1 files changed, 26 insertions, 0 deletions
diff --git a/winsup/cygwin/math/truncl.c b/winsup/cygwin/math/truncl.c
new file mode 100644
index 000000000..ddc6af68f
--- /dev/null
+++ b/winsup/cygwin/math/truncl.c
@@ -0,0 +1,26 @@
+/**
+ * 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>
+
+long double
+truncl (long double _x)
+{
+#if defined(_ARM_) || defined(__arm__)
+  return trunc(_x);
+#else
+  long double retval = 0.0L;
+  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;
+  __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 */
+  return retval;
+#endif /* defined(_ARM_) || defined(__arm__) */
+}