Intel ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS MANUAL VOLUME 1 REV 2.3 Manual page 1115

popcnt
popcnt — Population Count
( ) popcnt
Format: qp
The number of bits in GR
Description:
placed in GR
Operation: if (PR[qp]) {
check_target_register(r
res = 0;
// Count up all the one bits
for (i = 0; i < 64; i++) {
res += GR[r
}
GR[r ] = res;
1
GR[r ].nat = GR[r
1
}
Illegal Operation fault
Interruptions:
3:216
=
r r
1 3
having the value 1 is counted, and the resulting sum is
r
3
.
r
1
);
1
]{i};
3
].nat;
3
Volume 3: Instruction Reference
I9