diff options
Diffstat (limited to 'contrib/SDL-3.2.8/src/libm/s_floor.c')
| -rw-r--r-- | contrib/SDL-3.2.8/src/libm/s_floor.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/contrib/SDL-3.2.8/src/libm/s_floor.c b/contrib/SDL-3.2.8/src/libm/s_floor.c new file mode 100644 index 0000000..4809af1 --- /dev/null +++ b/contrib/SDL-3.2.8/src/libm/s_floor.c | |||
| @@ -0,0 +1,76 @@ | |||
| 1 | #include "SDL_internal.h" | ||
| 2 | /* | ||
| 3 | * ==================================================== | ||
| 4 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. | ||
| 5 | * | ||
| 6 | * Developed at SunPro, a Sun Microsystems, Inc. business. | ||
| 7 | * Permission to use, copy, modify, and distribute this | ||
| 8 | * software is freely granted, provided that this notice | ||
| 9 | * is preserved. | ||
| 10 | * ==================================================== | ||
| 11 | */ | ||
| 12 | |||
| 13 | /* | ||
| 14 | * floor(x) | ||
| 15 | * Return x rounded toward -inf to integral value | ||
| 16 | * Method: | ||
| 17 | * Bit twiddling. | ||
| 18 | * Exception: | ||
| 19 | * Inexact flag raised if x not equal to floor(x). | ||
| 20 | */ | ||
| 21 | |||
| 22 | /*#include <features.h>*/ | ||
| 23 | /* Prevent math.h from defining a colliding inline */ | ||
| 24 | #undef __USE_EXTERN_INLINES | ||
| 25 | #include "math_libm.h" | ||
| 26 | #include "math_private.h" | ||
| 27 | |||
| 28 | #ifdef __WATCOMC__ /* Watcom defines huge=__huge */ | ||
| 29 | #undef huge | ||
| 30 | #endif | ||
| 31 | |||
| 32 | static const double huge = 1.0e300; | ||
| 33 | |||
| 34 | double floor(double x) | ||
| 35 | { | ||
| 36 | int32_t i0,i1,j0; | ||
| 37 | u_int32_t i,j; | ||
| 38 | EXTRACT_WORDS(i0,i1,x); | ||
| 39 | j0 = ((i0>>20)&0x7ff)-0x3ff; | ||
| 40 | if(j0<20) { | ||
| 41 | if(j0<0) { /* raise inexact if x != 0 */ | ||
| 42 | if(huge+x>0.0) {/* return 0*sign(x) if |x|<1 */ | ||
| 43 | if(i0>=0) {i0=i1=0;} | ||
| 44 | else if(((i0&0x7fffffff)|i1)!=0) | ||
| 45 | { i0=0xbff00000;i1=0;} | ||
| 46 | } | ||
| 47 | } else { | ||
| 48 | i = (0x000fffff)>>j0; | ||
| 49 | if(((i0&i)|i1)==0) return x; /* x is integral */ | ||
| 50 | if(huge+x>0.0) { /* raise inexact flag */ | ||
| 51 | if(i0<0) i0 += (0x00100000)>>j0; | ||
| 52 | i0 &= (~i); i1=0; | ||
| 53 | } | ||
| 54 | } | ||
| 55 | } else if (j0>51) { | ||
| 56 | if(j0==0x400) return x+x; /* inf or NaN */ | ||
| 57 | else return x; /* x is integral */ | ||
| 58 | } else { | ||
| 59 | i = ((u_int32_t)(0xffffffff))>>(j0-20); | ||
| 60 | if((i1&i)==0) return x; /* x is integral */ | ||
| 61 | if(huge+x>0.0) { /* raise inexact flag */ | ||
| 62 | if(i0<0) { | ||
| 63 | if(j0==20) i0+=1; | ||
| 64 | else { | ||
| 65 | j = i1+(1<<(52-j0)); | ||
| 66 | if(j<(u_int32_t)i1) i0 +=1 ; /* got a carry */ | ||
| 67 | i1=j; | ||
| 68 | } | ||
| 69 | } | ||
| 70 | i1 &= (~i); | ||
| 71 | } | ||
| 72 | } | ||
| 73 | INSERT_WORDS(x,i0,i1); | ||
| 74 | return x; | ||
| 75 | } | ||
| 76 | libm_hidden_def(floor) | ||
