+/* Floating point library in optimized assembly for 8051
+ * Copyright (c) 2004, Paul Stoffregen, paul@pjrc.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+
+#define SDCC_FLOAT_LIB
+#include <float.h>
+
+
+#ifdef FLOAT_ASM_MCS51
+
+// float long __ulong2fs (float x)
+static void dummy(void) _naked
+{
+ _asm
+ .globl ___ulong2fs
+___ulong2fs:
+ mov r4, a
+ mov r3, b
+ mov r2, dph
+ mov r1, dpl
+ mov a, #158
+ .globl ulong2fs_doit
+ulong2fs_doit:
+ clr sign_a
+long2fs_doit:
+ mov exp_a, a
+ lcall fs_normalize_a
+ ljmp fs_round_and_return
+ _endasm;
+}
+
+#else
+
+
+
/*
** libgcc support for software floating point.
** Copyright (C) 1991 by Pipeline Associates, Inc. All rights reserved.
** 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.
-
-
**
** 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.
-*/
-
-/* the following deal with IEEE single-precision numbers */
-#define EXCESS 126
-#define SIGNBIT ((unsigned long)0x80000000)
-#define HIDDEN (unsigned long)(1 << 23)
-#define SIGN(fp) ((fp) & SIGNBIT)
-#define EXP(fp) (((fp) >> 23) & (unsigned int) 0x00FF)
-#define MANT(fp) (((fp) & (unsigned long)0x007FFFFF) | 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))
+/* (c)2000/2001: hacked a little by johan.knol@iduna.nl for sdcc */
union float_long
{
long l;
};
-float
-__ulong2fs (unsigned long a )
+float __ulong2fs (unsigned long a )
{
- long sign = 0;
int exp = 24 + EXCESS;
volatile union float_long fl;
- long a1 = a;
- if (!a1)
+ if (!a)
{
- fl.l = 0;
- return (fl.f);
+ return 0.0;
}
- if (a1 < 0)
+ while (a & NORM)
{
- sign = SIGNBIT;
- a1 = -a1;
+ // we lose accuracy here
+ a >>= 1;
+ exp++;
}
-
- while (a1 < HIDDEN)
+
+ while (a < HIDDEN)
{
- a1 <<= 1;
+ a <<= 1;
exp--;
}
- a1 &= ~HIDDEN ;
+#if 1
+ if ((a&0x7fffff)==0x7fffff) {
+ a=0;
+ exp++;
+ }
+#endif
+
+ a &= ~HIDDEN ;
/* pack up and go home */
- fl.l = PACK(sign,(unsigned long)exp, a1);
+ fl.l = PACK(0,(unsigned long)exp, a);
return (fl.f);
}
+
+#endif
+
projects / fw / sdcc / blobdiff