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Replace blas/f2c with clean C++ implementations

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libeigen/eigen!2402

Co-authored-by: Rasmus Munk Larsen <rmlarsen@gmail.com>
This commit is contained in:
Rasmus Munk Larsen
2026-04-05 16:04:41 -07:00
parent fe6ada10be
commit 4ad90a60f1
29 changed files with 1170 additions and 6371 deletions
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179
blas/level2_real_impl.h
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@@ -158,32 +158,187 @@ EIGEN_BLAS_FUNC(syr2)
// func[code](*n, a, *inca, b, *incb, c, *ldc, alpha);
}
/** DSBMV performs the matrix-vector operation
/** SBMV performs the matrix-vector operation
*
* y := alpha*A*x + beta*y,
*
* where alpha and beta are scalars, x and y are n element vectors and
* A is an n by n symmetric band matrix, with k super-diagonals.
*
* Band storage: upper triangle stores A[i,j] at a[(k+i-j) + j*lda],
* lower triangle stores A[i,j] at a[(i-j) + j*lda].
*/
// EIGEN_BLAS_FUNC(sbmv)( char *uplo, int *n, int *k, RealScalar *alpha, RealScalar *a, int *lda,
// RealScalar *x, int *incx, RealScalar *beta, RealScalar *y, int *incy)
// {
// return 1;
// }
EIGEN_BLAS_FUNC(sbmv)
(char *uplo, int *n, int *k, RealScalar *palpha, RealScalar *pa, int *lda, RealScalar *px, int *incx, RealScalar *pbeta,
RealScalar *py, int *incy) {
const Scalar alpha = *reinterpret_cast<const Scalar *>(palpha);
const Scalar beta = *reinterpret_cast<const Scalar *>(pbeta);
const Scalar *a = reinterpret_cast<const Scalar *>(pa);
const Scalar *x = reinterpret_cast<const Scalar *>(px);
Scalar *y = reinterpret_cast<Scalar *>(py);
/** DSPMV performs the matrix-vector operation
int info = 0;
if (UPLO(*uplo) == INVALID)
info = 1;
else if (*n < 0)
info = 2;
else if (*k < 0)
info = 3;
else if (*lda < *k + 1)
info = 6;
else if (*incx == 0)
info = 8;
else if (*incy == 0)
info = 11;
if (info) return xerbla_(SCALAR_SUFFIX_UP "SBMV ", &info);
if (*n == 0 || (alpha == Scalar(0) && beta == Scalar(1))) return;
int kx = *incx > 0 ? 0 : (1 - *n) * *incx;
int ky = *incy > 0 ? 0 : (1 - *n) * *incy;
// First form y := beta*y.
if (beta != Scalar(1)) {
int iy = ky;
for (int i = 0; i < *n; ++i) {
y[iy] = (beta == Scalar(0)) ? Scalar(0) : beta * y[iy];
iy += *incy;
}
}
if (alpha == Scalar(0)) return;
if (UPLO(*uplo) == UP) {
// Upper triangle: A[i,j] at a[(k+i-j) + j*lda], diagonal at row k.
int jx = kx, jy = ky;
for (int j = 0; j < *n; ++j) {
Scalar temp1 = alpha * x[jx];
Scalar temp2 = Scalar(0);
int ix = kx, iy = ky;
for (int i = std::max(0, j - *k); i < j; ++i) {
Scalar aij = a[(*k + i - j) + j * *lda];
y[iy] += temp1 * aij;
temp2 += aij * x[ix];
ix += *incx;
iy += *incy;
}
y[jy] += temp1 * a[*k + j * *lda] + alpha * temp2;
jx += *incx;
jy += *incy;
if (j >= *k) {
kx += *incx;
ky += *incy;
}
}
} else {
// Lower triangle: A[i,j] at a[(i-j) + j*lda], diagonal at row 0.
int jx = kx, jy = ky;
for (int j = 0; j < *n; ++j) {
Scalar temp1 = alpha * x[jx];
Scalar temp2 = Scalar(0);
y[jy] += temp1 * a[j * *lda];
int ix = jx, iy = jy;
for (int i = j + 1; i <= std::min(*n - 1, j + *k); ++i) {
ix += *incx;
iy += *incy;
Scalar aij = a[(i - j) + j * *lda];
y[iy] += temp1 * aij;
temp2 += aij * x[ix];
}
y[jy] += alpha * temp2;
jx += *incx;
jy += *incy;
}
}
}
/** SPMV performs the matrix-vector operation
*
* y := alpha*A*x + beta*y,
*
* where alpha and beta are scalars, x and y are n element vectors and
* A is an n by n symmetric matrix, supplied in packed form.
*
* Packed storage: upper triangle stores columns sequentially so that
* column j occupies positions kk..kk+j (where kk = j*(j+1)/2),
* lower triangle stores column j at positions kk..kk+(n-j-1).
*/
// EIGEN_BLAS_FUNC(spmv)(char *uplo, int *n, RealScalar *alpha, RealScalar *ap, RealScalar *x, int *incx, RealScalar
// *beta, RealScalar *y, int *incy)
// {
// return 1;
// }
EIGEN_BLAS_FUNC(spmv)
(char *uplo, int *n, RealScalar *palpha, RealScalar *pap, RealScalar *px, int *incx, RealScalar *pbeta, RealScalar *py,
int *incy) {
const Scalar alpha = *reinterpret_cast<const Scalar *>(palpha);
const Scalar beta = *reinterpret_cast<const Scalar *>(pbeta);
const Scalar *ap = reinterpret_cast<const Scalar *>(pap);
const Scalar *x = reinterpret_cast<const Scalar *>(px);
Scalar *y = reinterpret_cast<Scalar *>(py);
int info = 0;
if (UPLO(*uplo) == INVALID)
info = 1;
else if (*n < 0)
info = 2;
else if (*incx == 0)
info = 6;
else if (*incy == 0)
info = 9;
if (info) return xerbla_(SCALAR_SUFFIX_UP "SPMV ", &info);
if (*n == 0 || (alpha == Scalar(0) && beta == Scalar(1))) return;
int kx = *incx > 0 ? 0 : (1 - *n) * *incx;
int ky = *incy > 0 ? 0 : (1 - *n) * *incy;
// First form y := beta*y.
if (beta != Scalar(1)) {
int iy = ky;
for (int i = 0; i < *n; ++i) {
y[iy] = (beta == Scalar(0)) ? Scalar(0) : beta * y[iy];
iy += *incy;
}
}
if (alpha == Scalar(0)) return;
int kk = 0;
if (UPLO(*uplo) == UP) {
// Upper triangle packed.
int jx = kx, jy = ky;
for (int j = 0; j < *n; ++j) {
Scalar temp1 = alpha * x[jx];
Scalar temp2 = Scalar(0);
int ix = kx, iy = ky;
for (int i = 0; i < j; ++i) {
y[iy] += temp1 * ap[kk + i];
temp2 += ap[kk + i] * x[ix];
ix += *incx;
iy += *incy;
}
y[jy] += temp1 * ap[kk + j] + alpha * temp2;
jx += *incx;
jy += *incy;
kk += j + 1;
}
} else {
// Lower triangle packed.
int jx = kx, jy = ky;
for (int j = 0; j < *n; ++j) {
Scalar temp1 = alpha * x[jx];
Scalar temp2 = Scalar(0);
y[jy] += temp1 * ap[kk];
int ix = jx, iy = jy;
for (int i = 1; i < *n - j; ++i) {
ix += *incx;
iy += *incy;
y[iy] += temp1 * ap[kk + i];
temp2 += ap[kk + i] * x[ix];
}
y[jy] += alpha * temp2;
jx += *incx;
jy += *incy;
kk += *n - j;
}
}
}
/** DSPR performs the symmetric rank 1 operation
*