For the series: Reviewed-by: Chris Forbes <chr...@ijw.co.nz>
On Mon, Apr 29, 2013 at 10:29 AM, Matt Turner <matts...@gmail.com> wrote: > v2: Order bits from LSB end (31 - count) for ir_unop_find_msb. > --- > src/glsl/ir_constant_expression.cpp | 123 > ++++++++++++++++++++++++++++++++++++ > 1 file changed, 123 insertions(+) > > diff --git a/src/glsl/ir_constant_expression.cpp > b/src/glsl/ir_constant_expression.cpp > index c09e56a..66b0a64 100644 > --- a/src/glsl/ir_constant_expression.cpp > +++ b/src/glsl/ir_constant_expression.cpp > @@ -1248,6 +1248,102 @@ 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 +1357,33 @@ 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) { > -- > 1.8.1.5 > _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
