58 lines
1.6 KiB
C
58 lines
1.6 KiB
C
#include <fenv.h>
|
|
#include <float.h>
|
|
#include "cpu_features.h"
|
|
|
|
/* 7.6.4.3
|
|
The fesetenv function establishes the floating-point environment
|
|
represented by the object pointed to by envp. The argument envp
|
|
points to an object set by a call to fegetenv or feholdexcept, or
|
|
equal the macro FE_DFL_ENV or an implementation-defined environment
|
|
macro. Note that fesetenv merely installs the state of the exception
|
|
flags represented through its argument, and does not raise these
|
|
exceptions.
|
|
*/
|
|
|
|
extern void (*_imp___fpreset)( void ) ;
|
|
|
|
int fesetenv (const fenv_t * envp)
|
|
{
|
|
/* Default mxcsr status is to mask all exceptions. All other bits
|
|
are zero. */
|
|
|
|
unsigned int _csr = FE_ALL_EXCEPT << __MXCSR_EXCEPT_MASK_SHIFT /*= 0x1f80 */;
|
|
|
|
if (envp == FE_PC64_ENV)
|
|
/*
|
|
* fninit initializes the control register to 0x37f,
|
|
* the status register to zero and the tag word to 0FFFFh.
|
|
* The other registers are unaffected.
|
|
*/
|
|
__asm__ ("fninit");
|
|
|
|
else if (envp == FE_PC53_ENV)
|
|
/*
|
|
* MS _fpreset() does same *except* it sets control word
|
|
* to 0x27f (53-bit precison).
|
|
* We force calling _fpreset in msvcrt.dll
|
|
*/
|
|
|
|
(*_imp___fpreset)();
|
|
|
|
else if (envp == FE_DFL_ENV)
|
|
/* Use the choice made at app startup */
|
|
_fpreset();
|
|
|
|
else
|
|
{
|
|
__asm__ ("fldenv %0;" : : "m" (*envp));
|
|
/* Setting the reserved high order bits of MXCSR causes a segfault */
|
|
_csr = envp ->__mxcsr & 0xffff;
|
|
}
|
|
|
|
/* Set MXCSR */
|
|
if (__HAS_SSE)
|
|
__asm__ volatile ("ldmxcsr %0" : : "m" (_csr));
|
|
|
|
return 0;
|
|
}
|