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35 /*! \libinternal \file
37 * Declares OpenMP wrappers to avoid conditional compilation.
39 * This module defines wrappers for OpenMP API functions and enables compiling
40 * code without conditional compilation even when OpenMP is turned off in the
42 * Therefore, OpenMP API functions should always be used through these wrappers
43 * and omp.h should never be directly included. Instead, this header should be
44 * used whenever OpenMP API functions are needed.
47 * \ingroup module_utility
49 #ifndef GMX_UTILITY_OMP_H
50 #define GMX_UTILITY_OMP_H
56 /* Ugly hack because the openmp implementation below hacks into the SIMD
57 * settings to decide when to use _mm_pause(). This should eventually be
58 * changed into proper detection of the intrinsics uses, not SIMD.
60 #if (defined GMX_SIMD_X86_SSE2) || (defined GMX_SIMD_X86_SSE4_1) || \
61 (defined GMX_SIMD_X86_AVX_128_FMA) || (defined GMX_SIMD_X86_AVX_256) || \
62 (defined GMX_SIMD_X86_AVX2_256)
63 # include <xmmintrin.h>
66 #include "types/commrec.h"
74 /*! \addtogroup module_utility
79 * Returns an integer equal to or greater than the number of threads
80 * that would be available if a parallel region without num_threads were
81 * defined at that point in the code.
83 * Acts as a wrapper for omp_get_max_threads().
85 int gmx_omp_get_max_threads(void);
88 * Returns the number of processors available when the function is called.
90 * Acts as a wrapper around omp_get_num_procs().
92 int gmx_omp_get_num_procs(void);
95 * Returns the thread number of the thread executing within its thread team.
97 * Acts as a wrapper for omp_get_thread_num().
99 int gmx_omp_get_thread_num(void);
102 * Sets the number of threads in subsequent parallel regions, unless overridden
103 * by a num_threads clause.
105 * Acts as a wrapper for omp_set_num_threads().
107 void gmx_omp_set_num_threads(int num_threads);
110 * Check for externally set thread affinity to avoid conflicts with \Gromacs
113 void gmx_omp_check_thread_affinity(FILE *fplog, const t_commrec *cr,
114 gmx_hw_opt_t *hw_opt);
117 * Pause for use in a spin-wait loop.
119 static gmx_inline void gmx_pause()
121 /* Ugly hack because the openmp implementation below hacks into the SIMD
122 * settings to decide when to use _mm_pause(). This should eventually be
123 * changed into proper detection of the intrinsics uses, not SIMD.
125 #if (defined GMX_SIMD_X86_SSE2) || (defined GMX_SIMD_X86_SSE4_1) || \
126 (defined GMX_SIMD_X86_AVX_128_FMA) || (defined GMX_SIMD_X86_AVX_256) || \
127 (defined GMX_SIMD_X86_AVX2_256)
128 /* Replace with tbb::internal::atomic_backoff when/if we use TBB */
130 #elif defined __MIC__
133 /* No wait for unknown architecture */