feat: add simd uniform

Author: dancixx

Cargo.toml

@@ -48,6 +48,7 @@ ndarray-stats = "0.6.0"
 ndrustfft = "0.5.0"
 num-complex = { version = "0.4.6", features = ["rand"] }
 ordered-float = "5.0.0"
+# orx-parallel = "2.3.0"
 plotly = { version = "0.10.0", features = ["plotly_ndarray"] }
 polars = { version = "0.43.1", features = ["lazy"], optional = true }
 prettytable-rs = "0.10.0"

src/stats/distr.rs

@@ -15,6 +15,7 @@ pub mod normal_inverse_gauss;
 pub mod pareto;
 pub mod poisson;
 pub mod studentt;
+pub mod uniform;
 pub mod weibull;
 
 /// Fills a slice with random floating-point values in the range [0, 1).

src/stats/distr/uniform.rs

@@ -0,0 +1,58 @@
+use std::cell::UnsafeCell;
+
+use rand::Rng;
+use rand_distr::Distribution;
+use wide::f32x8;
+
+use super::fill_f32_zero_one;
+
+pub struct SimdUniform {
+  low: f32,
+  scale: f32, // = high - low
+  buffer: UnsafeCell<[f32; 8]>,
+  index: UnsafeCell<usize>,
+}
+
+impl SimdUniform {
+  pub fn new(low: f32, high: f32) -> Self {
+    assert!(high > low, "SimdUniform: high must be greater than low");
+    assert!(low.is_finite() && high.is_finite(), "bounds must be finite");
+    Self {
+      low,
+      scale: high - low,
+      buffer: UnsafeCell::new([0.0; 8]),
+      index: UnsafeCell::new(8), // kényszerít első refill-t
+    }
+  }
+
+  pub fn unit() -> Self {
+    Self::new(0.0, 1.0)
+  }
+
+  #[inline]
+  fn refill<R: Rng + ?Sized>(&self, rng: &mut R) {
+    let mut u = [0.0f32; 8];
+    fill_f32_zero_one(rng, &mut u);
+    let u = f32x8::from(u);
+
+    let vals = f32x8::splat(self.low) + u * f32x8::splat(self.scale);
+
+    unsafe {
+      *self.buffer.get() = vals.to_array();
+      *self.index.get() = 0;
+    }
+  }
+}
+
+impl Distribution<f32> for SimdUniform {
+  #[inline]
+  fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> f32 {
+    let index = unsafe { &mut *self.index.get() };
+    if *index >= 8 {
+      self.refill(rng);
+    }
+    let val = unsafe { (*self.buffer.get())[*index] };
+    *index += 1;
+    val
+  }
+}