1 files changed, 215 insertions, 0 deletions
diff --git a/src/f64/math.rs b/src/f64/math.rs
new file mode 100644
index 0000000..45ace5c
--- /dev/null
+++ b/src/f64/math.rs
@@ -0,0 +1,215 @@
+#[cfg(feature = "libm")]
+mod libm_math {
+    #[inline(always)]
+    pub(crate) fn abs(f: f64) -> f64 {
+        libm::fabs(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn acos_approx(f: f64) -> f64 {
+        libm::acos(f.clamp(-1.0, 1.0))
+    }
+
+    #[inline(always)]
+    pub(crate) fn asin(f: f64) -> f64 {
+        libm::asin(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn atan2(f: f64, other: f64) -> f64 {
+        libm::atan2(f, other)
+    }
+
+    #[inline(always)]
+    pub(crate) fn sin(f: f64) -> f64 {
+        libm::sin(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn sin_cos(f: f64) -> (f64, f64) {
+        libm::sincos(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn tan(f: f64) -> f64 {
+        libm::tan(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn sqrt(f: f64) -> f64 {
+        libm::sqrt(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn copysign(f: f64, sign: f64) -> f64 {
+        libm::copysign(f, sign)
+    }
+
+    #[inline(always)]
+    pub(crate) fn signum(f: f64) -> f64 {
+        if f.is_nan() {
+            f64::NAN
+        } else {
+            copysign(1.0, f)
+        }
+    }
+
+    #[inline(always)]
+    pub(crate) fn round(f: f64) -> f64 {
+        libm::round(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn trunc(f: f64) -> f64 {
+        libm::trunc(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn ceil(f: f64) -> f64 {
+        libm::ceil(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn floor(f: f64) -> f64 {
+        libm::floor(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn exp(f: f64) -> f64 {
+        libm::exp(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn powf(f: f64, n: f64) -> f64 {
+        libm::pow(f, n)
+    }
+
+    #[inline(always)]
+    pub(crate) fn mul_add(a: f64, b: f64, c: f64) -> f64 {
+        libm::fma(a, b, c)
+    }
+
+    #[inline]
+    pub fn div_euclid(a: f64, b: f64) -> f64 {
+        // Based on https://doc.rust-lang.org/src/std/f64.rs.html#293
+        let q = libm::trunc(a / b);
+        if a % b < 0.0 {
+            return if b > 0.0 { q - 1.0 } else { q + 1.0 };
+        }
+        q
+    }
+
+    #[inline]
+    pub fn rem_euclid(a: f64, b: f64) -> f64 {
+        let r = a % b;
+        if r < 0.0 {
+            r + abs(b)
+        } else {
+            r
+        }
+    }
+}
+
+#[cfg(not(feature = "libm"))]
+mod std_math {
+    #[inline(always)]
+    pub(crate) fn abs(f: f64) -> f64 {
+        f64::abs(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn acos_approx(f: f64) -> f64 {
+        f64::acos(f64::clamp(f, -1.0, 1.0))
+    }
+
+    #[inline(always)]
+    pub(crate) fn asin(f: f64) -> f64 {
+        f64::asin(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn atan2(f: f64, other: f64) -> f64 {
+        f64::atan2(f, other)
+    }
+
+    #[inline(always)]
+    pub(crate) fn sin(f: f64) -> f64 {
+        f64::sin(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn sin_cos(f: f64) -> (f64, f64) {
+        f64::sin_cos(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn tan(f: f64) -> f64 {
+        f64::tan(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn sqrt(f: f64) -> f64 {
+        f64::sqrt(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn copysign(f: f64, sign: f64) -> f64 {
+        f64::copysign(f, sign)
+    }
+
+    #[inline(always)]
+    pub(crate) fn signum(f: f64) -> f64 {
+        f64::signum(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn round(f: f64) -> f64 {
+        f64::round(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn trunc(f: f64) -> f64 {
+        f64::trunc(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn ceil(f: f64) -> f64 {
+        f64::ceil(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn floor(f: f64) -> f64 {
+        f64::floor(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn exp(f: f64) -> f64 {
+        f64::exp(f)
+    }
+
+    #[inline(always)]
+    pub(crate) fn powf(f: f64, n: f64) -> f64 {
+        f64::powf(f, n)
+    }
+
+    #[inline(always)]
+    pub(crate) fn mul_add(a: f64, b: f64, c: f64) -> f64 {
+        f64::mul_add(a, b, c)
+    }
+
+    #[inline]
+    pub fn div_euclid(a: f64, b: f64) -> f64 {
+        f64::div_euclid(a, b)
+    }
+
+    #[inline]
+    pub fn rem_euclid(a: f64, b: f64) -> f64 {
+        f64::rem_euclid(a, b)
+    }
+}
+
+#[cfg(feature = "libm")]
+pub(crate) use libm_math::*;
+
+#[cfg(not(feature = "libm"))]
+pub(crate) use std_math::*;