1 2 #include <stdio.h> 3 #include <math.h> 4 5 double d; 6 int i; 7 8 extern void do_fxam ( void ); 9 10 asm( 11 "\n" 12 "do_fxam:\n" 13 "\txorl %eax,%eax\n" 14 "\tfld d\n" 15 "\tfxam\n" 16 "\tfnstsw %ax\n" 17 "\tffree %st(0)\n" 18 "\tmovl %eax, i\n" 19 "\tret\n" 20 ); 21 22 23 double inf ( void ) { return 1.0 / 0.0; } 24 double nAn ( void ) { return 0.0 / 0.0; } 25 double den ( void ) { return 9.1e-220 / 1e100; } 26 27 /* Try positive and negative variants of: zero, infinity, 28 nAn, and denorm */ 29 30 int main ( void ) 31 { 32 d = 0.0; do_fxam(); printf("0x%4x: %f\n", i, d ); 33 d = -0.0; do_fxam(); printf("0x%4x: %f\n", i, d ); 34 35 d = inf(); do_fxam(); printf("0x%4x: %f\n", i, d ); 36 d = -inf(); do_fxam(); printf("0x%4x: %f\n", i, d ); 37 38 d = nAn(); do_fxam(); printf("0x%4x: %f\n", i, d ); 39 d = -nAn(); do_fxam(); printf("0x%4x: %f\n", i, d ); 40 41 d = den(); do_fxam(); printf("0x%4x: %f\n", i, d ); 42 d = -den(); do_fxam(); printf("0x%4x: %f\n", i, d ); 43 return 0; 44 } 45
