1 files changed, 41 insertions, 0 deletions
diff --git a/winsup/cygwin/math/modfl.c b/winsup/cygwin/math/modfl.c
new file mode 100644
index 000000000..af75a8b8c
--- /dev/null
+++ b/winsup/cygwin/math/modfl.c
@@ -0,0 +1,41 @@
+/**
+ * This file has no copyright assigned and is placed in the Public Domain.
+ * This file is part of the mingw-w64 runtime package.
+ * No warranty is given; refer to the file DISCLAIMER.PD within this package.
+ */
+#include <fenv.h>
+#include <math.h>
+#include <errno.h>
+
+long double
+modfl (long double value, long double* iptr)
+{
+  long double int_part = 0.0L;
+  /* truncate */
+#if defined(_AMD64_) || defined(__x86_64__)
+  asm ("subq $8, %%rsp\n"
+    "fnstcw 4(%%rsp)\n"
+    "movzwl 4(%%rsp), %%eax\n"
+    "orb $12, %%ah\n"
+    "movw %%ax, (%%rsp)\n"
+    "fldcw (%%rsp)\n"
+    "frndint\n"
+    "fldcw 4(%%rsp)\n"
+    "addq $8, %%rsp\n" : "=t" (int_part) : "0" (value)); /* round */
+#elif defined(_X86_) || defined(__i386__)
+  asm ("push %%eax\n\tsubl $8, %%esp\n"
+    "fnstcw 4(%%esp)\n"
+    "movzwl 4(%%esp), %%eax\n"
+    "orb $12, %%ah\n"
+    "movw %%ax, (%%esp)\n"
+    "fldcw (%%esp)\n"
+    "frndint\n"
+    "fldcw 4(%%esp)\n"
+    "addl $8, %%esp\n\tpop %%eax\n" : "=t" (int_part) : "0" (value)); /* round */
+#else
+  int_part = truncl(value);
+#endif
+  if (iptr)
+    *iptr = int_part;
+  return (isinf (value) ?  0.0L : value - int_part);
+}