microblaze: Restore soft-float

Software floating point for microblaze.

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

1 files changed, 85 insertions, 0 deletions

diff --git a/libc/sysdeps/linux/microblaze/fixdfsi.c b/libc/sysdeps/linux/microblaze/fixdfsi.c
new file mode 100644
index 000000000..1611176aa
--- /dev/null
+++ b/libc/sysdeps/linux/microblaze/fixdfsi.c
@@ -0,0 +1,85 @@
+/*
+** libgcc support for software floating point.
+** Copyright (C) 1991 by Pipeline Associates, Inc.  All rights reserved.
+** Permission is granted to do *anything* you want with this file,
+** commercial or otherwise, provided this message remains intact.  So there!
+** I would appreciate receiving any updates/patches/changes that anyone
+** makes, and am willing to be the repository for said changes (am I
+** making a big mistake?).
+
+Warning! Only single-precision is actually implemented.  This file
+won't really be much use until double-precision is supported.
+
+However, once that is done, this file might eventually become a
+replacement for libgcc1.c.  It might also make possible
+cross-compilation for an IEEE target machine from a non-IEEE
+host such as a VAX.
+
+If you'd like to work on completing this, please talk to rms@gnu.ai.mit.edu.
+
+--> Double precision floating support added by James Carlson on 20 April 1998.
+
+**
+** Pat Wood
+** Pipeline Associates, Inc.
+** pipeline!phw@motown.com or
+** sun!pipeline!phw or
+** uunet!motown!pipeline!phw
+**
+** 05/01/91 -- V1.0 -- first release to gcc mailing lists
+** 05/04/91 -- V1.1 -- added float and double prototypes and return values
+**                  -- fixed problems with adding and subtracting zero
+**                  -- fixed rounding in truncdfsf2
+**                  -- fixed SWAP define and tested on 386
+*/
+
+/*
+** The following are routines that replace the libgcc soft floating point
+** routines that are called automatically when -msoft-float is selected.
+** The support single and double precision IEEE format, with provisions
+** for byte-swapped machines (tested on 386).  Some of the double-precision
+** routines work at full precision, but most of the hard ones simply punt
+** and call the single precision routines, producing a loss of accuracy.
+** long long support is not assumed or included.
+** Overall accuracy is close to IEEE (actually 68882) for single-precision
+** arithmetic.  I think there may still be a 1 in 1000 chance of a bit
+** being rounded the wrong way during a multiply.  I'm not fussy enough to
+** bother with it, but if anyone is, knock yourself out.
+**
+** Efficiency has only been addressed where it was obvious that something
+** would make a big difference.  Anyone who wants to do this right for
+** best speed should go in and rewrite in assembler.
+**
+** I have tested this only on a 68030 workstation and 386/ix integrated
+** in with -msoft-float.
+*/
+
+#include "floatlib.h"
+
+/* convert double to int */
+long
+__fixdfsi (double a1)
+{
+  register union double_long dl1;
+  register int exp;
+  register long l;
+
+  dl1.d = a1;
+
+  if (!dl1.l.upper && !dl1.l.lower)
+    return (0);
+
+  exp = EXPD (dl1) - EXCESSD - 31;
+  l = MANTD (dl1);
+
+  if (exp > 0)
+      return SIGND(dl1) ? (1<<31) : ((1ul<<31)-1);
+
+  /* shift down until exp = 0 or l = 0 */
+  if (exp < 0 && exp > -32 && l)
+    l >>= -exp;
+  else
+    return (0);
+
+  return (SIGND (dl1) ? -l : l);
+}