| /* |
| * Copyright © 2010 Intel Corporation |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice (including the next |
| * paragraph) shall be included in all copies or substantial portions of the |
| * Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
| * DEALINGS IN THE SOFTWARE. |
| */ |
| |
| /** |
| * \file ir_constant_expression.cpp |
| * Evaluate and process constant valued expressions |
| * |
| * In GLSL, constant valued expressions are used in several places. These |
| * must be processed and evaluated very early in the compilation process. |
| * |
| * * Sizes of arrays |
| * * Initializers for uniforms |
| * * Initializers for \c const variables |
| */ |
| |
| #include <math.h> |
| #include "main/core.h" /* for MAX2, MIN2, CLAMP */ |
| #include "util/rounding.h" /* for _mesa_roundeven */ |
| #include "util/half_float.h" |
| #include "ir.h" |
| #include "compiler/glsl_types.h" |
| #include "util/hash_table.h" |
| |
| static float |
| dot_f(ir_constant *op0, ir_constant *op1) |
| { |
| assert(op0->type->is_float() && op1->type->is_float()); |
| |
| float result = 0; |
| for (unsigned c = 0; c < op0->type->components(); c++) |
| result += op0->value.f[c] * op1->value.f[c]; |
| |
| return result; |
| } |
| |
| static double |
| dot_d(ir_constant *op0, ir_constant *op1) |
| { |
| assert(op0->type->is_double() && op1->type->is_double()); |
| |
| double result = 0; |
| for (unsigned c = 0; c < op0->type->components(); c++) |
| result += op0->value.d[c] * op1->value.d[c]; |
| |
| return result; |
| } |
| |
| /* This method is the only one supported by gcc. Unions in particular |
| * are iffy, and read-through-converted-pointer is killed by strict |
| * aliasing. OTOH, the compiler sees through the memcpy, so the |
| * resulting asm is reasonable. |
| */ |
| static float |
| bitcast_u2f(unsigned int u) |
| { |
| assert(sizeof(float) == sizeof(unsigned int)); |
| float f; |
| memcpy(&f, &u, sizeof(f)); |
| return f; |
| } |
| |
| static unsigned int |
| bitcast_f2u(float f) |
| { |
| assert(sizeof(float) == sizeof(unsigned int)); |
| unsigned int u; |
| memcpy(&u, &f, sizeof(f)); |
| return u; |
| } |
| |
| /** |
| * Evaluate one component of a floating-point 4x8 unpacking function. |
| */ |
| typedef uint8_t |
| (*pack_1x8_func_t)(float); |
| |
| /** |
| * Evaluate one component of a floating-point 2x16 unpacking function. |
| */ |
| typedef uint16_t |
| (*pack_1x16_func_t)(float); |
| |
| /** |
| * Evaluate one component of a floating-point 4x8 unpacking function. |
| */ |
| typedef float |
| (*unpack_1x8_func_t)(uint8_t); |
| |
| /** |
| * Evaluate one component of a floating-point 2x16 unpacking function. |
| */ |
| typedef float |
| (*unpack_1x16_func_t)(uint16_t); |
| |
| /** |
| * Evaluate a 2x16 floating-point packing function. |
| */ |
| static uint32_t |
| pack_2x16(pack_1x16_func_t pack_1x16, |
| float x, float y) |
| { |
| /* From section 8.4 of the GLSL ES 3.00 spec: |
| * |
| * packSnorm2x16 |
| * ------------- |
| * The first component of the vector will be written to the least |
| * significant bits of the output; the last component will be written to |
| * the most significant bits. |
| * |
| * The specifications for the other packing functions contain similar |
| * language. |
| */ |
| uint32_t u = 0; |
| u |= ((uint32_t) pack_1x16(x) << 0); |
| u |= ((uint32_t) pack_1x16(y) << 16); |
| return u; |
| } |
| |
| /** |
| * Evaluate a 4x8 floating-point packing function. |
| */ |
| static uint32_t |
| pack_4x8(pack_1x8_func_t pack_1x8, |
| float x, float y, float z, float w) |
| { |
| /* From section 8.4 of the GLSL 4.30 spec: |
| * |
| * packSnorm4x8 |
| * ------------ |
| * The first component of the vector will be written to the least |
| * significant bits of the output; the last component will be written to |
| * the most significant bits. |
| * |
| * The specifications for the other packing functions contain similar |
| * language. |
| */ |
| uint32_t u = 0; |
| u |= ((uint32_t) pack_1x8(x) << 0); |
| u |= ((uint32_t) pack_1x8(y) << 8); |
| u |= ((uint32_t) pack_1x8(z) << 16); |
| u |= ((uint32_t) pack_1x8(w) << 24); |
| return u; |
| } |
| |
| /** |
| * Evaluate a 2x16 floating-point unpacking function. |
| */ |
| static void |
| unpack_2x16(unpack_1x16_func_t unpack_1x16, |
| uint32_t u, |
| float *x, float *y) |
| { |
| /* From section 8.4 of the GLSL ES 3.00 spec: |
| * |
| * unpackSnorm2x16 |
| * --------------- |
| * The first component of the returned vector will be extracted from |
| * the least significant bits of the input; the last component will be |
| * extracted from the most significant bits. |
| * |
| * The specifications for the other unpacking functions contain similar |
| * language. |
| */ |
| *x = unpack_1x16((uint16_t) (u & 0xffff)); |
| *y = unpack_1x16((uint16_t) (u >> 16)); |
| } |
| |
| /** |
| * Evaluate a 4x8 floating-point unpacking function. |
| */ |
| static void |
| unpack_4x8(unpack_1x8_func_t unpack_1x8, uint32_t u, |
| float *x, float *y, float *z, float *w) |
| { |
| /* From section 8.4 of the GLSL 4.30 spec: |
| * |
| * unpackSnorm4x8 |
| * -------------- |
| * The first component of the returned vector will be extracted from |
| * the least significant bits of the input; the last component will be |
| * extracted from the most significant bits. |
| * |
| * The specifications for the other unpacking functions contain similar |
| * language. |
| */ |
| *x = unpack_1x8((uint8_t) (u & 0xff)); |
| *y = unpack_1x8((uint8_t) (u >> 8)); |
| *z = unpack_1x8((uint8_t) (u >> 16)); |
| *w = unpack_1x8((uint8_t) (u >> 24)); |
| } |
| |
| /** |
| * Evaluate one component of packSnorm4x8. |
| */ |
| static uint8_t |
| pack_snorm_1x8(float x) |
| { |
| /* From section 8.4 of the GLSL 4.30 spec: |
| * |
| * packSnorm4x8 |
| * ------------ |
| * The conversion for component c of v to fixed point is done as |
| * follows: |
| * |
| * packSnorm4x8: round(clamp(c, -1, +1) * 127.0) |
| */ |
| return (uint8_t) |
| _mesa_lroundevenf(CLAMP(x, -1.0f, +1.0f) * 127.0f); |
| } |
| |
| /** |
| * Evaluate one component of packSnorm2x16. |
| */ |
| static uint16_t |
| pack_snorm_1x16(float x) |
| { |
| /* From section 8.4 of the GLSL ES 3.00 spec: |
| * |
| * packSnorm2x16 |
| * ------------- |
| * The conversion for component c of v to fixed point is done as |
| * follows: |
| * |
| * packSnorm2x16: round(clamp(c, -1, +1) * 32767.0) |
| */ |
| return (uint16_t) |
| _mesa_lroundevenf(CLAMP(x, -1.0f, +1.0f) * 32767.0f); |
| } |
| |
| /** |
| * Evaluate one component of unpackSnorm4x8. |
| */ |
| static float |
| unpack_snorm_1x8(uint8_t u) |
| { |
| /* From section 8.4 of the GLSL 4.30 spec: |
| * |
| * unpackSnorm4x8 |
| * -------------- |
| * The conversion for unpacked fixed-point value f to floating point is |
| * done as follows: |
| * |
| * unpackSnorm4x8: clamp(f / 127.0, -1, +1) |
| */ |
| return CLAMP((int8_t) u / 127.0f, -1.0f, +1.0f); |
| } |
| |
| /** |
| * Evaluate one component of unpackSnorm2x16. |
| */ |
| static float |
| unpack_snorm_1x16(uint16_t u) |
| { |
| /* From section 8.4 of the GLSL ES 3.00 spec: |
| * |
| * unpackSnorm2x16 |
| * --------------- |
| * The conversion for unpacked fixed-point value f to floating point is |
| * done as follows: |
| * |
| * unpackSnorm2x16: clamp(f / 32767.0, -1, +1) |
| */ |
| return CLAMP((int16_t) u / 32767.0f, -1.0f, +1.0f); |
| } |
| |
| /** |
| * Evaluate one component packUnorm4x8. |
| */ |
| static uint8_t |
| pack_unorm_1x8(float x) |
| { |
| /* From section 8.4 of the GLSL 4.30 spec: |
| * |
| * packUnorm4x8 |
| * ------------ |
| * The conversion for component c of v to fixed point is done as |
| * follows: |
| * |
| * packUnorm4x8: round(clamp(c, 0, +1) * 255.0) |
| */ |
| return (uint8_t) (int) _mesa_roundevenf(CLAMP(x, 0.0f, 1.0f) * 255.0f); |
| } |
| |
| /** |
| * Evaluate one component packUnorm2x16. |
| */ |
| static uint16_t |
| pack_unorm_1x16(float x) |
| { |
| /* From section 8.4 of the GLSL ES 3.00 spec: |
| * |
| * packUnorm2x16 |
| * ------------- |
| * The conversion for component c of v to fixed point is done as |
| * follows: |
| * |
| * packUnorm2x16: round(clamp(c, 0, +1) * 65535.0) |
| */ |
| return (uint16_t) (int) |
| _mesa_roundevenf(CLAMP(x, 0.0f, 1.0f) * 65535.0f); |
| } |
| |
| /** |
| * Evaluate one component of unpackUnorm4x8. |
| */ |
| static float |
| unpack_unorm_1x8(uint8_t u) |
| { |
| /* From section 8.4 of the GLSL 4.30 spec: |
| * |
| * unpackUnorm4x8 |
| * -------------- |
| * The conversion for unpacked fixed-point value f to floating point is |
| * done as follows: |
| * |
| * unpackUnorm4x8: f / 255.0 |
| */ |
| return (float) u / 255.0f; |
| } |
| |
| /** |
| * Evaluate one component of unpackUnorm2x16. |
| */ |
| static float |
| unpack_unorm_1x16(uint16_t u) |
| { |
| /* From section 8.4 of the GLSL ES 3.00 spec: |
| * |
| * unpackUnorm2x16 |
| * --------------- |
| * The conversion for unpacked fixed-point value f to floating point is |
| * done as follows: |
| * |
| * unpackUnorm2x16: f / 65535.0 |
| */ |
| return (float) u / 65535.0f; |
| } |
| |
| /** |
| * Evaluate one component of packHalf2x16. |
| */ |
| static uint16_t |
| pack_half_1x16(float x) |
| { |
| return _mesa_float_to_half(x); |
| } |
| |
| /** |
| * Evaluate one component of unpackHalf2x16. |
| */ |
| static float |
| unpack_half_1x16(uint16_t u) |
| { |
| return _mesa_half_to_float(u); |
| } |
| |
| /** |
| * Get the constant that is ultimately referenced by an r-value, in a constant |
| * expression evaluation context. |
| * |
| * The offset is used when the reference is to a specific column of a matrix. |
| */ |
| static bool |
| constant_referenced(const ir_dereference *deref, |
| struct hash_table *variable_context, |
| ir_constant *&store, int &offset) |
| { |
| store = NULL; |
| offset = 0; |
| |
| if (variable_context == NULL) |
| return false; |
| |
| switch (deref->ir_type) { |
| case ir_type_dereference_array: { |
| const ir_dereference_array *const da = |
| (const ir_dereference_array *) deref; |
| |
| ir_constant *const index_c = |
| da->array_index->constant_expression_value(variable_context); |
| |
| if (!index_c || !index_c->type->is_scalar() || !index_c->type->is_integer()) |
| break; |
| |
| const int index = index_c->type->base_type == GLSL_TYPE_INT ? |
| index_c->get_int_component(0) : |
| index_c->get_uint_component(0); |
| |
| ir_constant *substore; |
| int suboffset; |
| |
| const ir_dereference *const deref = da->array->as_dereference(); |
| if (!deref) |
| break; |
| |
| if (!constant_referenced(deref, variable_context, substore, suboffset)) |
| break; |
| |
| const glsl_type *const vt = da->array->type; |
| if (vt->is_array()) { |
| store = substore->get_array_element(index); |
| offset = 0; |
| } else if (vt->is_matrix()) { |
| store = substore; |
| offset = index * vt->vector_elements; |
| } else if (vt->is_vector()) { |
| store = substore; |
| offset = suboffset + index; |
| } |
| |
| break; |
| } |
| |
| case ir_type_dereference_record: { |
| const ir_dereference_record *const dr = |
| (const ir_dereference_record *) deref; |
| |
| const ir_dereference *const deref = dr->record->as_dereference(); |
| if (!deref) |
| break; |
| |
| ir_constant *substore; |
| int suboffset; |
| |
| if (!constant_referenced(deref, variable_context, substore, suboffset)) |
| break; |
| |
| /* Since we're dropping it on the floor... |
| */ |
| assert(suboffset == 0); |
| |
| store = substore->get_record_field(dr->field); |
| break; |
| } |
| |
| case ir_type_dereference_variable: { |
| const ir_dereference_variable *const dv = |
| (const ir_dereference_variable *) deref; |
| |
| hash_entry *entry = _mesa_hash_table_search(variable_context, dv->var); |
| if (entry) |
| store = (ir_constant *) entry->data; |
| break; |
| } |
| |
| default: |
| assert(!"Should not get here."); |
| break; |
| } |
| |
| return store != NULL; |
| } |
| |
| |
| ir_constant * |
| ir_rvalue::constant_expression_value(struct hash_table *) |
| { |
| assert(this->type->is_error()); |
| return NULL; |
| } |
| |
| static uint32_t |
| bitfield_reverse(uint32_t v) |
| { |
| /* http://graphics.stanford.edu/~seander/bithacks.html#BitReverseObvious */ |
| uint32_t r = v; // r will be reversed bits of v; first get LSB of v |
| int s = sizeof(v) * CHAR_BIT - 1; // extra shift needed at end |
| |
| for (v >>= 1; v; v >>= 1) { |
| r <<= 1; |
| r |= v & 1; |
| s--; |
| } |
| r <<= s; // shift when v's highest bits are zero |
| |
| return r; |
| } |
| |
| static int |
| find_msb_uint(uint32_t v) |
| { |
| int count = 0; |
| |
| /* If v == 0, then the loop will terminate when count == 32. In that case |
| * 31-count will produce the -1 result required by GLSL findMSB(). |
| */ |
| while (((v & (1u << 31)) == 0) && count != 32) { |
| count++; |
| v <<= 1; |
| } |
| |
| return 31 - count; |
| } |
| |
| static int |
| find_msb_int(int32_t v) |
| { |
| /* If v is signed, findMSB() returns the position of the most significant |
| * zero bit. |
| */ |
| return find_msb_uint(v < 0 ? ~v : v); |
| } |
| |
| static float |
| ldexpf_flush_subnormal(float x, int exp) |
| { |
| const float result = ldexpf(x, exp); |
| |
| /* Flush subnormal values to zero. */ |
| return !isnormal(result) ? copysignf(0.0f, x) : result; |
| } |
| |
| static double |
| ldexp_flush_subnormal(double x, int exp) |
| { |
| const double result = ldexp(x, exp); |
| |
| /* Flush subnormal values to zero. */ |
| return !isnormal(result) ? copysign(0.0, x) : result; |
| } |
| |
| static uint32_t |
| bitfield_extract_uint(uint32_t value, int offset, int bits) |
| { |
| if (bits == 0) |
| return 0; |
| else if (offset < 0 || bits < 0) |
| return 0; /* Undefined, per spec. */ |
| else if (offset + bits > 32) |
| return 0; /* Undefined, per spec. */ |
| else { |
| value <<= 32 - bits - offset; |
| value >>= 32 - bits; |
| return value; |
| } |
| } |
| |
| static int32_t |
| bitfield_extract_int(int32_t value, int offset, int bits) |
| { |
| if (bits == 0) |
| return 0; |
| else if (offset < 0 || bits < 0) |
| return 0; /* Undefined, per spec. */ |
| else if (offset + bits > 32) |
| return 0; /* Undefined, per spec. */ |
| else { |
| value <<= 32 - bits - offset; |
| value >>= 32 - bits; |
| return value; |
| } |
| } |
| |
| static uint32_t |
| bitfield_insert(uint32_t base, uint32_t insert, int offset, int bits) |
| { |
| if (bits == 0) |
| return base; |
| else if (offset < 0 || bits < 0) |
| return 0; /* Undefined, per spec. */ |
| else if (offset + bits > 32) |
| return 0; /* Undefined, per spec. */ |
| else { |
| unsigned insert_mask = ((1ull << bits) - 1) << offset; |
| |
| insert <<= offset; |
| insert &= insert_mask; |
| base &= ~insert_mask; |
| |
| return base | insert; |
| } |
| } |
| |
| ir_constant * |
| ir_expression::constant_expression_value(struct hash_table *variable_context) |
| { |
| if (this->type->is_error()) |
| return NULL; |
| |
| ir_constant *op[ARRAY_SIZE(this->operands)] = { NULL, }; |
| ir_constant_data data; |
| |
| memset(&data, 0, sizeof(data)); |
| |
| for (unsigned operand = 0; operand < this->get_num_operands(); operand++) { |
| op[operand] = this->operands[operand]->constant_expression_value(variable_context); |
| if (!op[operand]) |
| return NULL; |
| } |
| |
| if (op[1] != NULL) |
| switch (this->operation) { |
| case ir_binop_lshift: |
| case ir_binop_rshift: |
| case ir_binop_ldexp: |
| case ir_binop_interpolate_at_offset: |
| case ir_binop_interpolate_at_sample: |
| case ir_binop_vector_extract: |
| case ir_triop_csel: |
| case ir_triop_bitfield_extract: |
| break; |
| |
| default: |
| assert(op[0]->type->base_type == op[1]->type->base_type); |
| break; |
| } |
| |
| bool op0_scalar = op[0]->type->is_scalar(); |
| bool op1_scalar = op[1] != NULL && op[1]->type->is_scalar(); |
| |
| /* When iterating over a vector or matrix's components, we want to increase |
| * the loop counter. However, for scalars, we want to stay at 0. |
| */ |
| unsigned c0_inc = op0_scalar ? 0 : 1; |
| unsigned c1_inc = op1_scalar ? 0 : 1; |
| unsigned components; |
| if (op1_scalar || !op[1]) { |
| components = op[0]->type->components(); |
| } else { |
| components = op[1]->type->components(); |
| } |
| |
| void *ctx = ralloc_parent(this); |
| |
| /* Handle array operations here, rather than below. */ |
| if (op[0]->type->is_array()) { |
| assert(op[1] != NULL && op[1]->type->is_array()); |
| switch (this->operation) { |
| case ir_binop_all_equal: |
| return new(ctx) ir_constant(op[0]->has_value(op[1])); |
| case ir_binop_any_nequal: |
| return new(ctx) ir_constant(!op[0]->has_value(op[1])); |
| default: |
| break; |
| } |
| return NULL; |
| } |
| |
| #include "ir_expression_operation_constant.h" |
| |
| return new(ctx) ir_constant(this->type, &data); |
| } |
| |
| |
| ir_constant * |
| ir_texture::constant_expression_value(struct hash_table *) |
| { |
| /* texture lookups aren't constant expressions */ |
| return NULL; |
| } |
| |
| |
| ir_constant * |
| ir_swizzle::constant_expression_value(struct hash_table *variable_context) |
| { |
| ir_constant *v = this->val->constant_expression_value(variable_context); |
| |
| if (v != NULL) { |
| ir_constant_data data = { { 0 } }; |
| |
| const unsigned swiz_idx[4] = { |
| this->mask.x, this->mask.y, this->mask.z, this->mask.w |
| }; |
| |
| for (unsigned i = 0; i < this->mask.num_components; i++) { |
| switch (v->type->base_type) { |
| case GLSL_TYPE_UINT: |
| case GLSL_TYPE_INT: data.u[i] = v->value.u[swiz_idx[i]]; break; |
| case GLSL_TYPE_FLOAT: data.f[i] = v->value.f[swiz_idx[i]]; break; |
| case GLSL_TYPE_BOOL: data.b[i] = v->value.b[swiz_idx[i]]; break; |
| case GLSL_TYPE_DOUBLE:data.d[i] = v->value.d[swiz_idx[i]]; break; |
| default: assert(!"Should not get here."); break; |
| } |
| } |
| |
| void *ctx = ralloc_parent(this); |
| return new(ctx) ir_constant(this->type, &data); |
| } |
| return NULL; |
| } |
| |
| |
| ir_constant * |
| ir_dereference_variable::constant_expression_value(struct hash_table *variable_context) |
| { |
| assert(var); |
| |
| /* Give priority to the context hashtable, if it exists */ |
| if (variable_context) { |
| hash_entry *entry = _mesa_hash_table_search(variable_context, var); |
| |
| if(entry) |
| return (ir_constant *) entry->data; |
| } |
| |
| /* The constant_value of a uniform variable is its initializer, |
| * not the lifetime constant value of the uniform. |
| */ |
| if (var->data.mode == ir_var_uniform) |
| return NULL; |
| |
| if (!var->constant_value) |
| return NULL; |
| |
| return var->constant_value->clone(ralloc_parent(var), NULL); |
| } |
| |
| |
| ir_constant * |
| ir_dereference_array::constant_expression_value(struct hash_table *variable_context) |
| { |
| ir_constant *array = this->array->constant_expression_value(variable_context); |
| ir_constant *idx = this->array_index->constant_expression_value(variable_context); |
| |
| if ((array != NULL) && (idx != NULL)) { |
| void *ctx = ralloc_parent(this); |
| if (array->type->is_matrix()) { |
| /* Array access of a matrix results in a vector. |
| */ |
| const unsigned column = idx->value.u[0]; |
| |
| const glsl_type *const column_type = array->type->column_type(); |
| |
| /* Offset in the constant matrix to the first element of the column |
| * to be extracted. |
| */ |
| const unsigned mat_idx = column * column_type->vector_elements; |
| |
| ir_constant_data data = { { 0 } }; |
| |
| switch (column_type->base_type) { |
| case GLSL_TYPE_UINT: |
| case GLSL_TYPE_INT: |
| for (unsigned i = 0; i < column_type->vector_elements; i++) |
| data.u[i] = array->value.u[mat_idx + i]; |
| |
| break; |
| |
| case GLSL_TYPE_FLOAT: |
| for (unsigned i = 0; i < column_type->vector_elements; i++) |
| data.f[i] = array->value.f[mat_idx + i]; |
| |
| break; |
| |
| case GLSL_TYPE_DOUBLE: |
| for (unsigned i = 0; i < column_type->vector_elements; i++) |
| data.d[i] = array->value.d[mat_idx + i]; |
| |
| break; |
| |
| default: |
| assert(!"Should not get here."); |
| break; |
| } |
| |
| return new(ctx) ir_constant(column_type, &data); |
| } else if (array->type->is_vector()) { |
| const unsigned component = idx->value.u[0]; |
| |
| return new(ctx) ir_constant(array, component); |
| } else { |
| const unsigned index = idx->value.u[0]; |
| return array->get_array_element(index)->clone(ctx, NULL); |
| } |
| } |
| return NULL; |
| } |
| |
| |
| ir_constant * |
| ir_dereference_record::constant_expression_value(struct hash_table *) |
| { |
| ir_constant *v = this->record->constant_expression_value(); |
| |
| return (v != NULL) ? v->get_record_field(this->field) : NULL; |
| } |
| |
| |
| ir_constant * |
| ir_assignment::constant_expression_value(struct hash_table *) |
| { |
| /* FINISHME: Handle CEs involving assignment (return RHS) */ |
| return NULL; |
| } |
| |
| |
| ir_constant * |
| ir_constant::constant_expression_value(struct hash_table *) |
| { |
| return this; |
| } |
| |
| |
| ir_constant * |
| ir_call::constant_expression_value(struct hash_table *variable_context) |
| { |
| return this->callee->constant_expression_value(&this->actual_parameters, variable_context); |
| } |
| |
| |
| bool ir_function_signature::constant_expression_evaluate_expression_list(const struct exec_list &body, |
| struct hash_table *variable_context, |
| ir_constant **result) |
| { |
| foreach_in_list(ir_instruction, inst, &body) { |
| switch(inst->ir_type) { |
| |
| /* (declare () type symbol) */ |
| case ir_type_variable: { |
| ir_variable *var = inst->as_variable(); |
| _mesa_hash_table_insert(variable_context, var, ir_constant::zero(this, var->type)); |
| break; |
| } |
| |
| /* (assign [condition] (write-mask) (ref) (value)) */ |
| case ir_type_assignment: { |
| ir_assignment *asg = inst->as_assignment(); |
| if (asg->condition) { |
| ir_constant *cond = asg->condition->constant_expression_value(variable_context); |
| if (!cond) |
| return false; |
| if (!cond->get_bool_component(0)) |
| break; |
| } |
| |
| ir_constant *store = NULL; |
| int offset = 0; |
| |
| if (!constant_referenced(asg->lhs, variable_context, store, offset)) |
| return false; |
| |
| ir_constant *value = asg->rhs->constant_expression_value(variable_context); |
| |
| if (!value) |
| return false; |
| |
| store->copy_masked_offset(value, offset, asg->write_mask); |
| break; |
| } |
| |
| /* (return (expression)) */ |
| case ir_type_return: |
| assert (result); |
| *result = inst->as_return()->value->constant_expression_value(variable_context); |
| return *result != NULL; |
| |
| /* (call name (ref) (params))*/ |
| case ir_type_call: { |
| ir_call *call = inst->as_call(); |
| |
| /* Just say no to void functions in constant expressions. We |
| * don't need them at that point. |
| */ |
| |
| if (!call->return_deref) |
| return false; |
| |
| ir_constant *store = NULL; |
| int offset = 0; |
| |
| if (!constant_referenced(call->return_deref, variable_context, |
| store, offset)) |
| return false; |
| |
| ir_constant *value = call->constant_expression_value(variable_context); |
| |
| if(!value) |
| return false; |
| |
| store->copy_offset(value, offset); |
| break; |
| } |
| |
| /* (if condition (then-instructions) (else-instructions)) */ |
| case ir_type_if: { |
| ir_if *iif = inst->as_if(); |
| |
| ir_constant *cond = iif->condition->constant_expression_value(variable_context); |
| if (!cond || !cond->type->is_boolean()) |
| return false; |
| |
| exec_list &branch = cond->get_bool_component(0) ? iif->then_instructions : iif->else_instructions; |
| |
| *result = NULL; |
| if (!constant_expression_evaluate_expression_list(branch, variable_context, result)) |
| return false; |
| |
| /* If there was a return in the branch chosen, drop out now. */ |
| if (*result) |
| return true; |
| |
| break; |
| } |
| |
| /* Every other expression type, we drop out. */ |
| default: |
| return false; |
| } |
| } |
| |
| /* Reaching the end of the block is not an error condition */ |
| if (result) |
| *result = NULL; |
| |
| return true; |
| } |
| |
| ir_constant * |
| ir_function_signature::constant_expression_value(exec_list *actual_parameters, struct hash_table *variable_context) |
| { |
| const glsl_type *type = this->return_type; |
| if (type == glsl_type::void_type) |
| return NULL; |
| |
| /* From the GLSL 1.20 spec, page 23: |
| * "Function calls to user-defined functions (non-built-in functions) |
| * cannot be used to form constant expressions." |
| */ |
| if (!this->is_builtin()) |
| return NULL; |
| |
| /* |
| * Of the builtin functions, only the texture lookups and the noise |
| * ones must not be used in constant expressions. They all include |
| * specific opcodes so they don't need to be special-cased at this |
| * point. |
| */ |
| |
| /* Initialize the table of dereferencable names with the function |
| * parameters. Verify their const-ness on the way. |
| * |
| * We expect the correctness of the number of parameters to have |
| * been checked earlier. |
| */ |
| hash_table *deref_hash = _mesa_hash_table_create(NULL, _mesa_hash_pointer, |
| _mesa_key_pointer_equal); |
| |
| /* If "origin" is non-NULL, then the function body is there. So we |
| * have to use the variable objects from the object with the body, |
| * but the parameter instanciation on the current object. |
| */ |
| const exec_node *parameter_info = origin ? origin->parameters.get_head_raw() : parameters.get_head_raw(); |
| |
| foreach_in_list(ir_rvalue, n, actual_parameters) { |
| ir_constant *constant = n->constant_expression_value(variable_context); |
| if (constant == NULL) { |
| _mesa_hash_table_destroy(deref_hash, NULL); |
| return NULL; |
| } |
| |
| |
| ir_variable *var = (ir_variable *)parameter_info; |
| _mesa_hash_table_insert(deref_hash, var, constant); |
| |
| parameter_info = parameter_info->next; |
| } |
| |
| ir_constant *result = NULL; |
| |
| /* Now run the builtin function until something non-constant |
| * happens or we get the result. |
| */ |
| if (constant_expression_evaluate_expression_list(origin ? origin->body : body, deref_hash, &result) && result) |
| result = result->clone(ralloc_parent(this), NULL); |
| |
| _mesa_hash_table_destroy(deref_hash, NULL); |
| |
| return result; |
| } |