** 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 >> (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))
+/* (c)2000/2001: hacked a little by johan.knol@iduna.nl for sdcc */
-/* 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))
+#include <float.h>
union float_long
{
float f;
- long l;
+ unsigned long l;
};
/* multiply two floats */
-float
-__fsmul (float a1, float a2)
-{
+float __fsmul (float a1, float a2) {
volatile union float_long fl1, fl2;
volatile unsigned long result;
volatile int exp;
char sign;
-
+
fl1.f = a1;
fl2.f = a2;
result += ((fl1.l & (unsigned long) 0xFF) * (fl2.l >> 8)) >> 8;
result += ((fl2.l & (unsigned long) 0xFF) * (fl1.l >> 8)) >> 8;
- if (result & (unsigned long)0x80000000)
+ if (result & SIGNBIT)
{
/* round */
result += 0x80;
result &= ~HIDDEN;
/* pack up and go home */
- fl1.l = PACK (sign ? ((unsigned long) 0x80000000) : 0 , (unsigned long)exp, result);
+ fl1.l = PACK (sign ? SIGNBIT : 0 , (unsigned long)exp, result);
return (fl1.f);
}
+
+
+
+