+/* 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
+
+// unsigned long __fs2ulong (float x)
+static void dummy(void) __naked
+{
+ __asm
+ .globl ___fs2ulong
+___fs2ulong:
+ mov r7, #158
+ .globl fs2ulong_begin
+fs2ulong_begin:
+ lcall fsgetarg
+ jnb sign_a, fs2ulong_int
+ ljmp fs_return_zero
+
+fs2ulong_int:
+ clr c
+ mov a, r7
+ subb a, exp_a
+ jnc fs2ulong_int_ok
+ // if we get here, x >= 2^32
+ mov a, #0xFF
+ mov b, a
+ mov dph, a
+ mov dpl, a
+ ret
+
+fs2ulong_int_ok:
+ mov r1, #0
+ lcall fs_rshift_a
+
+fs2ulong_done:
+ mov dpl, r1
+ mov dph, r2
+ mov b, r3
+ mov a, r4
+ ret
+ __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.
-*/
+/* (c)2000/2001: hacked a little by johan.knol@iduna.nl for sdcc */
-/* 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 >> (8*sizeof(fp)-1)) & 1)
-#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))
union float_long
- {
- float f;
- long l;
- };
+{
+ float f;
+ long l;
+};
-/* convert double to int */
+/* convert float to unsigned long */
unsigned long
__fs2ulong (float a1)
{
volatile union float_long fl1;
volatile int exp;
volatile long l;
-
+
fl1.f = a1;
-
- if (!fl1.l)
+
+ if (!fl1.l || SIGN(fl1.l))
return (0);
exp = EXP (fl1.l) - EXCESS - 24;
l = MANT (fl1.l);
+
+ l >>= -exp;
- if (exp > 0)
- return (0x7F | SIGN(fl1.l)); /* largest integer */
-
- /* shift down until exp = 0 or l = 0 */
- if (exp < 0 && exp > -25 && l)
- l >>= -exp;
- else
- return (0);
-
- return (SIGN(fl1.l) ? -l : l);
+ return l;
}
+#endif
projects / fw / sdcc / blobdiff