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Again smaller fixed point exp()

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@10455 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Jens Arnold 2006-08-04 07:32:23 +00:00
parent f212e6cf5f
commit 51d3dba10a
1 changed files with 5 additions and 19 deletions
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16
apps/plugins/lib/gray_core.c
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@ -200,25 +200,11 @@ static int exp_s16p16(int x)
int t; int t;
int y = 0x00010000; int y = 0x00010000;
if (x == 0) if (x < 0) x += 0xb1721, y >>= 16;
{
return y;
}
else if (x > 0)
{
t = x - 0x58b91; if (t >= 0) x = t, y <<= 8; t = x - 0x58b91; if (t >= 0) x = t, y <<= 8;
t = x - 0x2c5c8; if (t >= 0) x = t, y <<= 4; t = x - 0x2c5c8; if (t >= 0) x = t, y <<= 4;
t = x - 0x162e4; if (t >= 0) x = t, y <<= 2; t = x - 0x162e4; if (t >= 0) x = t, y <<= 2;
t = x - 0x0b172; if (t >= 0) x = t, y <<= 1; t = x - 0x0b172; if (t >= 0) x = t, y <<= 1;
}
else
{
t = x + 0x58b91; if (t < 0) x = t, y >>= 8;
t = x + 0x2c5c8; if (t < 0) x = t, y >>= 4;
t = x + 0x162e4; if (t < 0) x = t, y >>= 2;
t = x + 0x0b172; if (t < 0) x = t, y >>= 1;
x += 0x0b172; y >>= 1;
}
t = x - 0x067cd; if (t >= 0) x = t, y += y >> 1; t = x - 0x067cd; if (t >= 0) x = t, y += y >> 1;
t = x - 0x03920; if (t >= 0) x = t, y += y >> 2; t = x - 0x03920; if (t >= 0) x = t, y += y >> 2;
t = x - 0x01e27; if (t >= 0) x = t, y += y >> 3; t = x - 0x01e27; if (t >= 0) x = t, y += y >> 3;