Intel ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS VOLUME 3 REV 2.3, Manual

Page: 1128 / 1898

Volume 3: Instruction Reference 3:229
psub
max = sign_ext(0x7fff, 16);
min = sign_ext(0x8000, 16);
for (i = 0; i < 4; i++) {
temp[i] = sign_ext(x[i], 16) - sign_ext(y[i], 16);
}
} else if (uus_saturation_form) { // uus_saturation_form
max = 0xffff;
min = 0x0000;
for (i = 0; i < 4; i++) {
temp[i] = zero_ext(x[i], 16) - sign_ext(y[i], 16);
}
} else if (uuu_saturation_form) { // uuu_saturation_form
max = 0xffff;
min = 0x0000;
for (i = 0; i < 4; i++) {
temp[i] = zero_ext(x[i], 16) - zero_ext(y[i], 16);
}
} else { // modulo_form
for (i = 0; i < 4; i++) {
temp[i] = zero_ext(x[i], 16) - zero_ext(y[i], 16);
}
}
if (sss_saturation_form || uus_saturation_form ||
uuu_saturation_form) {
for (i = 0; i < 4; i++) {
if (temp[i] > max)
temp[i] = max;
if (temp[i] < min)
temp[i] = min;
}
}
GR[ r
1
] = concatenate4(temp[3], temp[2], temp[1], temp[0]);
} else { // four-byte elements
x[0] = GR[ r
2
]{31:0}; y[0] = GR[ r
3
]{31:0};
x[1] = GR[ r
2
]{63:32}; y[1] = GR[ r
3
]{63:32};
for (i = 0; i < 2; i++) { // modulo_form
temp[i] = zero_ext(x[i], 32) - zero_ext(y[i], 32);
}
GR[ r
1
] = concatenate2(temp[1], temp[0]);
}
GR[ r
1
].nat = GR[ r
2
].nat || GR[ r
3
].nat;
}
Interruptions:
Illegal Operation fault