightSource_elements[] = {
                  SWIZZLE_Y,
                  SWIZZLE_Z,
                  SWIZZLE_Z)},
-   {"spotCosCutoff", {STATE_LIGHT, 0, STATE_SPOT_DIRECTION}, SWIZZLE_WWWW},
-   {"spotCutoff", {STATE_LIGHT, 0, STATE_SPOT_CUTOFF}, SWIZZLE_XXXX},
    {"spotExponent", {STATE_LIGHT, 0, STATE_ATTENUATION}, SWIZZLE_WWWW},
+   {"spotCutoff", {STATE_LIGHT, 0, STATE_SPOT_CUTOFF}, SWIZZLE_XXXX},
+   {"spotCosCutoff", {STATE_LIGHT, 0, STATE_SPOT_DIRECTION}, SWIZZLE_WWWW},
    {"constantAttenuation", {STATE_LIGHT, 0, STATE_ATTENUATION}, SWIZZLE_XXXX},
    {"linearAttenuation", {STATE_LIGHT, 0, STATE_ATTENUATION}, SWIZZLE_YYYY},
    {"quadraticAttenuation", {STATE_LIGHT, 0, STATE_ATTENUATION}, SWIZZLE_ZZZZ},
@@ -298,11 +314,12 @@ class per_vertex_accumulator
 {
 public:
    per_vertex_accumulator();
-   void add_field(int slot, const glsl_type *type, const char *name);
+   void add_field(int slot, const glsl_type *type, int precision,
+                  const char *name);
    const glsl_type *construct_interface_instance() const;
 
 private:
-   glsl_struct_field fields[10];
+   glsl_struct_field fields[11];
    unsigned num_fields;
 };
 
@@ -316,23 +333,28 @@ per_vertex_accumulator::per_vertex_accumulator()
 
 void
 per_vertex_accumulator::add_field(int slot, const glsl_type *type,
-                                  const char *name)
+                                  int precision, const char *name)
 {
    assert(this->num_fields < ARRAY_SIZE(this->fields));
    this->fields[this->num_fields].type = type;
    this->fields[this->num_fields].name = name;
    this->fields[this->num_fields].matrix_layout = GLSL_MATRIX_LAYOUT_INHERITED;
    this->fields[this->num_fields].location = slot;
-   this->fields[this->num_fields].interpolation = INTERP_QUALIFIER_NONE;
+   this->fields[this->num_fields].offset = -1;
+   this->fields[this->num_fields].interpolation = INTERP_MODE_NONE;
    this->fields[this->num_fields].centroid = 0;
    this->fields[this->num_fields].sample = 0;
    this->fields[this->num_fields].patch = 0;
-   this->fields[this->num_fields].precision = GLSL_PRECISION_NONE;
-   this->fields[this->num_fields].image_read_only = 0;
-   this->fields[this->num_fields].image_write_only = 0;
-   this->fields[this->num_fields].image_coherent = 0;
-   this->fields[this->num_fields].image_volatile = 0;
-   this->fields[this->num_fields].image_restrict = 0;
+   this->fields[this->num_fields].precision = precision;
+   this->fields[this->num_fields].memory_read_only = 0;
+   this->fields[this->num_fields].memory_write_only = 0;
+   this->fields[this->num_fields].memory_coherent = 0;
+   this->fields[this->num_fields].memory_volatile = 0;
+   this->fields[this->num_fields].memory_restrict = 0;
+   this->fields[this->num_fields].image_format = PIPE_FORMAT_NONE;
+   this->fields[this->num_fields].explicit_xfb_buffer = 0;
+   this->fields[this->num_fields].xfb_buffer = -1;
+   this->fields[this->num_fields].xfb_stride = -1;
    this->num_fields++;
 }
 
@@ -342,6 +364,7 @@ per_vertex_accumulator::construct_interface_instance() const
 {
    return glsl_type::get_interface_instance(this->fields, this->num_fields,
                                             GLSL_INTERFACE_PACKING_STD140,
+                                            false,
                                             "gl_PerVertex");
 }
 
@@ -353,6 +376,7 @@ public:
                               struct _mesa_glsl_parse_state *state);
    void generate_constants();
    void generate_uniforms();
+   void generate_special_vars();
    void generate_vs_special_vars();
    void generate_tcs_special_vars();
    void generate_tes_special_vars();
@@ -372,35 +396,70 @@ private:
       return symtab->get_type(name);
    }
 
+   ir_variable *add_input(int slot, const glsl_type *type, int precision,
+                          const char *name)
+   {
+      return add_variable(name, type, precision, ir_var_shader_in, slot);
+   }
+
    ir_variable *add_input(int slot, const glsl_type *type, const char *name)
    {
-      return add_variable(name, type, ir_var_shader_in, slot);
+      return add_input(slot, type, GLSL_PRECISION_NONE, name);
+   }
+
+   ir_variable *add_output(int slot, const glsl_type *type, int precision,
+                           const char *name)
+   {
+      return add_variable(name, type, precision, ir_var_shader_out, slot);
    }
 
    ir_variable *add_output(int slot, const glsl_type *type, const char *name)
    {
-      return add_variable(name, type, ir_var_shader_out, slot);
+      return add_output(slot, type, GLSL_PRECISION_NONE, name);
    }
 
-   ir_variable *add_index_output(int slot, int index, const glsl_type *type, const char *name)
+   ir_variable *add_index_output(int slot, int index, const glsl_type *type,
+                                 int precision, const char *name)
    {
-      return add_index_variable(name, type, ir_var_shader_out, slot, index);
+      return add_index_variable(name, type, precision, ir_var_shader_out, slot,
+                                index);
    }
 
+   ir_variable *add_system_value(int slot, const glsl_type *type, int precision,
+                                 const char *name)
+   {
+      return add_variable(name, type, precision, ir_var_system_value, slot);
+   }
    ir_variable *add_system_value(int slot, const glsl_type *type,
                                  const char *name)
    {
-      return add_variable(name, type, ir_var_system_value, slot);
+      return add_system_value(slot, type, GLSL_PRECISION_NONE, name);
    }
 
    ir_variable *add_variable(const char *name, const glsl_type *type,
-                             enum ir_variable_mode mode, int slot);
+                             int precision, enum ir_variable_mode mode,
+                             int slot);
    ir_variable *add_index_variable(const char *name, const glsl_type *type,
-                             enum ir_variable_mode mode, int slot, int index);
-   ir_variable *add_uniform(const glsl_type *type, const char *name);
-   ir_variable *add_const(const char *name, int value);
+                                   int precision, enum ir_variable_mode mode,
+                                   int slot, int index);
+   ir_variable *add_uniform(const glsl_type *type, int precision,
+                            const char *name);
+   ir_variable *add_uniform(const glsl_type *type, const char *name)
+   {
+      return add_uniform(type, GLSL_PRECISION_NONE, name);
+   }
+   ir_variable *add_const(const char *name, int precision, int value);
+   ir_variable *add_const(const char *name, int value)
+   {
+      return add_const(name, GLSL_PRECISION_MEDIUM, value);
+   }
    ir_variable *add_const_ivec3(const char *name, int x, int y, int z);
-   void add_varying(int slot, const glsl_type *type, const char *name);
+   void add_varying(int slot, const glsl_type *type, int precision,
+                    const char *name);
+   void add_varying(int slot, const glsl_type *type, const char *name)
+   {
+      add_varying(slot, type, GLSL_PRECISION_NONE, name);
+   }
 
    exec_list * const instructions;
    struct _mesa_glsl_parse_state * const state;
@@ -416,6 +475,7 @@ private:
    const glsl_type * const bool_t;
    const glsl_type * const int_t;
    const glsl_type * const uint_t;
+   const glsl_type * const uint64_t;
    const glsl_type * const float_t;
    const glsl_type * const vec2_t;
    const glsl_type * const vec3_t;
@@ -432,9 +492,10 @@ private:
 builtin_variable_generator::builtin_variable_generator(
    exec_list *instructions, struct _mesa_glsl_parse_state *state)
    : instructions(instructions), state(state), symtab(state->symbols),
-     compatibility(!state->is_version(140, 100)),
+     compatibility(state->compat_shader || state->ARB_compatibility_enable),
      bool_t(glsl_type::bool_type), int_t(glsl_type::int_type),
      uint_t(glsl_type::uint_type),
+     uint64_t(glsl_type::uint64_t_type),
      float_t(glsl_type::float_type), vec2_t(glsl_type::vec2_type),
      vec3_t(glsl_type::vec3_type), vec4_t(glsl_type::vec4_type),
      uvec3_t(glsl_type::uvec3_type),
@@ -444,8 +505,10 @@ builtin_variable_generator::builtin_variable_generator(
 
 ir_variable *
 builtin_variable_generator::add_index_variable(const char *name,
-                                         const glsl_type *type,
-                                         enum ir_variable_mode mode, int slot, int index)
+                                               const glsl_type *type,
+                                               int precision,
+                                               enum ir_variable_mode mode,
+                                               int slot, int index)
 {
    ir_variable *var = new(symtab) ir_variable(type, name, mode);
    var->data.how_declared = ir_var_declared_implicitly;
@@ -474,6 +537,9 @@ builtin_variable_generator::add_index_variable(const char *name,
    var->data.explicit_index = 1;
    var->data.index = index;
 
+   if (state->es_shader)
+      var->data.precision = precision;
+
    /* Once the variable is created an initialized, add it to the symbol table
     * and add the declaration to the IR stream.
     */
@@ -486,6 +552,7 @@ builtin_variable_generator::add_index_variable(const char *name,
 ir_variable *
 builtin_variable_generator::add_variable(const char *name,
                                          const glsl_type *type,
+                                         int precision,
                                          enum ir_variable_mode mode, int slot)
 {
    ir_variable *var = new(symtab) ir_variable(type, name, mode);
@@ -514,6 +581,9 @@ builtin_variable_generator::add_variable(const char *name,
    var->data.explicit_location = (slot >= 0);
    var->data.explicit_index = 0;
 
+   if (state->es_shader)
+      var->data.precision = precision;
+
    /* Once the variable is created an initialized, add it to the symbol table
     * and add the declaration to the IR stream.
     */
@@ -523,23 +593,28 @@ builtin_variable_generator::add_variable(const char *name,
    return var;
 }
 
+extern "C" const struct gl_builtin_uniform_desc *
+_mesa_glsl_get_builtin_uniform_desc(const char *name)
+{
+   for (unsigned i = 0; _mesa_builtin_uniform_desc[i].name != NULL; i++) {
+      if (strcmp(_mesa_builtin_uniform_desc[i].name, name) == 0) {
+         return &_mesa_builtin_uniform_desc[i];
+      }
+   }
+   return NULL;
+}
 
 ir_variable *
 builtin_variable_generator::add_uniform(const glsl_type *type,
+                                        int precision,
                                         const char *name)
 {
-   ir_variable *const uni = add_variable(name, type, ir_var_uniform, -1);
-
-   unsigned i;
-   for (i = 0; _mesa_builtin_uniform_desc[i].name != NULL; i++) {
-      if (strcmp(_mesa_builtin_uniform_desc[i].name, name) == 0) {
-        break;
-      }
-   }
+   ir_variable *const uni =
+      add_variable(name, type, precision, ir_var_uniform, -1);
 
-   assert(_mesa_builtin_uniform_desc[i].name != NULL);
    const struct gl_builtin_uniform_desc* const statevar =
-      &_mesa_builtin_uniform_desc[i];
+      _mesa_glsl_get_builtin_uniform_desc(name);
+   assert(statevar != NULL);
 
    const unsigned array_count = type->is_array() ? type->length : 1;
 
@@ -571,10 +646,11 @@ builtin_variable_generator::add_uniform(const glsl_type *type,
 
 
 ir_variable *
-builtin_variable_generator::add_const(const char *name, int value)
+builtin_variable_generator::add_const(const char *name, int precision,
+                                      int value)
 {
    ir_variable *const var = add_variable(name, glsl_type::int_type,
-                                        ir_var_auto, -1);
+                                         precision, ir_var_auto, -1);
    var->constant_value = new(var) ir_constant(value);
    var->constant_initializer = new(var) ir_constant(value);
    var->data.has_initializer = true;
@@ -587,6 +663,7 @@ builtin_variable_generator::add_const_ivec3(const char *name, int x, int y,
                                             int z)
 {
    ir_variable *const var = add_variable(name, glsl_type::ivec3_type,
+                                         GLSL_PRECISION_HIGH,
                                          ir_var_auto, -1);
    ir_constant_data data;
    memset(&data, 0, sizeof(data));
@@ -613,9 +690,17 @@ builtin_variable_generator::generate_constants()
    add_const("gl_MaxDrawBuffers", state->Const.MaxDrawBuffers);
 
    /* Max uniforms/varyings: GLSL ES counts these in units of vectors; desktop
-    * GL counts them in units of "components" or "floats".
+    * GL counts them in units of "components" or "floats" and also in units
+    * of vectors since GL 4.1
     */
-   if (state->es_shader) {
+   if (!state->es_shader) {
+      add_const("gl_MaxFragmentUniformComponents",
+                state->Const.MaxFragmentUniformComponents);
+      add_const("gl_MaxVertexUniformComponents",
+                state->Const.MaxVertexUniformComponents);
+   }
+
+   if (state->is_version(410, 100)) {
       add_const("gl_MaxVertexUniformVectors",
                 state->Const.MaxVertexUniformComponents / 4);
       add_const("gl_MaxFragmentUniformVectors",
@@ -642,16 +727,10 @@ builtin_variable_generator::generate_constants()
                    state->Const.MaxDualSourceDrawBuffers);
       }
    } else {
-      add_const("gl_MaxVertexUniformComponents",
-                state->Const.MaxVertexUniformComponents);
-
       /* Note: gl_MaxVaryingFloats was deprecated in GLSL 1.30+, but not
        * removed
        */
       add_const("gl_MaxVaryingFloats", state->ctx->Const.MaxVarying * 4);
-
-      add_const("gl_MaxFragmentUniformComponents",
-                state->Const.MaxFragmentUniformComponents);
    }
 
    /* Texel offsets were introduced in ARB_shading_language_420pack (which
@@ -667,10 +746,17 @@ builtin_variable_generator::generate_constants()
                 state->Const.MaxProgramTexelOffset);
    }
 
-   if (state->is_version(130, 0)) {
+   if (state->has_clip_distance()) {
       add_const("gl_MaxClipDistances", state->Const.MaxClipPlanes);
+   }
+   if (state->is_version(130, 0)) {
       add_const("gl_MaxVaryingComponents", state->ctx->Const.MaxVarying * 4);
    }
+   if (state->has_cull_distance()) {
+      add_const("gl_MaxCullDistances", state->Const.MaxClipPlanes);
+      add_const("gl_MaxCombinedClipAndCullDistances",
+                state->Const.MaxClipPlanes);
+   }
 
    if (state->has_geometry_shader()) {
       add_const("gl_MaxVertexOutputComponents",
@@ -739,7 +825,7 @@ builtin_variable_generator::generate_constants()
          add_const("gl_MaxGeometryAtomicCounters",
                    state->Const.MaxGeometryAtomicCounters);
       }
-      if (!state->es_shader) {
+      if (state->is_version(110, 320)) {
          add_const("gl_MaxTessControlAtomicCounters",
                    state->Const.MaxTessControlAtomicCounters);
          add_const("gl_MaxTessEvaluationAtomicCounters",
@@ -761,7 +847,7 @@ builtin_variable_generator::generate_constants()
          add_const("gl_MaxGeometryAtomicCounterBuffers",
                    state->Const.MaxGeometryAtomicCounterBuffers);
       }
-      if (!state->es_shader) {
+      if (state->is_version(110, 320)) {
          add_const("gl_MaxTessControlAtomicCounterBuffers",
                    state->Const.MaxTessControlAtomicCounterBuffers);
          add_const("gl_MaxTessEvaluationAtomicCounterBuffers",
@@ -811,8 +897,14 @@ builtin_variable_generator::generate_constants()
        */
    }
 
-   if (state->is_version(420, 310) ||
-       state->ARB_shader_image_load_store_enable) {
+   if (state->has_enhanced_layouts()) {
+      add_const("gl_MaxTransformFeedbackBuffers",
+                state->Const.MaxTransformFeedbackBuffers);
+      add_const("gl_MaxTransformFeedbackInterleavedComponents",
+                state->Const.MaxTransformFeedbackInterleavedComponents);
+   }
+
+   if (state->has_shader_image_load_store()) {
       add_const("gl_MaxImageUnits",
                 state->Const.MaxImageUnits);
       add_const("gl_MaxVertexImageUniforms",
@@ -834,13 +926,7 @@ builtin_variable_generator::generate_constants()
                    state->Const.MaxImageSamples);
       }
 
-      if (state->is_version(450, 310)) {
-         add_const("gl_MaxCombinedShaderOutputResources",
-                   state->Const.MaxCombinedShaderOutputResources);
-      }
-
-      if (state->is_version(400, 0) ||
-          state->ARB_tessellation_shader_enable) {
+      if (state->has_tessellation_shader()) {
          add_const("gl_MaxTessControlImageUniforms",
                    state->Const.MaxTessControlImageUniforms);
          add_const("gl_MaxTessEvaluationImageUniforms",
@@ -848,12 +934,20 @@ builtin_variable_generator::generate_constants()
       }
    }
 
+   if (state->is_version(440, 310) ||
+       state->ARB_ES3_1_compatibility_enable) {
+      add_const("gl_MaxCombinedShaderOutputResources",
+                state->Const.MaxCombinedShaderOutputResources);
+   }
+
    if (state->is_version(410, 0) ||
-       state->ARB_viewport_array_enable)
-      add_const("gl_MaxViewports", state->Const.MaxViewports);
+       state->ARB_viewport_array_enable ||
+       state->OES_viewport_array_enable) {
+      add_const("gl_MaxViewports", GLSL_PRECISION_HIGH,
+                state->Const.MaxViewports);
+   }
 
-   if (state->is_version(400, 0) ||
-       state->ARB_tessellation_shader_enable) {
+   if (state->has_tessellation_shader()) {
       add_const("gl_MaxPatchVertices", state->Const.MaxPatchVertices);
       add_const("gl_MaxTessGenLevel", state->Const.MaxTessGenLevel);
       add_const("gl_MaxTessControlInputComponents", state->Const.MaxTessControlInputComponents);
@@ -867,6 +961,11 @@ builtin_variable_generator::generate_constants()
       add_const("gl_MaxTessControlUniformComponents", state->Const.MaxTessControlUniformComponents);
       add_const("gl_MaxTessEvaluationUniformComponents", state->Const.MaxTessEvaluationUniformComponents);
    }
+
+   if (state->is_version(450, 320) ||
+       state->OES_sample_variables_enable ||
+       state->ARB_ES3_1_compatibility_enable)
+      add_const("gl_MaxSamples", state->Const.MaxSamples);
 }
 
 
@@ -876,8 +975,10 @@ builtin_variable_generator::generate_constants()
 void
 builtin_variable_generator::generate_uniforms()
 {
-   if (state->is_version(400, 0) || state->ARB_sample_shading_enable)
-      add_uniform(int_t, "gl_NumSamples");
+   if (state->is_version(400, 320) ||
+       state->ARB_sample_shading_enable ||
+       state->OES_sample_variables_enable)
+      add_uniform(int_t, GLSL_PRECISION_LOW, "gl_NumSamples");
    add_uniform(type("gl_DepthRangeParameters"), "gl_DepthRange");
    add_uniform(array(vec4_t, VERT_ATTRIB_MAX), "gl_CurrentAttribVertMESA");
    add_uniform(array(vec4_t, VARYING_SLOT_MAX), "gl_CurrentAttribFragMESA");
@@ -948,6 +1049,24 @@ builtin_variable_generator::generate_uniforms()
 }
 
 
+/**
+ * Generate special variables which exist in all shaders.
+ */
+void
+builtin_variable_generator::generate_special_vars()
+{
+   if (state->ARB_shader_ballot_enable) {
+      add_system_value(SYSTEM_VALUE_SUBGROUP_SIZE, uint_t, "gl_SubGroupSizeARB");
+      add_system_value(SYSTEM_VALUE_SUBGROUP_INVOCATION, uint_t, "gl_SubGroupInvocationARB");
+      add_system_value(SYSTEM_VALUE_SUBGROUP_EQ_MASK, uint64_t, "gl_SubGroupEqMaskARB");
+      add_system_value(SYSTEM_VALUE_SUBGROUP_GE_MASK, uint64_t, "gl_SubGroupGeMaskARB");
+      add_system_value(SYSTEM_VALUE_SUBGROUP_GT_MASK, uint64_t, "gl_SubGroupGtMaskARB");
+      add_system_value(SYSTEM_VALUE_SUBGROUP_LE_MASK, uint64_t, "gl_SubGroupLeMaskARB");
+      add_system_value(SYSTEM_VALUE_SUBGROUP_LT_MASK, uint64_t, "gl_SubGroupLtMaskARB");
+   }
+}
+
+
 /**
  * Generate variables which only exist in vertex shaders.
  */
@@ -956,24 +1075,58 @@ builtin_variable_generator::generate_vs_special_vars()
 {
    ir_variable *var;
 
-   if (state->is_version(130, 300))
-      add_system_value(SYSTEM_VALUE_VERTEX_ID, int_t, "gl_VertexID");
+   if (state->is_version(130, 300) || state->EXT_gpu_shader4_enable) {
+      add_system_value(SYSTEM_VALUE_VERTEX_ID, int_t, GLSL_PRECISION_HIGH,
+                       "gl_VertexID");
+   }
+   if (state->is_version(460, 0)) {
+      add_system_value(SYSTEM_VALUE_BASE_VERTEX, int_t, "gl_BaseVertex");
+      add_system_value(SYSTEM_VALUE_BASE_INSTANCE, int_t, "gl_BaseInstance");
+      add_system_value(SYSTEM_VALUE_DRAW_ID, int_t, "gl_DrawID");
+   }
+   if (state->EXT_draw_instanced_enable && state->is_version(0, 100))
+      add_system_value(SYSTEM_VALUE_INSTANCE_ID, int_t, GLSL_PRECISION_HIGH,
+                       "gl_InstanceIDEXT");
+
    if (state->ARB_draw_instanced_enable)
       add_system_value(SYSTEM_VALUE_INSTANCE_ID, int_t, "gl_InstanceIDARB");
-   if (state->ARB_draw_instanced_enable || state->is_version(140, 300))
-      add_system_value(SYSTEM_VALUE_INSTANCE_ID, int_t, "gl_InstanceID");
+
+   if (state->ARB_draw_instanced_enable || state->is_version(140, 300) ||
+       state->EXT_gpu_shader4_enable) {
+      add_system_value(SYSTEM_VALUE_INSTANCE_ID, int_t, GLSL_PRECISION_HIGH,
+                       "gl_InstanceID");
+   }
    if (state->ARB_shader_draw_parameters_enable) {
       add_system_value(SYSTEM_VALUE_BASE_VERTEX, int_t, "gl_BaseVertexARB");
       add_system_value(SYSTEM_VALUE_BASE_INSTANCE, int_t, "gl_BaseInstanceARB");
       add_system_value(SYSTEM_VALUE_DRAW_ID, int_t, "gl_DrawIDARB");
    }
-   if (state->AMD_vertex_shader_layer_enable) {
+   if (state->AMD_vertex_shader_layer_enable ||
+       state->ARB_shader_viewport_layer_array_enable ||
+       state->NV_viewport_array2_enable) {
       var = add_output(VARYING_SLOT_LAYER, int_t, "gl_Layer");
-      var->data.interpolation = INTERP_QUALIFIER_FLAT;
+      var->data.interpolation = INTERP_MODE_FLAT;
    }
-   if (state->AMD_vertex_shader_viewport_index_enable) {
+   if (state->AMD_vertex_shader_viewport_index_enable ||
+       state->ARB_shader_viewport_layer_array_enable ||
+       state->NV_viewport_array2_enable) {
       var = add_output(VARYING_SLOT_VIEWPORT, int_t, "gl_ViewportIndex");
-      var->data.interpolation = INTERP_QUALIFIER_FLAT;
+      var->data.interpolation = INTERP_MODE_FLAT;
+   }
+   if (state->NV_viewport_array2_enable) {
+      /* From the NV_viewport_array2 specification:
+       *
+       *    "The variable gl_ViewportMask[] is available as an output variable
+       *    in the VTG languages. The array has ceil(v/32) elements where v is
+       *    the maximum number of viewports supported by the implementation."
+       *
+       * Since no drivers expose more than 16 viewports, we can simply set the
+       * array size to 1 rather than computing it and dealing with varying
+       * slot complication.
+       */
+      var = add_output(VARYING_SLOT_VIEWPORT_MASK, array(int_t, 1),
+                       "gl_ViewportMask");
+      var->data.interpolation = INTERP_MODE_FLAT;
    }
    if (compatibility) {
       add_input(VERT_ATTRIB_POS, vec4_t, "gl_Vertex");
@@ -999,14 +1152,42 @@ builtin_variable_generator::generate_vs_special_vars()
 void
 builtin_variable_generator::generate_tcs_special_vars()
 {
-   add_system_value(SYSTEM_VALUE_PRIMITIVE_ID, int_t, "gl_PrimitiveID");
-   add_system_value(SYSTEM_VALUE_VERTICES_IN, int_t, "gl_PatchVerticesIn");
-   add_system_value(SYSTEM_VALUE_INVOCATION_ID, int_t, "gl_InvocationID");
+   add_system_value(SYSTEM_VALUE_PRIMITIVE_ID, int_t, GLSL_PRECISION_HIGH,
+                    "gl_PrimitiveID");
+   add_system_value(SYSTEM_VALUE_INVOCATION_ID, int_t, GLSL_PRECISION_HIGH,
+                    "gl_InvocationID");
+   add_system_value(SYSTEM_VALUE_VERTICES_IN, int_t, GLSL_PRECISION_HIGH,
+                    "gl_PatchVerticesIn");
 
    add_output(VARYING_SLOT_TESS_LEVEL_OUTER, array(float_t, 4),
-              "gl_TessLevelOuter")->data.patch = 1;
+              GLSL_PRECISION_HIGH, "gl_TessLevelOuter")->data.patch = 1;
    add_output(VARYING_SLOT_TESS_LEVEL_INNER, array(float_t, 2),
-              "gl_TessLevelInner")->data.patch = 1;
+              GLSL_PRECISION_HIGH, "gl_TessLevelInner")->data.patch = 1;
+   /* XXX What to do if multiple are flipped on? */
+   int bbox_slot = state->ctx->Const.NoPrimitiveBoundingBoxOutput ? -1 :
+      VARYING_SLOT_BOUNDING_BOX0;
+   if (state->EXT_primitive_bounding_box_enable)
+      add_output(bbox_slot, array(vec4_t, 2), "gl_BoundingBoxEXT")
+         ->data.patch = 1;
+   if (state->OES_primitive_bounding_box_enable) {
+      add_output(bbox_slot, array(vec4_t, 2), GLSL_PRECISION_HIGH,
+                 "gl_BoundingBoxOES")->data.patch = 1;
+   }
+   if (state->is_version(0, 320) || state->ARB_ES3_2_compatibility_enable) {
+      add_output(bbox_slot, array(vec4_t, 2), GLSL_PRECISION_HIGH,
+                 "gl_BoundingBox")->data.patch = 1;
+   }
+
+   /* NOTE: These are completely pointless. Writing these will never go
+    * anywhere. But the specs demands it. So we add them with a slot of -1,
+    * which makes the data go nowhere.
+    */
+   if (state->NV_viewport_array2_enable) {
+      add_output(-1, int_t, "gl_Layer");
+      add_output(-1, int_t, "gl_ViewportIndex");
+      add_output(-1, array(int_t, 1), "gl_ViewportMask");
+   }
+
 }
 
 
@@ -1016,13 +1197,37 @@ builtin_variable_generator::generate_tcs_special_vars()
 void
 builtin_variable_generator::generate_tes_special_vars()
 {
-   add_system_value(SYSTEM_VALUE_PRIMITIVE_ID, int_t, "gl_PrimitiveID");
-   add_system_value(SYSTEM_VALUE_VERTICES_IN, int_t, "gl_PatchVerticesIn");
-   add_system_value(SYSTEM_VALUE_TESS_COORD, vec3_t, "gl_TessCoord");
-   add_system_value(SYSTEM_VALUE_TESS_LEVEL_OUTER, array(float_t, 4),
-                    "gl_TessLevelOuter");
-   add_system_value(SYSTEM_VALUE_TESS_LEVEL_INNER, array(float_t, 2),
-                    "gl_TessLevelInner");
+   ir_variable *var;
+
+   add_system_value(SYSTEM_VALUE_PRIMITIVE_ID, int_t, GLSL_PRECISION_HIGH,
+                    "gl_PrimitiveID");
+   add_system_value(SYSTEM_VALUE_VERTICES_IN, int_t, GLSL_PRECISION_HIGH,
+                    "gl_PatchVerticesIn");
+   add_system_value(SYSTEM_VALUE_TESS_COORD, vec3_t, GLSL_PRECISION_HIGH,
+                    "gl_TessCoord");
+   if (this->state->ctx->Const.GLSLTessLevelsAsInputs) {
+      add_input(VARYING_SLOT_TESS_LEVEL_OUTER, array(float_t, 4),
+                GLSL_PRECISION_HIGH, "gl_TessLevelOuter")->data.patch = 1;
+      add_input(VARYING_SLOT_TESS_LEVEL_INNER, array(float_t, 2),
+                GLSL_PRECISION_HIGH, "gl_TessLevelInner")->data.patch = 1;
+   } else {
+      add_system_value(SYSTEM_VALUE_TESS_LEVEL_OUTER, array(float_t, 4),
+                       GLSL_PRECISION_HIGH, "gl_TessLevelOuter");
+      add_system_value(SYSTEM_VALUE_TESS_LEVEL_INNER, array(float_t, 2),
+                       GLSL_PRECISION_HIGH, "gl_TessLevelInner");
+   }
+   if (state->ARB_shader_viewport_layer_array_enable ||
+       state->NV_viewport_array2_enable) {
+      var = add_output(VARYING_SLOT_LAYER, int_t, "gl_Layer");
+      var->data.interpolation = INTERP_MODE_FLAT;
+      var = add_output(VARYING_SLOT_VIEWPORT, int_t, "gl_ViewportIndex");
+      var->data.interpolation = INTERP_MODE_FLAT;
+   }
+   if (state->NV_viewport_array2_enable) {
+      var = add_output(VARYING_SLOT_VIEWPORT_MASK, array(int_t, 1),
+                       "gl_ViewportMask");
+      var->data.interpolation = INTERP_MODE_FLAT;
+   }
 }
 
 
@@ -1034,14 +1239,24 @@ builtin_variable_generator::generate_gs_special_vars()
 {
    ir_variable *var;
 
-   var = add_output(VARYING_SLOT_LAYER, int_t, "gl_Layer");
-   var->data.interpolation = INTERP_QUALIFIER_FLAT;
-   if (state->is_version(410, 0) || state->ARB_viewport_array_enable) {
-      var = add_output(VARYING_SLOT_VIEWPORT, int_t, "gl_ViewportIndex");
-      var->data.interpolation = INTERP_QUALIFIER_FLAT;
+   var = add_output(VARYING_SLOT_LAYER, int_t, GLSL_PRECISION_HIGH, "gl_Layer");
+   var->data.interpolation = INTERP_MODE_FLAT;
+   if (state->is_version(410, 0) || state->ARB_viewport_array_enable ||
+       state->OES_viewport_array_enable) {
+      var = add_output(VARYING_SLOT_VIEWPORT, int_t, GLSL_PRECISION_HIGH,
+                       "gl_ViewportIndex");
+      var->data.interpolation = INTERP_MODE_FLAT;
+   }
+   if (state->NV_viewport_array2_enable) {
+      var = add_output(VARYING_SLOT_VIEWPORT_MASK, array(int_t, 1),
+                       "gl_ViewportMask");
+      var->data.interpolation = INTERP_MODE_FLAT;
+   }
+   if (state->is_version(400, 320) || state->ARB_gpu_shader5_enable ||
+       state->OES_geometry_shader_enable || state->EXT_geometry_shader_enable) {
+      add_system_value(SYSTEM_VALUE_INVOCATION_ID, int_t, GLSL_PRECISION_HIGH,
+                       "gl_InvocationID");
    }
-   if (state->is_version(400, 0) || state->ARB_gpu_shader5_enable)
-      add_system_value(SYSTEM_VALUE_INVOCATION_ID, int_t, "gl_InvocationID");
 
    /* Although gl_PrimitiveID appears in tessellation control and tessellation
     * evaluation shaders, it has a different function there than it has in
@@ -1053,10 +1268,12 @@ builtin_variable_generator::generate_gs_special_vars()
     * the specific case of gl_PrimitiveIDIn.  So we don't need to treat
     * gl_PrimitiveIDIn as an {ARB,EXT}_geometry_shader4-only variable.
     */
-   var = add_input(VARYING_SLOT_PRIMITIVE_ID, int_t, "gl_PrimitiveIDIn");
-   var->data.interpolation = INTERP_QUALIFIER_FLAT;
-   var = add_output(VARYING_SLOT_PRIMITIVE_ID, int_t, "gl_PrimitiveID");
-   var->data.interpolation = INTERP_QUALIFIER_FLAT;
+   var = add_input(VARYING_SLOT_PRIMITIVE_ID, int_t, GLSL_PRECISION_HIGH,
+                   "gl_PrimitiveIDIn");
+   var->data.interpolation = INTERP_MODE_FLAT;
+   var = add_output(VARYING_SLOT_PRIMITIVE_ID, int_t, GLSL_PRECISION_HIGH,
+                    "gl_PrimitiveID");
+   var->data.interpolation = INTERP_MODE_FLAT;
 }
 
 
@@ -1068,22 +1285,38 @@ builtin_variable_generator::generate_fs_special_vars()
 {
    ir_variable *var;
 
-   if (this->state->ctx->Const.GLSLFragCoordIsSysVal)
-      add_system_value(SYSTEM_VALUE_FRAG_COORD, vec4_t, "gl_FragCoord");
-   else
-      add_input(VARYING_SLOT_POS, vec4_t, "gl_FragCoord");
+   int frag_coord_precision = (state->is_version(0, 300) ?
+                               GLSL_PRECISION_HIGH :
+                               GLSL_PRECISION_MEDIUM);
 
-   if (this->state->ctx->Const.GLSLFrontFacingIsSysVal)
-      add_system_value(SYSTEM_VALUE_FRONT_FACE, bool_t, "gl_FrontFacing");
-   else
-      add_input(VARYING_SLOT_FACE, bool_t, "gl_FrontFacing");
+   if (this->state->ctx->Const.GLSLFragCoordIsSysVal) {
+      add_system_value(SYSTEM_VALUE_FRAG_COORD, vec4_t, frag_coord_precision,
+                       "gl_FragCoord");
+   } else {
+      add_input(VARYING_SLOT_POS, vec4_t, frag_coord_precision, "gl_FragCoord");
+   }
 
-   if (state->is_version(120, 100))
-      add_input(VARYING_SLOT_PNTC, vec2_t, "gl_PointCoord");
+   if (this->state->ctx->Const.GLSLFrontFacingIsSysVal) {
+      var = add_system_value(SYSTEM_VALUE_FRONT_FACE, bool_t, "gl_FrontFacing");
+      var->data.interpolation = INTERP_MODE_FLAT;
+   } else {
+      var = add_input(VARYING_SLOT_FACE, bool_t, "gl_FrontFacing");
+      var->data.interpolation = INTERP_MODE_FLAT;
+   }
 
-   if (state->has_geometry_shader()) {
-      var = add_input(VARYING_SLOT_PRIMITIVE_ID, int_t, "gl_PrimitiveID");
-      var->data.interpolation = INTERP_QUALIFIER_FLAT;
+   if (state->is_version(120, 100)) {
+      if (this->state->ctx->Const.GLSLPointCoordIsSysVal)
+         add_system_value(SYSTEM_VALUE_POINT_COORD, vec2_t,
+                          GLSL_PRECISION_MEDIUM, "gl_PointCoord");
+      else
+         add_input(VARYING_SLOT_PNTC, vec2_t, GLSL_PRECISION_MEDIUM,
+                   "gl_PointCoord");
+   }
+
+   if (state->has_geometry_shader() || state->EXT_gpu_shader4_enable) {
+      var = add_input(VARYING_SLOT_PRIMITIVE_ID, int_t, GLSL_PRECISION_HIGH,
+                      "gl_PrimitiveID");
+      var->data.interpolation = INTERP_MODE_FLAT;
    }
 
    /* gl_FragColor and gl_FragData were deprecated starting in desktop GLSL
@@ -1091,29 +1324,43 @@ builtin_variable_generator::generate_fs_special_vars()
     * They were removed from GLSL ES 3.00.
     */
    if (compatibility || !state->is_version(420, 300)) {
-      add_output(FRAG_RESULT_COLOR, vec4_t, "gl_FragColor");
+      add_output(FRAG_RESULT_COLOR, vec4_t, GLSL_PRECISION_MEDIUM,
+                 "gl_FragColor");
       add_output(FRAG_RESULT_DATA0,
-                 array(vec4_t, state->Const.MaxDrawBuffers), "gl_FragData");
+                 array(vec4_t, state->Const.MaxDrawBuffers),
+                 GLSL_PRECISION_MEDIUM,
+                 "gl_FragData");
+   }
+
+   if (state->has_framebuffer_fetch() && !state->is_version(130, 300)) {
+      ir_variable *const var =
+         add_output(FRAG_RESULT_DATA0,
+                    array(vec4_t, state->Const.MaxDrawBuffers),
+                    "gl_LastFragData");
+      var->data.precision = GLSL_PRECISION_MEDIUM;
+      var->data.read_only = 1;
+      var->data.fb_fetch_output = 1;
+      var->data.memory_coherent = 1;
    }
 
    if (state->es_shader && state->language_version == 100 && state->EXT_blend_func_extended_enable) {
-      /* We make an assumption here that there will only ever be one dual-source draw buffer
-       * In case this assumption is ever proven to be false, make sure to assert here
-       * since we don't handle this case.
-       * In practice, this issue will never arise since no hardware will support it.
-       */
-      assert(state->Const.MaxDualSourceDrawBuffers <= 1);
-      add_index_output(FRAG_RESULT_DATA0, 1, vec4_t, "gl_SecondaryFragColorEXT");
+      add_index_output(FRAG_RESULT_COLOR, 1, vec4_t,
+                       GLSL_PRECISION_MEDIUM, "gl_SecondaryFragColorEXT");
       add_index_output(FRAG_RESULT_DATA0, 1,
                        array(vec4_t, state->Const.MaxDualSourceDrawBuffers),
-                       "gl_SecondaryFragDataEXT");
+                       GLSL_PRECISION_MEDIUM, "gl_SecondaryFragDataEXT");
    }
 
    /* gl_FragDepth has always been in desktop GLSL, but did not appear in GLSL
     * ES 1.00.
     */
-   if (state->is_version(110, 300))
-      add_output(FRAG_RESULT_DEPTH, float_t, "gl_FragDepth");
+   if (state->is_version(110, 300)) {
+      add_output(FRAG_RESULT_DEPTH, float_t, GLSL_PRECISION_HIGH,
+                 "gl_FragDepth");
+   }
+
+   if (state->EXT_frag_depth_enable)
+      add_output(FRAG_RESULT_DEPTH, float_t, "gl_FragDepthEXT");
 
    if (state->ARB_shader_stencil_export_enable) {
       ir_variable *const var =
@@ -1129,9 +1376,13 @@ builtin_variable_generator::generate_fs_special_vars()
          var->enable_extension_warning("GL_AMD_shader_stencil_export");
    }
 
-   if (state->is_version(400, 0) || state->ARB_sample_shading_enable) {
-      add_system_value(SYSTEM_VALUE_SAMPLE_ID, int_t, "gl_SampleID");
-      add_system_value(SYSTEM_VALUE_SAMPLE_POS, vec2_t, "gl_SamplePosition");
+   if (state->is_version(400, 320) ||
+       state->ARB_sample_shading_enable ||
+       state->OES_sample_variables_enable) {
+      add_system_value(SYSTEM_VALUE_SAMPLE_ID, int_t, GLSL_PRECISION_LOW,
+                       "gl_SampleID");
+      add_system_value(SYSTEM_VALUE_SAMPLE_POS, vec2_t, GLSL_PRECISION_MEDIUM,
+                       "gl_SamplePosition");
       /* From the ARB_sample_shading specification:
        *    "The number of elements in the array is ceil(<s>/32), where
        *    <s> is the maximum number of color samples supported by the
@@ -1139,21 +1390,34 @@ builtin_variable_generator::generate_fs_special_vars()
        * Since no drivers expose more than 32x MSAA, we can simply set
        * the array size to 1 rather than computing it.
        */
-      add_output(FRAG_RESULT_SAMPLE_MASK, array(int_t, 1), "gl_SampleMask");
+      add_output(FRAG_RESULT_SAMPLE_MASK, array(int_t, 1),
+                 GLSL_PRECISION_HIGH, "gl_SampleMask");
    }
 
-   if (state->is_version(400, 0) || state->ARB_gpu_shader5_enable) {
-      add_system_value(SYSTEM_VALUE_SAMPLE_MASK_IN, array(int_t, 1), "gl_SampleMaskIn");
+   if (state->is_version(400, 320) ||
+       state->ARB_gpu_shader5_enable ||
+       state->OES_sample_variables_enable) {
+      add_system_value(SYSTEM_VALUE_SAMPLE_MASK_IN, array(int_t, 1),
+                       GLSL_PRECISION_HIGH, "gl_SampleMaskIn");
    }
 
-   if (state->is_version(430, 0) || state->ARB_fragment_layer_viewport_enable) {
-      var = add_input(VARYING_SLOT_LAYER, int_t, "gl_Layer");
-      var->data.interpolation = INTERP_QUALIFIER_FLAT;
+   if (state->is_version(430, 320) ||
+       state->ARB_fragment_layer_viewport_enable ||
+       state->OES_geometry_shader_enable ||
+       state->EXT_geometry_shader_enable) {
+      var = add_input(VARYING_SLOT_LAYER, int_t, GLSL_PRECISION_HIGH,
+                      "gl_Layer");
+      var->data.interpolation = INTERP_MODE_FLAT;
+   }
+
+   if (state->is_version(430, 0) ||
+       state->ARB_fragment_layer_viewport_enable ||
+       state->OES_viewport_array_enable) {
       var = add_input(VARYING_SLOT_VIEWPORT, int_t, "gl_ViewportIndex");
-      var->data.interpolation = INTERP_QUALIFIER_FLAT;
+      var->data.interpolation = INTERP_MODE_FLAT;
    }
 
-   if (state->is_version(450, 310)/* || state->ARB_ES3_1_compatibility_enable*/)
+   if (state->is_version(450, 310) || state->ARB_ES3_1_compatibility_enable)
       add_system_value(SYSTEM_VALUE_HELPER_INVOCATION, bool_t, "gl_HelperInvocation");
 }
 
@@ -1168,8 +1432,16 @@ builtin_variable_generator::generate_cs_special_vars()
                     "gl_LocalInvocationID");
    add_system_value(SYSTEM_VALUE_WORK_GROUP_ID, uvec3_t, "gl_WorkGroupID");
    add_system_value(SYSTEM_VALUE_NUM_WORK_GROUPS, uvec3_t, "gl_NumWorkGroups");
-   add_variable("gl_GlobalInvocationID", uvec3_t, ir_var_auto, 0);
-   add_variable("gl_LocalInvocationIndex", uint_t, ir_var_auto, 0);
+
+   if (state->ARB_compute_variable_group_size_enable) {
+      add_system_value(SYSTEM_VALUE_LOCAL_GROUP_SIZE,
+                       uvec3_t, "gl_LocalGroupSizeARB");
+   }
+
+   add_system_value(SYSTEM_VALUE_GLOBAL_INVOCATION_ID,
+                    uvec3_t, "gl_GlobalInvocationID");
+   add_system_value(SYSTEM_VALUE_LOCAL_INVOCATION_INDEX,
+                    uint_t, "gl_LocalInvocationIndex");
 }
 
 
@@ -1180,23 +1452,25 @@ builtin_variable_generator::generate_cs_special_vars()
  */
 void
 builtin_variable_generator::add_varying(int slot, const glsl_type *type,
-                                        const char *name)
+                                        int precision, const char *name)
 {
    switch (state->stage) {
    case MESA_SHADER_TESS_CTRL:
    case MESA_SHADER_TESS_EVAL:
    case MESA_SHADER_GEOMETRY:
-      this->per_vertex_in.add_field(slot, type, name);
+      this->per_vertex_in.add_field(slot, type, precision, name);
       /* FALLTHROUGH */
    case MESA_SHADER_VERTEX:
-      this->per_vertex_out.add_field(slot, type, name);
+      this->per_vertex_out.add_field(slot, type, precision, name);
       break;
    case MESA_SHADER_FRAGMENT:
-      add_input(slot, type, name);
+      add_input(slot, type, precision, name);
       break;
    case MESA_SHADER_COMPUTE:
       /* Compute shaders don't have varyings. */
       break;
+   default:
+      break;
    }
 }
 
@@ -1208,20 +1482,37 @@ builtin_variable_generator::add_varying(int slot, const glsl_type *type,
 void
 builtin_variable_generator::generate_varyings()
 {
+   struct gl_shader_compiler_options *options =
+      &state->ctx->Const.ShaderCompilerOptions[state->stage];
+
    /* gl_Position and gl_PointSize are not visible from fragment shaders. */
    if (state->stage != MESA_SHADER_FRAGMENT) {
-      add_varying(VARYING_SLOT_POS, vec4_t, "gl_Position");
+      add_varying(VARYING_SLOT_POS, vec4_t, GLSL_PRECISION_HIGH, "gl_Position");
       if (!state->es_shader ||
           state->stage == MESA_SHADER_VERTEX ||
           (state->stage == MESA_SHADER_GEOMETRY &&
-           state->OES_geometry_point_size_enable)) {
-         add_varying(VARYING_SLOT_PSIZ, float_t, "gl_PointSize");
+           (state->OES_geometry_point_size_enable ||
+            state->EXT_geometry_point_size_enable)) ||
+          ((state->stage == MESA_SHADER_TESS_CTRL ||
+            state->stage == MESA_SHADER_TESS_EVAL) &&
+           (state->OES_tessellation_point_size_enable ||
+            state->EXT_tessellation_point_size_enable))) {
+         add_varying(VARYING_SLOT_PSIZ,
+                     float_t,
+                     state->is_version(0, 300) ?
+                     GLSL_PRECISION_HIGH :
+                     GLSL_PRECISION_MEDIUM,
+                     "gl_PointSize");
       }
    }
 
-   if (state->is_version(130, 0)) {
+   if (state->has_clip_distance()) {
        add_varying(VARYING_SLOT_CLIP_DIST0, array(float_t, 0),
-                   "gl_ClipDistance");
+                   GLSL_PRECISION_HIGH, "gl_ClipDistance");
+   }
+   if (state->has_cull_distance()) {
+      add_varying(VARYING_SLOT_CULL_DIST0, array(float_t, 0),
+                  GLSL_PRECISION_HIGH, "gl_CullDistance");
    }
 
    if (compatibility) {
@@ -1256,19 +1547,19 @@ builtin_variable_generator::generate_varyings()
       const glsl_type *per_vertex_in_type =
          this->per_vertex_in.construct_interface_instance();
       add_variable("gl_in", array(per_vertex_in_type, state->Const.MaxPatchVertices),
-                   ir_var_shader_in, -1);
+                   GLSL_PRECISION_NONE, ir_var_shader_in, -1);
    }
    if (state->stage == MESA_SHADER_GEOMETRY) {
       const glsl_type *per_vertex_in_type =
          this->per_vertex_in.construct_interface_instance();
       add_variable("gl_in", array(per_vertex_in_type, 0),
-                   ir_var_shader_in, -1);
+                   GLSL_PRECISION_NONE, ir_var_shader_in, -1);
    }
    if (state->stage == MESA_SHADER_TESS_CTRL) {
       const glsl_type *per_vertex_out_type =
          this->per_vertex_out.construct_interface_instance();
       add_variable("gl_out", array(per_vertex_out_type, 0),
-                   ir_var_shader_out, -1);
+                   GLSL_PRECISION_NONE, ir_var_shader_out, -1);
    }
    if (state->stage == MESA_SHADER_VERTEX ||
        state->stage == MESA_SHADER_TESS_EVAL ||
@@ -1278,14 +1569,16 @@ builtin_variable_generator::generate_varyings()
       const glsl_struct_field *fields = per_vertex_out_type->fields.structure;
       for (unsigned i = 0; i < per_vertex_out_type->length; i++) {
          ir_variable *var =
-            add_variable(fields[i].name, fields[i].type, ir_var_shader_out,
-                         fields[i].location);
+            add_variable(fields[i].name, fields[i].type, fields[i].precision,
+                         ir_var_shader_out, fields[i].location);
          var->data.interpolation = fields[i].interpolation;
          var->data.centroid = fields[i].centroid;
          var->data.sample = fields[i].sample;
          var->data.patch = fields[i].patch;
-         var->data.precision = fields[i].precision;
          var->init_interface_type(per_vertex_out_type);
+
+         var->data.invariant = fields[i].location == VARYING_SLOT_POS &&
+                               options->PositionAlwaysInvariant;
       }
    }
 }
@@ -1302,6 +1595,7 @@ _mesa_glsl_initialize_variables(exec_list *instructions,
 
    gen.generate_constants();
    gen.generate_uniforms();
+   gen.generate_special_vars();
 
    gen.generate_varyings();
 
@@ -1324,86 +1618,7 @@ _mesa_glsl_initialize_variables(exec_list *instructions,
    case MESA_SHADER_COMPUTE:
       gen.generate_cs_special_vars();
       break;
+   default:
+      break;
    }
 }
-
-
-/**
- * Initialize compute shader variables with values that are derived from other
- * compute shader variable.
- */
-static void
-initialize_cs_derived_variables(gl_shader *shader,
-                                ir_function_signature *const main_sig)
-{
-   assert(shader->Stage == MESA_SHADER_COMPUTE);
-
-   ir_variable *gl_GlobalInvocationID =
-      shader->symbols->get_variable("gl_GlobalInvocationID");
-   assert(gl_GlobalInvocationID);
-   ir_variable *gl_WorkGroupID =
-      shader->symbols->get_variable("gl_WorkGroupID");
-   assert(gl_WorkGroupID);
-   ir_variable *gl_WorkGroupSize =
-      shader->symbols->get_variable("gl_WorkGroupSize");
-   if (gl_WorkGroupSize == NULL) {
-      void *const mem_ctx = ralloc_parent(shader->ir);
-      gl_WorkGroupSize = new(mem_ctx) ir_variable(glsl_type::uvec3_type,
-                                                  "gl_WorkGroupSize",
-                                                  ir_var_auto);
-      gl_WorkGroupSize->data.how_declared = ir_var_declared_implicitly;
-      gl_WorkGroupSize->data.read_only = true;
-      shader->ir->push_head(gl_WorkGroupSize);
-   }
-   ir_variable *gl_LocalInvocationID =
-      shader->symbols->get_variable("gl_LocalInvocationID");
-   assert(gl_LocalInvocationID);
-
-   /* gl_GlobalInvocationID =
-    *    gl_WorkGroupID * gl_WorkGroupSize + gl_LocalInvocationID
-    */
-   ir_instruction *inst =
-      assign(gl_GlobalInvocationID,
-             add(mul(gl_WorkGroupID, gl_WorkGroupSize),
-                 gl_LocalInvocationID));
-   main_sig->body.push_head(inst);
-
-   /* gl_LocalInvocationIndex =
-    *    gl_LocalInvocationID.z * gl_WorkGroupSize.x * gl_WorkGroupSize.y +
-    *    gl_LocalInvocationID.y * gl_WorkGroupSize.x +
-    *    gl_LocalInvocationID.x;
-    */
-   ir_expression *index_z =
-      mul(mul(swizzle_z(gl_LocalInvocationID), swizzle_x(gl_WorkGroupSize)),
-          swizzle_y(gl_WorkGroupSize));
-   ir_expression *index_y =
-      mul(swizzle_y(gl_LocalInvocationID), swizzle_x(gl_WorkGroupSize));
-   ir_expression *index_y_plus_z = add(index_y, index_z);
-   operand index_x(swizzle_x(gl_LocalInvocationID));
-   ir_expression *index_x_plus_y_plus_z = add(index_y_plus_z, index_x);
-   ir_variable *gl_LocalInvocationIndex =
-      shader->symbols->get_variable("gl_LocalInvocationIndex");
-   assert(gl_LocalInvocationIndex);
-   inst = assign(gl_LocalInvocationIndex, index_x_plus_y_plus_z);
-   main_sig->body.push_head(inst);
-}
-
-
-/**
- * Initialize builtin variables with values based on other builtin variables.
- * These are initialized in the main function.
- */
-void
-_mesa_glsl_initialize_derived_variables(gl_shader *shader)
-{
-   /* We only need to set CS variables currently. */
-   if (shader->Stage != MESA_SHADER_COMPUTE)
-      return;
-
-   ir_function_signature *const main_sig =
-      _mesa_get_main_function_signature(shader);
-   if (main_sig == NULL)
-      return;
-
-   initialize_cs_derived_variables(shader, main_sig);
-}