diff options
| -rw-r--r-- | winsup/cygwin/math/truncl.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/winsup/cygwin/math/truncl.c b/winsup/cygwin/math/truncl.c index ddc6af68f..9380f9571 100644 --- a/winsup/cygwin/math/truncl.c +++ b/winsup/cygwin/math/truncl.c @@ -6,6 +6,10 @@ #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) { @@ -16,8 +20,8 @@ truncl (long double _x) unsigned short saved_cw; unsigned short tmp_cw; __asm__ __volatile__ ("fnstcw %0;" : "=m" (saved_cw)); /* save FPU control word */ - tmp_cw = (saved_cw & ~(FE_TONEAREST | FE_DOWNWARD | FE_UPWARD | FE_TOWARDZERO)) - | FE_TOWARDZERO; + 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 */ |