Add incomplet long double math support to libmingwex.a

winsup/mingw/mingwex/math/modfl.c

@@ -0,0 +1,21 @@
+#include <fenv.h>
+#include <math.h>
+#include <errno.h>
+#define FE_ROUNDING_MASK \
+  (FE_TONEAREST | FE_DOWNWARD | FE_UPWARD | FE_TOWARDZERO)
+
+long double
+modfl (long double value, long double* iptr)
+{
+  long double int_part;
+  unsigned short saved_cw;
+  /* truncate */ 
+  asm ("fnstcw %0;" : "=m" (saved_cw)); /* save control word */
+  asm ("fldcw %0;" : : "m" ((saved_cw & ~FE_ROUNDING_MASK)
+			    | FE_TOWARDZERO));
+  asm ("frndint;" : "=t" (int_part) : "0" (value)); /* round */
+  asm ("fldcw %0;" : : "m" (saved_cw)); /* restore saved cw */
+  if (iptr)
+    *iptr = int_part;
+  return (isinf (value) ?  0.0L : value - int_part);
+}