Removed MathsCore usage from OriginSampler

Author: juntyr

necsim/impls/no-std/src/cogs/active_lineage_sampler/alias/sampler/tests.rs

@@ -3,7 +3,7 @@ use core::num::{NonZeroU128, NonZeroU64, NonZeroUsize};
 
 use necsim_core::cogs::{
     distribution::{IndexU128, IndexU64, IndexUsize, Length, UniformClosedOpenUnit},
-    DistributionSampler, Rng, RngCore,
+    Backup, DistributionSampler, Rng, RngCore,
 };
 use necsim_core_bond::{ClosedOpenUnitF64, NonNegativeF64, PositiveF64};
 use necsim_core_maths::MathsCore;
@@ -189,6 +189,13 @@ impl RngCore for DummyRng {
     }
 }
 
+#[contract_trait]
+impl Backup for DummyRng {
+    unsafe fn backup_unchecked(&self) -> Self {
+        Self(self.0.clone())
+    }
+}
+
 impl Rng<IntrinsicsMathsCore> for DummyRng {
     type Generator = Self;
     type Sampler = DummyDistributionSamplers;

necsim/impls/no-std/src/cogs/origin_sampler/almost_infinite.rs

@@ -15,9 +15,11 @@ use super::{TrustedOriginSampler, UntrustedOriginSampler};
 
 const HABITAT_CENTRE: u32 = u32::MAX / 2;
 
+// Note: The MathsCore should not be utilised in the origin sampler
+//       to improve compatibility
 #[allow(clippy::module_name_repetitions)]
 pub struct AlmostInfiniteOriginSampler<'h, M: MathsCore, I: Iterator<Item = u64>> {
-    pre_sampler: OriginPreSampler<M, I>,
+    pre_sampler: OriginPreSampler<I>,
     last_index: u64,
     location_iterator: LocationIterator,
     radius_squared: u64,
@@ -43,7 +45,7 @@ impl<'h, M: MathsCore, I: Iterator<Item = u64>> fmt::Debug
 impl<'h, M: MathsCore, I: Iterator<Item = u64>> AlmostInfiniteOriginSampler<'h, M, I> {
     #[must_use]
     pub fn new(
-        pre_sampler: OriginPreSampler<M, I>,
+        pre_sampler: OriginPreSampler<I>,
         habitat: &'h AlmostInfiniteHabitat<M>,
         radius: u16,
     ) -> Self {
@@ -60,12 +62,11 @@ impl<'h, M: MathsCore, I: Iterator<Item = u64>> AlmostInfiniteOriginSampler<'h,
         );
 
         #[allow(clippy::cast_possible_truncation, clippy::cast_sign_loss)]
-        let upper_bound_size_hint = M::ceil(
-            f64::from(radius)
-                * f64::from(radius)
-                * core::f64::consts::PI
-                * pre_sampler.get_sample_proportion().get(),
-        ) as u64;
+        let upper_bound_size_hint = (f64::from(radius)
+            * f64::from(radius)
+            * core::f64::consts::PI
+            * pre_sampler.get_sample_proportion().get()
+            + 1.0_f64) as u64;
 
         Self {
             pre_sampler,
@@ -89,7 +90,7 @@ impl<'h, M: MathsCore, I: Iterator<Item = u64>> UntrustedOriginSampler<'h, M>
         self.habitat
     }
 
-    fn into_pre_sampler(self) -> OriginPreSampler<M, Self::PreSampler> {
+    fn into_pre_sampler(self) -> OriginPreSampler<Self::PreSampler> {
         self.pre_sampler
     }
 

necsim/impls/no-std/src/cogs/origin_sampler/decomposition.rs

@@ -12,6 +12,8 @@ use crate::{
     decomposition::Decomposition,
 };
 
+// Note: The MathsCore should not be utilised in the origin sampler
+//       (only in the decomposition) to improve compatibility
 #[allow(clippy::module_name_repetitions)]
 #[derive(Debug)]
 pub struct DecompositionOriginSampler<
@@ -49,7 +51,7 @@ impl<'d, M: MathsCore, O: UntrustedOriginSampler<'d, M>, D: Decomposition<M, O::
         self.origin_sampler.habitat()
     }
 
-    fn into_pre_sampler(self) -> OriginPreSampler<M, Self::PreSampler> {
+    fn into_pre_sampler(self) -> OriginPreSampler<Self::PreSampler> {
         self.origin_sampler.into_pre_sampler()
     }
 

necsim/impls/no-std/src/cogs/origin_sampler/in_memory.rs

@@ -16,9 +16,11 @@ use crate::cogs::{
 
 use super::{TrustedOriginSampler, UntrustedOriginSampler};
 
+// Note: The MathsCore should not be utilised in the origin sampler
+//       to improve compatibility
 #[allow(clippy::module_name_repetitions)]
 pub struct InMemoryOriginSampler<'h, M: MathsCore, I: Iterator<Item = u64>> {
-    pre_sampler: OriginPreSampler<M, I>,
+    pre_sampler: OriginPreSampler<I>,
     last_index: u64,
     location_iterator: Peekable<LocationIterator>,
     next_location_index: u32,
@@ -39,7 +41,7 @@ impl<'h, M: MathsCore, I: Iterator<Item = u64>> fmt::Debug for InMemoryOriginSam
 
 impl<'h, M: MathsCore, I: Iterator<Item = u64>> InMemoryOriginSampler<'h, M, I> {
     #[must_use]
-    pub fn new(pre_sampler: OriginPreSampler<M, I>, habitat: &'h InMemoryHabitat<M>) -> Self {
+    pub fn new(pre_sampler: OriginPreSampler<I>, habitat: &'h InMemoryHabitat<M>) -> Self {
         Self {
             pre_sampler,
             last_index: 0_u64,
@@ -61,7 +63,7 @@ impl<'h, M: MathsCore, I: Iterator<Item = u64>> UntrustedOriginSampler<'h, M>
         self.habitat
     }
 
-    fn into_pre_sampler(self) -> OriginPreSampler<M, Self::PreSampler> {
+    fn into_pre_sampler(self) -> OriginPreSampler<Self::PreSampler> {
         self.pre_sampler
     }
 

necsim/impls/no-std/src/cogs/origin_sampler/mod.rs

@@ -19,6 +19,9 @@ use pre_sampler::OriginPreSampler;
 #[allow(clippy::module_name_repetitions)]
 /// `Lineage`s produced by the sampler's iterator must have
 /// * unique global references
+///
+/// Note: The MathsCore should not be utilised in the origin sampler
+///       to improve compatibility
 pub trait UntrustedOriginSampler<'h, M: MathsCore>:
     Sized + core::fmt::Debug + core::iter::Iterator<Item = Lineage>
 {
@@ -27,7 +30,7 @@ pub trait UntrustedOriginSampler<'h, M: MathsCore>:
 
     fn habitat(&self) -> &'h Self::Habitat;
 
-    fn into_pre_sampler(self) -> OriginPreSampler<M, Self::PreSampler>;
+    fn into_pre_sampler(self) -> OriginPreSampler<Self::PreSampler>;
 
     fn full_upper_bound_size_hint(&self) -> u64;
 }

necsim/impls/no-std/src/cogs/origin_sampler/non_spatial.rs

@@ -16,9 +16,11 @@ use crate::cogs::{
 
 use super::{TrustedOriginSampler, UntrustedOriginSampler};
 
+// Note: The MathsCore should not be utilised in the origin sampler
+//       to improve compatibility
 #[allow(clippy::module_name_repetitions)]
 pub struct NonSpatialOriginSampler<'h, M: MathsCore, I: Iterator<Item = u64>> {
-    pre_sampler: OriginPreSampler<M, I>,
+    pre_sampler: OriginPreSampler<I>,
     last_index: u64,
     location_iterator: Peekable<LocationIterator>,
     next_location_index: u32,
@@ -39,7 +41,7 @@ impl<'h, M: MathsCore, I: Iterator<Item = u64>> fmt::Debug for NonSpatialOriginS
 
 impl<'h, M: MathsCore, I: Iterator<Item = u64>> NonSpatialOriginSampler<'h, M, I> {
     #[must_use]
-    pub fn new(pre_sampler: OriginPreSampler<M, I>, habitat: &'h NonSpatialHabitat<M>) -> Self {
+    pub fn new(pre_sampler: OriginPreSampler<I>, habitat: &'h NonSpatialHabitat<M>) -> Self {
         Self {
             pre_sampler,
             last_index: 0_u64,
@@ -61,7 +63,7 @@ impl<'h, M: MathsCore, I: Iterator<Item = u64>> UntrustedOriginSampler<'h, M>
         self.habitat
     }
 
-    fn into_pre_sampler(self) -> OriginPreSampler<M, Self::PreSampler> {
+    fn into_pre_sampler(self) -> OriginPreSampler<Self::PreSampler> {
         self.pre_sampler
     }
 

necsim/impls/no-std/src/cogs/origin_sampler/pre_sampler.rs

@@ -1,80 +1,75 @@
 use core::{
     fmt,
     iter::Empty,
-    marker::PhantomData,
     ops::{Deref, DerefMut, RangeFrom},
 };
 
-use necsim_core::cogs::MathsCore;
 use necsim_core_bond::ClosedUnitF64;
 use necsim_partitioning_core::partition::Partition;
 
 const INV_PHI: f64 = 6.180_339_887_498_949e-1_f64;
 
 #[allow(clippy::module_name_repetitions)]
-pub struct OriginPreSampler<M: MathsCore, I: Iterator<Item = u64>> {
+pub struct OriginPreSampler<I: Iterator<Item = u64>> {
     inner: I,
     proportion: ClosedUnitF64,
-    _marker: PhantomData<M>,
 }
 
-impl<M: MathsCore, I: Iterator<Item = u64>> OriginPreSampler<M, I> {
+impl<I: Iterator<Item = u64>> OriginPreSampler<I> {
     pub fn get_sample_proportion(&self) -> ClosedUnitF64 {
         self.proportion
     }
 }
 
-impl<M: MathsCore, I: Iterator<Item = u64>> Deref for OriginPreSampler<M, I> {
+impl<I: Iterator<Item = u64>> Deref for OriginPreSampler<I> {
     type Target = I;
 
     fn deref(&self) -> &Self::Target {
         &self.inner
     }
 }
 
-impl<M: MathsCore, I: Iterator<Item = u64>> DerefMut for OriginPreSampler<M, I> {
+impl<I: Iterator<Item = u64>> DerefMut for OriginPreSampler<I> {
     fn deref_mut(&mut self) -> &mut Self::Target {
         &mut self.inner
     }
 }
 
-impl<M: MathsCore, I: Iterator<Item = u64>> fmt::Debug for OriginPreSampler<M, I> {
+impl<I: Iterator<Item = u64>> fmt::Debug for OriginPreSampler<I> {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         fmt.debug_struct(stringify!(OriginPreSampler))
             .field("proportion", &self.proportion)
             .finish()
     }
 }
 
-impl<M: MathsCore> OriginPreSampler<M, RangeFrom<u64>> {
+impl OriginPreSampler<RangeFrom<u64>> {
     #[must_use]
     pub fn all() -> Self {
         Self {
             inner: 0..,
             proportion: ClosedUnitF64::one(),
-            _marker: PhantomData::<M>,
         }
     }
 }
 
-impl<M: MathsCore> OriginPreSampler<M, Empty<u64>> {
+impl OriginPreSampler<Empty<u64>> {
     #[must_use]
     pub fn none() -> Self {
         Self {
             inner: core::iter::empty(),
             proportion: ClosedUnitF64::zero(),
-            _marker: PhantomData::<M>,
         }
     }
 }
 
-impl<M: MathsCore, I: Iterator<Item = u64>> OriginPreSampler<M, I> {
+impl<I: Iterator<Item = u64>> OriginPreSampler<I> {
     #[must_use]
     pub fn percentage(
         mut self,
         percentage: ClosedUnitF64,
-    ) -> OriginPreSampler<M, impl Iterator<Item = u64>> {
-        let inv_geometric_sample_rate = M::ln(1.0_f64 - percentage.get()).recip();
+    ) -> OriginPreSampler<impl Iterator<Item = u64>> {
+        let inv_geometric_sample_rate = libm::log(1.0_f64 - percentage.get()).recip();
 
         OriginPreSampler {
             proportion: self.proportion * percentage,
@@ -89,27 +84,29 @@ impl<M: MathsCore, I: Iterator<Item = u64>> OriginPreSampler<M, I> {
 
                 // q = (q + INV_PHI) % 1  where q >= 0
                 *quasi_random += INV_PHI;
-                *quasi_random -= M::floor(*quasi_random);
+                *quasi_random -= if *quasi_random >= 1.0_f64 {
+                    1.0_f64
+                } else {
+                    0.0_f64
+                };
 
                 #[allow(clippy::cast_sign_loss, clippy::cast_possible_truncation)]
-                let skip = M::floor(M::ln(*quasi_random) * inv_geometric_sample_rate) as usize;
+                let skip = (libm::log(*quasi_random) * inv_geometric_sample_rate) as usize;
 
                 self.nth(skip)
             }),
-            _marker: PhantomData::<M>,
         }
     }
 
     pub fn partition(
         mut self,
         partition: Partition,
-    ) -> OriginPreSampler<M, impl Iterator<Item = u64>> {
+    ) -> OriginPreSampler<impl Iterator<Item = u64>> {
         let _ = self.advance_by(partition.rank() as usize);
 
         OriginPreSampler {
             proportion: self.proportion / partition.size(),
             inner: self.inner.step_by(partition.size().get() as usize),
-            _marker: PhantomData::<M>,
         }
     }
 }

necsim/impls/no-std/src/cogs/origin_sampler/resuming.rs

@@ -1,4 +1,4 @@
-use core::{fmt, iter::ExactSizeIterator};
+use core::{fmt, iter::ExactSizeIterator, marker::PhantomData};
 
 use necsim_core::{
     cogs::{Habitat, MathsCore},
@@ -9,6 +9,8 @@ use crate::cogs::origin_sampler::{pre_sampler::OriginPreSampler, TrustedOriginSa
 
 use super::UntrustedOriginSampler;
 
+// Note: The MathsCore should not be utilised in the origin sampler
+//       to improve compatibility
 #[allow(clippy::module_name_repetitions)]
 pub struct ResumingOriginSampler<
     'h,
@@ -18,9 +20,10 @@ pub struct ResumingOriginSampler<
     I: Iterator<Item = u64>,
 > {
     lineage_iterator: L,
-    pre_sampler: OriginPreSampler<M, I>,
+    pre_sampler: OriginPreSampler<I>,
     last_index: u64,
     habitat: &'h H,
+    marker: PhantomData<M>,
 }
 
 impl<
@@ -49,12 +52,13 @@ impl<
     > ResumingOriginSampler<'h, M, H, L, I>
 {
     #[must_use]
-    pub fn new(habitat: &'h H, pre_sampler: OriginPreSampler<M, I>, lineage_iterator: L) -> Self {
+    pub fn new(habitat: &'h H, pre_sampler: OriginPreSampler<I>, lineage_iterator: L) -> Self {
         Self {
             lineage_iterator,
             pre_sampler,
             last_index: 0_u64,
             habitat,
+            marker: PhantomData::<M>,
         }
     }
 }
@@ -75,7 +79,7 @@ impl<
         self.habitat
     }
 
-    fn into_pre_sampler(self) -> OriginPreSampler<M, Self::PreSampler> {
+    fn into_pre_sampler(self) -> OriginPreSampler<Self::PreSampler> {
         self.pre_sampler
     }
 
@@ -85,9 +89,9 @@ impl<
             clippy::cast_possible_truncation,
             clippy::cast_sign_loss
         )]
-        let upper_bound_size_hint = M::ceil(
-            (self.lineage_iterator.len() as f64) * self.pre_sampler.get_sample_proportion().get(),
-        ) as u64;
+        let upper_bound_size_hint = ((self.lineage_iterator.len() as f64)
+            * self.pre_sampler.get_sample_proportion().get())
+            as u64;
 
         upper_bound_size_hint
     }

necsim/impls/no-std/src/cogs/origin_sampler/spatially_implicit.rs

@@ -9,6 +9,8 @@ use crate::cogs::{
 
 use super::{TrustedOriginSampler, UntrustedOriginSampler};
 
+// Note: The MathsCore should not be utilised in the origin sampler
+//       to improve compatibility
 #[allow(clippy::module_name_repetitions)]
 pub struct SpatiallyImplicitOriginSampler<'h, M: MathsCore, I: Iterator<Item = u64>> {
     local_iterator: NonSpatialOriginSampler<'h, M, I>,
@@ -28,10 +30,7 @@ impl<'h, M: MathsCore, I: Iterator<Item = u64>> fmt::Debug
 
 impl<'h, M: MathsCore, I: Iterator<Item = u64>> SpatiallyImplicitOriginSampler<'h, M, I> {
     #[must_use]
-    pub fn new(
-        pre_sampler: OriginPreSampler<M, I>,
-        habitat: &'h SpatiallyImplicitHabitat<M>,
-    ) -> Self {
+    pub fn new(pre_sampler: OriginPreSampler<I>, habitat: &'h SpatiallyImplicitHabitat<M>) -> Self {
         Self {
             local_iterator: NonSpatialOriginSampler::new(pre_sampler, habitat.local()),
             habitat,
@@ -50,7 +49,7 @@ impl<'h, M: MathsCore, I: Iterator<Item = u64>> UntrustedOriginSampler<'h, M>
         self.habitat
     }
 
-    fn into_pre_sampler(self) -> OriginPreSampler<M, Self::PreSampler> {
+    fn into_pre_sampler(self) -> OriginPreSampler<Self::PreSampler> {
         self.local_iterator.into_pre_sampler()
     }