newlib-cygwin/winsup/mingw/mingwex/feholdexcept.c

31 lines
983 B
C

#include <fenv.h>
#include "cpu_features.h"
/* 7.6.4.2
The feholdexcept function saves the current floating-point
environment in the object pointed to by envp, clears the exception
flags, and then installs a non-stop (continue on exceptions) mode,
if available, for all exceptions. */
int feholdexcept (fenv_t * envp)
{
__asm__ ("fnstenv %0;" : "=m" (* envp)); /* save current into envp */
/* fnstenv sets control word to non-stop for all exceptions, so all we
need to do is clear the exception flags. */
__asm__ ("fnclex");
if (__HAS_SSE)
{
unsigned int _csr;
/* Save the SSE MXCSR register. */
__asm__ ("stmxcsr %0" : "=m" (envp->__mxcsr));
/* Clear the exception flags. */
_csr = envp->__mxcsr & ~FE_ALL_EXCEPT;
/* Set exception mask to non-stop */
_csr |= (FE_ALL_EXCEPT << __MXCSR_EXCEPT_MASK_SHIFT) /*= 0x1f80 */;
__asm__ volatile ("ldmxcsr %0" : : "m" (_csr));
}
return 0;
}