Date: 2026-03-01T05:24:52+00:00

Actual source code: blas_cyclic.h

      1: #pragma once

      3: #include <petscvec.h>
      4: #include <petscmat.h>

      6: /*
      7:   Dense linear algebra for vectors and matrices that are _cyclically indexed_.

      9:   For a Vec, this means that it has a fixed size m, but it is for storing data from a sliding window of _history
     10:   indices_.  Rather than rearranging the vector as the window slides, we insert the value v_i for history index i in the
     11:   location v[i % m].

     13:   This has the following effects on linear algebra:

     15:   - Sometimes we are dealing with a window that is smaller than m, e.g. doing y[i % m] <- alpha x[i % m], but not all
     16:     values in [0, m) are active.  We want the linear algebra routines to leave the inactive indices
     17:     untouched.

     19:   - We sometimes need operations that work on the upper triangle of a matrix _with respect to history indices_, i.e.
     20:     operating on the values

     22:       A[i % m, j % m], i <= j

     24:   The functions defined here dispatch linear algebra operations, described by the range of history indices [oldest, next) that
     25:   they act on, to the appropriate backend blas-like (BLAS, cuBLAS, hipBLAS) libraries.
     26:  */

     28: PETSC_INTERN PetscLogEvent AXPBY_Cyc;
     29: PETSC_INTERN PetscLogEvent DMV_Cyc;
     30: PETSC_INTERN PetscLogEvent DSV_Cyc;
     31: PETSC_INTERN PetscLogEvent TRSV_Cyc;
     32: PETSC_INTERN PetscLogEvent GEMV_Cyc;
     33: PETSC_INTERN PetscLogEvent HEMV_Cyc;

     35: /* These methods are intended for small vectors / dense matrices that are either sequential or have all of their entries on the first rank */
     36: // y <- alpha * x + beta * y
     37: PETSC_INTERN PetscErrorCode VecAXPBYCyclic(PetscInt, PetscInt, PetscScalar, Vec, PetscScalar, Vec);
     38: // y <- alpha * (A .* x) + beta * y
     39: PETSC_INTERN PetscErrorCode VecDMVCyclic(PetscBool, PetscInt, PetscInt, PetscScalar, Vec, Vec, PetscScalar, Vec);
     40: // y <- (x ./ A)
     41: PETSC_INTERN PetscErrorCode VecDSVCyclic(PetscBool, PetscInt, PetscInt, Vec, Vec, Vec);
     42: // y <- (triu(A) \ x)
     43: PETSC_INTERN PetscErrorCode MatSeqDenseTRSVCyclic(PetscBool, PetscInt, PetscInt, Mat, Vec, Vec);
     44: // y <- alpha * A * x + beta * y
     45: PETSC_INTERN PetscErrorCode MatSeqDenseGEMVCyclic(PetscBool, PetscInt, PetscInt, PetscScalar, Mat, Vec, PetscScalar, Vec);
     46: // y <- alpha * symm(A) * x + beta * y   [sym(A) = triu(A) + striu(A)^H]
     47: PETSC_INTERN PetscErrorCode MatSeqDenseHEMVCyclic(PetscInt, PetscInt, PetscScalar, Mat, Vec, PetscScalar, Vec);
     48: // A[i,:] <- alpha * x + beta * A[i,:]
     49: PETSC_INTERN PetscErrorCode MatSeqDenseRowAXPBYCyclic(PetscInt, PetscInt, PetscScalar, Vec, PetscScalar, Mat, PetscInt);

     51: /* These methods are intended for for tall matrices of column vectors where we would like to compute products with ranges of the
     52:    vectors.  The column layout should place all columns on the first rank.  Because they may involve MPI communication,
     53:    they rely on implementations from the dense matrix backends */
     54: PETSC_INTERN PetscErrorCode MatMultColumnRange(Mat, Vec, Vec, PetscInt, PetscInt);
     55: PETSC_INTERN PetscErrorCode MatMultAddColumnRange(Mat, Vec, Vec, Vec, PetscInt, PetscInt);
     56: PETSC_INTERN PetscErrorCode MatMultHermitianTransposeColumnRange(Mat, Vec, Vec, PetscInt, PetscInt);
     57: PETSC_INTERN PetscErrorCode MatMultHermitianTransposeAddColumnRange(Mat, Vec, Vec, Vec, PetscInt, PetscInt);