diff options
Diffstat (limited to 'src/glsl')
| -rw-r--r-- | src/glsl/ir_constant_expression.cpp | 126 |
1 files changed, 125 insertions, 1 deletions
diff --git a/src/glsl/ir_constant_expression.cpp b/src/glsl/ir_constant_expression.cpp index c09e56a3d08..a4a117e683d 100644 --- a/src/glsl/ir_constant_expression.cpp +++ b/src/glsl/ir_constant_expression.cpp @@ -393,7 +393,8 @@ ir_expression::constant_expression_value(struct hash_table *variable_context) if (op[1] != NULL) assert(op[0]->type->base_type == op[1]->type->base_type || this->operation == ir_binop_lshift || - this->operation == ir_binop_rshift); + this->operation == ir_binop_rshift || + this->operation == ir_triop_bitfield_extract); bool op0_scalar = op[0]->type->is_scalar(); bool op1_scalar = op[1] != NULL && op[1]->type->is_scalar(); @@ -1248,6 +1249,102 @@ ir_expression::constant_expression_value(struct hash_table *variable_context) } break; + case ir_unop_bitfield_reverse: + /* http://graphics.stanford.edu/~seander/bithacks.html#BitReverseObvious */ + for (unsigned c = 0; c < components; c++) { + unsigned int v = op[0]->value.u[c]; // input bits to be reversed + unsigned int 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 + + data.u[c] = r; + } + break; + + case ir_unop_bit_count: + for (unsigned c = 0; c < components; c++) { + unsigned count = 0; + unsigned v = op[0]->value.u[c]; + + for (; v; count++) { + v &= v - 1; + } + data.u[c] = count; + } + break; + + case ir_unop_find_msb: + for (unsigned c = 0; c < components; c++) { + int v = op[0]->value.i[c]; + + if (v == 0 || (op[0]->type->base_type == GLSL_TYPE_INT && v == -1)) + data.i[c] = -1; + else { + int count = 0; + int top_bit = op[0]->type->base_type == GLSL_TYPE_UINT + ? 0 : v & (1 << 31); + + while (((v & (1 << 31)) == top_bit) && count != 32) { + count++; + v <<= 1; + } + + data.i[c] = 31 - count; + } + } + break; + + case ir_unop_find_lsb: + for (unsigned c = 0; c < components; c++) { + if (op[0]->value.i[c] == 0) + data.i[c] = -1; + else { + unsigned pos = 0; + unsigned v = op[0]->value.u[c]; + + for (; !(v & 1); v >>= 1) { + pos++; + } + data.u[c] = pos; + } + } + break; + + case ir_triop_bitfield_extract: { + int offset = op[1]->value.i[0]; + int bits = op[2]->value.i[0]; + + for (unsigned c = 0; c < components; c++) { + if (bits == 0) + data.u[c] = 0; + else if (offset < 0 || bits < 0) + data.u[c] = 0; /* Undefined, per spec. */ + else if (offset + bits > 32) + data.u[c] = 0; /* Undefined, per spec. */ + else { + if (op[0]->type->base_type == GLSL_TYPE_INT) { + /* int so that the right shift will sign-extend. */ + int value = op[0]->value.i[c]; + value <<= 32 - bits - offset; + value >>= 32 - bits; + data.i[c] = value; + } else { + unsigned value = op[0]->value.u[c]; + value <<= 32 - bits - offset; + value >>= 32 - bits; + data.u[c] = value; + } + } + } + break; + } + case ir_triop_lrp: { assert(op[0]->type->base_type == GLSL_TYPE_FLOAT); assert(op[1]->type->base_type == GLSL_TYPE_FLOAT); @@ -1261,6 +1358,33 @@ ir_expression::constant_expression_value(struct hash_table *variable_context) break; } + case ir_quadop_bitfield_insert: { + int offset = op[2]->value.i[0]; + int bits = op[3]->value.i[0]; + + for (unsigned c = 0; c < components; c++) { + if (bits == 0) + data.u[c] = op[0]->value.u[c]; + else if (offset < 0 || bits < 0) + data.u[c] = 0; /* Undefined, per spec. */ + else if (offset + bits > 32) + data.u[c] = 0; /* Undefined, per spec. */ + else { + unsigned insert_mask = ((1 << bits) - 1) << offset; + + unsigned insert = op[1]->value.u[c]; + insert <<= offset; + insert &= insert_mask; + + unsigned base = op[0]->value.u[c]; + base &= ~insert_mask; + + data.u[c] = base | insert; + } + } + break; + } + case ir_quadop_vector: for (unsigned c = 0; c < this->type->vector_elements; c++) { switch (this->type->base_type) { |