30 lines
1 KiB
C
30 lines
1 KiB
C
/**
|
|
* This file has no copyright assigned and is placed in the Public Domain.
|
|
* This file is part of the mingw-w64 runtime package.
|
|
* No warranty is given; refer to the file DISCLAIMER.PD within this package.
|
|
*/
|
|
#include <fenv.h>
|
|
#include <math.h>
|
|
|
|
/* Mask and shift amount for rounding bits on x86/x86_64. */
|
|
#define FE_CW_ROUND_MASK (0x0c00)
|
|
#define FE_CW_ROUND_SHIFT (10)
|
|
|
|
long double
|
|
truncl (long double _x)
|
|
{
|
|
#if defined(_ARM_) || defined(__arm__)
|
|
return trunc(_x);
|
|
#else
|
|
long double retval = 0.0L;
|
|
unsigned short saved_cw;
|
|
unsigned short tmp_cw;
|
|
__asm__ __volatile__ ("fnstcw %0;" : "=m" (saved_cw)); /* save FPU control word */
|
|
tmp_cw = (saved_cw & ~FE_CW_ROUND_MASK)
|
|
| (FE_TOWARDZERO << FE_CW_ROUND_SHIFT);
|
|
__asm__ __volatile__ ("fldcw %0;" : : "m" (tmp_cw));
|
|
__asm__ __volatile__ ("frndint;" : "=t" (retval) : "0" (_x)); /* round towards zero */
|
|
__asm__ __volatile__ ("fldcw %0;" : : "m" (saved_cw) ); /* restore saved control word */
|
|
return retval;
|
|
#endif /* defined(_ARM_) || defined(__arm__) */
|
|
}
|