1 2 #include <stdio.h> 3 4 typedef unsigned long long int ULong; 5 typedef unsigned int UInt; 6 7 __attribute__((noinline)) 8 void do_lzcnt64 ( /*OUT*/UInt* flags, /*OUT*/ULong* res, ULong arg ) 9 { 10 ULong block[3] = { arg, 0ULL, 0ULL }; 11 __asm__ __volatile__( 12 "movabsq $0x5555555555555555, %%r11" "\n\t" 13 "lzcntq 0(%0), %%r11" "\n\t" 14 "movq %%r11, 8(%0)" "\n\t" 15 "pushfq" "\n\t" 16 "popq %%r11" "\n\t" 17 "movq %%r11, 16(%0)" "\n" 18 : : "r"(&block[0]) : "r11","cc","memory" 19 ); 20 *res = block[1]; 21 *flags = block[2] & 0x8d5; 22 } 23 24 __attribute__((noinline)) 25 void do_lzcnt32 ( /*OUT*/UInt* flags, /*OUT*/ULong* res, ULong arg ) 26 { 27 ULong block[3] = { arg, 0ULL, 0ULL }; 28 __asm__ __volatile__( 29 "movabsq $0x5555555555555555, %%r11" "\n\t" 30 "lzcntl 0(%0), %%r11d" "\n\t" 31 "movq %%r11, 8(%0)" "\n\t" 32 "pushfq" "\n\t" 33 "popq %%r11" "\n\t" 34 "movq %%r11, 16(%0)" "\n" 35 : : "r"(&block[0]) : "r11","cc","memory" 36 ); 37 *res = block[1]; 38 *flags = block[2] & 0x8d5; 39 } 40 41 __attribute__((noinline)) 42 void do_lzcnt16 ( /*OUT*/UInt* flags, /*OUT*/ULong* res, ULong arg ) 43 { 44 ULong block[3] = { arg, 0ULL, 0ULL }; 45 __asm__ __volatile__( 46 "movabsq $0x5555555555555555, %%r11" "\n\t" 47 "lzcntw 0(%0), %%r11w" "\n\t" 48 "movq %%r11, 8(%0)" "\n\t" 49 "pushfq" "\n\t" 50 "popq %%r11" "\n\t" 51 "movq %%r11, 16(%0)" "\n" 52 : : "r"(&block[0]) : "r11","cc","memory" 53 ); 54 *res = block[1]; 55 *flags = block[2] & 0x8d5; 56 } 57 58 int main ( void ) 59 { 60 ULong w; 61 62 w = 0xFEDC192837475675ULL; 63 while (1) { 64 ULong res; 65 UInt flags; 66 do_lzcnt64(&flags, &res, w); 67 printf("lzcntq %016llx -> %016llx %04x\n", w, res, flags); 68 if (w == 0) break; 69 w = ((w >> 2) | (w >> 1)) + (w / 17ULL); 70 } 71 72 w = 0xFEDC192837475675ULL; 73 while (1) { 74 ULong res; 75 UInt flags; 76 do_lzcnt32(&flags, &res, w); 77 printf("lzcntl %016llx -> %016llx %04x\n", w, res, flags); 78 if (w == 0) break; 79 w = ((w >> 2) | (w >> 1)) + (w / 17ULL); 80 } 81 82 w = 0xFEDC192837475675ULL; 83 while (1) { 84 ULong res; 85 UInt flags; 86 do_lzcnt16(&flags, &res, w); 87 printf("lzcntw %016llx -> %016llx %04x\n", w, res, flags); 88 if (w == 0) break; 89 w = ((w >> 2) | (w >> 1)) + (w / 17ULL); 90 } 91 92 return 0; 93 } 94
