+ brw_set_acc_write_control(p, 0);
+
+ /* The VUE layout is documented in Volume 2a. */
+ if (intel->gen >= 6) {
+ /* There are 8 or 16 DWs (D0-D15) in VUE header on Sandybridge:
+ * dword 0-3 (m1) of the header is indices, point width, clip flags.
+ * dword 4-7 (m2) is the 4D space position
+ * dword 8-15 (m3,m4) of the vertex header is the user clip distance if
+ * enabled.
+ * m3 or 5 is the first vertex element data we fill, which is
+ * the vertex position.
+ */
+ brw_MOV(p, brw_message_reg(2), pos);
+ len_vertex_header = 1;
+ if (c->key.nr_userclip > 0)
+ len_vertex_header += 2;
+ } else if (intel->gen == 5) {
+ /* There are 20 DWs (D0-D19) in VUE header on Ironlake:
+ * dword 0-3 (m1) of the header is indices, point width, clip flags.
+ * dword 4-7 (m2) is the ndc position (set above)
+ * dword 8-11 (m3) of the vertex header is the 4D space position
+ * dword 12-19 (m4,m5) of the vertex header is the user clip distance.
+ * m6 is a pad so that the vertex element data is aligned
+ * m7 is the first vertex data we fill, which is the vertex position.
+ */
+ brw_MOV(p, brw_message_reg(2), ndc);
+ brw_MOV(p, brw_message_reg(3), pos);
+ brw_MOV(p, brw_message_reg(7), pos);
+ len_vertex_header = 6;
+ } else {
+ /* There are 8 dwords in VUE header pre-Ironlake:
+ * dword 0-3 (m1) is indices, point width, clip flags.
+ * dword 4-7 (m2) is ndc position (set above)
+ *
+ * dword 8-11 (m3) is the first vertex data, which we always have be the
+ * vertex position.
+ */
+ brw_MOV(p, brw_message_reg(2), ndc);
+ brw_MOV(p, brw_message_reg(3), pos);
+ len_vertex_header = 2;
+ }
+
+ /* Move variable-addressed, non-overflow outputs to their MRFs. */
+ next_mrf = 2 + len_vertex_header;
+ for (i = 0; i < VERT_RESULT_MAX; i++) {
+ if (c->first_overflow_output > 0 && i >= c->first_overflow_output)
+ break;
+ if (!(c->prog_data.outputs_written & BITFIELD64_BIT(i)))
+ continue;
+ if (i == VERT_RESULT_PSIZ)
+ continue;
+
+ if (i >= VERT_RESULT_TEX0 &&
+ c->regs[PROGRAM_OUTPUT][i].file == BRW_GENERAL_REGISTER_FILE) {
+ brw_MOV(p, brw_message_reg(next_mrf), c->regs[PROGRAM_OUTPUT][i]);
+ next_mrf++;
+ } else if (c->regs[PROGRAM_OUTPUT][i].file == BRW_MESSAGE_REGISTER_FILE) {
+ next_mrf = c->regs[PROGRAM_OUTPUT][i].nr + 1;
+ }
+ }
+
+ eot = (c->first_overflow_output == 0);