Intel ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS MANUAL VOLUME 1 REV 2.3 Manual page 1031

frsqrta
fp_update_psr(f
} else {
PR[p ] = 0;
2
}
// fp_ieee_recip_sqrt()
fp_ieee_recip_sqrt(root)
{
RECIP_SQRT_TABLE[256] = {
0x1a5, 0x1a0, 0x19a, 0x195, 0x18f, 0x18a, 0x185, 0x180,
0x17a, 0x175, 0x170, 0x16b, 0x166, 0x161, 0x15d, 0x158,
0x153, 0x14e, 0x14a, 0x145, 0x140, 0x13c, 0x138, 0x133,
0x12f, 0x12a, 0x126, 0x122, 0x11e, 0x11a, 0x115, 0x111,
0x10d, 0x109, 0x105, 0x101, 0x0fd, 0x0fa, 0x0f6, 0x0f2,
0x0ee, 0x0ea, 0x0e7, 0x0e3, 0x0df, 0x0dc, 0x0d8, 0x0d5,
0x0d1, 0x0ce, 0x0ca, 0x0c7, 0x0c3, 0x0c0, 0x0bd, 0x0b9,
0x0b6, 0x0b3, 0x0b0, 0x0ad, 0x0a9, 0x0a6, 0x0a3, 0x0a0,
0x09d, 0x09a, 0x097, 0x094, 0x091, 0x08e, 0x08b, 0x088,
0x085, 0x082, 0x07f, 0x07d, 0x07a, 0x077, 0x074, 0x071,
0x06f, 0x06c, 0x069, 0x067, 0x064, 0x061, 0x05f, 0x05c,
0x05a, 0x057, 0x054, 0x052, 0x04f, 0x04d, 0x04a, 0x048,
0x045, 0x043, 0x041, 0x03e, 0x03c, 0x03a, 0x037, 0x035,
0x033, 0x030, 0x02e, 0x02c, 0x029, 0x027, 0x025, 0x023,
0x020, 0x01e, 0x01c, 0x01a, 0x018, 0x016, 0x014, 0x011,
0x00f, 0x00d, 0x00b, 0x009, 0x007, 0x005, 0x003, 0x001,
0x3fc, 0x3f4, 0x3ec, 0x3e5, 0x3dd, 0x3d5, 0x3ce, 0x3c7,
0x3bf, 0x3b8, 0x3b1, 0x3aa, 0x3a3, 0x39c, 0x395, 0x38e,
0x388, 0x381, 0x37a, 0x374, 0x36d, 0x367, 0x361, 0x35a,
0x354, 0x34e, 0x348, 0x342, 0x33c, 0x336, 0x330, 0x32b,
0x325, 0x31f, 0x31a, 0x314, 0x30f, 0x309, 0x304, 0x2fe,
0x2f9, 0x2f4, 0x2ee, 0x2e9, 0x2e4, 0x2df, 0x2da, 0x2d5,
0x2d0, 0x2cb, 0x2c6, 0x2c1, 0x2bd, 0x2b8, 0x2b3, 0x2ae,
0x2aa, 0x2a5, 0x2a1, 0x29c, 0x298, 0x293, 0x28f, 0x28a,
0x286, 0x282, 0x27d, 0x279, 0x275, 0x271, 0x26d, 0x268,
0x264, 0x260, 0x25c, 0x258, 0x254, 0x250, 0x24c, 0x249,
0x245, 0x241, 0x23d, 0x239, 0x235, 0x232, 0x22e, 0x22a,
0x227, 0x223, 0x220, 0x21c, 0x218, 0x215, 0x211, 0x20e,
0x20a, 0x207, 0x204, 0x200, 0x1fd, 0x1f9, 0x1f6, 0x1f3,
0x1f0, 0x1ec, 0x1e9, 0x1e6, 0x1e3, 0x1df, 0x1dc, 0x1d9,
0x1d6, 0x1d3, 0x1d0, 0x1cd, 0x1ca, 0x1c7, 0x1c4, 0x1c1,
0x1be, 0x1bb, 0x1b8, 0x1b5, 0x1b2, 0x1af, 0x1ac, 0x1aa,
};
tmp_index = (root.exponent{0} << 7) | root.significand{62:56};
tmp_res.significand = (1 << 63) | (RECIP_SQRT_TABLE[tmp_index] << 53);
tmp_res.exponent = FP_REG_EXP_HALF -
tmp_res.sign = FP_SIGN_POSITIVE;
return (tmp_res);
}
Invalid Operation (V)
FP Exceptions:
Denormal/Unnormal Operand (D)
Software Assist (SWA) fault
3:132
);
1
((root.exponent - FP_REG_BIAS) >> 1);
Volume 3: Instruction Reference