diff options
Diffstat (limited to 'Eigen/src/Core/products/Parallelizer.h')
| -rw-r--r-- | Eigen/src/Core/products/Parallelizer.h | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/Eigen/src/Core/products/Parallelizer.h b/Eigen/src/Core/products/Parallelizer.h index 15b5c5f94..92e9b0d9f 100644 --- a/Eigen/src/Core/products/Parallelizer.h +++ b/Eigen/src/Core/products/Parallelizer.h @@ -10,6 +10,10 @@ #ifndef EIGEN_PARALLELIZER_H #define EIGEN_PARALLELIZER_H +#if EIGEN_HAS_CXX11_ATOMIC +#include <atomic> +#endif + namespace Eigen { namespace internal { @@ -75,8 +79,17 @@ template<typename Index> struct GemmParallelInfo { GemmParallelInfo() : sync(-1), users(0), lhs_start(0), lhs_length(0) {} + // volatile is not enough on all architectures (see bug 1572) + // to guarantee that when thread A says to thread B that it is + // done with packing a block, then all writes have been really + // carried out... C++11 memory model+atomic guarantees this. +#if EIGEN_HAS_CXX11_ATOMIC + std::atomic<Index> sync; + std::atomic<int> users; +#else Index volatile sync; int volatile users; +#endif Index lhs_start; Index lhs_length; @@ -87,7 +100,10 @@ void parallelize_gemm(const Functor& func, Index rows, Index cols, Index depth, { // TODO when EIGEN_USE_BLAS is defined, // we should still enable OMP for other scalar types -#if !(defined (EIGEN_HAS_OPENMP)) || defined (EIGEN_USE_BLAS) + // Without C++11, we have to disable GEMM's parallelization on + // non x86 architectures because there volatile is not enough for our purpose. + // See bug 1572. +#if (! defined(EIGEN_HAS_OPENMP)) || defined(EIGEN_USE_BLAS) || ((!EIGEN_HAS_CXX11_ATOMIC) && !(EIGEN_ARCH_i386_OR_x86_64)) // FIXME the transpose variable is only needed to properly split // the matrix product when multithreading is enabled. This is a temporary // fix to support row-major destination matrices. This whole |