@@ -17,14 +17,13 @@
<http://www.gnu.org/licenses/>. */
#include <fenv.h>
-#include <fpu_control.h>
#include <arm-features.h>
int
fesetenv (const fenv_t *envp)
{
- fpu_control_t fpscr;
+ fpu_control_t fpscr, new_fpscr, updated_fpscr;
/* Fail if a VFP unit isn't present. */
if (!ARM_HAVE_VFP)
@@ -32,25 +31,31 @@ fesetenv (const fenv_t *envp)
_FPU_GETCW (fpscr);
- /* Preserve the reserved FPSCR flags. */
- fpscr &= _FPU_RESERVED;
+ if ((envp != FE_DFL_ENV) && (envp != FE_NOMASK_ENV))
+ {
+ /* The new FPSCR is valid, so don't merge the reserved flags. */
+ new_fpscr = envp->__cw;
- if (envp == FE_DFL_ENV)
- fpscr |= _FPU_DEFAULT;
- else if (envp == FE_NOMASK_ENV)
- fpscr |= _FPU_IEEE;
- else
- fpscr |= envp->__cw & ~_FPU_RESERVED;
+ /* Write new FPSCR if different (ignoring NZCV flags). */
+ if (((fpscr ^ new_fpscr) & ~_FPU_MASK_NZCV) != 0)
+ _FPU_SETCW (new_fpscr);
- _FPU_SETCW (fpscr);
+ return 0;
+ }
- if (envp == FE_NOMASK_ENV)
+ /* Preserve the reserved FPSCR flags. */
+ new_fpscr = fpscr & _FPU_RESERVED;
+ new_fpscr |= (envp == FE_DFL_ENV) ? _FPU_DEFAULT : _FPU_IEEE;
+
+ if (((new_fpscr ^ fpscr) & ~_FPU_MASK_NZCV) != 0)
{
+ _FPU_SETCW (new_fpscr);
+
/* Not all VFP architectures support trapping exceptions, so
test whether the relevant bits were set and fail if not. */
- _FPU_GETCW (fpscr);
- if ((fpscr & _FPU_IEEE) != _FPU_IEEE)
- return 1;
+ _FPU_GETCW (updated_fpscr);
+
+ return new_fpscr & ~updated_fpscr;
}
return 0;