30 lines
824 B
Rust
30 lines
824 B
Rust
// [See license/rust-lang/libm] Copyright (c) 2018 Jorge Aparicio
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#[cfg(not(all(any(target_arch = "x86", target_arch = "x86_64"), feature = "simd")))]
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pub fn trunc(x: f32) -> f32 {
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let mut i: u32 = x.to_bits();
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let mut e: i32 = (i >> 23 & 0xff) as i32 - 0x7f + 9;
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let m: u32;
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if e >= 23 + 9 {
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return x;
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}
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if e < 9 {
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e = 1;
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}
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m = -1i32 as u32 >> e;
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if (i & m) == 0 {
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return x;
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}
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i &= !m;
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f32::from_bits(i)
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}
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#[cfg(all(any(target_arch = "x86", target_arch = "x86_64"), feature = "simd"))]
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#[inline(always)]
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pub fn trunc(value: f32) -> f32 {
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#[cfg(target_arch = "x86")]
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use core::arch::x86::*;
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#[cfg(target_arch = "x86_64")]
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use core::arch::x86_64::*;
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unsafe { _mm_cvtss_f32(_mm_cvtepi32_ps(_mm_cvttps_epi32(_mm_set_ss(value)))) }
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}
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