1 files changed, 38 insertions, 0 deletions
diff --git a/contrib/gcc/config/floatdisf.c b/contrib/gcc/config/floatdisf.c
new file mode 100644
index 0000000..b306044
--- /dev/null
+++ b/contrib/gcc/config/floatdisf.c
@@ -0,0 +1,38 @@
+/* Public domain.  */
+typedef int DItype __attribute__ ((mode (DI)));
+typedef unsigned int UDItype __attribute__ ((mode (DI)));
+typedef int SItype __attribute__ ((mode (SI)));
+typedef unsigned int USItype __attribute__ ((mode (SI)));
+typedef float SFtype __attribute__ ((mode (SF)));
+typedef float DFtype __attribute__ ((mode (DF)));
+
+SFtype __floatdisf (DItype);
+
+SFtype
+__floatdisf (DItype u)
+{
+  /* Protect against double-rounding error.
+     Represent any low-order bits, that might be truncated by a bit that
+     won't be lost.  The bit can go in anywhere below the rounding position
+     of SFtype.  A fixed mask and bit position handles all usual
+     configurations.  */
+  if (53 < (sizeof (DItype) * 8)
+      && 53 > ((sizeof (DItype) * 8) - 53 + 24))
+    {
+      if (!(- ((DItype) 1 << 53) < u
+	    && u < ((DItype) 1 << 53)))
+	{
+	  if ((UDItype) u & (((UDItype) 1 << (sizeof (DItype) * 8 - 53)) - 1))
+	    {
+	      u &= ~ (((UDItype) 1 << (sizeof (DItype) * 8 - 53)) - 1);
+	      u |= (UDItype) 1 << (sizeof (DItype) * 8 - 53);
+	    }
+	}
+    }
+  /* Do the calculation in a wider type so that we don't lose any of
+     the precision of the high word while multiplying it.  */
+  DFtype f = (SItype) (u >> (sizeof (SItype) * 8));
+  f *= 0x1p32f;
+  f += (USItype) u;
+  return (SFtype) f;
+}