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Diffstat (limited to 'libgomp/testsuite/libgomp.c/sort-1.c')
-rw-r--r-- | libgomp/testsuite/libgomp.c/sort-1.c | 379 |
1 files changed, 379 insertions, 0 deletions
diff --git a/libgomp/testsuite/libgomp.c/sort-1.c b/libgomp/testsuite/libgomp.c/sort-1.c new file mode 100644 index 000000000..269d69da1 --- /dev/null +++ b/libgomp/testsuite/libgomp.c/sort-1.c @@ -0,0 +1,379 @@ +/* Test and benchmark of a couple of parallel sorting algorithms. + Copyright (C) 2008 Free Software Foundation, Inc. + + GCC is free software; you can redistribute it and/or modify it under + the terms of the GNU General Public License as published by the Free + Software Foundation; either version 3, or (at your option) any later + version. + + GCC is distributed in the hope that it will be useful, but WITHOUT ANY + WARRANTY; without even the implied warranty of MERCHANTABILITY or + FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + for more details. + + You should have received a copy of the GNU General Public License + along with GCC; see the file COPYING3. If not see + <http://www.gnu.org/licenses/>. */ + +#include <limits.h> +#include <omp.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +int failures; + +#define THRESHOLD 100 + +static void +verify (const char *name, double stime, int *array, int count) +{ + int i; + double etime = omp_get_wtime (); + + printf ("%s: %g\n", name, etime - stime); + for (i = 1; i < count; i++) + if (array[i] < array[i - 1]) + { + printf ("%s: incorrectly sorted\n", name); + failures = 1; + } +} + +static void +insertsort (int *array, int s, int e) +{ + int i, j, val; + for (i = s + 1; i <= e; i++) + { + val = array[i]; + j = i; + while (j-- > s && val < array[j]) + array[j + 1] = array[j]; + array[j + 1] = val; + } +} + +struct int_pair +{ + int lo; + int hi; +}; + +struct int_pair_stack +{ + struct int_pair *top; +#define STACK_SIZE 4 * CHAR_BIT * sizeof (int) + struct int_pair arr[STACK_SIZE]; +}; + +static inline void +init_int_pair_stack (struct int_pair_stack *stack) +{ + stack->top = &stack->arr[0]; +} + +static inline void +push_int_pair_stack (struct int_pair_stack *stack, int lo, int hi) +{ + stack->top->lo = lo; + stack->top->hi = hi; + stack->top++; +} + +static inline void +pop_int_pair_stack (struct int_pair_stack *stack, int *lo, int *hi) +{ + stack->top--; + *lo = stack->top->lo; + *hi = stack->top->hi; +} + +static inline int +size_int_pair_stack (struct int_pair_stack *stack) +{ + return stack->top - &stack->arr[0]; +} + +static inline void +busy_wait (void) +{ +#if defined __i386__ || defined __x86_64__ + __asm volatile ("rep; nop" : : : "memory"); +#elif defined __ia64__ + __asm volatile ("hint @pause" : : : "memory"); +#elif defined __sparc__ && (defined __arch64__ || defined __sparc_v9__) + __asm volatile ("membar #LoadLoad" : : : "memory"); +#else + __asm volatile ("" : : : "memory"); +#endif +} + +static inline void +swap (int *array, int a, int b) +{ + int val = array[a]; + array[a] = array[b]; + array[b] = val; +} + +static inline int +choose_pivot (int *array, int lo, int hi) +{ + int mid = (lo + hi) / 2; + + if (array[mid] < array[lo]) + swap (array, lo, mid); + if (array[hi] < array[mid]) + { + swap (array, mid, hi); + if (array[mid] < array[lo]) + swap (array, lo, mid); + } + return array[mid]; +} + +static inline int +partition (int *array, int lo, int hi) +{ + int pivot = choose_pivot (array, lo, hi); + int left = lo; + int right = hi; + + for (;;) + { + while (array[++left] < pivot); + while (array[--right] > pivot); + if (left >= right) + break; + swap (array, left, right); + } + return left; +} + +static void +sort1 (int *array, int count) +{ + omp_lock_t lock; + struct int_pair_stack global_stack; + int busy = 1; + int num_threads; + + omp_init_lock (&lock); + init_int_pair_stack (&global_stack); + #pragma omp parallel firstprivate (array, count) + { + int lo = 0, hi = 0, mid, next_lo, next_hi; + bool idle = true; + struct int_pair_stack local_stack; + + init_int_pair_stack (&local_stack); + if (omp_get_thread_num () == 0) + { + num_threads = omp_get_num_threads (); + hi = count - 1; + idle = false; + } + + for (;;) + { + if (hi - lo < THRESHOLD) + { + insertsort (array, lo, hi); + lo = hi; + } + if (lo >= hi) + { + if (size_int_pair_stack (&local_stack) == 0) + { + again: + omp_set_lock (&lock); + if (size_int_pair_stack (&global_stack) == 0) + { + if (!idle) + busy--; + if (busy == 0) + { + omp_unset_lock (&lock); + break; + } + omp_unset_lock (&lock); + idle = true; + while (size_int_pair_stack (&global_stack) == 0 + && busy) + busy_wait (); + goto again; + } + if (idle) + busy++; + pop_int_pair_stack (&global_stack, &lo, &hi); + omp_unset_lock (&lock); + idle = false; + } + else + pop_int_pair_stack (&local_stack, &lo, &hi); + } + + mid = partition (array, lo, hi); + if (mid - lo < hi - mid) + { + next_lo = mid; + next_hi = hi; + hi = mid - 1; + } + else + { + next_lo = lo; + next_hi = mid - 1; + lo = mid; + } + + if (next_hi - next_lo < THRESHOLD) + insertsort (array, next_lo, next_hi); + else + { + if (size_int_pair_stack (&global_stack) < num_threads - 1) + { + int size; + + omp_set_lock (&lock); + size = size_int_pair_stack (&global_stack); + if (size < num_threads - 1 && size < STACK_SIZE) + push_int_pair_stack (&global_stack, next_lo, next_hi); + else + push_int_pair_stack (&local_stack, next_lo, next_hi); + omp_unset_lock (&lock); + } + else + push_int_pair_stack (&local_stack, next_lo, next_hi); + } + } + } + omp_destroy_lock (&lock); +} + +static void +sort2_1 (int *array, int lo, int hi, int num_threads, int *busy) +{ + int mid; + + if (hi - lo < THRESHOLD) + { + insertsort (array, lo, hi); + return; + } + + mid = partition (array, lo, hi); + + if (*busy >= num_threads) + { + sort2_1 (array, lo, mid - 1, num_threads, busy); + sort2_1 (array, mid, hi, num_threads, busy); + return; + } + + #pragma omp atomic + *busy += 1; + + #pragma omp parallel num_threads (2) \ + firstprivate (array, lo, hi, mid, num_threads, busy) + { + if (omp_get_thread_num () == 0) + sort2_1 (array, lo, mid - 1, num_threads, busy); + else + { + sort2_1 (array, mid, hi, num_threads, busy); + #pragma omp atomic + *busy -= 1; + } + } +} + +static void +sort2 (int *array, int count) +{ + int num_threads; + int busy = 1; + + #pragma omp parallel + #pragma omp single nowait + num_threads = omp_get_num_threads (); + + sort2_1 (array, 0, count - 1, num_threads, &busy); +} + +#if _OPENMP >= 200805 +static void +sort3_1 (int *array, int lo, int hi) +{ + int mid; + + if (hi - lo < THRESHOLD) + { + insertsort (array, lo, hi); + return; + } + + mid = partition (array, lo, hi); + #pragma omp task + sort3_1 (array, lo, mid - 1); + sort3_1 (array, mid, hi); +} + +static void +sort3 (int *array, int count) +{ + #pragma omp parallel + #pragma omp single + sort3_1 (array, 0, count - 1); +} +#endif + +int +main (int argc, char **argv) +{ + int i, count = 1000000; + double stime; + int *unsorted, *sorted, num_threads; + if (argc >= 2) + count = strtoul (argv[1], NULL, 0); + + unsorted = malloc (count * sizeof (int)); + sorted = malloc (count * sizeof (int)); + if (unsorted == NULL || sorted == NULL) + { + puts ("allocation failure"); + exit (1); + } + + srand (0xdeadbeef); + for (i = 0; i < count; i++) + unsorted[i] = rand (); + + omp_set_nested (1); + omp_set_dynamic (0); + #pragma omp parallel + #pragma omp single nowait + num_threads = omp_get_num_threads (); + printf ("Threads: %d\n", num_threads); + + memcpy (sorted, unsorted, count * sizeof (int)); + stime = omp_get_wtime (); + sort1 (sorted, count); + verify ("sort1", stime, sorted, count); + + memcpy (sorted, unsorted, count * sizeof (int)); + stime = omp_get_wtime (); + sort2 (sorted, count); + verify ("sort2", stime, sorted, count); + +#if _OPENMP >= 200805 + memcpy (sorted, unsorted, count * sizeof (int)); + stime = omp_get_wtime (); + sort3 (sorted, count); + verify ("sort3", stime, sorted, count); +#endif + + return 0; +} |