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

Page: 1106 / 1898

Volume 3: Instruction Reference 3:207
pcmp
Operation: if (PR[ qp ]) {
check_target_register( r
1
);
if (one_byte_form) { // one-byte elements
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++) {
if ( prel == ‘eq’)
tmp_rel = x[i] == y[i];
else // ‘gt’
tmp_rel = greater_signed(sign_ext(x[i], 8),
sign_ext(y[i], 8));
if (tmp_rel)
res[i] = 0xff;
else
res[i] = 0x00;
}
GR[
r
1
] = concatenate8(res[7], res[6], res[5], res[4],
res[3], res[2], res[1], res[0]);
} else if (two_byte_form) { // two-byte elements
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++) {
if ( prel == ‘eq’)
tmp_rel = x[i] == y[i];
else // ‘gt’
tmp_rel = greater_signed(sign_ext(x[i], 16),
sign_ext(y[i], 16));
if (tmp_rel)
res[i] = 0xffff;
else
res[i] = 0x0000;
}
GR[
r
1
] = concatenate4(res[3], res[2], res[1], res[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++) {
if ( prel == ‘eq’)
tmp_rel = x[i] == y[i];
else // ‘gt’
tmp_rel = greater_signed(sign_ext(x[i], 32),
sign_ext(y[i], 32));
if (tmp_rel)
res[i] = 0xffffffff;