diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/mesa/program/ir_to_mesa.cpp | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/src/mesa/program/ir_to_mesa.cpp b/src/mesa/program/ir_to_mesa.cpp index debadb9a398..9b615b68a23 100644 --- a/src/mesa/program/ir_to_mesa.cpp +++ b/src/mesa/program/ir_to_mesa.cpp @@ -915,10 +915,30 @@ ir_to_mesa_visitor::try_emit_sat(ir_expression *ir) sat_src->accept(this); src_reg src = this->result; - this->result = get_temp(ir->type); - ir_to_mesa_instruction *inst; - inst = emit(ir, OPCODE_MOV, dst_reg(this->result), src); - inst->saturate = true; + /* If we generated an expression instruction into a temporary in + * processing the saturate's operand, apply the saturate to that + * instruction. Otherwise, generate a MOV to do the saturate. + * + * Note that we have to be careful to only do this optimization if + * the instruction in question was what generated src->result. For + * example, ir_dereference_array might generate a MUL instruction + * to create the reladdr, and return us a src reg using that + * reladdr. That MUL result is not the value we're trying to + * saturate. + */ + ir_expression *sat_src_expr = sat_src->as_expression(); + ir_to_mesa_instruction *new_inst; + new_inst = (ir_to_mesa_instruction *)this->instructions.get_tail(); + if (sat_src_expr && (sat_src_expr->operation == ir_binop_mul || + sat_src_expr->operation == ir_binop_add || + sat_src_expr->operation == ir_binop_dot)) { + new_inst->saturate = true; + } else { + this->result = get_temp(ir->type); + ir_to_mesa_instruction *inst; + inst = emit(ir, OPCODE_MOV, dst_reg(this->result), src); + inst->saturate = true; + } return true; } |