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Diffstat (limited to 'vendor/libm/src/math/floorf.rs')
-rw-r--r-- | vendor/libm/src/math/floorf.rs | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/vendor/libm/src/math/floorf.rs b/vendor/libm/src/math/floorf.rs new file mode 100644 index 000000000..ae605e191 --- /dev/null +++ b/vendor/libm/src/math/floorf.rs @@ -0,0 +1,50 @@ +use core::f32; + +/// Floor (f64) +/// +/// Finds the nearest integer less than or equal to `x`. +#[inline] +#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)] +pub fn floorf(x: f32) -> f32 { + // On wasm32 we know that LLVM's intrinsic will compile to an optimized + // `f32.floor` native instruction, so we can leverage this for both code size + // and speed. + llvm_intrinsically_optimized! { + #[cfg(target_arch = "wasm32")] { + return unsafe { ::core::intrinsics::floorf32(x) } + } + } + let mut ui = x.to_bits(); + let e = (((ui >> 23) as i32) & 0xff) - 0x7f; + + if e >= 23 { + return x; + } + if e >= 0 { + let m: u32 = 0x007fffff >> e; + if (ui & m) == 0 { + return x; + } + force_eval!(x + f32::from_bits(0x7b800000)); + if ui >> 31 != 0 { + ui += m; + } + ui &= !m; + } else { + force_eval!(x + f32::from_bits(0x7b800000)); + if ui >> 31 == 0 { + ui = 0; + } else if ui << 1 != 0 { + return -1.0; + } + } + f32::from_bits(ui) +} + +#[cfg(test)] +mod tests { + #[test] + fn no_overflow() { + assert_eq!(super::floorf(0.5), 0.0); + } +} |