Intel Itanium 9150M, Manual

Page: 214 / 420

Volume 3: Instruction Reference 3:205
pavgsub
Operation: if (PR[ qp ]) {
check_target_register( r
1
);
if (one_byte_form) {
x[0] = GR[ r
2
]{7:0}; y[0] = GR[ r
3
]{7:0};
x[1] = GR[ r
2
]{15:8}; y[1] = GR[ r
3
]{15:8};
x[2] = GR[ r
2
]{23:16}; y[2] = GR[ r
3
]{23:16};
x[3] = GR[ r
2
]{31:24}; y[3] = GR[ r
3
]{31:24};
x[4] = GR[ r
2
]{39:32}; y[4] = GR[ r
3
]{39:32};
x[5] = GR[ r
2
]{47:40}; y[5] = GR[ r
3
]{47:40};
x[6] = GR[ r
2
]{55:48}; y[6] = GR[ r
3
]{55:48};
x[7] = GR[ r
2
]{63:56}; y[7] = GR[ r
3
]{63:56};
for (i = 0; i < 8; i++) {
temp[i] = zero_ext(x[i], 8) - zero_ext(y[i], 8);
res[i] = (temp[i]{8:0} u>> 1) | (temp[i]{0});
}
GR[
r
1
] = concatenate8(res[7], res[6], res[5], res[4],
res[3], res[2], res[1], res[0]);
} else { // two_byte_form
x[0] = GR[ r
2
]{15:0}; y[0] = GR[ r
3
]{15:0};
x[1] = GR[ r
2
]{31:16}; y[1] = GR[ r
3
]{31:16};
x[2] = GR[ r
2
]{47:32}; y[2] = GR[ r
3
]{47:32};
x[3] = GR[ r
2
]{63:48}; y[3] = GR[ r
3
]{63:48};
for (i = 0; i < 4; i++) {
temp[i] = zero_ext(x[i], 16) - zero_ext(y[i], 16);
res[i] = (temp[i]{16:0} u>> 1) | (temp[i]{0});
}
GR[
r
1
] = concatenate4(res[3], res[2], res[1], res[0]);
}
GR[
r
1
].nat = GR[ r
2
].nat || GR[ r
3
].nat;
}
Interruptions:
Illegal Operation fault