diff options
Diffstat (limited to 'vendor/libm/src/math/ceil.rs')
| -rw-r--r-- | vendor/libm/src/math/ceil.rs | 37 |
1 files changed, 34 insertions, 3 deletions
diff --git a/vendor/libm/src/math/ceil.rs b/vendor/libm/src/math/ceil.rs index 59883a8a7..22d892971 100644 --- a/vendor/libm/src/math/ceil.rs +++ b/vendor/libm/src/math/ceil.rs @@ -1,3 +1,4 @@ +#![allow(unreachable_code)] use core::f64; const TOINT: f64 = 1. / f64::EPSILON; @@ -5,7 +6,6 @@ const TOINT: f64 = 1. / f64::EPSILON; /// Ceil (f64) /// /// Finds the nearest integer greater than or equal to `x`. -#[inline] #[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)] pub fn ceil(x: f64) -> f64 { // On wasm32 we know that LLVM's intrinsic will compile to an optimized @@ -16,6 +16,24 @@ pub fn ceil(x: f64) -> f64 { return unsafe { ::core::intrinsics::ceilf64(x) } } } + #[cfg(all(target_arch = "x86", not(target_feature = "sse2")))] + { + //use an alternative implementation on x86, because the + //main implementation fails with the x87 FPU used by + //debian i386, probablly due to excess precision issues. + //basic implementation taken from https://github.com/rust-lang/libm/issues/219 + use super::fabs; + if fabs(x).to_bits() < 4503599627370496.0_f64.to_bits() { + let truncated = x as i64 as f64; + if truncated < x { + return truncated + 1.0; + } else { + return truncated; + } + } else { + return x; + } + } let u: u64 = x.to_bits(); let e: i64 = (u >> 52 & 0x7ff) as i64; let y: f64; @@ -43,9 +61,22 @@ pub fn ceil(x: f64) -> f64 { #[cfg(test)] mod tests { + use super::*; + use core::f64::*; + #[test] fn sanity_check() { - assert_eq!(super::ceil(1.1), 2.0); - assert_eq!(super::ceil(2.9), 3.0); + assert_eq!(ceil(1.1), 2.0); + assert_eq!(ceil(2.9), 3.0); + } + + /// The spec: https://en.cppreference.com/w/cpp/numeric/math/ceil + #[test] + fn spec_tests() { + // Not Asserted: that the current rounding mode has no effect. + assert!(ceil(NAN).is_nan()); + for f in [0.0, -0.0, INFINITY, NEG_INFINITY].iter().copied() { + assert_eq!(ceil(f), f); + } } } |