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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-18 02:49:50 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-18 02:49:50 +0000 |
commit | 9835e2ae736235810b4ea1c162ca5e65c547e770 (patch) | |
tree | 3fcebf40ed70e581d776a8a4c65923e8ec20e026 /vendor/libm-0.1.4/src/math/trunc.rs | |
parent | Releasing progress-linux version 1.70.0+dfsg2-1~progress7.99u1. (diff) | |
download | rustc-9835e2ae736235810b4ea1c162ca5e65c547e770.tar.xz rustc-9835e2ae736235810b4ea1c162ca5e65c547e770.zip |
Merging upstream version 1.71.1+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/libm-0.1.4/src/math/trunc.rs')
-rw-r--r-- | vendor/libm-0.1.4/src/math/trunc.rs | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/vendor/libm-0.1.4/src/math/trunc.rs b/vendor/libm-0.1.4/src/math/trunc.rs new file mode 100644 index 000000000..1ee46fc7d --- /dev/null +++ b/vendor/libm-0.1.4/src/math/trunc.rs @@ -0,0 +1,41 @@ +use core::f64; + +#[inline] +#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)] +pub fn trunc(x: f64) -> f64 { + // On wasm32 we know that LLVM's intrinsic will compile to an optimized + // `f64.trunc` native instruction, so we can leverage this for both code size + // and speed. + llvm_intrinsically_optimized! { + #[cfg(target_arch = "wasm32")] { + return unsafe { ::core::intrinsics::truncf64(x) } + } + } + let x1p120 = f64::from_bits(0x4770000000000000); // 0x1p120f === 2 ^ 120 + + let mut i: u64 = x.to_bits(); + let mut e: i64 = (i >> 52 & 0x7ff) as i64 - 0x3ff + 12; + let m: u64; + + if e >= 52 + 12 { + return x; + } + if e < 12 { + e = 1; + } + m = -1i64 as u64 >> e; + if (i & m) == 0 { + return x; + } + force_eval!(x + x1p120); + i &= !m; + f64::from_bits(i) +} + +#[cfg(test)] +mod tests { + #[test] + fn sanity_check() { + assert_eq!(super::trunc(1.1), 1.0); + } +} |