benchmarks/rsort/rsort.c

   1 // See LICENSE for license details.
   2
   3 //**************************************************************************
   4 // Quicksort benchmark
   5 //--------------------------------------------------------------------------
   6 //
   7 // This benchmark uses quicksort to sort an array of integers. The
   8 // implementation is largely adapted from Numerical Recipes for C. The
   9 // input data (and reference data) should be generated using the
  10 // qsort_gendata.pl perl script and dumped to a file named
  11 // dataset1.h The smips-gcc toolchain does not support system calls
  12 // so printf's can only be used on a host system, not on the smips
  13 // processor simulator itself. You should not change anything except
  14 // the HOST_DEBUG and PREALLOCATE macros for your timing run.
  15
  16 #include "util.h"
  17 #include <string.h>
  18 #include <limits.h>
  19
  20 //--------------------------------------------------------------------------
  21 // Input/Reference Data
  22
  23 #define type unsigned int
  24 #include "dataset1.h"
  25
  26 #define LOG_BASE 8
  27 #define BASE (1 << LOG_BASE)
  28
  29 void sort(size_t n, type* arrIn, type* scratchIn)
  30 {
  31   size_t log_exp = 0;
  32   size_t buckets[BASE];
  33   size_t *bucket = buckets;
  34   asm("":"+r"(bucket));
  35   type *arr = arrIn, *scratch = scratchIn, *p;
  36   size_t *b;
  37
  38   while (log_exp < CHAR_BIT * sizeof(type))
  39   {
  40     for (b = bucket; b < bucket + BASE; b++)
  41       *b = 0;
  42
  43     for (p = arr; p < &arr[n-3]; p += 4)
  44     {
  45       type a0 = p[0];
  46       type a1 = p[1];
  47       type a2 = p[2];
  48       type a3 = p[3];
  49       __sync_fetch_and_add(&bucket[(a0 >> log_exp) % BASE], 1);
  50       __sync_fetch_and_add(&bucket[(a1 >> log_exp) % BASE], 1);
  51       __sync_fetch_and_add(&bucket[(a2 >> log_exp) % BASE], 1);
  52       __sync_fetch_and_add(&bucket[(a3 >> log_exp) % BASE], 1);
  53     }
  54     for ( ; p < &arr[n]; p++)
  55       bucket[(*p >> log_exp) % BASE]++;
  56
  57     size_t prev = bucket[0];
  58     prev += __sync_fetch_and_add(&bucket[1], prev);
  59     for (b = &bucket[2]; b < bucket + BASE; b += 2)
  60     {
  61       prev += __sync_fetch_and_add(&b[0], prev);
  62       prev += __sync_fetch_and_add(&b[1], prev);
  63     }
  64     static_assert(BASE % 2 == 0);
  65
  66     for (p = &arr[n-1]; p >= &arr[3]; p -= 4)
  67     {
  68       type a0 = p[-0];
  69       type a1 = p[-1];
  70       type a2 = p[-2];
  71       type a3 = p[-3];
  72       size_t* pb0 = &bucket[(a0 >> log_exp) % BASE];
  73       size_t* pb1 = &bucket[(a1 >> log_exp) % BASE];
  74       size_t* pb2 = &bucket[(a2 >> log_exp) % BASE];
  75       size_t* pb3 = &bucket[(a3 >> log_exp) % BASE];
  76       type* s0 = scratch + __sync_fetch_and_add(pb0, -1);
  77       type* s1 = scratch + __sync_fetch_and_add(pb1, -1);
  78       type* s2 = scratch + __sync_fetch_and_add(pb2, -1);
  79       type* s3 = scratch + __sync_fetch_and_add(pb3, -1);
  80       s0[-1] = a0;
  81       s1[-1] = a1;
  82       s2[-1] = a2;
  83       s3[-1] = a3;
  84     }
  85     for ( ; p >= &arr[0]; p--)
  86       scratch[--bucket[(*p >> log_exp) % BASE]] = *p;
  87
  88     type* tmp = arr;
  89     arr = scratch;
  90     scratch = tmp;
  91
  92     log_exp += LOG_BASE;
  93   }
  94   if (arr != arrIn)
  95     memcpy(arr, scratch, n*sizeof(type));
  96 }
  97
  98 //--------------------------------------------------------------------------
  99 // Main
 100
 101 int main( int argc, char* argv[] )
 102 {
 103   static type scratch[DATA_SIZE];
 104   // Output the input array
 105   printArray( "input", DATA_SIZE, input_data );
 106   printArray( "verify", DATA_SIZE, verify_data );
 107
 108 #if PREALLOCATE
 109   // If needed we preallocate everything in the caches
 110   sort(DATA_SIZE, verify_data, scratch);
 111   if (verify(DATA_SIZE, input_data, input_data))
 112     return 1;
 113 #endif
 114
 115   // Do the sort
 116   setStats(1);
 117   sort(DATA_SIZE, input_data, scratch);
 118   setStats(0);
 119
 120   // Print out the results
 121   printArray( "test", DATA_SIZE, input_data );
 122
 123   // Check the results
 124   return verify( DATA_SIZE, input_data, verify_data );
 125 }