} else if (devinfo->gen < 6 &&
brw_inst_opcode(devinfo, inst) == BRW_OPCODE_SEND) {
if (brw_inst_sfid(devinfo, inst) == BRW_SFID_MATH) {
- math_function = brw_inst_math_msg_function(devinfo, inst);
+ /* src1 must be a descriptor (including the information to determine
+ * that the SEND is doing an extended math operation), but src0 can
+ * actually be null since it serves as the source of the implicit GRF
+ * to MRF move.
+ *
+ * If we stop using that functionality, we'll have to revisit this.
+ */
+ return 2;
} else {
/* Send instructions are allowed to have null sources since they use
* the base_mrf field to specify which message register source.