Intel ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS MANUAL VOLUME 3 REV 2.3 Manual page 46

clrrrb — Clear RRB
clrrrb
Format:
clrrrb.pr
In the all_form, the register rename base registers (CFM.rrb.gr, CFM.rrb.fr, and
Description:
CFM.rrb.pr) are cleared. In the pred_form, the single register rename base register for
the predicates (CFM.rrb.pr) is cleared.
This instruction must be the last instruction in an instruction group; otherwise,
operation is undefined.
This instruction cannot be predicated.
Operation:
if (!followed_by_stop())
undefined_behavior();
if (all_form) {
CFM.rrb.gr = 0;
CFM.rrb.fr = 0;
CFM.rrb.pr = 0;
} else { // pred_form
CFM.rrb.pr = 0;
}
None
Interruptions:
Volume 3: Instruction Reference
clrrrb
all_form B8
pred_form B8
3:37