check_lz.c (775B)
1 #include <stdio.h> 2 #include <stdlib.h> 3 #include <stdint.h> 4 #include "sys.h" 5 6 static always_inline int cris_lz(int x) 7 { 8 int r; 9 asm ("lz\t%1, %0\n" : "=r" (r) : "r" (x)); 10 return r; 11 } 12 13 void check_lz(void) 14 { 15 int i; 16 17 if (cris_lz(0) != 32) 18 err(); 19 if (cris_lz(1) != 31) 20 err(); 21 if (cris_lz(2) != 30) 22 err(); 23 if (cris_lz(4) != 29) 24 err(); 25 if (cris_lz(8) != 28) 26 err(); 27 28 /* try all positions with a single bit. */ 29 for (i = 1; i < 32; i++) { 30 if (cris_lz(1 << (i-1)) != (32 - i)) 31 err(); 32 } 33 34 /* try all positions with all bits. */ 35 for (i = 1; i < 32; i++) { 36 /* split up this computation to clarify it. */ 37 uint32_t val; 38 val = (unsigned int)-1 >> (32 - i); 39 if (cris_lz(val) != (32 - i)) 40 err(); 41 } 42 } 43 44 int main(void) 45 { 46 check_lz(); 47 pass(); 48 exit(0); 49 }