1 files changed, 74 insertions, 0 deletions
diff --git a/StdLib/LibC/Math/s_floor.c b/StdLib/LibC/Math/s_floor.c
new file mode 100644
index 0000000000..d63ef13c0d
--- /dev/null
+++ b/StdLib/LibC/Math/s_floor.c
@@ -0,0 +1,74 @@
+/* @(#)s_floor.c 5.1 93/09/24 */
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+#include  <LibConfig.h>
+#include  <sys/EfiCdefs.h>
+#if defined(LIBM_SCCS) && !defined(lint)
+__RCSID("$NetBSD: s_floor.c,v 1.11 2002/05/26 22:01:56 wiz Exp $");
+#endif
+
+/*
+ * floor(x)
+ * Return x rounded toward -inf to integral value
+ * Method:
+ *  Bit twiddling.
+ * Exception:
+ *  Inexact flag raised if x not equal to floor(x).
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+static const double huge = 1.0e300;
+
+double
+floor(double x)
+{
+  int32_t i0,i1,j0;
+  u_int32_t i,j;
+  EXTRACT_WORDS(i0,i1,x);
+  j0 = ((i0>>20)&0x7ff)-0x3ff;
+  if(j0<20) {
+      if(j0<0) {  /* raise inexact if x != 0 */
+    if(huge+x>0.0) {/* return 0*sign(x) if |x|<1 */
+        if(i0>=0) {i0=i1=0;}
+        else if(((i0&0x7fffffff)|i1)!=0)
+      { i0=0xbff00000;i1=0;}
+    }
+      } else {
+    i = (0x000fffff)>>j0;
+    if(((i0&i)|i1)==0) return x; /* x is integral */
+    if(huge+x>0.0) {  /* raise inexact flag */
+        if(i0<0) i0 += (0x00100000)>>j0;
+        i0 &= (~i); i1=0;
+    }
+      }
+  } else if (j0>51) {
+      if(j0==0x400) return x+x; /* inf or NaN */
+      else return x;    /* x is integral */
+  } else {
+      i = ((u_int32_t)(0xffffffff))>>(j0-20);
+      if((i1&i)==0) return x; /* x is integral */
+      if(huge+x>0.0) {    /* raise inexact flag */
+    if(i0<0) {
+        if(j0==20) i0+=1;
+        else {
+      j = i1+(1<<(52-j0));
+      if((int32_t)j<i1) i0 +=1 ;   /* got a carry */
+      i1=j;
+        }
+    }
+    i1 &= (~i);
+      }
+  }
+  INSERT_WORDS(x,i0,i1);
+  return x;
+}