Merge remote-tracking branch 'origin/released'

Conflicts:
	mesalib/src/mesa/main/imports.h

16 files changed, 813 insertions, 241 deletions

diff --git a/mesalib/src/glsl/Makefile.am b/mesalib/src/glsl/Makefile.am
index 534eaa385..fd0e837d1 100644
--- a/mesalib/src/glsl/Makefile.am
+++ b/mesalib/src/glsl/Makefile.am
@@ -61,7 +61,9 @@ tests_general_ir_test_SOURCES =		\
 	$(GLSL_SRCDIR)/standalone_scaffolding.cpp \
 	tests/builtin_variable_test.cpp			\
 	tests/invalidate_locations_test.cpp		\
-	tests/general_ir_test.cpp
+	tests/general_ir_test.cpp			\
+	tests/varyings_test.cpp				\
+	tests/common.c
 tests_general_ir_test_CFLAGS =				\
 	$(PTHREAD_CFLAGS)
 tests_general_ir_test_LDADD =				\
@@ -76,7 +78,8 @@ tests_uniform_initializer_test_SOURCES =		\
 	$(top_srcdir)/src/mesa/program/symbol_table.c	\
 	tests/copy_constant_to_storage_tests.cpp	\
 	tests/set_uniform_initializer_tests.cpp		\
-	tests/uniform_initializer_utils.cpp
+	tests/uniform_initializer_utils.cpp		\
+	tests/common.c
 tests_uniform_initializer_test_CFLAGS =			\
 	$(PTHREAD_CFLAGS)
 tests_uniform_initializer_test_LDADD =			\
@@ -95,7 +98,8 @@ tests_ralloc_test_LDADD =				\
 tests_sampler_types_test_SOURCES =			\
 	$(top_srcdir)/src/mesa/program/prog_hash_table.c\
 	$(top_srcdir)/src/mesa/program/symbol_table.c	\
-	tests/sampler_types_test.cpp
+	tests/sampler_types_test.cpp			\
+	tests/common.c
 tests_sampler_types_test_CFLAGS =			\
 	$(PTHREAD_CFLAGS)
 tests_sampler_types_test_LDADD =			\
@@ -138,6 +142,7 @@ glsl_test_SOURCES = \
 	$(top_srcdir)/src/mesa/program/prog_hash_table.c \
 	$(top_srcdir)/src/mesa/program/symbol_table.c \
 	$(GLSL_SRCDIR)/standalone_scaffolding.cpp \
+	tests/common.c \
 	test.cpp \
 	test_optpass.cpp
 
diff --git a/mesalib/src/glsl/ast_to_hir.cpp b/mesalib/src/glsl/ast_to_hir.cpp
index 0411befa9..7516c33e1 100644
--- a/mesalib/src/glsl/ast_to_hir.cpp
+++ b/mesalib/src/glsl/ast_to_hir.cpp
@@ -123,6 +123,11 @@ _mesa_ast_to_hir(exec_list *instructions, struct _mesa_glsl_parse_state *state)
       instructions->push_head(var);
    }
 
+   /* Figure out if gl_FragCoord is actually used in fragment shader */
+   ir_variable *const var = state->symbols->get_variable("gl_FragCoord");
+   if (var != NULL)
+      state->fs_uses_gl_fragcoord = var->data.used;
+
    /* From section 7.1 (Built-In Language Variables) of the GLSL 4.10 spec:
     *
     *     If multiple shaders using members of a built-in block belonging to
@@ -2341,6 +2346,34 @@ apply_image_qualifier_to_variable(const struct ast_type_qualifier *qual,
    }
 }
 
+static inline const char*
+get_layout_qualifier_string(bool origin_upper_left, bool pixel_center_integer)
+{
+   if (origin_upper_left && pixel_center_integer)
+      return "origin_upper_left, pixel_center_integer";
+   else if (origin_upper_left)
+      return "origin_upper_left";
+   else if (pixel_center_integer)
+      return "pixel_center_integer";
+   else
+      return " ";
+}
+
+static inline bool
+is_conflicting_fragcoord_redeclaration(struct _mesa_glsl_parse_state *state,
+                                       const struct ast_type_qualifier *qual)
+{
+   /* If gl_FragCoord was previously declared, and the qualifiers were
+    * different in any way, return true.
+    */
+   if (state->fs_redeclares_gl_fragcoord) {
+      return (state->fs_pixel_center_integer != qual->flags.q.pixel_center_integer
+         || state->fs_origin_upper_left != qual->flags.q.origin_upper_left);
+   }
+
+   return false;
+}
+
 static void
 apply_type_qualifier_to_variable(const struct ast_type_qualifier *qual,
                                  ir_variable *var,
@@ -2505,6 +2538,53 @@ apply_type_qualifier_to_variable(const struct ast_type_qualifier *qual,
 		       qual_string);
    }
 
+   if (var->name != NULL && strcmp(var->name, "gl_FragCoord") == 0) {
+
+      /* Section 4.3.8.1, page 39 of GLSL 1.50 spec says:
+       *
+       *    "Within any shader, the first redeclarations of gl_FragCoord
+       *     must appear before any use of gl_FragCoord."
+       *
+       * Generate a compiler error if above condition is not met by the
+       * fragment shader.
+       */
+      ir_variable *earlier = state->symbols->get_variable("gl_FragCoord");
+      if (earlier != NULL &&
+          earlier->data.used &&
+          !state->fs_redeclares_gl_fragcoord) {
+         _mesa_glsl_error(loc, state,
+                          "gl_FragCoord used before its first redeclaration "
+                          "in fragment shader");
+      }
+
+      /* Make sure all gl_FragCoord redeclarations specify the same layout
+       * qualifiers.
+       */
+      if (is_conflicting_fragcoord_redeclaration(state, qual)) {
+         const char *const qual_string =
+            get_layout_qualifier_string(qual->flags.q.origin_upper_left,
+                                        qual->flags.q.pixel_center_integer);
+
+         const char *const state_string =
+            get_layout_qualifier_string(state->fs_origin_upper_left,
+                                        state->fs_pixel_center_integer);
+
+         _mesa_glsl_error(loc, state,
+                          "gl_FragCoord redeclared with different layout "
+                          "qualifiers (%s) and (%s) ",
+                          state_string,
+                          qual_string);
+      }
+      state->fs_origin_upper_left = qual->flags.q.origin_upper_left;
+      state->fs_pixel_center_integer = qual->flags.q.pixel_center_integer;
+      state->fs_redeclares_gl_fragcoord_with_no_layout_qualifiers =
+         !qual->flags.q.origin_upper_left && !qual->flags.q.pixel_center_integer;
+      state->fs_redeclares_gl_fragcoord =
+         state->fs_origin_upper_left ||
+         state->fs_pixel_center_integer ||
+         state->fs_redeclares_gl_fragcoord_with_no_layout_qualifiers;
+   }
+
    if (qual->flags.q.explicit_location) {
       validate_explicit_location(qual, var, state, loc);
    } else if (qual->flags.q.explicit_index) {
diff --git a/mesalib/src/glsl/builtin_types.cpp b/mesalib/src/glsl/builtin_types.cpp
index dd42ecb05..0a0fa8cd3 100644
--- a/mesalib/src/glsl/builtin_types.cpp
+++ b/mesalib/src/glsl/builtin_types.cpp
@@ -241,7 +241,7 @@ const static struct builtin_type_versions {
    T(atomic_uint,                     420, 999)
 };
 
-const glsl_type *const deprecated_types[] = {
+static const glsl_type *const deprecated_types[] = {
    glsl_type::struct_gl_PointParameters_type,
    glsl_type::struct_gl_MaterialParameters_type,
    glsl_type::struct_gl_LightSourceParameters_type,
diff --git a/mesalib/src/glsl/builtin_variables.cpp b/mesalib/src/glsl/builtin_variables.cpp
index 4176ae6e6..9b35850ee 100644
--- a/mesalib/src/glsl/builtin_variables.cpp
+++ b/mesalib/src/glsl/builtin_variables.cpp
@@ -30,21 +30,21 @@
 #include "program/prog_statevars.h"
 #include "program/prog_instruction.h"
 
-static struct gl_builtin_uniform_element gl_NumSamples_elements[] = {
+static const struct gl_builtin_uniform_element gl_NumSamples_elements[] = {
    {NULL, {STATE_NUM_SAMPLES, 0, 0}, SWIZZLE_XXXX}
 };
 
-static struct gl_builtin_uniform_element gl_DepthRange_elements[] = {
+static const struct gl_builtin_uniform_element gl_DepthRange_elements[] = {
    {"near", {STATE_DEPTH_RANGE, 0, 0}, SWIZZLE_XXXX},
    {"far", {STATE_DEPTH_RANGE, 0, 0}, SWIZZLE_YYYY},
    {"diff", {STATE_DEPTH_RANGE, 0, 0}, SWIZZLE_ZZZZ},
 };
 
-static struct gl_builtin_uniform_element gl_ClipPlane_elements[] = {
+static const struct gl_builtin_uniform_element gl_ClipPlane_elements[] = {
    {NULL, {STATE_CLIPPLANE, 0, 0}, SWIZZLE_XYZW}
 };
 
-static struct gl_builtin_uniform_element gl_Point_elements[] = {
+static const struct gl_builtin_uniform_element gl_Point_elements[] = {
    {"size", {STATE_POINT_SIZE}, SWIZZLE_XXXX},
    {"sizeMin", {STATE_POINT_SIZE}, SWIZZLE_YYYY},
    {"sizeMax", {STATE_POINT_SIZE}, SWIZZLE_ZZZZ},
@@ -54,7 +54,7 @@ static struct gl_builtin_uniform_element gl_Point_elements[] = {
    {"distanceQuadraticAttenuation", {STATE_POINT_ATTENUATION}, SWIZZLE_ZZZZ},
 };
 
-static struct gl_builtin_uniform_element gl_FrontMaterial_elements[] = {
+static const struct gl_builtin_uniform_element gl_FrontMaterial_elements[] = {
    {"emission", {STATE_MATERIAL, 0, STATE_EMISSION}, SWIZZLE_XYZW},
    {"ambient", {STATE_MATERIAL, 0, STATE_AMBIENT}, SWIZZLE_XYZW},
    {"diffuse", {STATE_MATERIAL, 0, STATE_DIFFUSE}, SWIZZLE_XYZW},
@@ -62,7 +62,7 @@ static struct gl_builtin_uniform_element gl_FrontMaterial_elements[] = {
    {"shininess", {STATE_MATERIAL, 0, STATE_SHININESS}, SWIZZLE_XXXX},
 };
 
-static struct gl_builtin_uniform_element gl_BackMaterial_elements[] = {
+static const struct gl_builtin_uniform_element gl_BackMaterial_elements[] = {
    {"emission", {STATE_MATERIAL, 1, STATE_EMISSION}, SWIZZLE_XYZW},
    {"ambient", {STATE_MATERIAL, 1, STATE_AMBIENT}, SWIZZLE_XYZW},
    {"diffuse", {STATE_MATERIAL, 1, STATE_DIFFUSE}, SWIZZLE_XYZW},
@@ -70,7 +70,7 @@ static struct gl_builtin_uniform_element gl_BackMaterial_elements[] = {
    {"shininess", {STATE_MATERIAL, 1, STATE_SHININESS}, SWIZZLE_XXXX},
 };
 
-static struct gl_builtin_uniform_element gl_LightSource_elements[] = {
+static const struct gl_builtin_uniform_element gl_LightSource_elements[] = {
    {"ambient", {STATE_LIGHT, 0, STATE_AMBIENT}, SWIZZLE_XYZW},
    {"diffuse", {STATE_LIGHT, 0, STATE_DIFFUSE}, SWIZZLE_XYZW},
    {"specular", {STATE_LIGHT, 0, STATE_SPECULAR}, SWIZZLE_XYZW},
@@ -89,67 +89,67 @@ static struct gl_builtin_uniform_element gl_LightSource_elements[] = {
    {"quadraticAttenuation", {STATE_LIGHT, 0, STATE_ATTENUATION}, SWIZZLE_ZZZZ},
 };
 
-static struct gl_builtin_uniform_element gl_LightModel_elements[] = {
+static const struct gl_builtin_uniform_element gl_LightModel_elements[] = {
    {"ambient", {STATE_LIGHTMODEL_AMBIENT, 0}, SWIZZLE_XYZW},
 };
 
-static struct gl_builtin_uniform_element gl_FrontLightModelProduct_elements[] = {
+static const struct gl_builtin_uniform_element gl_FrontLightModelProduct_elements[] = {
    {"sceneColor", {STATE_LIGHTMODEL_SCENECOLOR, 0}, SWIZZLE_XYZW},
 };
 
-static struct gl_builtin_uniform_element gl_BackLightModelProduct_elements[] = {
+static const struct gl_builtin_uniform_element gl_BackLightModelProduct_elements[] = {
    {"sceneColor", {STATE_LIGHTMODEL_SCENECOLOR, 1}, SWIZZLE_XYZW},
 };
 
-static struct gl_builtin_uniform_element gl_FrontLightProduct_elements[] = {
+static const struct gl_builtin_uniform_element gl_FrontLightProduct_elements[] = {
    {"ambient", {STATE_LIGHTPROD, 0, 0, STATE_AMBIENT}, SWIZZLE_XYZW},
    {"diffuse", {STATE_LIGHTPROD, 0, 0, STATE_DIFFUSE}, SWIZZLE_XYZW},
    {"specular", {STATE_LIGHTPROD, 0, 0, STATE_SPECULAR}, SWIZZLE_XYZW},
 };
 
-static struct gl_builtin_uniform_element gl_BackLightProduct_elements[] = {
+static const struct gl_builtin_uniform_element gl_BackLightProduct_elements[] = {
    {"ambient", {STATE_LIGHTPROD, 0, 1, STATE_AMBIENT}, SWIZZLE_XYZW},
    {"diffuse", {STATE_LIGHTPROD, 0, 1, STATE_DIFFUSE}, SWIZZLE_XYZW},
    {"specular", {STATE_LIGHTPROD, 0, 1, STATE_SPECULAR}, SWIZZLE_XYZW},
 };
 
-static struct gl_builtin_uniform_element gl_TextureEnvColor_elements[] = {
+static const struct gl_builtin_uniform_element gl_TextureEnvColor_elements[] = {
    {NULL, {STATE_TEXENV_COLOR, 0}, SWIZZLE_XYZW},
 };
 
-static struct gl_builtin_uniform_element gl_EyePlaneS_elements[] = {
+static const struct gl_builtin_uniform_element gl_EyePlaneS_elements[] = {
    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_EYE_S}, SWIZZLE_XYZW},
 };
 
-static struct gl_builtin_uniform_element gl_EyePlaneT_elements[] = {
+static const struct gl_builtin_uniform_element gl_EyePlaneT_elements[] = {
    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_EYE_T}, SWIZZLE_XYZW},
 };
 
-static struct gl_builtin_uniform_element gl_EyePlaneR_elements[] = {
+static const struct gl_builtin_uniform_element gl_EyePlaneR_elements[] = {
    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_EYE_R}, SWIZZLE_XYZW},
 };
 
-static struct gl_builtin_uniform_element gl_EyePlaneQ_elements[] = {
+static const struct gl_builtin_uniform_element gl_EyePlaneQ_elements[] = {
    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_EYE_Q}, SWIZZLE_XYZW},
 };
 
-static struct gl_builtin_uniform_element gl_ObjectPlaneS_elements[] = {
+static const struct gl_builtin_uniform_element gl_ObjectPlaneS_elements[] = {
    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_OBJECT_S}, SWIZZLE_XYZW},
 };
 
-static struct gl_builtin_uniform_element gl_ObjectPlaneT_elements[] = {
+static const struct gl_builtin_uniform_element gl_ObjectPlaneT_elements[] = {
    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_OBJECT_T}, SWIZZLE_XYZW},
 };
 
-static struct gl_builtin_uniform_element gl_ObjectPlaneR_elements[] = {
+static const struct gl_builtin_uniform_element gl_ObjectPlaneR_elements[] = {
    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_OBJECT_R}, SWIZZLE_XYZW},
 };
 
-static struct gl_builtin_uniform_element gl_ObjectPlaneQ_elements[] = {
+static const struct gl_builtin_uniform_element gl_ObjectPlaneQ_elements[] = {
    {NULL, {STATE_TEXGEN, 0, STATE_TEXGEN_OBJECT_Q}, SWIZZLE_XYZW},
 };
 
-static struct gl_builtin_uniform_element gl_Fog_elements[] = {
+static const struct gl_builtin_uniform_element gl_Fog_elements[] = {
    {"color", {STATE_FOG_COLOR}, SWIZZLE_XYZW},
    {"density", {STATE_FOG_PARAMS}, SWIZZLE_XXXX},
    {"start", {STATE_FOG_PARAMS}, SWIZZLE_YYYY},
@@ -157,32 +157,32 @@ static struct gl_builtin_uniform_element gl_Fog_elements[] = {
    {"scale", {STATE_FOG_PARAMS}, SWIZZLE_WWWW},
 };
 
-static struct gl_builtin_uniform_element gl_NormalScale_elements[] = {
+static const struct gl_builtin_uniform_element gl_NormalScale_elements[] = {
    {NULL, {STATE_NORMAL_SCALE}, SWIZZLE_XXXX},
 };
 
-static struct gl_builtin_uniform_element gl_BumpRotMatrix0MESA_elements[] = {
+static const struct gl_builtin_uniform_element gl_BumpRotMatrix0MESA_elements[] = {
    {NULL, {STATE_INTERNAL, STATE_ROT_MATRIX_0}, SWIZZLE_XYZW},
 };
 
-static struct gl_builtin_uniform_element gl_BumpRotMatrix1MESA_elements[] = {
+static const struct gl_builtin_uniform_element gl_BumpRotMatrix1MESA_elements[] = {
    {NULL, {STATE_INTERNAL, STATE_ROT_MATRIX_1}, SWIZZLE_XYZW},
 };
 
-static struct gl_builtin_uniform_element gl_FogParamsOptimizedMESA_elements[] = {
+static const struct gl_builtin_uniform_element gl_FogParamsOptimizedMESA_elements[] = {
    {NULL, {STATE_INTERNAL, STATE_FOG_PARAMS_OPTIMIZED}, SWIZZLE_XYZW},
 };
 
-static struct gl_builtin_uniform_element gl_CurrentAttribVertMESA_elements[] = {
+static const struct gl_builtin_uniform_element gl_CurrentAttribVertMESA_elements[] = {
    {NULL, {STATE_INTERNAL, STATE_CURRENT_ATTRIB, 0}, SWIZZLE_XYZW},
 };
 
-static struct gl_builtin_uniform_element gl_CurrentAttribFragMESA_elements[] = {
+static const struct gl_builtin_uniform_element gl_CurrentAttribFragMESA_elements[] = {
    {NULL, {STATE_INTERNAL, STATE_CURRENT_ATTRIB_MAYBE_VP_CLAMPED, 0}, SWIZZLE_XYZW},
 };
 
 #define MATRIX(name, statevar, modifier)				\
-   static struct gl_builtin_uniform_element name ## _elements[] = {	\
+   static const struct gl_builtin_uniform_element name ## _elements[] = { \
       { NULL, { statevar, 0, 0, 0, modifier}, SWIZZLE_XYZW },		\
       { NULL, { statevar, 0, 1, 1, modifier}, SWIZZLE_XYZW },		\
       { NULL, { statevar, 0, 2, 2, modifier}, SWIZZLE_XYZW },		\
@@ -225,7 +225,7 @@ MATRIX(gl_TextureMatrixTranspose,
 MATRIX(gl_TextureMatrixInverseTranspose,
        STATE_TEXTURE_MATRIX, STATE_MATRIX_INVERSE);
 
-static struct gl_builtin_uniform_element gl_NormalMatrix_elements[] = {
+static const struct gl_builtin_uniform_element gl_NormalMatrix_elements[] = {
    { NULL, { STATE_MODELVIEW_MATRIX, 0, 0, 0, STATE_MATRIX_INVERSE},
      MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_Z, SWIZZLE_Z) },
    { NULL, { STATE_MODELVIEW_MATRIX, 0, 1, 1, STATE_MATRIX_INVERSE},
@@ -498,7 +498,8 @@ builtin_variable_generator::add_uniform(const glsl_type *type,
 
    for (unsigned a = 0; a < array_count; a++) {
       for (unsigned j = 0; j < statevar->num_elements; j++) {
-	 struct gl_builtin_uniform_element *element = &statevar->elements[j];
+	 const struct gl_builtin_uniform_element *element =
+	    &statevar->elements[j];
 
 	 memcpy(slots->tokens, element->tokens, sizeof(element->tokens));
 	 if (type->is_array()) {
diff --git a/mesalib/src/glsl/glcpp/glcpp-parse.y b/mesalib/src/glsl/glcpp/glcpp-parse.y
index f28d8531e..98875837c 100644
--- a/mesalib/src/glsl/glcpp/glcpp-parse.y
+++ b/mesalib/src/glsl/glcpp/glcpp-parse.y
@@ -2062,6 +2062,7 @@ _glcpp_parser_handle_version_declaration(glcpp_parser_t *parser, intmax_t versio
 	/* Add pre-defined macros. */
 	if (parser->is_gles) {
 	   add_builtin_define(parser, "GL_ES", 1);
+           add_builtin_define(parser, "GL_EXT_separate_shader_objects", 1);
 
 	   if (extensions != NULL) {
 	      if (extensions->OES_EGL_image_external)
@@ -2069,6 +2070,7 @@ _glcpp_parser_handle_version_declaration(glcpp_parser_t *parser, intmax_t versio
 	   }
 	} else {
 	   add_builtin_define(parser, "GL_ARB_draw_buffers", 1);
+           add_builtin_define(parser, "GL_ARB_separate_shader_objects", 1);
 	   add_builtin_define(parser, "GL_ARB_texture_rectangle", 1);
            add_builtin_define(parser, "GL_AMD_shader_trinary_minmax", 1);
 
@@ -2134,9 +2136,6 @@ _glcpp_parser_handle_version_declaration(glcpp_parser_t *parser, intmax_t versio
 	      if (extensions->ARB_texture_gather)
 	         add_builtin_define(parser, "GL_ARB_texture_gather", 1);
 
-              if (extensions->ARB_separate_shader_objects)
-                 add_builtin_define(parser, "GL_ARB_separate_shader_objects", 1);
-
 	      if (extensions->ARB_shader_atomic_counters)
 	         add_builtin_define(parser, "GL_ARB_shader_atomic_counters", 1);
 
diff --git a/mesalib/src/glsl/glsl_parser.yy b/mesalib/src/glsl/glsl_parser.yy
index 531ae394b..b71b240de 100644
--- a/mesalib/src/glsl/glsl_parser.yy
+++ b/mesalib/src/glsl/glsl_parser.yy
@@ -1215,7 +1215,7 @@ layout_qualifier_id:
 
       /* Layout qualifiers for GLSL 1.50 geometry shaders. */
       if (!$$.flags.i) {
-         struct {
+         static const struct {
             const char *s;
             GLenum e;
          } map[] = {
@@ -1320,6 +1320,13 @@ layout_qualifier_id:
       if (match_layout_qualifier("location", $1, state) == 0) {
          $$.flags.q.explicit_location = 1;
 
+         if ($$.flags.q.attribute == 1 &&
+             state->ARB_explicit_attrib_location_warn) {
+            _mesa_glsl_warning(& @1, state,
+                               "GL_ARB_explicit_attrib_location layout "
+                               "identifier `%s' used", $1);
+         }
+
          if ($3 >= 0) {
             $$.location = $3;
          } else {
@@ -1369,7 +1376,7 @@ layout_qualifier_id:
          }
       }
 
-      static const char *local_size_qualifiers[3] = {
+      static const char * const local_size_qualifiers[3] = {
          "local_size_x",
          "local_size_y",
          "local_size_z",
@@ -1427,10 +1434,6 @@ layout_qualifier_id:
          _mesa_glsl_error(& @1, state, "unrecognized layout identifier "
                           "`%s'", $1);
          YYERROR;
-      } else if (state->ARB_explicit_attrib_location_warn) {
-         _mesa_glsl_warning(& @1, state,
-                            "GL_ARB_explicit_attrib_location layout "
-                            "identifier `%s' used", $1);
       }
    }
    | interface_block_layout_qualifier
diff --git a/mesalib/src/glsl/glsl_parser_extras.cpp b/mesalib/src/glsl/glsl_parser_extras.cpp
index 03c2a972a..d3339e779 100644
--- a/mesalib/src/glsl/glsl_parser_extras.cpp
+++ b/mesalib/src/glsl/glsl_parser_extras.cpp
@@ -49,7 +49,7 @@ glsl_compute_version_string(void *mem_ctx, bool is_es, unsigned version)
 }
 
 
-static unsigned known_desktop_glsl_versions[] =
+static const unsigned known_desktop_glsl_versions[] =
    { 110, 120, 130, 140, 150, 330, 400, 410, 420, 430, 440 };
 
 
@@ -197,6 +197,12 @@ _mesa_glsl_parse_state::_mesa_glsl_parse_state(struct gl_context *_ctx,
    this->default_uniform_qualifier->flags.q.shared = 1;
    this->default_uniform_qualifier->flags.q.column_major = 1;
 
+   this->fs_uses_gl_fragcoord = false;
+   this->fs_redeclares_gl_fragcoord = false;
+   this->fs_origin_upper_left = false;
+   this->fs_pixel_center_integer = false;
+   this->fs_redeclares_gl_fragcoord_with_no_layout_qualifiers = false;
+
    this->gs_input_prim_type_specified = false;
    this->gs_input_size = 0;
    this->in_qualifier = new(this) ast_type_qualifier();
@@ -500,40 +506,53 @@ struct _mesa_glsl_extension {
 static const _mesa_glsl_extension _mesa_glsl_supported_extensions[] = {
    /*                                  API availability */
    /* name                             GL     ES         supported flag */
+
+   /* ARB extensions go here, sorted alphabetically.
+    */
    EXT(ARB_arrays_of_arrays,           true,  false,     ARB_arrays_of_arrays),
+   EXT(ARB_compute_shader,             true,  false,     ARB_compute_shader),
    EXT(ARB_conservative_depth,         true,  false,     ARB_conservative_depth),
    EXT(ARB_draw_buffers,               true,  false,     dummy_true),
    EXT(ARB_draw_instanced,             true,  false,     ARB_draw_instanced),
    EXT(ARB_explicit_attrib_location,   true,  false,     ARB_explicit_attrib_location),
    EXT(ARB_fragment_coord_conventions, true,  false,     ARB_fragment_coord_conventions),
-   EXT(ARB_texture_rectangle,          true,  false,     dummy_true),
-   EXT(EXT_texture_array,              true,  false,     EXT_texture_array),
-   EXT(ARB_separate_shader_objects,    true,  false,     ARB_separate_shader_objects),
-   EXT(ARB_shader_texture_lod,         true,  false,     ARB_shader_texture_lod),
-   EXT(ARB_shader_stencil_export,      true,  false,     ARB_shader_stencil_export),
-   EXT(AMD_conservative_depth,         true,  false,     ARB_conservative_depth),
-   EXT(AMD_shader_stencil_export,      true,  false,     ARB_shader_stencil_export),
-   EXT(OES_texture_3D,                 false, true,      EXT_texture3D),
-   EXT(OES_EGL_image_external,         false, true,      OES_EGL_image_external),
+   EXT(ARB_gpu_shader5,                true,  false,     ARB_gpu_shader5),
+   EXT(ARB_sample_shading,             true,  false,     ARB_sample_shading),
+   EXT(ARB_separate_shader_objects,    true,  false,     dummy_true),
+   EXT(ARB_shader_atomic_counters,     true,  false,     ARB_shader_atomic_counters),
    EXT(ARB_shader_bit_encoding,        true,  false,     ARB_shader_bit_encoding),
-   EXT(ARB_uniform_buffer_object,      true,  false,     ARB_uniform_buffer_object),
-   EXT(OES_standard_derivatives,       false,  true,     OES_standard_derivatives),
-   EXT(ARB_texture_cube_map_array,     true,  false,     ARB_texture_cube_map_array),
-   EXT(ARB_shading_language_packing,   true,  false,     ARB_shading_language_packing),
+   EXT(ARB_shader_image_load_store,    true,  false,     ARB_shader_image_load_store),
+   EXT(ARB_shader_stencil_export,      true,  false,     ARB_shader_stencil_export),
+   EXT(ARB_shader_texture_lod,         true,  false,     ARB_shader_texture_lod),
    EXT(ARB_shading_language_420pack,   true,  false,     ARB_shading_language_420pack),
+   EXT(ARB_shading_language_packing,   true,  false,     ARB_shading_language_packing),
+   EXT(ARB_texture_cube_map_array,     true,  false,     ARB_texture_cube_map_array),
+   EXT(ARB_texture_gather,             true,  false,     ARB_texture_gather),
    EXT(ARB_texture_multisample,        true,  false,     ARB_texture_multisample),
    EXT(ARB_texture_query_levels,       true,  false,     ARB_texture_query_levels),
    EXT(ARB_texture_query_lod,          true,  false,     ARB_texture_query_lod),
-   EXT(ARB_gpu_shader5,                true,  false,     ARB_gpu_shader5),
+   EXT(ARB_texture_rectangle,          true,  false,     dummy_true),
+   EXT(ARB_uniform_buffer_object,      true,  false,     ARB_uniform_buffer_object),
+   EXT(ARB_viewport_array,             true,  false,     ARB_viewport_array),
+
+   /* KHR extensions go here, sorted alphabetically.
+    */
+
+   /* OES extensions go here, sorted alphabetically.
+    */
+   EXT(OES_EGL_image_external,         false, true,      OES_EGL_image_external),
+   EXT(OES_standard_derivatives,       false, true,      OES_standard_derivatives),
+   EXT(OES_texture_3D,                 false, true,      EXT_texture3D),
+
+   /* All other extensions go here, sorted alphabetically.
+    */
+   EXT(AMD_conservative_depth,         true,  false,     ARB_conservative_depth),
+   EXT(AMD_shader_stencil_export,      true,  false,     ARB_shader_stencil_export),
+   EXT(AMD_shader_trinary_minmax,      true,  false,     dummy_true),
    EXT(AMD_vertex_shader_layer,        true,  false,     AMD_vertex_shader_layer),
+   EXT(EXT_separate_shader_objects,    false, true,      dummy_true),
    EXT(EXT_shader_integer_mix,         true,  true,      EXT_shader_integer_mix),
-   EXT(ARB_texture_gather,             true,  false,     ARB_texture_gather),
-   EXT(ARB_shader_atomic_counters,     true,  false,     ARB_shader_atomic_counters),
-   EXT(ARB_sample_shading,             true,  false,     ARB_sample_shading),
-   EXT(AMD_shader_trinary_minmax,      true,  false,     dummy_true),
-   EXT(ARB_viewport_array,             true,  false,     ARB_viewport_array),
-   EXT(ARB_compute_shader,             true,  false,     ARB_compute_shader),
-   EXT(ARB_shader_image_load_store,    true,  false,     ARB_shader_image_load_store),
+   EXT(EXT_texture_array,              true,  false,     EXT_texture_array),
 };
 
 #undef EXT
@@ -637,7 +656,7 @@ _mesa_glsl_process_extension(const char *name, YYLTYPE *name_locp,
       if (extension && extension->compatible_with_state(state)) {
          extension->set_flags(state, behavior);
       } else {
-         static const char *const fmt = "extension `%s' unsupported in %s shader";
+         static const char fmt[] = "extension `%s' unsupported in %s shader";
 
          if (behavior == extension_require) {
             _mesa_glsl_error(name_locp, state, fmt,
@@ -1356,6 +1375,14 @@ set_shader_inout_layout(struct gl_shader *shader,
       assert(!state->cs_input_local_size_specified);
    }
 
+   if (shader->Stage != MESA_SHADER_FRAGMENT) {
+      /* Should have been prevented by the parser. */
+      assert(!state->fs_uses_gl_fragcoord);
+      assert(!state->fs_redeclares_gl_fragcoord);
+      assert(!state->fs_pixel_center_integer);
+      assert(!state->fs_origin_upper_left);
+   }
+
    switch (shader->Stage) {
    case MESA_SHADER_GEOMETRY:
       shader->Geom.VerticesOut = 0;
@@ -1389,6 +1416,15 @@ set_shader_inout_layout(struct gl_shader *shader,
       }
       break;
 
+   case MESA_SHADER_FRAGMENT:
+      shader->redeclares_gl_fragcoord = state->fs_redeclares_gl_fragcoord;
+      shader->uses_gl_fragcoord = state->fs_uses_gl_fragcoord;
+      shader->pixel_center_integer = state->fs_pixel_center_integer;
+      shader->origin_upper_left = state->fs_origin_upper_left;
+      shader->ARB_fragment_coord_conventions_enable =
+         state->ARB_fragment_coord_conventions_enable;
+      break;
+
    default:
       /* Nothing to do. */
       break;
diff --git a/mesalib/src/glsl/glsl_parser_extras.h b/mesalib/src/glsl/glsl_parser_extras.h
index 0fd778dc3..49402fa21 100644
--- a/mesalib/src/glsl/glsl_parser_extras.h
+++ b/mesalib/src/glsl/glsl_parser_extras.h
@@ -144,8 +144,7 @@ struct _mesa_glsl_parse_state {
    {
       if (!this->has_separate_shader_objects()) {
          const char *const requirement = this->es_shader
-            ? "GL_EXT_separate_shader_objects (not supported by this "
-              "implementation)"
+            ? "GL_EXT_separate_shader_objects extension"
             : "GL_ARB_separate_shader_objects extension or GLSL 420";
 
          _mesa_glsl_error(locp, this, "%s explicit location requires %s",
@@ -168,7 +167,8 @@ struct _mesa_glsl_parse_state {
 
    bool has_separate_shader_objects() const
    {
-      return ARB_separate_shader_objects_enable || is_version(410, 0);
+      return ARB_separate_shader_objects_enable || is_version(410, 0)
+         || EXT_separate_shader_objects_enable;
    }
 
    void process_version_directive(YYLTYPE *locp, int version,
@@ -204,6 +204,18 @@ struct _mesa_glsl_parse_state {
    struct ast_type_qualifier *default_uniform_qualifier;
 
    /**
+    * Variables to track different cases if a fragment shader redeclares
+    * built-in variable gl_FragCoord.
+    *
+    * Note: These values are computed at ast_to_hir time rather than at parse
+    * time.
+    */
+   bool fs_redeclares_gl_fragcoord;
+   bool fs_origin_upper_left;
+   bool fs_pixel_center_integer;
+   bool fs_redeclares_gl_fragcoord_with_no_layout_qualifiers;
+
+   /**
     * True if a geometry shader input primitive type was specified using a
     * layout directive.
     *
@@ -341,8 +353,14 @@ struct _mesa_glsl_parse_state {
     * \name Enable bits for GLSL extensions
     */
    /*@{*/
+   /* ARB extensions go here, sorted alphabetically.
+    */
    bool ARB_arrays_of_arrays_enable;
    bool ARB_arrays_of_arrays_warn;
+   bool ARB_compute_shader_enable;
+   bool ARB_compute_shader_warn;
+   bool ARB_conservative_depth_enable;
+   bool ARB_conservative_depth_warn;
    bool ARB_draw_buffers_enable;
    bool ARB_draw_buffers_warn;
    bool ARB_draw_instanced_enable;
@@ -351,70 +369,78 @@ struct _mesa_glsl_parse_state {
    bool ARB_explicit_attrib_location_warn;
    bool ARB_fragment_coord_conventions_enable;
    bool ARB_fragment_coord_conventions_warn;
-   bool ARB_texture_rectangle_enable;
-   bool ARB_texture_rectangle_warn;
-   bool ARB_texture_gather_enable;
-   bool ARB_texture_gather_warn;
-   bool EXT_texture_array_enable;
-   bool EXT_texture_array_warn;
+   bool ARB_gpu_shader5_enable;
+   bool ARB_gpu_shader5_warn;
+   bool ARB_sample_shading_enable;
+   bool ARB_sample_shading_warn;
    bool ARB_separate_shader_objects_enable;
    bool ARB_separate_shader_objects_warn;
-   bool ARB_shader_texture_lod_enable;
-   bool ARB_shader_texture_lod_warn;
-   bool ARB_shader_stencil_export_enable;
-   bool ARB_shader_stencil_export_warn;
-   bool AMD_conservative_depth_enable;
-   bool AMD_conservative_depth_warn;
-   bool ARB_conservative_depth_enable;
-   bool ARB_conservative_depth_warn;
-   bool AMD_shader_stencil_export_enable;
-   bool AMD_shader_stencil_export_warn;
-   bool OES_texture_3D_enable;
-   bool OES_texture_3D_warn;
-   bool OES_EGL_image_external_enable;
-   bool OES_EGL_image_external_warn;
+   bool ARB_shader_atomic_counters_enable;
+   bool ARB_shader_atomic_counters_warn;
    bool ARB_shader_bit_encoding_enable;
    bool ARB_shader_bit_encoding_warn;
-   bool ARB_uniform_buffer_object_enable;
-   bool ARB_uniform_buffer_object_warn;
-   bool OES_standard_derivatives_enable;
-   bool OES_standard_derivatives_warn;
-   bool ARB_texture_cube_map_array_enable;
-   bool ARB_texture_cube_map_array_warn;
+   bool ARB_shader_image_load_store_enable;
+   bool ARB_shader_image_load_store_warn;
+   bool ARB_shader_stencil_export_enable;
+   bool ARB_shader_stencil_export_warn;
+   bool ARB_shader_texture_lod_enable;
+   bool ARB_shader_texture_lod_warn;
+   bool ARB_shading_language_420pack_enable;
+   bool ARB_shading_language_420pack_warn;
    bool ARB_shading_language_packing_enable;
    bool ARB_shading_language_packing_warn;
+   bool ARB_texture_cube_map_array_enable;
+   bool ARB_texture_cube_map_array_warn;
+   bool ARB_texture_gather_enable;
+   bool ARB_texture_gather_warn;
    bool ARB_texture_multisample_enable;
    bool ARB_texture_multisample_warn;
    bool ARB_texture_query_levels_enable;
    bool ARB_texture_query_levels_warn;
    bool ARB_texture_query_lod_enable;
    bool ARB_texture_query_lod_warn;
-   bool ARB_gpu_shader5_enable;
-   bool ARB_gpu_shader5_warn;
+   bool ARB_texture_rectangle_enable;
+   bool ARB_texture_rectangle_warn;
+   bool ARB_uniform_buffer_object_enable;
+   bool ARB_uniform_buffer_object_warn;
+   bool ARB_viewport_array_enable;
+   bool ARB_viewport_array_warn;
+
+   /* KHR extensions go here, sorted alphabetically.
+    */
+
+   /* OES extensions go here, sorted alphabetically.
+    */
+   bool OES_EGL_image_external_enable;
+   bool OES_EGL_image_external_warn;
+   bool OES_standard_derivatives_enable;
+   bool OES_standard_derivatives_warn;
+   bool OES_texture_3D_enable;
+   bool OES_texture_3D_warn;
+
+   /* All other extensions go here, sorted alphabetically.
+    */
+   bool AMD_conservative_depth_enable;
+   bool AMD_conservative_depth_warn;
+   bool AMD_shader_stencil_export_enable;
+   bool AMD_shader_stencil_export_warn;
+   bool AMD_shader_trinary_minmax_enable;
+   bool AMD_shader_trinary_minmax_warn;
    bool AMD_vertex_shader_layer_enable;
    bool AMD_vertex_shader_layer_warn;
-   bool ARB_shading_language_420pack_enable;
-   bool ARB_shading_language_420pack_warn;
-   bool ARB_sample_shading_enable;
-   bool ARB_sample_shading_warn;
+   bool EXT_separate_shader_objects_enable;
+   bool EXT_separate_shader_objects_warn;
    bool EXT_shader_integer_mix_enable;
    bool EXT_shader_integer_mix_warn;
-   bool ARB_shader_atomic_counters_enable;
-   bool ARB_shader_atomic_counters_warn;
-   bool AMD_shader_trinary_minmax_enable;
-   bool AMD_shader_trinary_minmax_warn;
-   bool ARB_viewport_array_enable;
-   bool ARB_viewport_array_warn;
-   bool ARB_compute_shader_enable;
-   bool ARB_compute_shader_warn;
-   bool ARB_shader_image_load_store_enable;
-   bool ARB_shader_image_load_store_warn;
+   bool EXT_texture_array_enable;
+   bool EXT_texture_array_warn;
    /*@}*/
 
    /** Extensions supported by the OpenGL implementation. */
    const struct gl_extensions *extensions;
 
    bool uses_builtin_functions;
+   bool fs_uses_gl_fragcoord;
 
    /**
     * For geometry shaders, size of the most recently seen input declaration
diff --git a/mesalib/src/glsl/ir.cpp b/mesalib/src/glsl/ir.cpp
index f8f661d5e..dec49bd64 100644
--- a/mesalib/src/glsl/ir.cpp
+++ b/mesalib/src/glsl/ir.cpp
@@ -1333,7 +1333,7 @@ ir_dereference::is_lvalue() const
 }
 
 
-static const char *tex_opcode_strs[] = { "tex", "txb", "txl", "txd", "txf", "txf_ms", "txs", "lod", "tg4", "query_levels" };
+static const char * const tex_opcode_strs[] = { "tex", "txb", "txl", "txd", "txf", "txf_ms", "txs", "lod", "tg4", "query_levels" };
 
 const char *ir_texture::opcode_string()
 {
diff --git a/mesalib/src/glsl/ir_optimization.h b/mesalib/src/glsl/ir_optimization.h
index 40bb61392..c63921c26 100644
--- a/mesalib/src/glsl/ir_optimization.h
+++ b/mesalib/src/glsl/ir_optimization.h
@@ -38,6 +38,8 @@
 #define INT_DIV_TO_MUL_RCP 0x40
 #define BITFIELD_INSERT_TO_BFM_BFI 0x80
 #define LDEXP_TO_ARITH     0x100
+#define CARRY_TO_ARITH     0x200
+#define BORROW_TO_ARITH    0x400
 
 /**
  * \see class lower_packing_builtins_visitor
@@ -112,7 +114,7 @@ bool lower_clip_distance(gl_shader *shader);
 void lower_output_reads(exec_list *instructions);
 bool lower_packing_builtins(exec_list *instructions, int op_mask);
 void lower_ubo_reference(struct gl_shader *shader, exec_list *instructions);
-void lower_packed_varyings(void *mem_ctx, unsigned location_base,
+void lower_packed_varyings(void *mem_ctx,
                            unsigned locations_used, ir_variable_mode mode,
                            unsigned gs_input_vertices, gl_shader *shader);
 bool lower_vector_insert(exec_list *instructions, bool lower_nonconstant_index);
diff --git a/mesalib/src/glsl/link_varyings.cpp b/mesalib/src/glsl/link_varyings.cpp
index c925c00e3..71998dfa9 100644
--- a/mesalib/src/glsl/link_varyings.cpp
+++ b/mesalib/src/glsl/link_varyings.cpp
@@ -172,6 +172,7 @@ cross_validate_outputs_to_inputs(struct gl_shader_program *prog,
 				 gl_shader *producer, gl_shader *consumer)
 {
    glsl_symbol_table parameters;
+   ir_variable *explicit_locations[MAX_VARYING] = { NULL, };
 
    /* Find all shader outputs in the "producer" stage.
     */
@@ -181,7 +182,26 @@ cross_validate_outputs_to_inputs(struct gl_shader_program *prog,
       if ((var == NULL) || (var->data.mode != ir_var_shader_out))
 	 continue;
 
-      parameters.add_variable(var);
+      if (!var->data.explicit_location
+          || var->data.location < VARYING_SLOT_VAR0)
+         parameters.add_variable(var);
+      else {
+         /* User-defined varyings with explicit locations are handled
+          * differently because they do not need to have matching names.
+          */
+         const unsigned idx = var->data.location - VARYING_SLOT_VAR0;
+
+         if (explicit_locations[idx] != NULL) {
+            linker_error(prog,
+                         "%s shader has multiple outputs explicitly "
+                         "assigned to location %d\n",
+                         _mesa_shader_stage_to_string(producer->Stage),
+                         idx);
+            return;
+         }
+
+         explicit_locations[idx] = var;
+      }
    }
 
 
@@ -220,7 +240,27 @@ cross_validate_outputs_to_inputs(struct gl_shader_program *prog,
                                              front_color, back_color,
                                              consumer->Stage, producer->Stage);
       } else {
-         ir_variable *const output = parameters.get_variable(input->name);
+         /* The rules for connecting inputs and outputs change in the presence
+          * of explicit locations.  In this case, we no longer care about the
+          * names of the variables.  Instead, we care only about the
+          * explicitly assigned location.
+          */
+         ir_variable *output = NULL;
+         if (input->data.explicit_location
+             && input->data.location >= VARYING_SLOT_VAR0) {
+            output = explicit_locations[input->data.location - VARYING_SLOT_VAR0];
+
+            if (output == NULL) {
+               linker_error(prog,
+                            "%s shader input `%s' with explicit location "
+                            "has no matching output\n",
+                            _mesa_shader_stage_to_string(consumer->Stage),
+                            input->name);
+            }
+         } else {
+            output = parameters.get_variable(input->name);
+         }
+
          if (output != NULL) {
             cross_validate_types_and_qualifiers(prog, input, output,
                                                 consumer->Stage, producer->Stage);
@@ -622,7 +662,7 @@ public:
    ~varying_matches();
    void record(ir_variable *producer_var, ir_variable *consumer_var);
    unsigned assign_locations();
-   void store_locations(unsigned producer_base, unsigned consumer_base) const;
+   void store_locations() const;
 
 private:
    /**
@@ -648,8 +688,8 @@ private:
       PACKING_ORDER_VEC3,
    };
 
-   static unsigned compute_packing_class(ir_variable *var);
-   static packing_order_enum compute_packing_order(ir_variable *var);
+   static unsigned compute_packing_class(const ir_variable *var);
+   static packing_order_enum compute_packing_order(const ir_variable *var);
    static int match_comparator(const void *x_generic, const void *y_generic);
 
    /**
@@ -746,7 +786,10 @@ varying_matches::~varying_matches()
 void
 varying_matches::record(ir_variable *producer_var, ir_variable *consumer_var)
 {
-   if (!producer_var->data.is_unmatched_generic_inout) {
+   assert(producer_var != NULL || consumer_var != NULL);
+
+   if ((producer_var && !producer_var->data.is_unmatched_generic_inout)
+       || (consumer_var && !consumer_var->data.is_unmatched_generic_inout)) {
       /* Either a location already exists for this variable (since it is part
        * of fixed functionality), or it has already been recorded as part of a
        * previous match.
@@ -781,24 +824,28 @@ varying_matches::record(ir_variable *producer_var, ir_variable *consumer_var)
          realloc(this->matches,
                  sizeof(*this->matches) * this->matches_capacity);
    }
+
+   const ir_variable *const var = (producer_var != NULL)
+      ? producer_var : consumer_var;
+
    this->matches[this->num_matches].packing_class
-      = this->compute_packing_class(producer_var);
+      = this->compute_packing_class(var);
    this->matches[this->num_matches].packing_order
-      = this->compute_packing_order(producer_var);
+      = this->compute_packing_order(var);
    if (this->disable_varying_packing) {
-      unsigned slots = producer_var->type->is_array()
-         ? (producer_var->type->length
-            * producer_var->type->fields.array->matrix_columns)
-         : producer_var->type->matrix_columns;
+      unsigned slots = var->type->is_array()
+         ? (var->type->length * var->type->fields.array->matrix_columns)
+         : var->type->matrix_columns;
       this->matches[this->num_matches].num_components = 4 * slots;
    } else {
       this->matches[this->num_matches].num_components
-         = producer_var->type->component_slots();
+         = var->type->component_slots();
    }
    this->matches[this->num_matches].producer_var = producer_var;
    this->matches[this->num_matches].consumer_var = consumer_var;
    this->num_matches++;
-   producer_var->data.is_unmatched_generic_inout = 0;
+   if (producer_var)
+      producer_var->data.is_unmatched_generic_inout = 0;
    if (consumer_var)
       consumer_var->data.is_unmatched_generic_inout = 0;
 }
@@ -842,8 +889,7 @@ varying_matches::assign_locations()
  * assignments that were made by varying_matches::assign_locations().
  */
 void
-varying_matches::store_locations(unsigned producer_base,
-                                 unsigned consumer_base) const
+varying_matches::store_locations() const
 {
    for (unsigned i = 0; i < this->num_matches; i++) {
       ir_variable *producer_var = this->matches[i].producer_var;
@@ -852,11 +898,14 @@ varying_matches::store_locations(unsigned producer_base,
       unsigned slot = generic_location / 4;
       unsigned offset = generic_location % 4;
 
-      producer_var->data.location = producer_base + slot;
-      producer_var->data.location_frac = offset;
+      if (producer_var) {
+         producer_var->data.location = VARYING_SLOT_VAR0 + slot;
+         producer_var->data.location_frac = offset;
+      }
+
       if (consumer_var) {
          assert(consumer_var->data.location == -1);
-         consumer_var->data.location = consumer_base + slot;
+         consumer_var->data.location = VARYING_SLOT_VAR0 + slot;
          consumer_var->data.location_frac = offset;
       }
    }
@@ -869,7 +918,7 @@ varying_matches::store_locations(unsigned producer_base,
  * be safely backed into the same vec4.
  */
 unsigned
-varying_matches::compute_packing_class(ir_variable *var)
+varying_matches::compute_packing_class(const ir_variable *var)
 {
    /* Without help from the back-end, there is no way to pack together
     * variables with different interpolation types, because
@@ -900,7 +949,7 @@ varying_matches::compute_packing_class(ir_variable *var)
  * other varyings in the same packing class.
  */
 varying_matches::packing_order_enum
-varying_matches::compute_packing_order(ir_variable *var)
+varying_matches::compute_packing_order(const ir_variable *var)
 {
    const glsl_type *element_type = var->type;
 
@@ -943,7 +992,7 @@ varying_matches::match_comparator(const void *x_generic, const void *y_generic)
  * varyings, but excludes variables such as gl_FrontFacing and gl_FragCoord.
  */
 static bool
-is_varying_var(gl_shader_stage stage, const ir_variable *var)
+var_counts_against_varying_limit(gl_shader_stage stage, const ir_variable *var)
 {
    /* Only fragment shaders will take a varying variable as an input */
    if (stage == MESA_SHADER_FRAGMENT &&
@@ -1037,6 +1086,157 @@ private:
 };
 
 
+namespace linker {
+
+bool
+populate_consumer_input_sets(void *mem_ctx, exec_list *ir,
+                             hash_table *consumer_inputs,
+                             hash_table *consumer_interface_inputs,
+                             ir_variable *consumer_inputs_with_locations[VARYING_SLOT_MAX])
+{
+   memset(consumer_inputs_with_locations,
+          0,
+          sizeof(consumer_inputs_with_locations[0]) * VARYING_SLOT_MAX);
+
+   foreach_list(node, ir) {
+      ir_variable *const input_var = ((ir_instruction *) node)->as_variable();
+
+      if ((input_var != NULL) && (input_var->data.mode == ir_var_shader_in)) {
+         if (input_var->type->is_interface())
+            return false;
+
+         if (input_var->data.explicit_location) {
+            /* assign_varying_locations only cares about finding the
+             * ir_variable at the start of a contiguous location block.
+             *
+             *     - For !producer, consumer_inputs_with_locations isn't used.
+             *
+             *     - For !consumer, consumer_inputs_with_locations is empty.
+             *
+             * For consumer && producer, if you were trying to set some
+             * ir_variable to the middle of a location block on the other side
+             * of producer/consumer, cross_validate_outputs_to_inputs() should
+             * be link-erroring due to either type mismatch or location
+             * overlaps.  If the variables do match up, then they've got a
+             * matching data.location and you only looked at
+             * consumer_inputs_with_locations[var->data.location], not any
+             * following entries for the array/structure.
+             */
+            consumer_inputs_with_locations[input_var->data.location] =
+               input_var;
+         } else if (input_var->get_interface_type() != NULL) {
+            char *const iface_field_name =
+               ralloc_asprintf(mem_ctx, "%s.%s",
+                               input_var->get_interface_type()->name,
+                               input_var->name);
+            hash_table_insert(consumer_interface_inputs, input_var,
+                              iface_field_name);
+         } else {
+            hash_table_insert(consumer_inputs, input_var,
+                              ralloc_strdup(mem_ctx, input_var->name));
+         }
+      }
+   }
+
+   return true;
+}
+
+/**
+ * Find a variable from the consumer that "matches" the specified variable
+ *
+ * This function only finds inputs with names that match.  There is no
+ * validation (here) that the types, etc. are compatible.
+ */
+ir_variable *
+get_matching_input(void *mem_ctx,
+                   const ir_variable *output_var,
+                   hash_table *consumer_inputs,
+                   hash_table *consumer_interface_inputs,
+                   ir_variable *consumer_inputs_with_locations[VARYING_SLOT_MAX])
+{
+   ir_variable *input_var;
+
+   if (output_var->data.explicit_location) {
+      input_var = consumer_inputs_with_locations[output_var->data.location];
+   } else if (output_var->get_interface_type() != NULL) {
+      char *const iface_field_name =
+         ralloc_asprintf(mem_ctx, "%s.%s",
+                         output_var->get_interface_type()->name,
+                         output_var->name);
+      input_var =
+         (ir_variable *) hash_table_find(consumer_interface_inputs,
+                                         iface_field_name);
+   } else {
+      input_var =
+         (ir_variable *) hash_table_find(consumer_inputs, output_var->name);
+   }
+
+   return (input_var == NULL || input_var->data.mode != ir_var_shader_in)
+      ? NULL : input_var;
+}
+
+}
+
+static int
+io_variable_cmp(const void *_a, const void *_b)
+{
+   const ir_variable *const a = *(const ir_variable **) _a;
+   const ir_variable *const b = *(const ir_variable **) _b;
+
+   if (a->data.explicit_location && b->data.explicit_location)
+      return b->data.location - a->data.location;
+
+   if (a->data.explicit_location && !b->data.explicit_location)
+      return 1;
+
+   if (!a->data.explicit_location && b->data.explicit_location)
+      return -1;
+
+   return -strcmp(a->name, b->name);
+}
+
+/**
+ * Sort the shader IO variables into canonical order
+ */
+static void
+canonicalize_shader_io(exec_list *ir, enum ir_variable_mode io_mode)
+{
+   ir_variable *var_table[MAX_PROGRAM_OUTPUTS * 4];
+   unsigned num_variables = 0;
+
+   foreach_list(node, ir) {
+      ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+      if (var == NULL || var->data.mode != io_mode)
+         continue;
+
+      /* If we have already encountered more I/O variables that could
+       * successfully link, bail.
+       */
+      if (num_variables == ARRAY_SIZE(var_table))
+         return;
+
+      var_table[num_variables++] = var;
+   }
+
+   if (num_variables == 0)
+      return;
+
+   /* Sort the list in reverse order (io_variable_cmp handles this).  Later
+    * we're going to push the variables on to the IR list as a stack, so we
+    * want the last variable (in canonical order) to be first in the list.
+    */
+   qsort(var_table, num_variables, sizeof(var_table[0]), io_variable_cmp);
+
+   /* Remove the variable from it's current location in the IR, and put it at
+    * the front.
+    */
+   for (unsigned i = 0; i < num_variables; i++) {
+      var_table[i]->remove();
+      ir->push_head(var_table[i]);
+   }
+}
+
 /**
  * Assign locations for all variables that are produced in one pipeline stage
  * (the "producer") and consumed in the next stage (the "consumer").
@@ -1069,8 +1269,6 @@ assign_varying_locations(struct gl_context *ctx,
                          tfeedback_decl *tfeedback_decls,
                          unsigned gs_input_vertices)
 {
-   const unsigned producer_base = VARYING_SLOT_VAR0;
-   const unsigned consumer_base = VARYING_SLOT_VAR0;
    varying_matches matches(ctx->Const.DisableVaryingPacking,
                            consumer && consumer->Stage == MESA_SHADER_FRAGMENT);
    hash_table *tfeedback_candidates
@@ -1079,67 +1277,85 @@ assign_varying_locations(struct gl_context *ctx,
       = hash_table_ctor(0, hash_table_string_hash, hash_table_string_compare);
    hash_table *consumer_interface_inputs
       = hash_table_ctor(0, hash_table_string_hash, hash_table_string_compare);
+   ir_variable *consumer_inputs_with_locations[VARYING_SLOT_MAX] = {
+      NULL,
+   };
 
-   /* Operate in a total of three passes.
+   /* Operate in a total of four passes.
+    *
+    * 1. Sort inputs / outputs into a canonical order.  This is necessary so
+    *    that inputs / outputs of separable shaders will be assigned
+    *    predictable locations regardless of the order in which declarations
+    *    appeared in the shader source.
     *
-    * 1. Assign locations for any matching inputs and outputs.
+    * 2. Assign locations for any matching inputs and outputs.
     *
-    * 2. Mark output variables in the producer that do not have locations as
+    * 3. Mark output variables in the producer that do not have locations as
     *    not being outputs.  This lets the optimizer eliminate them.
     *
-    * 3. Mark input variables in the consumer that do not have locations as
+    * 4. Mark input variables in the consumer that do not have locations as
     *    not being inputs.  This lets the optimizer eliminate them.
     */
+   if (consumer)
+      canonicalize_shader_io(consumer->ir, ir_var_shader_in);
+
+   if (producer)
+      canonicalize_shader_io(producer->ir, ir_var_shader_out);
+
+   if (consumer
+       && !linker::populate_consumer_input_sets(mem_ctx,
+                                                consumer->ir,
+                                                consumer_inputs,
+                                                consumer_interface_inputs,
+                                                consumer_inputs_with_locations)) {
+      assert(!"populate_consumer_input_sets failed");
+      hash_table_dtor(tfeedback_candidates);
+      hash_table_dtor(consumer_inputs);
+      hash_table_dtor(consumer_interface_inputs);
+      return false;
+   }
 
-   if (consumer) {
-      foreach_list(node, consumer->ir) {
-         ir_variable *const input_var =
+   if (producer) {
+      foreach_list(node, producer->ir) {
+         ir_variable *const output_var =
             ((ir_instruction *) node)->as_variable();
 
-         if ((input_var != NULL) && (input_var->data.mode == ir_var_shader_in)) {
-            if (input_var->get_interface_type() != NULL) {
-               char *const iface_field_name =
-                  ralloc_asprintf(mem_ctx, "%s.%s",
-                                  input_var->get_interface_type()->name,
-                                  input_var->name);
-               hash_table_insert(consumer_interface_inputs, input_var,
-                                 iface_field_name);
-            } else {
-               hash_table_insert(consumer_inputs, input_var,
-                                 ralloc_strdup(mem_ctx, input_var->name));
-            }
-         }
-      }
-   }
-
-   foreach_list(node, producer->ir) {
-      ir_variable *const output_var = ((ir_instruction *) node)->as_variable();
+         if ((output_var == NULL) ||
+             (output_var->data.mode != ir_var_shader_out))
+            continue;
 
-      if ((output_var == NULL) || (output_var->data.mode != ir_var_shader_out))
-	 continue;
+         tfeedback_candidate_generator g(mem_ctx, tfeedback_candidates);
+         g.process(output_var);
 
-      tfeedback_candidate_generator g(mem_ctx, tfeedback_candidates);
-      g.process(output_var);
-
-      ir_variable *input_var;
-      if (output_var->get_interface_type() != NULL) {
-         char *const iface_field_name =
-            ralloc_asprintf(mem_ctx, "%s.%s",
-                            output_var->get_interface_type()->name,
-                            output_var->name);
-         input_var =
-            (ir_variable *) hash_table_find(consumer_interface_inputs,
-                                            iface_field_name);
-      } else {
-         input_var =
-            (ir_variable *) hash_table_find(consumer_inputs, output_var->name);
+         ir_variable *const input_var =
+            linker::get_matching_input(mem_ctx, output_var, consumer_inputs,
+                                       consumer_interface_inputs,
+                                       consumer_inputs_with_locations);
+
+         /* If a matching input variable was found, add this ouptut (and the
+          * input) to the set.  If this is a separable program and there is no
+          * consumer stage, add the output.
+          */
+         if (input_var || (prog->SeparateShader && consumer == NULL)) {
+            matches.record(output_var, input_var);
+         }
       }
+   } else {
+      /* If there's no producer stage, then this must be a separable program.
+       * For example, we may have a program that has just a fragment shader.
+       * Later this program will be used with some arbitrary vertex (or
+       * geometry) shader program.  This means that locations must be assigned
+       * for all the inputs.
+       */
+      foreach_list(node, consumer->ir) {
+         ir_variable *const input_var =
+            ((ir_instruction *) node)->as_variable();
 
-      if (input_var && input_var->data.mode != ir_var_shader_in)
-         input_var = NULL;
+         if ((input_var == NULL) ||
+             (input_var->data.mode != ir_var_shader_in))
+            continue;
 
-      if (input_var) {
-         matches.record(output_var, input_var);
+         matches.record(NULL, input_var);
       }
    }
 
@@ -1162,7 +1378,7 @@ assign_varying_locations(struct gl_context *ctx,
    }
 
    const unsigned slots_used = matches.assign_locations();
-   matches.store_locations(producer_base, consumer_base);
+   matches.store_locations();
 
    for (unsigned i = 0; i < num_tfeedback_decls; ++i) {
       if (!tfeedback_decls[i].is_varying())
@@ -1187,15 +1403,17 @@ assign_varying_locations(struct gl_context *ctx,
        */
       assert(!ctx->Extensions.EXT_transform_feedback);
    } else {
-      lower_packed_varyings(mem_ctx, producer_base, slots_used,
-                            ir_var_shader_out, 0, producer);
+      if (producer) {
+         lower_packed_varyings(mem_ctx, slots_used, ir_var_shader_out,
+                               0, producer);
+      }
       if (consumer) {
-         lower_packed_varyings(mem_ctx, consumer_base, slots_used,
-                               ir_var_shader_in, gs_input_vertices, consumer);
+         lower_packed_varyings(mem_ctx, slots_used, ir_var_shader_in,
+                               gs_input_vertices, consumer);
       }
    }
 
-   if (consumer) {
+   if (consumer && producer) {
       foreach_list(node, consumer->ir) {
          ir_variable *const var = ((ir_instruction *) node)->as_variable();
 
@@ -1244,7 +1462,7 @@ check_against_output_limit(struct gl_context *ctx,
       ir_variable *const var = ((ir_instruction *) node)->as_variable();
 
       if (var && var->data.mode == ir_var_shader_out &&
-          is_varying_var(producer->Stage, var)) {
+          var_counts_against_varying_limit(producer->Stage, var)) {
          output_vectors += var->type->count_attribute_slots();
       }
    }
@@ -1283,7 +1501,7 @@ check_against_input_limit(struct gl_context *ctx,
       ir_variable *const var = ((ir_instruction *) node)->as_variable();
 
       if (var && var->data.mode == ir_var_shader_in &&
-          is_varying_var(consumer->Stage, var)) {
+          var_counts_against_varying_limit(consumer->Stage, var)) {
          input_vectors += var->type->count_attribute_slots();
       }
    }
diff --git a/mesalib/src/glsl/linker.cpp b/mesalib/src/glsl/linker.cpp
index c2f7f4863..a43d23082 100644
--- a/mesalib/src/glsl/linker.cpp
+++ b/mesalib/src/glsl/linker.cpp
@@ -1195,6 +1195,83 @@ private:
 };
 
 /**
+ * Performs the cross-validation of layout qualifiers specified in
+ * redeclaration of gl_FragCoord for the attached fragment shaders,
+ * and propagates them to the linked FS and linked shader program.
+ */
+static void
+link_fs_input_layout_qualifiers(struct gl_shader_program *prog,
+	                        struct gl_shader *linked_shader,
+	                        struct gl_shader **shader_list,
+	                        unsigned num_shaders)
+{
+   linked_shader->redeclares_gl_fragcoord = false;
+   linked_shader->uses_gl_fragcoord = false;
+   linked_shader->origin_upper_left = false;
+   linked_shader->pixel_center_integer = false;
+
+   if (linked_shader->Stage != MESA_SHADER_FRAGMENT ||
+       (prog->Version < 150 && !prog->ARB_fragment_coord_conventions_enable))
+      return;
+
+   for (unsigned i = 0; i < num_shaders; i++) {
+      struct gl_shader *shader = shader_list[i];
+      /* From the GLSL 1.50 spec, page 39:
+       *
+       *   "If gl_FragCoord is redeclared in any fragment shader in a program,
+       *    it must be redeclared in all the fragment shaders in that program
+       *    that have a static use gl_FragCoord."
+       *
+       * Exclude the case when one of the 'linked_shader' or 'shader' redeclares
+       * gl_FragCoord with no layout qualifiers but the other one doesn't
+       * redeclare it. If we strictly follow GLSL 1.50 spec's language, it
+       * should be a link error. But, generating link error for this case will
+       * be a wrong behaviour which spec didn't intend to do and it could also
+       * break some applications.
+       */
+      if ((linked_shader->redeclares_gl_fragcoord
+           && !shader->redeclares_gl_fragcoord
+           && shader->uses_gl_fragcoord
+           && (linked_shader->origin_upper_left
+               || linked_shader->pixel_center_integer))
+          || (shader->redeclares_gl_fragcoord
+              && !linked_shader->redeclares_gl_fragcoord
+              && linked_shader->uses_gl_fragcoord
+              && (shader->origin_upper_left
+                  || shader->pixel_center_integer))) {
+             linker_error(prog, "fragment shader defined with conflicting "
+                         "layout qualifiers for gl_FragCoord\n");
+      }
+
+      /* From the GLSL 1.50 spec, page 39:
+       *
+       *   "All redeclarations of gl_FragCoord in all fragment shaders in a
+       *    single program must have the same set of qualifiers."
+       */
+      if (linked_shader->redeclares_gl_fragcoord && shader->redeclares_gl_fragcoord
+          && (shader->origin_upper_left != linked_shader->origin_upper_left
+          || shader->pixel_center_integer != linked_shader->pixel_center_integer)) {
+         linker_error(prog, "fragment shader defined with conflicting "
+                      "layout qualifiers for gl_FragCoord\n");
+      }
+
+      /* Update the linked shader state.  Note that uses_gl_fragcoord should
+       * accumulate the results.  The other values should replace.  If there
+       * are multiple redeclarations, all the fields except uses_gl_fragcoord
+       * are already known to be the same.
+       */
+      if (shader->redeclares_gl_fragcoord || shader->uses_gl_fragcoord) {
+         linked_shader->redeclares_gl_fragcoord =
+            shader->redeclares_gl_fragcoord;
+         linked_shader->uses_gl_fragcoord = linked_shader->uses_gl_fragcoord
+            || shader->uses_gl_fragcoord;
+         linked_shader->origin_upper_left = shader->origin_upper_left;
+         linked_shader->pixel_center_integer = shader->pixel_center_integer;
+      }
+   }
+}
+
+/**
  * Performs the cross-validation of geometry shader max_vertices and
  * primitive type layout qualifiers for the attached geometry shaders,
  * and propagates them to the linked GS and linked shader program.
@@ -1471,6 +1548,7 @@ link_intrastage_shaders(void *mem_ctx,
    linked->NumUniformBlocks = num_uniform_blocks;
    ralloc_steal(linked, linked->UniformBlocks);
 
+   link_fs_input_layout_qualifiers(prog, linked, shader_list, num_shaders);
    link_gs_inout_layout_qualifiers(prog, linked, shader_list, num_shaders);
    link_cs_input_layout_qualifiers(prog, linked, shader_list, num_shaders);
 
@@ -1798,10 +1876,12 @@ assign_attribute_or_color_locations(gl_shader_program *prog,
 	     *     active attribute array, both of which require multiple
 	     *     contiguous generic attributes."
 	     *
-	     * Previous versions of the spec contain similar language but omit
-	     * the bit about attribute arrays.
+	     * I think above text prohibits the aliasing of explicit and
+	     * automatic assignments. But, aliasing is allowed in manual
+	     * assignments of attribute locations. See below comments for
+	     * the details.
 	     *
-	     * Page 61 of the OpenGL 4.0 spec also says:
+	     * From OpenGL 4.0 spec, page 61:
 	     *
 	     *     "It is possible for an application to bind more than one
 	     *     attribute name to the same location. This is referred to as
@@ -1814,29 +1894,84 @@ assign_attribute_or_color_locations(gl_shader_program *prog,
 	     *     but implementations are not required to generate an error
 	     *     in this case."
 	     *
-	     * These two paragraphs are either somewhat contradictory, or I
-	     * don't fully understand one or both of them.
-	     */
-	    /* FINISHME: The code as currently written does not support
-	     * FINISHME: attribute location aliasing (see comment above).
+	     * From GLSL 4.30 spec, page 54:
+	     *
+	     *    "A program will fail to link if any two non-vertex shader
+	     *     input variables are assigned to the same location. For
+	     *     vertex shaders, multiple input variables may be assigned
+	     *     to the same location using either layout qualifiers or via
+	     *     the OpenGL API. However, such aliasing is intended only to
+	     *     support vertex shaders where each execution path accesses
+	     *     at most one input per each location. Implementations are
+	     *     permitted, but not required, to generate link-time errors
+	     *     if they detect that every path through the vertex shader
+	     *     executable accesses multiple inputs assigned to any single
+	     *     location. For all shader types, a program will fail to link
+	     *     if explicit location assignments leave the linker unable
+	     *     to find space for other variables without explicit
+	     *     assignments."
+	     *
+	     * From OpenGL ES 3.0 spec, page 56:
+	     *
+	     *    "Binding more than one attribute name to the same location
+	     *     is referred to as aliasing, and is not permitted in OpenGL
+	     *     ES Shading Language 3.00 vertex shaders. LinkProgram will
+	     *     fail when this condition exists. However, aliasing is
+	     *     possible in OpenGL ES Shading Language 1.00 vertex shaders.
+	     *     This will only work if only one of the aliased attributes
+	     *     is active in the executable program, or if no path through
+	     *     the shader consumes more than one attribute of a set of
+	     *     attributes aliased to the same location. A link error can
+	     *     occur if the linker determines that every path through the
+	     *     shader consumes multiple aliased attributes, but implemen-
+	     *     tations are not required to generate an error in this case."
+	     *
+	     * After looking at above references from OpenGL, OpenGL ES and
+	     * GLSL specifications, we allow aliasing of vertex input variables
+	     * in: OpenGL 2.0 (and above) and OpenGL ES 2.0.
+	     *
+	     * NOTE: This is not required by the spec but its worth mentioning
+	     * here that we're not doing anything to make sure that no path
+	     * through the vertex shader executable accesses multiple inputs
+	     * assigned to any single location.
 	     */
+
 	    /* Mask representing the contiguous slots that will be used by
 	     * this attribute.
 	     */
 	    const unsigned attr = var->data.location - generic_base;
 	    const unsigned use_mask = (1 << slots) - 1;
+            const char *const string = (target_index == MESA_SHADER_VERTEX)
+               ? "vertex shader input" : "fragment shader output";
+
+            /* Generate a link error if the requested locations for this
+             * attribute exceed the maximum allowed attribute location.
+             */
+            if (attr + slots > max_index) {
+               linker_error(prog,
+                           "insufficient contiguous locations "
+                           "available for %s `%s' %d %d %d", string,
+                           var->name, used_locations, use_mask, attr);
+               return false;
+            }
 
 	    /* Generate a link error if the set of bits requested for this
 	     * attribute overlaps any previously allocated bits.
 	     */
 	    if ((~(use_mask << attr) & used_locations) != used_locations) {
-	       const char *const string = (target_index == MESA_SHADER_VERTEX)
-		  ? "vertex shader input" : "fragment shader output";
-	       linker_error(prog,
-			    "insufficient contiguous locations "
-			    "available for %s `%s' %d %d %d", string,
-			    var->name, used_locations, use_mask, attr);
-	       return false;
+               if (target_index == MESA_SHADER_FRAGMENT ||
+                   (prog->IsES && prog->Version >= 300)) {
+                  linker_error(prog,
+                               "overlapping location is assigned "
+                               "to %s `%s' %d %d %d\n", string,
+                               var->name, used_locations, use_mask, attr);
+                  return false;
+               } else {
+                  linker_warning(prog,
+                                 "overlapping location is assigned "
+                                 "to %s `%s' %d %d %d\n", string,
+                                 var->name, used_locations, use_mask, attr);
+               }
 	    }
 
 	    used_locations |= (use_mask << attr);
@@ -2115,6 +2250,7 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
    ralloc_free(prog->AtomicBuffers);
    prog->AtomicBuffers = NULL;
    prog->NumAtomicBuffers = 0;
+   prog->ARB_fragment_coord_conventions_enable = false;
 
    /* Separate the shaders into groups based on their type.
     */
@@ -2141,6 +2277,9 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
 	 goto done;
       }
 
+      prog->ARB_fragment_coord_conventions_enable |=
+         prog->Shaders[i]->ARB_fragment_coord_conventions_enable;
+
       gl_shader_stage shader_type = prog->Shaders[i]->Stage;
       shader_list[shader_type][num_shaders[shader_type]] = prog->Shaders[i];
       num_shaders[shader_type]++;
@@ -2161,7 +2300,8 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
    /* Geometry shaders have to be linked with vertex shaders.
     */
    if (num_shaders[MESA_SHADER_GEOMETRY] > 0 &&
-       num_shaders[MESA_SHADER_VERTEX] == 0) {
+       num_shaders[MESA_SHADER_VERTEX] == 0 &&
+       !prog->SeparateShader) {
       linker_error(prog, "Geometry shader must be linked with "
 		   "vertex shader\n");
       goto done;
@@ -2363,7 +2503,7 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
    if (last >= 0 && last < MESA_SHADER_FRAGMENT) {
       gl_shader *const sh = prog->_LinkedShaders[last];
 
-      if (num_tfeedback_decls != 0) {
+      if (num_tfeedback_decls != 0 || prog->SeparateShader) {
          /* There was no fragment shader, but we still have to assign varying
           * locations for use by transform feedback.
           */
@@ -2377,7 +2517,8 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
       do_dead_builtin_varyings(ctx, sh, NULL,
                                num_tfeedback_decls, tfeedback_decls);
 
-      demote_shader_inputs_and_outputs(sh, ir_var_shader_out);
+      if (!prog->SeparateShader)
+         demote_shader_inputs_and_outputs(sh, ir_var_shader_out);
 
       /* Eliminate code that is now dead due to unused outputs being demoted.
        */
@@ -2392,7 +2533,16 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
       do_dead_builtin_varyings(ctx, NULL, sh,
                                num_tfeedback_decls, tfeedback_decls);
 
-      demote_shader_inputs_and_outputs(sh, ir_var_shader_in);
+      if (prog->SeparateShader) {
+         if (!assign_varying_locations(ctx, mem_ctx, prog,
+                                       NULL /* producer */,
+                                       sh /* consumer */,
+                                       0 /* num_tfeedback_decls */,
+                                       NULL /* tfeedback_decls */,
+                                       0 /* gs_input_vertices */))
+            goto done;
+      } else
+         demote_shader_inputs_and_outputs(sh, ir_var_shader_in);
 
       while (do_dead_code(sh->ir, false))
          ;
@@ -2457,7 +2607,7 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
     * fragment shader) is absent. So, the extension shouldn't change the
     * behavior specified in GLSL specification.
     */
-   if (!prog->InternalSeparateShader && ctx->API == API_OPENGLES2) {
+   if (!prog->SeparateShader && ctx->API == API_OPENGLES2) {
       if (prog->_LinkedShaders[MESA_SHADER_VERTEX] == NULL) {
 	 linker_error(prog, "program lacks a vertex shader\n");
       } else if (prog->_LinkedShaders[MESA_SHADER_FRAGMENT] == NULL) {
diff --git a/mesalib/src/glsl/lower_instructions.cpp b/mesalib/src/glsl/lower_instructions.cpp
index 49316d002..176070c87 100644
--- a/mesalib/src/glsl/lower_instructions.cpp
+++ b/mesalib/src/glsl/lower_instructions.cpp
@@ -39,6 +39,8 @@
  * - MOD_TO_FRACT
  * - LDEXP_TO_ARITH
  * - BITFIELD_INSERT_TO_BFM_BFI
+ * - CARRY_TO_ARITH
+ * - BORROW_TO_ARITH
  *
  * SUB_TO_ADD_NEG:
  * ---------------
@@ -94,6 +96,14 @@
  * Many GPUs implement the bitfieldInsert() built-in from ARB_gpu_shader_5
  * with a pair of instructions.
  *
+ * CARRY_TO_ARITH:
+ * ---------------
+ * Converts ir_carry into (x + y) < x.
+ *
+ * BORROW_TO_ARITH:
+ * ----------------
+ * Converts ir_borrow into (x < y).
+ *
  */
 
 #include "main/core.h" /* for M_LOG2E */
@@ -127,6 +137,8 @@ private:
    void log_to_log2(ir_expression *);
    void bitfield_insert_to_bfm_bfi(ir_expression *);
    void ldexp_to_arith(ir_expression *);
+   void carry_to_arith(ir_expression *);
+   void borrow_to_arith(ir_expression *);
 };
 
 } /* anonymous namespace */
@@ -436,6 +448,42 @@ lower_instructions_visitor::ldexp_to_arith(ir_expression *ir)
    this->progress = true;
 }
 
+void
+lower_instructions_visitor::carry_to_arith(ir_expression *ir)
+{
+   /* Translates
+    *   ir_binop_carry x y
+    * into
+    *   sum = ir_binop_add x y
+    *   bcarry = ir_binop_less sum x
+    *   carry = ir_unop_b2i bcarry
+    */
+
+   ir_rvalue *x_clone = ir->operands[0]->clone(ir, NULL);
+   ir->operation = ir_unop_i2u;
+   ir->operands[0] = b2i(less(add(ir->operands[0], ir->operands[1]), x_clone));
+   ir->operands[1] = NULL;
+
+   this->progress = true;
+}
+
+void
+lower_instructions_visitor::borrow_to_arith(ir_expression *ir)
+{
+   /* Translates
+    *   ir_binop_borrow x y
+    * into
+    *   bcarry = ir_binop_less x y
+    *   carry = ir_unop_b2i bcarry
+    */
+
+   ir->operation = ir_unop_i2u;
+   ir->operands[0] = b2i(less(ir->operands[0], ir->operands[1]));
+   ir->operands[1] = NULL;
+
+   this->progress = true;
+}
+
 ir_visitor_status
 lower_instructions_visitor::visit_leave(ir_expression *ir)
 {
@@ -482,6 +530,16 @@ lower_instructions_visitor::visit_leave(ir_expression *ir)
          ldexp_to_arith(ir);
       break;
 
+   case ir_binop_carry:
+      if (lowering(CARRY_TO_ARITH))
+         carry_to_arith(ir);
+      break;
+
+   case ir_binop_borrow:
+      if (lowering(BORROW_TO_ARITH))
+         borrow_to_arith(ir);
+      break;
+
    default:
       return visit_continue;
    }
diff --git a/mesalib/src/glsl/lower_packed_varyings.cpp b/mesalib/src/glsl/lower_packed_varyings.cpp
index 8c1b8850b..e8654748f 100644
--- a/mesalib/src/glsl/lower_packed_varyings.cpp
+++ b/mesalib/src/glsl/lower_packed_varyings.cpp
@@ -160,8 +160,7 @@ namespace {
 class lower_packed_varyings_visitor
 {
 public:
-   lower_packed_varyings_visitor(void *mem_ctx, unsigned location_base,
-                                 unsigned locations_used,
+   lower_packed_varyings_visitor(void *mem_ctx, unsigned locations_used,
                                  ir_variable_mode mode,
                                  unsigned gs_input_vertices,
                                  exec_list *out_instructions);
@@ -190,18 +189,10 @@ private:
    void * const mem_ctx;
 
    /**
-    * Location representing the first generic varying slot for this shader
-    * stage (e.g. VARYING_SLOT_VAR0 if we are packing vertex shader outputs).
-    * Varyings whose location is less than this value are assumed to
-    * correspond to special fixed function hardware, so they are not lowered.
-    */
-   const unsigned location_base;
-
-   /**
     * Number of generic varying slots which are used by this shader.  This is
     * used to allocate temporary intermediate data structures.  If any varying
     * used by this shader has a location greater than or equal to
-    * location_base + locations_used, an assertion will fire.
+    * VARYING_SLOT_VAR0 + locations_used, an assertion will fire.
     */
    const unsigned locations_used;
 
@@ -235,11 +226,9 @@ private:
 } /* anonymous namespace */
 
 lower_packed_varyings_visitor::lower_packed_varyings_visitor(
-      void *mem_ctx, unsigned location_base, unsigned locations_used,
-      ir_variable_mode mode, unsigned gs_input_vertices,
-      exec_list *out_instructions)
+      void *mem_ctx, unsigned locations_used, ir_variable_mode mode,
+      unsigned gs_input_vertices, exec_list *out_instructions)
    : mem_ctx(mem_ctx),
-     location_base(location_base),
      locations_used(locations_used),
      packed_varyings((ir_variable **)
                      rzalloc_array_size(mem_ctx, sizeof(*packed_varyings),
@@ -259,7 +248,7 @@ lower_packed_varyings_visitor::run(exec_list *instructions)
          continue;
 
       if (var->data.mode != this->mode ||
-          var->data.location < (int) this->location_base ||
+          var->data.location < VARYING_SLOT_VAR0 ||
           !this->needs_lowering(var))
          continue;
 
@@ -542,7 +531,7 @@ lower_packed_varyings_visitor::get_packed_varying_deref(
       unsigned location, ir_variable *unpacked_var, const char *name,
       unsigned vertex_index)
 {
-   unsigned slot = location - this->location_base;
+   unsigned slot = location - VARYING_SLOT_VAR0;
    assert(slot < locations_used);
    if (this->packed_varyings[slot] == NULL) {
       char *packed_name = ralloc_asprintf(this->mem_ctx, "packed:%s", name);
@@ -595,7 +584,12 @@ lower_packed_varyings_visitor::get_packed_varying_deref(
 bool
 lower_packed_varyings_visitor::needs_lowering(ir_variable *var)
 {
-   /* Things composed of vec4's don't need lowering.  Everything else does. */
+   /* Things composed of vec4's and varyings with explicitly assigned
+    * locations don't need lowering.  Everything else does.
+    */
+   if (var->data.explicit_location)
+      return false;
+
    const glsl_type *type = var->type;
    if (this->gs_input_vertices != 0) {
       assert(type->is_array());
@@ -654,9 +648,9 @@ lower_packed_varyings_gs_splicer::visit(ir_emit_vertex *ev)
 
 
 void
-lower_packed_varyings(void *mem_ctx, unsigned location_base,
-                      unsigned locations_used, ir_variable_mode mode,
-                      unsigned gs_input_vertices, gl_shader *shader)
+lower_packed_varyings(void *mem_ctx, unsigned locations_used,
+                      ir_variable_mode mode, unsigned gs_input_vertices,
+                      gl_shader *shader)
 {
    exec_list *instructions = shader->ir;
    ir_function *main_func = shader->symbols->get_function("main");
@@ -664,8 +658,7 @@ lower_packed_varyings(void *mem_ctx, unsigned location_base,
    ir_function_signature *main_func_sig
       = main_func->matching_signature(NULL, &void_parameters);
    exec_list new_instructions;
-   lower_packed_varyings_visitor visitor(mem_ctx, location_base,
-                                         locations_used, mode,
+   lower_packed_varyings_visitor visitor(mem_ctx, locations_used, mode,
                                          gs_input_vertices, &new_instructions);
    visitor.run(instructions);
    if (mode == ir_var_shader_out) {
diff --git a/mesalib/src/glsl/main.cpp b/mesalib/src/glsl/main.cpp
index 0d8c01f6a..6c229465c 100644
--- a/mesalib/src/glsl/main.cpp
+++ b/mesalib/src/glsl/main.cpp
@@ -51,6 +51,12 @@
 
 static int glsl_version = 330;
 
+extern "C" void
+_mesa_error_no_memory(const char *caller)
+{
+   fprintf(stderr, "Mesa error: out of memory in %s", caller);
+}
+
 static void
 initialize_context(struct gl_context *ctx, gl_api api)
 {
diff --git a/mesalib/src/glsl/opt_dead_builtin_varyings.cpp b/mesalib/src/glsl/opt_dead_builtin_varyings.cpp
index c2a306e7b..6612592aa 100644
--- a/mesalib/src/glsl/opt_dead_builtin_varyings.cpp
+++ b/mesalib/src/glsl/opt_dead_builtin_varyings.cpp
@@ -518,14 +518,9 @@ do_dead_builtin_varyings(struct gl_context *ctx,
 
    /* Lowering of built-in varyings has no effect with the core context and
     * GLES2, because they are not available there.
-    *
-    * EXT_separate_shader_objects doesn't allow this optimization,
-    * because a program object can be bound partially (e.g. only one
-    * stage of a program object can be bound).
     */
    if (ctx->API == API_OPENGL_CORE ||
-       ctx->API == API_OPENGLES2 ||
-       ctx->Extensions.EXT_separate_shader_objects) {
+       ctx->API == API_OPENGLES2) {
       return;
    }