# HG changeset patch # User Leif Leonhardy # Date 1261670894 28800 # Node ID 0ca12d759af10c5bb8ba0b59d2c46857fb04d30e # Parent 906f05c99ca779a4e0756e972b5ff834353dc164 first patch of Leif_attachment1.zip, i.e. Silva.c.diff0 diff -r 906f05c99ca7 -r 0ca12d759af1 Silva.c --- a/Silva.c +++ b/Silva.c @@ -22,7 +22,7 @@ // approximately 8*pi(sqrt(N)), where N is the last number of the interval, and pi(x) is // the usual prime counting function. // -// Assumptions: pointers have 4 bytes, gcc compiler +// Assumptions: pointers have either 4 or 8 bytes, gcc compiler // // Modifications made by Kevin Stueve 2009-09-04 // kstueve@uw.edu @@ -50,6 +50,8 @@ #include #include #include +#include +#include // @@ -86,9 +88,9 @@ // basic type definitions // -typedef unsigned char u08; -typedef unsigned int u32; -typedef unsigned long long u64; +typedef uint8_t u08; +typedef uint32_t u32; +typedef uint64_t u64; // @@ -97,9 +99,9 @@ static void *get_memory(u32 size) { - u32 m; + uintptr_t m; - m = (u32)malloc(size + 255); // this assumes that sizeof(void *) = sizeof(u32) + m = (uintptr_t)malloc((size_t)(size + 255)); if((void *)m == NULL) exit(1); m = (m + 255) & ~255; @@ -113,7 +115,7 @@ static u32 count_zero_bits(u08 *addr,u32 size) { - static u32 data[256]; + static u32 data[256]; // NYI: use uint_fast8_t rather than u32 (at most 8 zero bits per byte) u32 i,j; if(data[1] == 0) @@ -132,7 +134,7 @@ // generation of the (small) primes used by the main sieve // -#define number_of_small_primes 6541 +#define number_of_small_primes 6541 // less than 2^16, excluding 2 static u32 small_primes[number_of_small_primes]; static u32 small_sieve[1024]; static u32 small_base; @@ -220,12 +222,21 @@ // be small (and a multiple of the L1 or L2 data cache line size) // +#if __SIZEOF_POINTER__ == 4 #define primes_per_bucket ((1 << (_bucket_size_log2_ - 3)) - 1) +#elif __SIZEOF_POINTER__ == 8 +#define primes_per_bucket ((1 << (_bucket_size_log2_ - 3)) - 2) +#else +#error "sizeof(void*) neither 4 nor 8" +#endif typedef struct bucket { struct bucket *next; // pointer to next bucket u32 count; // count of the number of primes in this bucket +#if __SIZEOF_POINTER__ == 8 + u32 pad; // dummy word to align next structure element +#endif struct { u32 p; // prime @@ -247,11 +258,11 @@ #endif #if _implementation_ == 0 -# define new_bucket() do { bucket *b; b = get_memory(sizeof(bucket)); \ +# define new_bucket() do { bucket *b; b = get_memory((u32)sizeof(bucket)); \ b->next = main_list; b->count = 0; main_list = b; } while(0) #else # define more_buckets() do { u32 i,j; i = 1 << (20 - _bucket_size_log2_); \ - available_buckets = (bucket *)get_memory(i * sizeof(bucket)); for(j = 0;j < i;j++) \ + available_buckets = (bucket *)get_memory(i * (u32)sizeof(bucket)); for(j = 0;j < i;j++) \ available_buckets[j].next = (j < i - 1) ? &available_buckets[j + 1] : NULL; } while(0) # define new_bucket(k) do { bucket *b; if(available_buckets == NULL) more_buckets(); \ b = available_buckets; available_buckets = available_buckets->next; \ @@ -278,7 +289,7 @@ ; current_list = 0; available_buckets = NULL; - main_lists = (bucket **)get_memory((1 << list_size_log2) * sizeof(bucket *)); + main_lists = (bucket **)get_memory((1 << list_size_log2) * (u32)sizeof(bucket *)); for(k = 0;k < (1 << list_size_log2);k++) { main_lists[k] = NULL; @@ -435,6 +446,15 @@ double t; u32 i,j; u64 pi; + const u32 bytes_per_segment = 1 << (_sieve_bits_log2_ - 3); + u64 bytes_remaining; // u32 overflows on large intervals + +#ifdef DEBUG + fprintf(stderr,"log2(bucket_size)=%u\n",(unsigned)_bucket_size_log2_); + fprintf(stderr,"primes_per_bucket=%u\n",(unsigned)primes_per_bucket); + fprintf(stderr,"sizeof(bucket)=%u\n",(unsigned)sizeof(bucket)); + fprintf(stderr,"log2(sieve_bits)=%u\n",(unsigned)_sieve_bits_log2_); +#endif #if 0//#ifdef _test_small_sieve_ test_small_sieve(); @@ -443,14 +463,32 @@ test_main_sieve(); #endif +#if 0 main_base = atoll(argv[1]); main_limit = atoll(argv[2]); //printf("%d\n",main_base); - //printf("%d\n",main_limit); + //printf("%d\n",main_limit); +#else + if(argc==3) // progname + { + if(sscanf(argv[1],"%"SCNu64,&main_base)!=1 || sscanf(argv[2],"%"SCNu64,&main_limit)!=1 + || main_limit<=main_base) + { // handle bad parameters... + // (could check if main_base%64==0 and main_limit%64==0 here, too) + fprintf(stderr,"%s: Bad parameters\n",argv[0]); + exit(1); + } + } + else + { // handle usage/command line syntax error... + fprintf(stderr,"Usage: %s \n",argv[0]); + exit(1); + } +#endif next_prime = 0; - j = 1 << (_sieve_bits_log2_ - 3); - pi = 0ull; + // j = 1 << (_sieve_bits_log2_ - 3); + pi = 0; if(((u32)main_base | (u32)main_limit) & 63) { fprintf(stderr,"Warning: prime number counts may be incorrect\n"); @@ -460,28 +498,32 @@ for(;;) { do_main_sieve(); - i = (u32)(main_limit - main_base) >> 4; - if(i <= j) + bytes_remaining = (main_limit - main_base) >> 4; + if(bytes_remaining <= bytes_per_segment) break; - pi += (u64)count_zero_bits((u08 *)main_sieve,j); + pi += (u64)count_zero_bits((u08 *)main_sieve,bytes_per_segment); #if 0 // // example code to print the prime numbers between - // main_base and main_base+2*j + // main_base and main_base+2*8*bytes_per_segment // { u32 k; - for(k = 0;k < (j << 3);k++) + for(k = 0;k < (bytes_per_segment << 3);k++) if((main_sieve[k >> 5] & (1 << (k & 31))) == 0) - printf("%llu\n",main_base + (u32)(2 * k + 1)); + printf("%"PRIu64"\n",main_base + (u32)(2 * k + 1)); } #endif - main_base += (u64)j << 4; + main_base += (u64)bytes_per_segment << 4; } - pi += (u64)count_zero_bits((u08 *)main_sieve,i); + pi += (u64)count_zero_bits((u08 *)main_sieve,(u32)bytes_remaining); // t = ((double)clock() - t) / (double)CLOCKS_PER_SEC; +#if 0 printf("%d\n",pi); +#else + printf("%"PRIu64"\n",pi); +#endif return 0; }