2 * Copyright © 2010 Intel Corporation
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
24 #include "main/core.h" /* for MAX2 */
26 #include "compiler/glsl_types.h"
28 ir_rvalue::ir_rvalue(enum ir_node_type t)
31 this->type = glsl_type::error_type;
34 bool ir_rvalue::is_zero() const
39 bool ir_rvalue::is_one() const
44 bool ir_rvalue::is_negative_one() const
50 * Modify the swizzle make to move one component to another
52 * \param m IR swizzle to be modified
53 * \param from Component in the RHS that is to be swizzled
54 * \param to Desired swizzle location of \c from
57 update_rhs_swizzle(ir_swizzle_mask &m, unsigned from, unsigned to)
60 case 0: m.x = from; break;
61 case 1: m.y = from; break;
62 case 2: m.z = from; break;
63 case 3: m.w = from; break;
64 default: assert(!"Should not get here.");
69 ir_assignment::set_lhs(ir_rvalue *lhs)
72 bool swizzled = false;
75 ir_swizzle *swiz = lhs->as_swizzle();
80 unsigned write_mask = 0;
81 ir_swizzle_mask rhs_swiz = { 0, 0, 0, 0, 0, 0 };
83 for (unsigned i = 0; i < swiz->mask.num_components; i++) {
87 case 0: c = swiz->mask.x; break;
88 case 1: c = swiz->mask.y; break;
89 case 2: c = swiz->mask.z; break;
90 case 3: c = swiz->mask.w; break;
91 default: assert(!"Should not get here.");
94 write_mask |= (((this->write_mask >> i) & 1) << c);
95 update_rhs_swizzle(rhs_swiz, i, c);
96 rhs_swiz.num_components = swiz->val->type->vector_elements;
99 this->write_mask = write_mask;
102 this->rhs = new(mem_ctx) ir_swizzle(this->rhs, rhs_swiz);
107 /* Now, RHS channels line up with the LHS writemask. Collapse it
108 * to just the channels that will be written.
110 ir_swizzle_mask rhs_swiz = { 0, 0, 0, 0, 0, 0 };
112 for (int i = 0; i < 4; i++) {
113 if (write_mask & (1 << i))
114 update_rhs_swizzle(rhs_swiz, i, rhs_chan++);
116 rhs_swiz.num_components = rhs_chan;
117 this->rhs = new(mem_ctx) ir_swizzle(this->rhs, rhs_swiz);
120 assert((lhs == NULL) || lhs->as_dereference());
122 this->lhs = (ir_dereference *) lhs;
126 ir_assignment::whole_variable_written()
128 ir_variable *v = this->lhs->whole_variable_referenced();
133 if (v->type->is_scalar())
136 if (v->type->is_vector()) {
137 const unsigned mask = (1U << v->type->vector_elements) - 1;
139 if (mask != this->write_mask)
143 /* Either all the vector components are assigned or the variable is some
144 * composite type (and the whole thing is assigned.
149 ir_assignment::ir_assignment(ir_dereference *lhs, ir_rvalue *rhs,
150 ir_rvalue *condition, unsigned write_mask)
151 : ir_instruction(ir_type_assignment)
153 this->condition = condition;
156 this->write_mask = write_mask;
158 if (lhs->type->is_scalar() || lhs->type->is_vector()) {
159 int lhs_components = 0;
160 for (int i = 0; i < 4; i++) {
161 if (write_mask & (1 << i))
165 assert(lhs_components == this->rhs->type->vector_elements);
169 ir_assignment::ir_assignment(ir_rvalue *lhs, ir_rvalue *rhs,
170 ir_rvalue *condition)
171 : ir_instruction(ir_type_assignment)
173 this->condition = condition;
176 /* If the RHS is a vector type, assume that all components of the vector
177 * type are being written to the LHS. The write mask comes from the RHS
178 * because we can have a case where the LHS is a vec4 and the RHS is a
179 * vec3. In that case, the assignment is:
181 * (assign (...) (xyz) (var_ref lhs) (var_ref rhs))
183 if (rhs->type->is_vector())
184 this->write_mask = (1U << rhs->type->vector_elements) - 1;
185 else if (rhs->type->is_scalar())
186 this->write_mask = 1;
188 this->write_mask = 0;
193 ir_expression::ir_expression(int op, const struct glsl_type *type,
194 ir_rvalue *op0, ir_rvalue *op1,
195 ir_rvalue *op2, ir_rvalue *op3)
196 : ir_rvalue(ir_type_expression)
199 this->operation = ir_expression_operation(op);
200 this->operands[0] = op0;
201 this->operands[1] = op1;
202 this->operands[2] = op2;
203 this->operands[3] = op3;
205 int num_operands = get_num_operands(this->operation);
206 for (int i = num_operands; i < 4; i++) {
207 assert(this->operands[i] == NULL);
212 ir_expression::ir_expression(int op, ir_rvalue *op0)
213 : ir_rvalue(ir_type_expression)
215 this->operation = ir_expression_operation(op);
216 this->operands[0] = op0;
217 this->operands[1] = NULL;
218 this->operands[2] = NULL;
219 this->operands[3] = NULL;
221 assert(op <= ir_last_unop);
223 switch (this->operation) {
224 case ir_unop_bit_not:
225 case ir_unop_logic_not:
240 case ir_unop_round_even:
244 case ir_unop_dFdx_coarse:
245 case ir_unop_dFdx_fine:
247 case ir_unop_dFdy_coarse:
248 case ir_unop_dFdy_fine:
249 case ir_unop_bitfield_reverse:
250 case ir_unop_interpolate_at_centroid:
251 case ir_unop_saturate:
252 this->type = op0->type;
259 case ir_unop_bitcast_f2i:
260 case ir_unop_bit_count:
261 case ir_unop_find_msb:
262 case ir_unop_find_lsb:
263 case ir_unop_subroutine_to_int:
264 this->type = glsl_type::get_instance(GLSL_TYPE_INT,
265 op0->type->vector_elements, 1);
272 case ir_unop_bitcast_i2f:
273 case ir_unop_bitcast_u2f:
274 this->type = glsl_type::get_instance(GLSL_TYPE_FLOAT,
275 op0->type->vector_elements, 1);
281 this->type = glsl_type::get_instance(GLSL_TYPE_BOOL,
282 op0->type->vector_elements, 1);
288 this->type = glsl_type::get_instance(GLSL_TYPE_DOUBLE,
289 op0->type->vector_elements, 1);
295 case ir_unop_bitcast_f2u:
296 this->type = glsl_type::get_instance(GLSL_TYPE_UINT,
297 op0->type->vector_elements, 1);
301 this->type = glsl_type::float_type;
304 case ir_unop_unpack_double_2x32:
305 this->type = glsl_type::uvec2_type;
308 case ir_unop_pack_snorm_2x16:
309 case ir_unop_pack_snorm_4x8:
310 case ir_unop_pack_unorm_2x16:
311 case ir_unop_pack_unorm_4x8:
312 case ir_unop_pack_half_2x16:
313 this->type = glsl_type::uint_type;
316 case ir_unop_pack_double_2x32:
317 this->type = glsl_type::double_type;
320 case ir_unop_unpack_snorm_2x16:
321 case ir_unop_unpack_unorm_2x16:
322 case ir_unop_unpack_half_2x16:
323 this->type = glsl_type::vec2_type;
326 case ir_unop_unpack_snorm_4x8:
327 case ir_unop_unpack_unorm_4x8:
328 this->type = glsl_type::vec4_type;
331 case ir_unop_frexp_sig:
332 this->type = op0->type;
334 case ir_unop_frexp_exp:
335 this->type = glsl_type::get_instance(GLSL_TYPE_INT,
336 op0->type->vector_elements, 1);
339 case ir_unop_get_buffer_size:
340 case ir_unop_ssbo_unsized_array_length:
341 this->type = glsl_type::int_type;
345 assert(!"not reached: missing automatic type setup for ir_expression");
346 this->type = op0->type;
351 ir_expression::ir_expression(int op, ir_rvalue *op0, ir_rvalue *op1)
352 : ir_rvalue(ir_type_expression)
354 this->operation = ir_expression_operation(op);
355 this->operands[0] = op0;
356 this->operands[1] = op1;
357 this->operands[2] = NULL;
358 this->operands[3] = NULL;
360 assert(op > ir_last_unop);
362 switch (this->operation) {
363 case ir_binop_all_equal:
364 case ir_binop_any_nequal:
365 this->type = glsl_type::bool_type;
376 if (op0->type->is_scalar()) {
377 this->type = op1->type;
378 } else if (op1->type->is_scalar()) {
379 this->type = op0->type;
381 if (this->operation == ir_binop_mul) {
382 this->type = glsl_type::get_mul_type(op0->type, op1->type);
384 assert(op0->type == op1->type);
385 this->type = op0->type;
390 case ir_binop_logic_and:
391 case ir_binop_logic_xor:
392 case ir_binop_logic_or:
393 case ir_binop_bit_and:
394 case ir_binop_bit_xor:
395 case ir_binop_bit_or:
396 assert(!op0->type->is_matrix());
397 assert(!op1->type->is_matrix());
398 if (op0->type->is_scalar()) {
399 this->type = op1->type;
400 } else if (op1->type->is_scalar()) {
401 this->type = op0->type;
403 assert(op0->type->vector_elements == op1->type->vector_elements);
404 this->type = op0->type;
409 case ir_binop_nequal:
410 case ir_binop_lequal:
411 case ir_binop_gequal:
413 case ir_binop_greater:
414 assert(op0->type == op1->type);
415 this->type = glsl_type::get_instance(GLSL_TYPE_BOOL,
416 op0->type->vector_elements, 1);
420 this->type = op0->type->get_base_type();
423 case ir_binop_imul_high:
425 case ir_binop_borrow:
426 case ir_binop_lshift:
427 case ir_binop_rshift:
429 case ir_binop_interpolate_at_offset:
430 case ir_binop_interpolate_at_sample:
431 this->type = op0->type;
434 case ir_binop_vector_extract:
435 this->type = op0->type->get_scalar_type();
439 assert(!"not reached: missing automatic type setup for ir_expression");
440 this->type = glsl_type::float_type;
444 ir_expression::ir_expression(int op, ir_rvalue *op0, ir_rvalue *op1,
446 : ir_rvalue(ir_type_expression)
448 this->operation = ir_expression_operation(op);
449 this->operands[0] = op0;
450 this->operands[1] = op1;
451 this->operands[2] = op2;
452 this->operands[3] = NULL;
454 assert(op > ir_last_binop && op <= ir_last_triop);
456 switch (this->operation) {
459 case ir_triop_bitfield_extract:
460 case ir_triop_vector_insert:
461 this->type = op0->type;
465 this->type = op1->type;
469 assert(!"not reached: missing automatic type setup for ir_expression");
470 this->type = glsl_type::float_type;
475 ir_expression::get_num_operands(ir_expression_operation op)
477 assert(op <= ir_last_opcode);
479 if (op <= ir_last_unop)
482 if (op <= ir_last_binop)
485 if (op <= ir_last_triop)
488 if (op <= ir_last_quadop)
495 static const char *const operator_strs[] = {
563 "interpolate_at_centroid",
565 "ssbo_unsized_array_length",
597 "interpolate_at_offset",
598 "interpolate_at_sample",
608 const char *ir_expression::operator_string(ir_expression_operation op)
610 assert((unsigned int) op < ARRAY_SIZE(operator_strs));
611 assert(ARRAY_SIZE(operator_strs) == (ir_quadop_vector + 1));
612 return operator_strs[op];
615 const char *ir_expression::operator_string()
617 return operator_string(this->operation);
621 depth_layout_string(ir_depth_layout layout)
624 case ir_depth_layout_none: return "";
625 case ir_depth_layout_any: return "depth_any";
626 case ir_depth_layout_greater: return "depth_greater";
627 case ir_depth_layout_less: return "depth_less";
628 case ir_depth_layout_unchanged: return "depth_unchanged";
636 ir_expression_operation
637 ir_expression::get_operator(const char *str)
639 const int operator_count = sizeof(operator_strs) / sizeof(operator_strs[0]);
640 for (int op = 0; op < operator_count; op++) {
641 if (strcmp(str, operator_strs[op]) == 0)
642 return (ir_expression_operation) op;
644 return (ir_expression_operation) -1;
648 ir_expression::variable_referenced() const
651 case ir_binop_vector_extract:
652 case ir_triop_vector_insert:
653 /* We get these for things like a[0] where a is a vector type. In these
654 * cases we want variable_referenced() to return the actual vector
655 * variable this is wrapping.
657 return operands[0]->variable_referenced();
659 return ir_rvalue::variable_referenced();
663 ir_constant::ir_constant()
664 : ir_rvalue(ir_type_constant)
668 ir_constant::ir_constant(const struct glsl_type *type,
669 const ir_constant_data *data)
670 : ir_rvalue(ir_type_constant)
672 assert((type->base_type >= GLSL_TYPE_UINT)
673 && (type->base_type <= GLSL_TYPE_BOOL));
676 memcpy(& this->value, data, sizeof(this->value));
679 ir_constant::ir_constant(float f, unsigned vector_elements)
680 : ir_rvalue(ir_type_constant)
682 assert(vector_elements <= 4);
683 this->type = glsl_type::get_instance(GLSL_TYPE_FLOAT, vector_elements, 1);
684 for (unsigned i = 0; i < vector_elements; i++) {
685 this->value.f[i] = f;
687 for (unsigned i = vector_elements; i < 16; i++) {
688 this->value.f[i] = 0;
692 ir_constant::ir_constant(double d, unsigned vector_elements)
693 : ir_rvalue(ir_type_constant)
695 assert(vector_elements <= 4);
696 this->type = glsl_type::get_instance(GLSL_TYPE_DOUBLE, vector_elements, 1);
697 for (unsigned i = 0; i < vector_elements; i++) {
698 this->value.d[i] = d;
700 for (unsigned i = vector_elements; i < 16; i++) {
701 this->value.d[i] = 0.0;
705 ir_constant::ir_constant(unsigned int u, unsigned vector_elements)
706 : ir_rvalue(ir_type_constant)
708 assert(vector_elements <= 4);
709 this->type = glsl_type::get_instance(GLSL_TYPE_UINT, vector_elements, 1);
710 for (unsigned i = 0; i < vector_elements; i++) {
711 this->value.u[i] = u;
713 for (unsigned i = vector_elements; i < 16; i++) {
714 this->value.u[i] = 0;
718 ir_constant::ir_constant(int integer, unsigned vector_elements)
719 : ir_rvalue(ir_type_constant)
721 assert(vector_elements <= 4);
722 this->type = glsl_type::get_instance(GLSL_TYPE_INT, vector_elements, 1);
723 for (unsigned i = 0; i < vector_elements; i++) {
724 this->value.i[i] = integer;
726 for (unsigned i = vector_elements; i < 16; i++) {
727 this->value.i[i] = 0;
731 ir_constant::ir_constant(bool b, unsigned vector_elements)
732 : ir_rvalue(ir_type_constant)
734 assert(vector_elements <= 4);
735 this->type = glsl_type::get_instance(GLSL_TYPE_BOOL, vector_elements, 1);
736 for (unsigned i = 0; i < vector_elements; i++) {
737 this->value.b[i] = b;
739 for (unsigned i = vector_elements; i < 16; i++) {
740 this->value.b[i] = false;
744 ir_constant::ir_constant(const ir_constant *c, unsigned i)
745 : ir_rvalue(ir_type_constant)
747 this->type = c->type->get_base_type();
749 switch (this->type->base_type) {
750 case GLSL_TYPE_UINT: this->value.u[0] = c->value.u[i]; break;
751 case GLSL_TYPE_INT: this->value.i[0] = c->value.i[i]; break;
752 case GLSL_TYPE_FLOAT: this->value.f[0] = c->value.f[i]; break;
753 case GLSL_TYPE_BOOL: this->value.b[0] = c->value.b[i]; break;
754 case GLSL_TYPE_DOUBLE: this->value.d[0] = c->value.d[i]; break;
755 default: assert(!"Should not get here."); break;
759 ir_constant::ir_constant(const struct glsl_type *type, exec_list *value_list)
760 : ir_rvalue(ir_type_constant)
764 assert(type->is_scalar() || type->is_vector() || type->is_matrix()
765 || type->is_record() || type->is_array());
767 if (type->is_array()) {
768 this->array_elements = ralloc_array(this, ir_constant *, type->length);
770 foreach_in_list(ir_constant, value, value_list) {
771 assert(value->as_constant() != NULL);
773 this->array_elements[i++] = value;
778 /* If the constant is a record, the types of each of the entries in
779 * value_list must be a 1-for-1 match with the structure components. Each
780 * entry must also be a constant. Just move the nodes from the value_list
781 * to the list in the ir_constant.
783 /* FINISHME: Should there be some type checking and / or assertions here? */
784 /* FINISHME: Should the new constant take ownership of the nodes from
785 * FINISHME: value_list, or should it make copies?
787 if (type->is_record()) {
788 value_list->move_nodes_to(& this->components);
792 for (unsigned i = 0; i < 16; i++) {
793 this->value.u[i] = 0;
796 ir_constant *value = (ir_constant *) (value_list->head);
798 /* Constructors with exactly one scalar argument are special for vectors
799 * and matrices. For vectors, the scalar value is replicated to fill all
800 * the components. For matrices, the scalar fills the components of the
801 * diagonal while the rest is filled with 0.
803 if (value->type->is_scalar() && value->next->is_tail_sentinel()) {
804 if (type->is_matrix()) {
805 /* Matrix - fill diagonal (rest is already set to 0) */
806 assert(type->base_type == GLSL_TYPE_FLOAT ||
807 type->base_type == GLSL_TYPE_DOUBLE);
808 for (unsigned i = 0; i < type->matrix_columns; i++) {
809 if (type->base_type == GLSL_TYPE_FLOAT)
810 this->value.f[i * type->vector_elements + i] =
813 this->value.d[i * type->vector_elements + i] =
817 /* Vector or scalar - fill all components */
818 switch (type->base_type) {
821 for (unsigned i = 0; i < type->components(); i++)
822 this->value.u[i] = value->value.u[0];
824 case GLSL_TYPE_FLOAT:
825 for (unsigned i = 0; i < type->components(); i++)
826 this->value.f[i] = value->value.f[0];
828 case GLSL_TYPE_DOUBLE:
829 for (unsigned i = 0; i < type->components(); i++)
830 this->value.d[i] = value->value.d[0];
833 for (unsigned i = 0; i < type->components(); i++)
834 this->value.b[i] = value->value.b[0];
837 assert(!"Should not get here.");
844 if (type->is_matrix() && value->type->is_matrix()) {
845 assert(value->next->is_tail_sentinel());
847 /* From section 5.4.2 of the GLSL 1.20 spec:
848 * "If a matrix is constructed from a matrix, then each component
849 * (column i, row j) in the result that has a corresponding component
850 * (column i, row j) in the argument will be initialized from there."
852 unsigned cols = MIN2(type->matrix_columns, value->type->matrix_columns);
853 unsigned rows = MIN2(type->vector_elements, value->type->vector_elements);
854 for (unsigned i = 0; i < cols; i++) {
855 for (unsigned j = 0; j < rows; j++) {
856 const unsigned src = i * value->type->vector_elements + j;
857 const unsigned dst = i * type->vector_elements + j;
858 this->value.f[dst] = value->value.f[src];
862 /* "All other components will be initialized to the identity matrix." */
863 for (unsigned i = cols; i < type->matrix_columns; i++)
864 this->value.f[i * type->vector_elements + i] = 1.0;
869 /* Use each component from each entry in the value_list to initialize one
870 * component of the constant being constructed.
874 assert(value->as_constant() != NULL);
875 assert(!value->is_tail_sentinel());
877 for (unsigned j = 0; j < value->type->components(); j++) {
878 switch (type->base_type) {
880 this->value.u[i] = value->get_uint_component(j);
883 this->value.i[i] = value->get_int_component(j);
885 case GLSL_TYPE_FLOAT:
886 this->value.f[i] = value->get_float_component(j);
889 this->value.b[i] = value->get_bool_component(j);
891 case GLSL_TYPE_DOUBLE:
892 this->value.d[i] = value->get_double_component(j);
895 /* FINISHME: What to do? Exceptions are not the answer.
901 if (i >= type->components())
905 if (i >= type->components())
906 break; /* avoid downcasting a list sentinel */
907 value = (ir_constant *) value->next;
912 ir_constant::zero(void *mem_ctx, const glsl_type *type)
914 assert(type->is_scalar() || type->is_vector() || type->is_matrix()
915 || type->is_record() || type->is_array());
917 ir_constant *c = new(mem_ctx) ir_constant;
919 memset(&c->value, 0, sizeof(c->value));
921 if (type->is_array()) {
922 c->array_elements = ralloc_array(c, ir_constant *, type->length);
924 for (unsigned i = 0; i < type->length; i++)
925 c->array_elements[i] = ir_constant::zero(c, type->fields.array);
928 if (type->is_record()) {
929 for (unsigned i = 0; i < type->length; i++) {
930 ir_constant *comp = ir_constant::zero(mem_ctx, type->fields.structure[i].type);
931 c->components.push_tail(comp);
939 ir_constant::get_bool_component(unsigned i) const
941 switch (this->type->base_type) {
942 case GLSL_TYPE_UINT: return this->value.u[i] != 0;
943 case GLSL_TYPE_INT: return this->value.i[i] != 0;
944 case GLSL_TYPE_FLOAT: return ((int)this->value.f[i]) != 0;
945 case GLSL_TYPE_BOOL: return this->value.b[i];
946 case GLSL_TYPE_DOUBLE: return this->value.d[i] != 0.0;
947 default: assert(!"Should not get here."); break;
950 /* Must return something to make the compiler happy. This is clearly an
957 ir_constant::get_float_component(unsigned i) const
959 switch (this->type->base_type) {
960 case GLSL_TYPE_UINT: return (float) this->value.u[i];
961 case GLSL_TYPE_INT: return (float) this->value.i[i];
962 case GLSL_TYPE_FLOAT: return this->value.f[i];
963 case GLSL_TYPE_BOOL: return this->value.b[i] ? 1.0f : 0.0f;
964 case GLSL_TYPE_DOUBLE: return (float) this->value.d[i];
965 default: assert(!"Should not get here."); break;
968 /* Must return something to make the compiler happy. This is clearly an
975 ir_constant::get_double_component(unsigned i) const
977 switch (this->type->base_type) {
978 case GLSL_TYPE_UINT: return (double) this->value.u[i];
979 case GLSL_TYPE_INT: return (double) this->value.i[i];
980 case GLSL_TYPE_FLOAT: return (double) this->value.f[i];
981 case GLSL_TYPE_BOOL: return this->value.b[i] ? 1.0 : 0.0;
982 case GLSL_TYPE_DOUBLE: return this->value.d[i];
983 default: assert(!"Should not get here."); break;
986 /* Must return something to make the compiler happy. This is clearly an
993 ir_constant::get_int_component(unsigned i) const
995 switch (this->type->base_type) {
996 case GLSL_TYPE_UINT: return this->value.u[i];
997 case GLSL_TYPE_INT: return this->value.i[i];
998 case GLSL_TYPE_FLOAT: return (int) this->value.f[i];
999 case GLSL_TYPE_BOOL: return this->value.b[i] ? 1 : 0;
1000 case GLSL_TYPE_DOUBLE: return (int) this->value.d[i];
1001 default: assert(!"Should not get here."); break;
1004 /* Must return something to make the compiler happy. This is clearly an
1011 ir_constant::get_uint_component(unsigned i) const
1013 switch (this->type->base_type) {
1014 case GLSL_TYPE_UINT: return this->value.u[i];
1015 case GLSL_TYPE_INT: return this->value.i[i];
1016 case GLSL_TYPE_FLOAT: return (unsigned) this->value.f[i];
1017 case GLSL_TYPE_BOOL: return this->value.b[i] ? 1 : 0;
1018 case GLSL_TYPE_DOUBLE: return (unsigned) this->value.d[i];
1019 default: assert(!"Should not get here."); break;
1022 /* Must return something to make the compiler happy. This is clearly an
1029 ir_constant::get_array_element(unsigned i) const
1031 assert(this->type->is_array());
1033 /* From page 35 (page 41 of the PDF) of the GLSL 1.20 spec:
1035 * "Behavior is undefined if a shader subscripts an array with an index
1036 * less than 0 or greater than or equal to the size the array was
1039 * Most out-of-bounds accesses are removed before things could get this far.
1040 * There are cases where non-constant array index values can get constant
1045 else if (i >= this->type->length)
1046 i = this->type->length - 1;
1048 return array_elements[i];
1052 ir_constant::get_record_field(const char *name)
1054 int idx = this->type->field_index(name);
1059 if (this->components.is_empty())
1062 exec_node *node = this->components.head;
1063 for (int i = 0; i < idx; i++) {
1066 /* If the end of the list is encountered before the element matching the
1067 * requested field is found, return NULL.
1069 if (node->is_tail_sentinel())
1073 return (ir_constant *) node;
1077 ir_constant::copy_offset(ir_constant *src, int offset)
1079 switch (this->type->base_type) {
1080 case GLSL_TYPE_UINT:
1082 case GLSL_TYPE_FLOAT:
1083 case GLSL_TYPE_DOUBLE:
1084 case GLSL_TYPE_BOOL: {
1085 unsigned int size = src->type->components();
1086 assert (size <= this->type->components() - offset);
1087 for (unsigned int i=0; i<size; i++) {
1088 switch (this->type->base_type) {
1089 case GLSL_TYPE_UINT:
1090 value.u[i+offset] = src->get_uint_component(i);
1093 value.i[i+offset] = src->get_int_component(i);
1095 case GLSL_TYPE_FLOAT:
1096 value.f[i+offset] = src->get_float_component(i);
1098 case GLSL_TYPE_BOOL:
1099 value.b[i+offset] = src->get_bool_component(i);
1101 case GLSL_TYPE_DOUBLE:
1102 value.d[i+offset] = src->get_double_component(i);
1104 default: // Shut up the compiler
1111 case GLSL_TYPE_STRUCT: {
1112 assert (src->type == this->type);
1113 this->components.make_empty();
1114 foreach_in_list(ir_constant, orig, &src->components) {
1115 this->components.push_tail(orig->clone(this, NULL));
1120 case GLSL_TYPE_ARRAY: {
1121 assert (src->type == this->type);
1122 for (unsigned i = 0; i < this->type->length; i++) {
1123 this->array_elements[i] = src->array_elements[i]->clone(this, NULL);
1129 assert(!"Should not get here.");
1135 ir_constant::copy_masked_offset(ir_constant *src, int offset, unsigned int mask)
1137 assert (!type->is_array() && !type->is_record());
1139 if (!type->is_vector() && !type->is_matrix()) {
1145 for (int i=0; i<4; i++) {
1146 if (mask & (1 << i)) {
1147 switch (this->type->base_type) {
1148 case GLSL_TYPE_UINT:
1149 value.u[i+offset] = src->get_uint_component(id++);
1152 value.i[i+offset] = src->get_int_component(id++);
1154 case GLSL_TYPE_FLOAT:
1155 value.f[i+offset] = src->get_float_component(id++);
1157 case GLSL_TYPE_BOOL:
1158 value.b[i+offset] = src->get_bool_component(id++);
1160 case GLSL_TYPE_DOUBLE:
1161 value.d[i+offset] = src->get_double_component(id++);
1164 assert(!"Should not get here.");
1172 ir_constant::has_value(const ir_constant *c) const
1174 if (this->type != c->type)
1177 if (this->type->is_array()) {
1178 for (unsigned i = 0; i < this->type->length; i++) {
1179 if (!this->array_elements[i]->has_value(c->array_elements[i]))
1185 if (this->type->base_type == GLSL_TYPE_STRUCT) {
1186 const exec_node *a_node = this->components.head;
1187 const exec_node *b_node = c->components.head;
1189 while (!a_node->is_tail_sentinel()) {
1190 assert(!b_node->is_tail_sentinel());
1192 const ir_constant *const a_field = (ir_constant *) a_node;
1193 const ir_constant *const b_field = (ir_constant *) b_node;
1195 if (!a_field->has_value(b_field))
1198 a_node = a_node->next;
1199 b_node = b_node->next;
1205 for (unsigned i = 0; i < this->type->components(); i++) {
1206 switch (this->type->base_type) {
1207 case GLSL_TYPE_UINT:
1208 if (this->value.u[i] != c->value.u[i])
1212 if (this->value.i[i] != c->value.i[i])
1215 case GLSL_TYPE_FLOAT:
1216 if (this->value.f[i] != c->value.f[i])
1219 case GLSL_TYPE_BOOL:
1220 if (this->value.b[i] != c->value.b[i])
1223 case GLSL_TYPE_DOUBLE:
1224 if (this->value.d[i] != c->value.d[i])
1228 assert(!"Should not get here.");
1237 ir_constant::is_value(float f, int i) const
1239 if (!this->type->is_scalar() && !this->type->is_vector())
1242 /* Only accept boolean values for 0/1. */
1243 if (int(bool(i)) != i && this->type->is_boolean())
1246 for (unsigned c = 0; c < this->type->vector_elements; c++) {
1247 switch (this->type->base_type) {
1248 case GLSL_TYPE_FLOAT:
1249 if (this->value.f[c] != f)
1253 if (this->value.i[c] != i)
1256 case GLSL_TYPE_UINT:
1257 if (this->value.u[c] != unsigned(i))
1260 case GLSL_TYPE_BOOL:
1261 if (this->value.b[c] != bool(i))
1264 case GLSL_TYPE_DOUBLE:
1265 if (this->value.d[c] != double(f))
1269 /* The only other base types are structures, arrays, and samplers.
1270 * Samplers cannot be constants, and the others should have been
1271 * filtered out above.
1273 assert(!"Should not get here.");
1282 ir_constant::is_zero() const
1284 return is_value(0.0, 0);
1288 ir_constant::is_one() const
1290 return is_value(1.0, 1);
1294 ir_constant::is_negative_one() const
1296 return is_value(-1.0, -1);
1300 ir_constant::is_uint16_constant() const
1302 if (!type->is_integer())
1305 return value.u[0] < (1 << 16);
1309 : ir_instruction(ir_type_loop)
1314 ir_dereference_variable::ir_dereference_variable(ir_variable *var)
1315 : ir_dereference(ir_type_dereference_variable)
1317 assert(var != NULL);
1320 this->type = var->type;
1324 ir_dereference_array::ir_dereference_array(ir_rvalue *value,
1325 ir_rvalue *array_index)
1326 : ir_dereference(ir_type_dereference_array)
1328 this->array_index = array_index;
1329 this->set_array(value);
1333 ir_dereference_array::ir_dereference_array(ir_variable *var,
1334 ir_rvalue *array_index)
1335 : ir_dereference(ir_type_dereference_array)
1337 void *ctx = ralloc_parent(var);
1339 this->array_index = array_index;
1340 this->set_array(new(ctx) ir_dereference_variable(var));
1345 ir_dereference_array::set_array(ir_rvalue *value)
1347 assert(value != NULL);
1349 this->array = value;
1351 const glsl_type *const vt = this->array->type;
1353 if (vt->is_array()) {
1354 type = vt->fields.array;
1355 } else if (vt->is_matrix()) {
1356 type = vt->column_type();
1357 } else if (vt->is_vector()) {
1358 type = vt->get_base_type();
1363 ir_dereference_record::ir_dereference_record(ir_rvalue *value,
1365 : ir_dereference(ir_type_dereference_record)
1367 assert(value != NULL);
1369 this->record = value;
1370 this->field = ralloc_strdup(this, field);
1371 this->type = this->record->type->field_type(field);
1375 ir_dereference_record::ir_dereference_record(ir_variable *var,
1377 : ir_dereference(ir_type_dereference_record)
1379 void *ctx = ralloc_parent(var);
1381 this->record = new(ctx) ir_dereference_variable(var);
1382 this->field = ralloc_strdup(this, field);
1383 this->type = this->record->type->field_type(field);
1387 ir_dereference::is_lvalue() const
1389 ir_variable *var = this->variable_referenced();
1391 /* Every l-value derference chain eventually ends in a variable.
1393 if ((var == NULL) || var->data.read_only)
1396 /* From section 4.1.7 of the GLSL 4.40 spec:
1398 * "Opaque variables cannot be treated as l-values; hence cannot
1399 * be used as out or inout function parameters, nor can they be
1402 if (this->type->contains_opaque())
1409 static const char * const tex_opcode_strs[] = { "tex", "txb", "txl", "txd", "txf", "txf_ms", "txs", "lod", "tg4", "query_levels", "texture_samples", "samples_identical" };
1411 const char *ir_texture::opcode_string()
1413 assert((unsigned int) op < ARRAY_SIZE(tex_opcode_strs));
1414 return tex_opcode_strs[op];
1418 ir_texture::get_opcode(const char *str)
1420 const int count = sizeof(tex_opcode_strs) / sizeof(tex_opcode_strs[0]);
1421 for (int op = 0; op < count; op++) {
1422 if (strcmp(str, tex_opcode_strs[op]) == 0)
1423 return (ir_texture_opcode) op;
1425 return (ir_texture_opcode) -1;
1430 ir_texture::set_sampler(ir_dereference *sampler, const glsl_type *type)
1432 assert(sampler != NULL);
1433 assert(type != NULL);
1434 this->sampler = sampler;
1437 if (this->op == ir_txs || this->op == ir_query_levels ||
1438 this->op == ir_texture_samples) {
1439 assert(type->base_type == GLSL_TYPE_INT);
1440 } else if (this->op == ir_lod) {
1441 assert(type->vector_elements == 2);
1442 assert(type->base_type == GLSL_TYPE_FLOAT);
1443 } else if (this->op == ir_samples_identical) {
1444 assert(type == glsl_type::bool_type);
1445 assert(sampler->type->base_type == GLSL_TYPE_SAMPLER);
1446 assert(sampler->type->sampler_dimensionality == GLSL_SAMPLER_DIM_MS);
1448 assert(sampler->type->sampled_type == (int) type->base_type);
1449 if (sampler->type->sampler_shadow)
1450 assert(type->vector_elements == 4 || type->vector_elements == 1);
1452 assert(type->vector_elements == 4);
1458 ir_swizzle::init_mask(const unsigned *comp, unsigned count)
1460 assert((count >= 1) && (count <= 4));
1462 memset(&this->mask, 0, sizeof(this->mask));
1463 this->mask.num_components = count;
1465 unsigned dup_mask = 0;
1468 assert(comp[3] <= 3);
1469 dup_mask |= (1U << comp[3])
1470 & ((1U << comp[0]) | (1U << comp[1]) | (1U << comp[2]));
1471 this->mask.w = comp[3];
1474 assert(comp[2] <= 3);
1475 dup_mask |= (1U << comp[2])
1476 & ((1U << comp[0]) | (1U << comp[1]));
1477 this->mask.z = comp[2];
1480 assert(comp[1] <= 3);
1481 dup_mask |= (1U << comp[1])
1482 & ((1U << comp[0]));
1483 this->mask.y = comp[1];
1486 assert(comp[0] <= 3);
1487 this->mask.x = comp[0];
1490 this->mask.has_duplicates = dup_mask != 0;
1492 /* Based on the number of elements in the swizzle and the base type
1493 * (i.e., float, int, unsigned, or bool) of the vector being swizzled,
1494 * generate the type of the resulting value.
1496 type = glsl_type::get_instance(val->type->base_type, mask.num_components, 1);
1499 ir_swizzle::ir_swizzle(ir_rvalue *val, unsigned x, unsigned y, unsigned z,
1500 unsigned w, unsigned count)
1501 : ir_rvalue(ir_type_swizzle), val(val)
1503 const unsigned components[4] = { x, y, z, w };
1504 this->init_mask(components, count);
1507 ir_swizzle::ir_swizzle(ir_rvalue *val, const unsigned *comp,
1509 : ir_rvalue(ir_type_swizzle), val(val)
1511 this->init_mask(comp, count);
1514 ir_swizzle::ir_swizzle(ir_rvalue *val, ir_swizzle_mask mask)
1515 : ir_rvalue(ir_type_swizzle)
1519 this->type = glsl_type::get_instance(val->type->base_type,
1520 mask.num_components, 1);
1529 ir_swizzle::create(ir_rvalue *val, const char *str, unsigned vector_length)
1531 void *ctx = ralloc_parent(val);
1533 /* For each possible swizzle character, this table encodes the value in
1534 * \c idx_map that represents the 0th element of the vector. For invalid
1535 * swizzle characters (e.g., 'k'), a special value is used that will allow
1536 * detection of errors.
1538 static const unsigned char base_idx[26] = {
1539 /* a b c d e f g h i j k l m */
1540 R, R, I, I, I, I, R, I, I, I, I, I, I,
1541 /* n o p q r s t u v w x y z */
1542 I, I, S, S, R, S, S, I, I, X, X, X, X
1545 /* Each valid swizzle character has an entry in the previous table. This
1546 * table encodes the base index encoded in the previous table plus the actual
1547 * index of the swizzle character. When processing swizzles, the first
1548 * character in the string is indexed in the previous table. Each character
1549 * in the string is indexed in this table, and the value found there has the
1550 * value form the first table subtracted. The result must be on the range
1553 * For example, the string "wzyx" will get X from the first table. Each of
1554 * the charcaters will get X+3, X+2, X+1, and X+0 from this table. After
1555 * subtraction, the swizzle values are { 3, 2, 1, 0 }.
1557 * The string "wzrg" will get X from the first table. Each of the characters
1558 * will get X+3, X+2, R+0, and R+1 from this table. After subtraction, the
1559 * swizzle values are { 3, 2, 4, 5 }. Since 4 and 5 are outside the range
1560 * [0,3], the error is detected.
1562 static const unsigned char idx_map[26] = {
1563 /* a b c d e f g h i j k l m */
1564 R+3, R+2, 0, 0, 0, 0, R+1, 0, 0, 0, 0, 0, 0,
1565 /* n o p q r s t u v w x y z */
1566 0, 0, S+2, S+3, R+0, S+0, S+1, 0, 0, X+3, X+0, X+1, X+2
1569 int swiz_idx[4] = { 0, 0, 0, 0 };
1573 /* Validate the first character in the swizzle string and look up the base
1574 * index value as described above.
1576 if ((str[0] < 'a') || (str[0] > 'z'))
1579 const unsigned base = base_idx[str[0] - 'a'];
1582 for (i = 0; (i < 4) && (str[i] != '\0'); i++) {
1583 /* Validate the next character, and, as described above, convert it to a
1586 if ((str[i] < 'a') || (str[i] > 'z'))
1589 swiz_idx[i] = idx_map[str[i] - 'a'] - base;
1590 if ((swiz_idx[i] < 0) || (swiz_idx[i] >= (int) vector_length))
1597 return new(ctx) ir_swizzle(val, swiz_idx[0], swiz_idx[1], swiz_idx[2],
1607 ir_swizzle::variable_referenced() const
1609 return this->val->variable_referenced();
1613 bool ir_variable::temporaries_allocate_names = false;
1615 const char ir_variable::tmp_name[] = "compiler_temp";
1617 ir_variable::ir_variable(const struct glsl_type *type, const char *name,
1618 ir_variable_mode mode)
1619 : ir_instruction(ir_type_variable)
1623 if (mode == ir_var_temporary && !ir_variable::temporaries_allocate_names)
1626 /* The ir_variable clone method may call this constructor with name set to
1630 || mode == ir_var_temporary
1631 || mode == ir_var_function_in
1632 || mode == ir_var_function_out
1633 || mode == ir_var_function_inout);
1634 assert(name != ir_variable::tmp_name
1635 || mode == ir_var_temporary);
1636 if (mode == ir_var_temporary
1637 && (name == NULL || name == ir_variable::tmp_name)) {
1638 this->name = ir_variable::tmp_name;
1640 this->name = ralloc_strdup(this, name);
1643 this->u.max_ifc_array_access = NULL;
1645 this->data.explicit_location = false;
1646 this->data.has_initializer = false;
1647 this->data.location = -1;
1648 this->data.location_frac = 0;
1649 this->data.binding = 0;
1650 this->data.warn_extension_index = 0;
1651 this->constant_value = NULL;
1652 this->constant_initializer = NULL;
1653 this->data.origin_upper_left = false;
1654 this->data.pixel_center_integer = false;
1655 this->data.depth_layout = ir_depth_layout_none;
1656 this->data.used = false;
1657 this->data.always_active_io = false;
1658 this->data.read_only = false;
1659 this->data.centroid = false;
1660 this->data.sample = false;
1661 this->data.patch = false;
1662 this->data.invariant = false;
1663 this->data.how_declared = ir_var_declared_normally;
1664 this->data.mode = mode;
1665 this->data.interpolation = INTERP_QUALIFIER_NONE;
1666 this->data.max_array_access = 0;
1667 this->data.offset = 0;
1668 this->data.precision = GLSL_PRECISION_NONE;
1669 this->data.image_read_only = false;
1670 this->data.image_write_only = false;
1671 this->data.image_coherent = false;
1672 this->data.image_volatile = false;
1673 this->data.image_restrict = false;
1674 this->data.from_ssbo_unsized_array = false;
1677 if (type->base_type == GLSL_TYPE_SAMPLER)
1678 this->data.read_only = true;
1680 if (type->is_interface())
1681 this->init_interface_type(type);
1682 else if (type->without_array()->is_interface())
1683 this->init_interface_type(type->without_array());
1689 interpolation_string(unsigned interpolation)
1691 switch (interpolation) {
1692 case INTERP_QUALIFIER_NONE: return "no";
1693 case INTERP_QUALIFIER_SMOOTH: return "smooth";
1694 case INTERP_QUALIFIER_FLAT: return "flat";
1695 case INTERP_QUALIFIER_NOPERSPECTIVE: return "noperspective";
1698 assert(!"Should not get here.");
1702 const char *const ir_variable::warn_extension_table[] = {
1704 "GL_ARB_shader_stencil_export",
1705 "GL_AMD_shader_stencil_export",
1709 ir_variable::enable_extension_warning(const char *extension)
1711 for (unsigned i = 0; i < ARRAY_SIZE(warn_extension_table); i++) {
1712 if (strcmp(warn_extension_table[i], extension) == 0) {
1713 this->data.warn_extension_index = i;
1718 assert(!"Should not get here.");
1719 this->data.warn_extension_index = 0;
1723 ir_variable::get_extension_warning() const
1725 return this->data.warn_extension_index == 0
1726 ? NULL : warn_extension_table[this->data.warn_extension_index];
1729 ir_function_signature::ir_function_signature(const glsl_type *return_type,
1730 builtin_available_predicate b)
1731 : ir_instruction(ir_type_function_signature),
1732 return_type(return_type), is_defined(false), is_intrinsic(false),
1733 builtin_avail(b), _function(NULL)
1735 this->origin = NULL;
1740 ir_function_signature::is_builtin() const
1742 return builtin_avail != NULL;
1747 ir_function_signature::is_builtin_available(const _mesa_glsl_parse_state *state) const
1749 /* We can't call the predicate without a state pointer, so just say that
1750 * the signature is available. At compile time, we need the filtering,
1751 * but also receive a valid state pointer. At link time, we're resolving
1752 * imported built-in prototypes to their definitions, which will always
1753 * be an exact match. So we can skip the filtering.
1758 assert(builtin_avail != NULL);
1759 return builtin_avail(state);
1764 modes_match(unsigned a, unsigned b)
1769 /* Accept "in" vs. "const in" */
1770 if ((a == ir_var_const_in && b == ir_var_function_in) ||
1771 (b == ir_var_const_in && a == ir_var_function_in))
1779 ir_function_signature::qualifiers_match(exec_list *params)
1781 /* check that the qualifiers match. */
1782 foreach_two_lists(a_node, &this->parameters, b_node, params) {
1783 ir_variable *a = (ir_variable *) a_node;
1784 ir_variable *b = (ir_variable *) b_node;
1786 if (a->data.read_only != b->data.read_only ||
1787 !modes_match(a->data.mode, b->data.mode) ||
1788 a->data.interpolation != b->data.interpolation ||
1789 a->data.centroid != b->data.centroid ||
1790 a->data.sample != b->data.sample ||
1791 a->data.patch != b->data.patch ||
1792 a->data.image_read_only != b->data.image_read_only ||
1793 a->data.image_write_only != b->data.image_write_only ||
1794 a->data.image_coherent != b->data.image_coherent ||
1795 a->data.image_volatile != b->data.image_volatile ||
1796 a->data.image_restrict != b->data.image_restrict) {
1798 /* parameter a's qualifiers don't match */
1807 ir_function_signature::replace_parameters(exec_list *new_params)
1809 /* Destroy all of the previous parameter information. If the previous
1810 * parameter information comes from the function prototype, it may either
1811 * specify incorrect parameter names or not have names at all.
1813 new_params->move_nodes_to(¶meters);
1817 ir_function::ir_function(const char *name)
1818 : ir_instruction(ir_type_function)
1820 this->subroutine_index = -1;
1821 this->name = ralloc_strdup(this, name);
1826 ir_function::has_user_signature()
1828 foreach_in_list(ir_function_signature, sig, &this->signatures) {
1829 if (!sig->is_builtin())
1837 ir_rvalue::error_value(void *mem_ctx)
1839 ir_rvalue *v = new(mem_ctx) ir_rvalue(ir_type_unset);
1841 v->type = glsl_type::error_type;
1847 visit_exec_list(exec_list *list, ir_visitor *visitor)
1849 foreach_in_list_safe(ir_instruction, node, list) {
1850 node->accept(visitor);
1856 steal_memory(ir_instruction *ir, void *new_ctx)
1858 ir_variable *var = ir->as_variable();
1859 ir_function *fn = ir->as_function();
1860 ir_constant *constant = ir->as_constant();
1861 if (var != NULL && var->constant_value != NULL)
1862 steal_memory(var->constant_value, ir);
1864 if (var != NULL && var->constant_initializer != NULL)
1865 steal_memory(var->constant_initializer, ir);
1867 if (fn != NULL && fn->subroutine_types)
1868 ralloc_steal(new_ctx, fn->subroutine_types);
1870 /* The components of aggregate constants are not visited by the normal
1871 * visitor, so steal their values by hand.
1873 if (constant != NULL) {
1874 if (constant->type->is_record()) {
1875 foreach_in_list(ir_constant, field, &constant->components) {
1876 steal_memory(field, ir);
1878 } else if (constant->type->is_array()) {
1879 for (unsigned int i = 0; i < constant->type->length; i++) {
1880 steal_memory(constant->array_elements[i], ir);
1885 ralloc_steal(new_ctx, ir);
1890 reparent_ir(exec_list *list, void *mem_ctx)
1892 foreach_in_list(ir_instruction, node, list) {
1893 visit_tree(node, steal_memory, mem_ctx);
1899 try_min_one(ir_rvalue *ir)
1901 ir_expression *expr = ir->as_expression();
1903 if (!expr || expr->operation != ir_binop_min)
1906 if (expr->operands[0]->is_one())
1907 return expr->operands[1];
1909 if (expr->operands[1]->is_one())
1910 return expr->operands[0];
1916 try_max_zero(ir_rvalue *ir)
1918 ir_expression *expr = ir->as_expression();
1920 if (!expr || expr->operation != ir_binop_max)
1923 if (expr->operands[0]->is_zero())
1924 return expr->operands[1];
1926 if (expr->operands[1]->is_zero())
1927 return expr->operands[0];
1933 ir_rvalue::as_rvalue_to_saturate()
1935 ir_expression *expr = this->as_expression();
1940 ir_rvalue *max_zero = try_max_zero(expr);
1942 return try_min_one(max_zero);
1944 ir_rvalue *min_one = try_min_one(expr);
1946 return try_max_zero(min_one);
1955 vertices_per_prim(GLenum prim)
1964 case GL_LINES_ADJACENCY:
1966 case GL_TRIANGLES_ADJACENCY:
1969 assert(!"Bad primitive");
1975 * Generate a string describing the mode of a variable
1978 mode_string(const ir_variable *var)
1980 switch (var->data.mode) {
1982 return (var->data.read_only) ? "global constant" : "global variable";
1984 case ir_var_uniform:
1987 case ir_var_shader_storage:
1990 case ir_var_shader_in:
1991 return "shader input";
1993 case ir_var_shader_out:
1994 return "shader output";
1996 case ir_var_function_in:
1997 case ir_var_const_in:
1998 return "function input";
2000 case ir_var_function_out:
2001 return "function output";
2003 case ir_var_function_inout:
2004 return "function inout";
2006 case ir_var_system_value:
2007 return "shader input";
2009 case ir_var_temporary:
2010 return "compiler temporary";
2012 case ir_var_mode_count:
2016 assert(!"Should not get here.");
2017 return "invalid variable";