Standard Libraries for EDK II.

[mirror_edk2.git] / StdLib / LibC / gdtoa / ulp.c

diff --git a/StdLib/LibC/gdtoa/ulp.c b/StdLib/LibC/gdtoa/ulp.c
new file mode 100644 (file)
index 0000000..6f2780c
--- /dev/null
+++ b/StdLib/LibC/gdtoa/ulp.c
@@ -0,0 +1,73 @@
+/* $NetBSD: ulp.c,v 1.2 2006/01/25 15:27:42 kleink Exp $ */\r
+\r
+/****************************************************************\r
+\r
+The author of this software is David M. Gay.\r
+\r
+Copyright (C) 1998, 1999 by Lucent Technologies\r
+All Rights Reserved\r
+\r
+Permission to use, copy, modify, and distribute this software and\r
+its documentation for any purpose and without fee is hereby\r
+granted, provided that the above copyright notice appear in all\r
+copies and that both that the copyright notice and this\r
+permission notice and warranty disclaimer appear in supporting\r
+documentation, and that the name of Lucent or any of its entities\r
+not be used in advertising or publicity pertaining to\r
+distribution of the software without specific, written prior\r
+permission.\r
+\r
+LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,\r
+INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.\r
+IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY\r
+SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES\r
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER\r
+IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,\r
+ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF\r
+THIS SOFTWARE.\r
+\r
+****************************************************************/\r
+\r
+/* Please send bug reports to David M. Gay (dmg at acm dot org,\r
+ * with " at " changed at "@" and " dot " changed to ".").  */\r
+#include  <LibConfig.h>\r
+\r
+#include "gdtoaimp.h"\r
+\r
+ double\r
+ulp\r
+#ifdef KR_headers\r
+  (x) double x;\r
+#else\r
+  (double x)\r
+#endif\r
+{\r
+  Long L;\r
+  double a;\r
+\r
+  L = (word0(x) & Exp_mask) - (P-1)*Exp_msk1;\r
+#ifndef Sudden_Underflow\r
+  if (L > 0) {\r
+#endif\r
+#ifdef IBM\r
+    L |= Exp_msk1 >> 4;\r
+#endif\r
+    word0(a) = (UINT32)L;\r
+    word1(a) = 0;\r
+#ifndef Sudden_Underflow\r
+    }\r
+  else {\r
+    L = (unsigned int)-L >> Exp_shift;\r
+    if (L < Exp_shift) {\r
+      word0(a) = 0x80000 >> L;\r
+      word1(a) = 0;\r
+      }\r
+    else {\r
+      word0(a) = 0;\r
+      L -= Exp_shift;\r
+      word1(a) = L >= 31 ? 1 : 1 << (31 - L);\r
+      }\r
+    }\r
+#endif\r
+  return a;\r
+  }\r