llvm-project/flang/runtime/matmul.cpp

351 lines
13 KiB
C++

//===-- runtime/matmul.cpp ------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// Implements all forms of MATMUL (Fortran 2018 16.9.124)
//
// There are two main entry points; one establishes a descriptor for the
// result and allocates it, and the other expects a result descriptor that
// points to existing storage.
//
// This implementation must handle all combinations of numeric types and
// kinds (100 - 165 cases depending on the target), plus all combinations
// of logical kinds (16). A single template undergoes many instantiations
// to cover all of the valid possibilities.
//
// Places where BLAS routines could be called are marked as TODO items.
#include "flang/Runtime/matmul.h"
#include "terminator.h"
#include "tools.h"
#include "flang/Runtime/c-or-cpp.h"
#include "flang/Runtime/cpp-type.h"
#include "flang/Runtime/descriptor.h"
#include <cstring>
namespace Fortran::runtime {
// General accumulator for any type and stride; this is not used for
// contiguous numeric cases.
template <TypeCategory RCAT, int RKIND, typename XT, typename YT>
class Accumulator {
public:
using Result = AccumulationType<RCAT, RKIND>;
Accumulator(const Descriptor &x, const Descriptor &y) : x_{x}, y_{y} {}
void Accumulate(const SubscriptValue xAt[], const SubscriptValue yAt[]) {
if constexpr (RCAT == TypeCategory::Logical) {
sum_ = sum_ ||
(IsLogicalElementTrue(x_, xAt) && IsLogicalElementTrue(y_, yAt));
} else {
sum_ += static_cast<Result>(*x_.Element<XT>(xAt)) *
static_cast<Result>(*y_.Element<YT>(yAt));
}
}
Result GetResult() const { return sum_; }
private:
const Descriptor &x_, &y_;
Result sum_{};
};
// Contiguous numeric matrix*matrix multiplication
// matrix(rows,n) * matrix(n,cols) -> matrix(rows,cols)
// Straightforward algorithm:
// DO 1 I = 1, NROWS
// DO 1 J = 1, NCOLS
// RES(I,J) = 0
// DO 1 K = 1, N
// 1 RES(I,J) = RES(I,J) + X(I,K)*Y(K,J)
// With loop distribution and transposition to avoid the inner sum
// reduction and to avoid non-unit strides:
// DO 1 I = 1, NROWS
// DO 1 J = 1, NCOLS
// 1 RES(I,J) = 0
// DO 2 K = 1, N
// DO 2 J = 1, NCOLS
// DO 2 I = 1, NROWS
// 2 RES(I,J) = RES(I,J) + X(I,K)*Y(K,J) ! loop-invariant last term
template <TypeCategory RCAT, int RKIND, typename XT, typename YT>
inline void MatrixTimesMatrix(CppTypeFor<RCAT, RKIND> *RESTRICT product,
SubscriptValue rows, SubscriptValue cols, const XT *RESTRICT x,
const YT *RESTRICT y, SubscriptValue n) {
using ResultType = CppTypeFor<RCAT, RKIND>;
std::memset(product, 0, rows * cols * sizeof *product);
const XT *RESTRICT xp0{x};
for (SubscriptValue k{0}; k < n; ++k) {
ResultType *RESTRICT p{product};
for (SubscriptValue j{0}; j < cols; ++j) {
const XT *RESTRICT xp{xp0};
auto yv{static_cast<ResultType>(y[k + j * n])};
for (SubscriptValue i{0}; i < rows; ++i) {
*p++ += static_cast<ResultType>(*xp++) * yv;
}
}
xp0 += rows;
}
}
// Contiguous numeric matrix*vector multiplication
// matrix(rows,n) * column vector(n) -> column vector(rows)
// Straightforward algorithm:
// DO 1 J = 1, NROWS
// RES(J) = 0
// DO 1 K = 1, N
// 1 RES(J) = RES(J) + X(J,K)*Y(K)
// With loop distribution and transposition to avoid the inner
// sum reduction and to avoid non-unit strides:
// DO 1 J = 1, NROWS
// 1 RES(J) = 0
// DO 2 K = 1, N
// DO 2 J = 1, NROWS
// 2 RES(J) = RES(J) + X(J,K)*Y(K)
template <TypeCategory RCAT, int RKIND, typename XT, typename YT>
inline void MatrixTimesVector(CppTypeFor<RCAT, RKIND> *RESTRICT product,
SubscriptValue rows, SubscriptValue n, const XT *RESTRICT x,
const YT *RESTRICT y) {
using ResultType = CppTypeFor<RCAT, RKIND>;
std::memset(product, 0, rows * sizeof *product);
for (SubscriptValue k{0}; k < n; ++k) {
ResultType *RESTRICT p{product};
auto yv{static_cast<ResultType>(*y++)};
for (SubscriptValue j{0}; j < rows; ++j) {
*p++ += static_cast<ResultType>(*x++) * yv;
}
}
}
// Contiguous numeric vector*matrix multiplication
// row vector(n) * matrix(n,cols) -> row vector(cols)
// Straightforward algorithm:
// DO 1 J = 1, NCOLS
// RES(J) = 0
// DO 1 K = 1, N
// 1 RES(J) = RES(J) + X(K)*Y(K,J)
// With loop distribution and transposition to avoid the inner
// sum reduction and one non-unit stride (the other remains):
// DO 1 J = 1, NCOLS
// 1 RES(J) = 0
// DO 2 K = 1, N
// DO 2 J = 1, NCOLS
// 2 RES(J) = RES(J) + X(K)*Y(K,J)
template <TypeCategory RCAT, int RKIND, typename XT, typename YT>
inline void VectorTimesMatrix(CppTypeFor<RCAT, RKIND> *RESTRICT product,
SubscriptValue n, SubscriptValue cols, const XT *RESTRICT x,
const YT *RESTRICT y) {
using ResultType = CppTypeFor<RCAT, RKIND>;
std::memset(product, 0, cols * sizeof *product);
for (SubscriptValue k{0}; k < n; ++k) {
ResultType *RESTRICT p{product};
auto xv{static_cast<ResultType>(*x++)};
const YT *RESTRICT yp{&y[k]};
for (SubscriptValue j{0}; j < cols; ++j) {
*p++ += xv * static_cast<ResultType>(*yp);
yp += n;
}
}
}
// Implements an instance of MATMUL for given argument types.
template <bool IS_ALLOCATING, TypeCategory RCAT, int RKIND, typename XT,
typename YT>
static inline void DoMatmul(
std::conditional_t<IS_ALLOCATING, Descriptor, const Descriptor> &result,
const Descriptor &x, const Descriptor &y, Terminator &terminator) {
int xRank{x.rank()};
int yRank{y.rank()};
int resRank{xRank + yRank - 2};
if (xRank * yRank != 2 * resRank) {
terminator.Crash("MATMUL: bad argument ranks (%d * %d)", xRank, yRank);
}
SubscriptValue extent[2]{
xRank == 2 ? x.GetDimension(0).Extent() : y.GetDimension(1).Extent(),
resRank == 2 ? y.GetDimension(1).Extent() : 0};
if constexpr (IS_ALLOCATING) {
result.Establish(
RCAT, RKIND, nullptr, resRank, extent, CFI_attribute_allocatable);
for (int j{0}; j < resRank; ++j) {
result.GetDimension(j).SetBounds(1, extent[j]);
}
if (int stat{result.Allocate()}) {
terminator.Crash(
"MATMUL: could not allocate memory for result; STAT=%d", stat);
}
} else {
RUNTIME_CHECK(terminator, resRank == result.rank());
RUNTIME_CHECK(
terminator, result.ElementBytes() == static_cast<std::size_t>(RKIND));
RUNTIME_CHECK(terminator, result.GetDimension(0).Extent() == extent[0]);
RUNTIME_CHECK(terminator,
resRank == 1 || result.GetDimension(1).Extent() == extent[1]);
}
SubscriptValue n{x.GetDimension(xRank - 1).Extent()};
if (n != y.GetDimension(0).Extent()) {
terminator.Crash("MATMUL: arrays do not conform (%jd != %jd)",
static_cast<std::intmax_t>(n),
static_cast<std::intmax_t>(y.GetDimension(0).Extent()));
}
using WriteResult =
CppTypeFor<RCAT == TypeCategory::Logical ? TypeCategory::Integer : RCAT,
RKIND>;
if constexpr (RCAT != TypeCategory::Logical) {
if (x.IsContiguous() && y.IsContiguous() &&
(IS_ALLOCATING || result.IsContiguous())) {
// Contiguous numeric matrices
if (resRank == 2) { // M*M -> M
if (std::is_same_v<XT, YT>) {
if constexpr (std::is_same_v<XT, float>) {
// TODO: call BLAS-3 SGEMM
} else if constexpr (std::is_same_v<XT, double>) {
// TODO: call BLAS-3 DGEMM
} else if constexpr (std::is_same_v<XT, std::complex<float>>) {
// TODO: call BLAS-3 CGEMM
} else if constexpr (std::is_same_v<XT, std::complex<double>>) {
// TODO: call BLAS-3 ZGEMM
}
}
MatrixTimesMatrix<RCAT, RKIND, XT, YT>(
result.template OffsetElement<WriteResult>(), extent[0], extent[1],
x.OffsetElement<XT>(), y.OffsetElement<YT>(), n);
return;
} else if (xRank == 2) { // M*V -> V
if (std::is_same_v<XT, YT>) {
if constexpr (std::is_same_v<XT, float>) {
// TODO: call BLAS-2 SGEMV(x,y)
} else if constexpr (std::is_same_v<XT, double>) {
// TODO: call BLAS-2 DGEMV(x,y)
} else if constexpr (std::is_same_v<XT, std::complex<float>>) {
// TODO: call BLAS-2 CGEMV(x,y)
} else if constexpr (std::is_same_v<XT, std::complex<double>>) {
// TODO: call BLAS-2 ZGEMV(x,y)
}
}
MatrixTimesVector<RCAT, RKIND, XT, YT>(
result.template OffsetElement<WriteResult>(), extent[0], n,
x.OffsetElement<XT>(), y.OffsetElement<YT>());
return;
} else { // V*M -> V
if (std::is_same_v<XT, YT>) {
if constexpr (std::is_same_v<XT, float>) {
// TODO: call BLAS-2 SGEMV(y,x)
} else if constexpr (std::is_same_v<XT, double>) {
// TODO: call BLAS-2 DGEMV(y,x)
} else if constexpr (std::is_same_v<XT, std::complex<float>>) {
// TODO: call BLAS-2 CGEMV(y,x)
} else if constexpr (std::is_same_v<XT, std::complex<double>>) {
// TODO: call BLAS-2 ZGEMV(y,x)
}
}
VectorTimesMatrix<RCAT, RKIND, XT, YT>(
result.template OffsetElement<WriteResult>(), n, extent[0],
x.OffsetElement<XT>(), y.OffsetElement<YT>());
return;
}
}
}
// General algorithms for LOGICAL and noncontiguity
SubscriptValue xAt[2], yAt[2], resAt[2];
x.GetLowerBounds(xAt);
y.GetLowerBounds(yAt);
result.GetLowerBounds(resAt);
if (resRank == 2) { // M*M -> M
SubscriptValue x1{xAt[1]}, y0{yAt[0]}, y1{yAt[1]}, res1{resAt[1]};
for (SubscriptValue i{0}; i < extent[0]; ++i) {
for (SubscriptValue j{0}; j < extent[1]; ++j) {
Accumulator<RCAT, RKIND, XT, YT> accumulator{x, y};
yAt[1] = y1 + j;
for (SubscriptValue k{0}; k < n; ++k) {
xAt[1] = x1 + k;
yAt[0] = y0 + k;
accumulator.Accumulate(xAt, yAt);
}
resAt[1] = res1 + j;
*result.template Element<WriteResult>(resAt) = accumulator.GetResult();
}
++resAt[0];
++xAt[0];
}
} else if (xRank == 2) { // M*V -> V
SubscriptValue x1{xAt[1]}, y0{yAt[0]};
for (SubscriptValue j{0}; j < extent[0]; ++j) {
Accumulator<RCAT, RKIND, XT, YT> accumulator{x, y};
for (SubscriptValue k{0}; k < n; ++k) {
xAt[1] = x1 + k;
yAt[0] = y0 + k;
accumulator.Accumulate(xAt, yAt);
}
*result.template Element<WriteResult>(resAt) = accumulator.GetResult();
++resAt[0];
++xAt[0];
}
} else { // V*M -> V
SubscriptValue x0{xAt[0]}, y0{yAt[0]};
for (SubscriptValue j{0}; j < extent[0]; ++j) {
Accumulator<RCAT, RKIND, XT, YT> accumulator{x, y};
for (SubscriptValue k{0}; k < n; ++k) {
xAt[0] = x0 + k;
yAt[0] = y0 + k;
accumulator.Accumulate(xAt, yAt);
}
*result.template Element<WriteResult>(resAt) = accumulator.GetResult();
++resAt[0];
++yAt[1];
}
}
}
// Maps the dynamic type information from the arguments' descriptors
// to the right instantiation of DoMatmul() for valid combinations of
// types.
template <bool IS_ALLOCATING> struct Matmul {
using ResultDescriptor =
std::conditional_t<IS_ALLOCATING, Descriptor, const Descriptor>;
template <TypeCategory XCAT, int XKIND> struct MM1 {
template <TypeCategory YCAT, int YKIND> struct MM2 {
void operator()(ResultDescriptor &result, const Descriptor &x,
const Descriptor &y, Terminator &terminator) const {
if constexpr (constexpr auto resultType{
GetResultType(XCAT, XKIND, YCAT, YKIND)}) {
if constexpr (common::IsNumericTypeCategory(resultType->first) ||
resultType->first == TypeCategory::Logical) {
return DoMatmul<IS_ALLOCATING, resultType->first,
resultType->second, CppTypeFor<XCAT, XKIND>,
CppTypeFor<YCAT, YKIND>>(result, x, y, terminator);
}
}
terminator.Crash("MATMUL: bad operand types (%d(%d), %d(%d))",
static_cast<int>(XCAT), XKIND, static_cast<int>(YCAT), YKIND);
}
};
void operator()(ResultDescriptor &result, const Descriptor &x,
const Descriptor &y, Terminator &terminator, TypeCategory yCat,
int yKind) const {
ApplyType<MM2, void>(yCat, yKind, terminator, result, x, y, terminator);
}
};
void operator()(ResultDescriptor &result, const Descriptor &x,
const Descriptor &y, const char *sourceFile, int line) const {
Terminator terminator{sourceFile, line};
auto xCatKind{x.type().GetCategoryAndKind()};
auto yCatKind{y.type().GetCategoryAndKind()};
RUNTIME_CHECK(terminator, xCatKind.has_value() && yCatKind.has_value());
ApplyType<MM1, void>(xCatKind->first, xCatKind->second, terminator, result,
x, y, terminator, yCatKind->first, yCatKind->second);
}
};
extern "C" {
void RTNAME(Matmul)(Descriptor &result, const Descriptor &x,
const Descriptor &y, const char *sourceFile, int line) {
Matmul<true>{}(result, x, y, sourceFile, line);
}
void RTNAME(MatmulDirect)(const Descriptor &result, const Descriptor &x,
const Descriptor &y, const char *sourceFile, int line) {
Matmul<false>{}(result, x, y, sourceFile, line);
}
} // extern "C"
} // namespace Fortran::runtime