Merge pull request #1081 from smr97/dev

Make sparse-times-sparse faster

nalgebra-sparse/src/ops/impl_std_ops.rs

@@ -3,7 +3,7 @@ use crate::csr::CsrMatrix;
 
 use crate::ops::serial::{
     spadd_csc_prealloc, spadd_csr_prealloc, spadd_pattern, spmm_csc_dense, spmm_csc_pattern,
-    spmm_csc_prealloc, spmm_csr_dense, spmm_csr_pattern, spmm_csr_prealloc,
+    spmm_csc_prealloc_unchecked, spmm_csr_dense, spmm_csr_pattern, spmm_csr_prealloc_unchecked,
 };
 use crate::ops::Op;
 use nalgebra::allocator::Allocator;
@@ -112,9 +112,9 @@ macro_rules! impl_spmm {
     }
 }
 
-impl_spmm!(CsrMatrix, spmm_csr_pattern, spmm_csr_prealloc);
+impl_spmm!(CsrMatrix, spmm_csr_pattern, spmm_csr_prealloc_unchecked);
 // Need to switch order of operations for CSC pattern
-impl_spmm!(CscMatrix, spmm_csc_pattern, spmm_csc_prealloc);
+impl_spmm!(CscMatrix, spmm_csc_pattern, spmm_csc_prealloc_unchecked);
 
 /// Implements Scalar * Matrix operations for *concrete* scalar types. The reason this is necessary
 /// is that we are not able to implement Mul<Matrix<T>> for all T generically due to orphan rules.

nalgebra-sparse/src/ops/serial/cs.rs

@@ -20,6 +20,51 @@ fn spmm_cs_unexpected_entry() -> OperationError {
 /// reversed (since transpose(AB) = transpose(B) * transpose(A) and CSC(A) = transpose(CSR(A)).
 ///
 /// We assume here that the matrices have already been verified to be dimensionally compatible.
+pub fn spmm_cs_prealloc_unchecked<T>(
+    beta: T,
+    c: &mut CsMatrix<T>,
+    alpha: T,
+    a: &CsMatrix<T>,
+    b: &CsMatrix<T>,
+) -> Result<(), OperationError>
+where
+    T: Scalar + ClosedAdd + ClosedMul + Zero + One,
+{
+    assert_eq!(c.pattern().major_dim(), a.pattern().major_dim());
+    assert_eq!(c.pattern().minor_dim(), b.pattern().minor_dim());
+    let some_val = Zero::zero();
+    let mut scratchpad_values: Vec<T> = vec![some_val; b.pattern().minor_dim()];
+    for i in 0..c.pattern().major_dim() {
+        let a_lane_i = a.get_lane(i).unwrap();
+
+        let mut c_lane_i = c.get_lane_mut(i).unwrap();
+
+        for (&k, a_ik) in a_lane_i.minor_indices().iter().zip(a_lane_i.values()) {
+            let b_lane_k = b.get_lane(k).unwrap();
+            let alpha_aik = alpha.clone() * a_ik.clone();
+            for (j, b_kj) in b_lane_k.minor_indices().iter().zip(b_lane_k.values()) {
+                // use a dense scatter vector to accumulate non-zeros quickly
+                unsafe {
+                    *scratchpad_values.get_unchecked_mut(*j) += alpha_aik.clone() * b_kj.clone();
+                }
+            }
+        }
+
+        //Get indices from C pattern and gather from the dense scratchpad_values
+        let (indices, values) = c_lane_i.indices_and_values_mut();
+        values
+            .iter_mut()
+            .zip(indices)
+            .for_each(|(output_ref, index)| unsafe {
+                *output_ref = beta.clone() * output_ref.clone()
+                    + scratchpad_values.get_unchecked(*index).clone();
+                *scratchpad_values.get_unchecked_mut(*index) = Zero::zero();
+            });
+    }
+
+    Ok(())
+}
+
 pub fn spmm_cs_prealloc<T>(
     beta: T,
     c: &mut CsMatrix<T>,

nalgebra-sparse/src/ops/serial/csc.rs

@@ -1,5 +1,7 @@
 use crate::csc::CscMatrix;
-use crate::ops::serial::cs::{spadd_cs_prealloc, spmm_cs_dense, spmm_cs_prealloc};
+use crate::ops::serial::cs::{
+    spadd_cs_prealloc, spmm_cs_dense, spmm_cs_prealloc, spmm_cs_prealloc_unchecked,
+};
 use crate::ops::serial::{OperationError, OperationErrorKind};
 use crate::ops::Op;
 use nalgebra::{ClosedAdd, ClosedMul, DMatrixSlice, DMatrixSliceMut, RealField, Scalar};
@@ -83,14 +85,65 @@ where
 {
     assert_compatible_spmm_dims!(c, a, b);
 
-    use Op::{NoOp, Transpose};
+    use Op::NoOp;
 
     match (&a, &b) {
         (NoOp(ref a), NoOp(ref b)) => {
             // Note: We have to reverse the order for CSC matrices
             spmm_cs_prealloc(beta, &mut c.cs, alpha, &b.cs, &a.cs)
         }
-        _ => {
+        _ => spmm_csc_transposed(beta, c, alpha, a, b, spmm_csc_prealloc),
+    }
+}
+
+/// Faster sparse-sparse matrix multiplication, `C <- beta * C + alpha * op(A) * op(B)`.
+/// This will not return an error even if the patterns don't match.
+/// Should be used for situations where pattern creation immediately preceeds multiplication.
+///
+/// Panics if the dimensions of the matrices involved are not compatible with the expression.
+pub fn spmm_csc_prealloc_unchecked<T>(
+    beta: T,
+    c: &mut CscMatrix<T>,
+    alpha: T,
+    a: Op<&CscMatrix<T>>,
+    b: Op<&CscMatrix<T>>,
+) -> Result<(), OperationError>
+where
+    T: Scalar + ClosedAdd + ClosedMul + Zero + One,
+{
+    assert_compatible_spmm_dims!(c, a, b);
+
+    use Op::NoOp;
+
+    match (&a, &b) {
+        (NoOp(ref a), NoOp(ref b)) => {
+            // Note: We have to reverse the order for CSC matrices
+            spmm_cs_prealloc_unchecked(beta, &mut c.cs, alpha, &b.cs, &a.cs)
+        }
+        _ => spmm_csc_transposed(beta, c, alpha, a, b, spmm_csc_prealloc_unchecked),
+    }
+}
+
+fn spmm_csc_transposed<T, F>(
+    beta: T,
+    c: &mut CscMatrix<T>,
+    alpha: T,
+    a: Op<&CscMatrix<T>>,
+    b: Op<&CscMatrix<T>>,
+    spmm_kernel: F,
+) -> Result<(), OperationError>
+where
+    T: Scalar + ClosedAdd + ClosedMul + Zero + One,
+    F: Fn(
+        T,
+        &mut CscMatrix<T>,
+        T,
+        Op<&CscMatrix<T>>,
+        Op<&CscMatrix<T>>,
+    ) -> Result<(), OperationError>,
+{
+    use Op::{NoOp, Transpose};
+
     // Currently we handle transposition by explicitly precomputing transposed matrices
     // and calling the operation again without transposition
     let a_ref: &CscMatrix<T> = a.inner_ref();
@@ -101,15 +154,10 @@ where
             (NoOp(_), NoOp(_)) => unreachable!(),
             (Transpose(ref a), NoOp(_)) => (Owned(a.transpose()), Borrowed(b_ref)),
             (NoOp(_), Transpose(ref b)) => (Borrowed(a_ref), Owned(b.transpose())),
-                    (Transpose(ref a), Transpose(ref b)) => {
+            (Transpose(ref a), Transpose(ref b)) => (Owned(a.transpose()), Owned(b.transpose())),
-                        (Owned(a.transpose()), Owned(b.transpose()))
-                    }
         }
     };
-
+    spmm_kernel(beta, c, alpha, NoOp(a.as_ref()), NoOp(b.as_ref()))
-            spmm_csc_prealloc(beta, c, alpha, NoOp(a.as_ref()), NoOp(b.as_ref()))
-        }
-    }
 }
 
 /// Solve the lower triangular system `op(L) X = B`.

nalgebra-sparse/src/ops/serial/csr.rs

@@ -1,5 +1,7 @@
 use crate::csr::CsrMatrix;
-use crate::ops::serial::cs::{spadd_cs_prealloc, spmm_cs_dense, spmm_cs_prealloc};
+use crate::ops::serial::cs::{
+    spadd_cs_prealloc, spmm_cs_dense, spmm_cs_prealloc, spmm_cs_prealloc_unchecked,
+};
 use crate::ops::serial::OperationError;
 use crate::ops::Op;
 use nalgebra::{ClosedAdd, ClosedMul, DMatrixSlice, DMatrixSliceMut, Scalar};
@@ -77,15 +79,63 @@ where
 {
     assert_compatible_spmm_dims!(c, a, b);
 
-    use Op::{NoOp, Transpose};
+    use Op::NoOp;
 
     match (&a, &b) {
         (NoOp(ref a), NoOp(ref b)) => spmm_cs_prealloc(beta, &mut c.cs, alpha, &a.cs, &b.cs),
-        _ => {
+        _ => spmm_csr_transposed(beta, c, alpha, a, b, spmm_csr_prealloc),
+    }
+}
+
+/// Faster sparse-sparse matrix multiplication, `C <- beta * C + alpha * op(A) * op(B)`.
+/// This will not return an error even if the patterns don't match.
+/// Should be used for situations where pattern creation immediately preceeds multiplication.
+///
+/// Panics if the dimensions of the matrices involved are not compatible with the expression.
+pub fn spmm_csr_prealloc_unchecked<T>(
+    beta: T,
+    c: &mut CsrMatrix<T>,
+    alpha: T,
+    a: Op<&CsrMatrix<T>>,
+    b: Op<&CsrMatrix<T>>,
+) -> Result<(), OperationError>
+where
+    T: Scalar + ClosedAdd + ClosedMul + Zero + One,
+{
+    assert_compatible_spmm_dims!(c, a, b);
+
+    use Op::NoOp;
+
+    match (&a, &b) {
+        (NoOp(ref a), NoOp(ref b)) => {
+            spmm_cs_prealloc_unchecked(beta, &mut c.cs, alpha, &a.cs, &b.cs)
+        }
+        _ => spmm_csr_transposed(beta, c, alpha, a, b, spmm_csr_prealloc_unchecked),
+    }
+}
+
+fn spmm_csr_transposed<T, F>(
+    beta: T,
+    c: &mut CsrMatrix<T>,
+    alpha: T,
+    a: Op<&CsrMatrix<T>>,
+    b: Op<&CsrMatrix<T>>,
+    spmm_kernel: F,
+) -> Result<(), OperationError>
+where
+    T: Scalar + ClosedAdd + ClosedMul + Zero + One,
+    F: Fn(
+        T,
+        &mut CsrMatrix<T>,
+        T,
+        Op<&CsrMatrix<T>>,
+        Op<&CsrMatrix<T>>,
+    ) -> Result<(), OperationError>,
+{
+    use Op::{NoOp, Transpose};
+
     // Currently we handle transposition by explicitly precomputing transposed matrices
     // and calling the operation again without transposition
-            // TODO: At least use workspaces to allow control of allocations. Maybe
-            // consider implementing certain patterns (like A^T * B) explicitly
     let a_ref: &CsrMatrix<T> = a.inner_ref();
     let b_ref: &CsrMatrix<T> = b.inner_ref();
     let (a, b) = {
@@ -94,13 +144,8 @@ where
             (NoOp(_), NoOp(_)) => unreachable!(),
             (Transpose(ref a), NoOp(_)) => (Owned(a.transpose()), Borrowed(b_ref)),
             (NoOp(_), Transpose(ref b)) => (Borrowed(a_ref), Owned(b.transpose())),
-                    (Transpose(ref a), Transpose(ref b)) => {
+            (Transpose(ref a), Transpose(ref b)) => (Owned(a.transpose()), Owned(b.transpose())),
-                        (Owned(a.transpose()), Owned(b.transpose()))
-                    }
         }
     };
-
+    spmm_kernel(beta, c, alpha, NoOp(a.as_ref()), NoOp(b.as_ref()))
-            spmm_csr_prealloc(beta, c, alpha, NoOp(a.as_ref()), NoOp(b.as_ref()))
-        }
-    }
 }

nalgebra-sparse/tests/unit_tests/ops.rs

@@ -6,7 +6,8 @@ use nalgebra_sparse::csc::CscMatrix;
 use nalgebra_sparse::csr::CsrMatrix;
 use nalgebra_sparse::ops::serial::{
     spadd_csc_prealloc, spadd_csr_prealloc, spadd_pattern, spmm_csc_dense, spmm_csc_prealloc,
-    spmm_csr_dense, spmm_csr_pattern, spmm_csr_prealloc, spsolve_csc_lower_triangular,
+    spmm_csc_prealloc_unchecked, spmm_csr_dense, spmm_csr_pattern, spmm_csr_prealloc,
+    spmm_csr_prealloc_unchecked, spsolve_csc_lower_triangular,
 };
 use nalgebra_sparse::ops::Op;
 use nalgebra_sparse::pattern::SparsityPattern;
@@ -543,6 +544,29 @@ proptest! {
         prop_assert_eq!(&c_pattern, c_csr.pattern());
     }
 
+    #[test]
+    fn spmm_csr_prealloc_unchecked_test(SpmmCsrArgs { c, beta, alpha, a, b }
+        in spmm_csr_prealloc_args_strategy()
+    ) {
+        // Test that we get the expected result by comparing to an equivalent dense operation
+        // (here we give in the C matrix, so the sparsity pattern is essentially fixed)
+        let mut c_sparse = c.clone();
+        spmm_csr_prealloc_unchecked(beta, &mut c_sparse, alpha, a.as_ref(), b.as_ref()).unwrap();
+
+        let mut c_dense = DMatrix::from(&c);
+        let op_a_dense = match a {
+            Op::NoOp(ref a) => DMatrix::from(a),
+            Op::Transpose(ref a) => DMatrix::from(a).transpose(),
+        };
+        let op_b_dense = match b {
+            Op::NoOp(ref b) => DMatrix::from(b),
+            Op::Transpose(ref b) => DMatrix::from(b).transpose(),
+        };
+        c_dense = beta * c_dense + alpha * &op_a_dense * op_b_dense;
+
+        prop_assert_eq!(&DMatrix::from(&c_sparse), &c_dense);
+    }
+
     #[test]
     fn spmm_csr_prealloc_test(SpmmCsrArgs { c, beta, alpha, a, b }
         in spmm_csr_prealloc_args_strategy()
@@ -705,6 +729,29 @@ proptest! {
         prop_assert_eq!(&DMatrix::from(&c_sparse), &c_dense);
     }
 
+    #[test]
+    fn spmm_csc_prealloc_unchecked_test(SpmmCscArgs { c, beta, alpha, a, b }
+        in spmm_csc_prealloc_args_strategy()
+    ) {
+        // Test that we get the expected result by comparing to an equivalent dense operation
+        // (here we give in the C matrix, so the sparsity pattern is essentially fixed)
+        let mut c_sparse = c.clone();
+        spmm_csc_prealloc_unchecked(beta, &mut c_sparse, alpha, a.as_ref(), b.as_ref()).unwrap();
+
+        let mut c_dense = DMatrix::from(&c);
+        let op_a_dense = match a {
+            Op::NoOp(ref a) => DMatrix::from(a),
+            Op::Transpose(ref a) => DMatrix::from(a).transpose(),
+        };
+        let op_b_dense = match b {
+            Op::NoOp(ref b) => DMatrix::from(b),
+            Op::Transpose(ref b) => DMatrix::from(b).transpose(),
+        };
+        c_dense = beta * c_dense + alpha * &op_a_dense * op_b_dense;
+
+        prop_assert_eq!(&DMatrix::from(&c_sparse), &c_dense);
+    }
+
     #[test]
     fn spmm_csc_prealloc_panics_on_dim_mismatch(
         (alpha, beta, c, a, b)