[PATCH 05/10] microblaze: Restore soft-float

Steven J. Magnani steve at digidescorp.com
Tue Oct 5 14:23:18 UTC 2010


Software floating point for microblaze.

Signed-off-by: Steven J. Magnani <steve at digidescorp.com>
---
diff -uprN a/libc/sysdeps/linux/microblaze/fixdfsi.c b/libc/sysdeps/linux/microblaze/fixdfsi.c
--- a/libc/sysdeps/linux/microblaze/fixdfsi.c	1969-12-31 18:00:00.000000000 -0600
+++ b/libc/sysdeps/linux/microblaze/fixdfsi.c	2010-09-21 20:10:24.000000000 -0500
@@ -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 at gnu.ai.mit.edu.
+
+--> Double precision floating support added by James Carlson on 20 April 1998.
+
+**
+** Pat Wood
+** Pipeline Associates, Inc.
+** pipeline!phw at 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);
+}
diff -uprN a/libc/sysdeps/linux/microblaze/floatlib.h b/libc/sysdeps/linux/microblaze/floatlib.h
--- a/libc/sysdeps/linux/microblaze/floatlib.h	1969-12-31 18:00:00.000000000 -0600
+++ b/libc/sysdeps/linux/microblaze/floatlib.h	2010-09-21 20:10:24.000000000 -0500
@@ -0,0 +1,144 @@
+/*
+** 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 at gnu.ai.mit.edu.
+
+--> Double precision floating support added by James Carlson on 20 April 1998.
+
+**
+** Pat Wood
+** Pipeline Associates, Inc.
+** pipeline!phw at 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.
+*/
+
+#ifndef __FLOAT_LIB_H__
+#define __FLOAT_LIB_H__
+/* the following deal with IEEE single-precision numbers */
+#define EXCESS		126
+#define SIGNBIT		0x80000000
+#define HIDDEN		(1 << 23)
+#define SIGN(fp)	((fp) & SIGNBIT)
+#define EXP(fp)		(((fp) >> 23) & 0xFF)
+#define MANT(fp)	(((fp) & 0x7FFFFF) | HIDDEN)
+#define PACK(s,e,m)	((s) | ((e) << 23) | (m))
+
+/* the following deal with IEEE double-precision numbers */
+#define EXCESSD		1022
+#define HIDDEND		(1 << 20)
+#define EXPD(fp)	(((fp.l.upper) >> 20) & 0x7FF)
+#define SIGND(fp)	((fp.l.upper) & SIGNBIT)
+#define MANTD(fp)	(((((fp.l.upper) & 0xFFFFF) | HIDDEND) << 10) | \
+				(fp.l.lower >> 22))
+#define HIDDEND_LL	((long long)1 << 52)
+#define MANTD_LL(fp)	((fp.ll & (HIDDEND_LL-1)) | HIDDEND_LL)
+#define PACKD_LL(s,e,m)	(((long long)((s)+((e)<<20))<<32)|(m))
+
+/* define SWAP for 386/960 reverse-byte-order brain-damaged CPUs */
+union double_long {
+    double d;
+#ifdef SWAP
+    struct {
+      unsigned long lower;
+      long upper;
+    } l;
+#else
+    struct {
+      long upper;
+      unsigned long lower;
+    } l;
+#endif
+    long long ll;
+};
+
+union float_long
+  {
+    float f;
+    long l;
+  };
+
+#endif
+
+/* Functions defined in different files */
+
+float __addsf3 (float, float);
+float __subsf3 (float, float);
+long __cmpsf2 (float, float);
+float __mulsf3 (float, float);
+float __divsf3 (float, float);
+double __floatsidf (register long);
+double __floatdidf (register long long);
+float __floatsisf (register long );
+float __floatdisf (register long long );
+float __negsf2 (float);
+double __negdf2 (double);
+double __extendsfdf2 (float);
+float __truncdfsf2 (double);
+long __cmpdf2 (double, double);
+long __fixsfsi (float);
+long __fixdfsi (double);
+long long __fixdfdi (double);
+unsigned long __fixunsdfsi (double);
+unsigned long long __fixunsdfdi (double);
+double __adddf3 (double, double);
+double __subdf3 (double, double);
+double __muldf3 (double, double);
+double __divdf3 (double, double);
+int __gtdf2 (double, double);
+int __gedf2 (double, double);
+int __ltdf2 (double, double);
+int __ledf2 (double, double);
+int __eqdf2 (double, double);
+int __nedf2 (double, double);
+int __gtsf2 (float, float);
+int __gesf2 (float, float);
+int __ltsf2 (float, float);
+int __lesf2 (float, float);
+int __eqsf2 (float, float);
+int __nesf2 (float, float);
+
+
+
+



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