91 lines
1.5 KiB
Rust
91 lines
1.5 KiB
Rust
use core::u32;
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use super::isnanf;
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#[inline]
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pub fn fmodf(x: f32, y: f32) -> f32 {
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let mut uxi = x.to_bits();
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let mut uyi = y.to_bits();
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let mut ex = (uxi >> 23 & 0xff) as i32;
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let mut ey = (uyi >> 23 & 0xff) as i32;
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let sx = uxi & 0x80000000;
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let mut i;
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if uyi << 1 == 0 || isnanf(y) || ex == 0xff {
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return (x * y) / (x * y);
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}
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if uxi << 1 <= uyi << 1 {
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if uxi << 1 == uyi << 1 {
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return 0.0 * x;
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}
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return x;
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}
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/* normalize x and y */
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if ex == 0 {
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i = uxi << 9;
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while i >> 31 == 0 {
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ex -= 1;
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i <<= 1;
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}
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uxi <<= -ex + 1;
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} else {
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uxi &= u32::MAX >> 9;
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uxi |= 1 << 23;
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}
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if ey == 0 {
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i = uyi << 9;
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while i >> 31 == 0 {
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ey -= 1;
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i <<= 1;
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}
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uyi <<= -ey + 1;
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} else {
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uyi &= u32::MAX >> 9;
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uyi |= 1 << 23;
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}
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/* x mod y */
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while ex > ey {
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i = uxi - uyi;
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if i >> 31 == 0 {
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if i == 0 {
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return 0.0 * x;
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}
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uxi = i;
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}
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uxi <<= 1;
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ex -= 1;
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}
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i = uxi - uyi;
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if i >> 31 == 0 {
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if i == 0 {
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return 0.0 * x;
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}
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uxi = i;
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}
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while uxi >> 23 == 0 {
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uxi <<= 1;
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ex -= 1;
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}
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/* scale result up */
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if ex > 0 {
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uxi -= 1 << 23;
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uxi |= (ex as u32) << 23;
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} else {
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uxi >>= -ex + 1;
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}
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uxi |= sx;
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f32::from_bits(uxi)
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}
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