2 ** libgcc support for software floating point.
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3 ** Copyright (C) 1991 by Pipeline Associates, Inc. All rights reserved.
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4 ** Permission is granted to do *anything* you want with this file,
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5 ** commercial or otherwise, provided this message remains intact. So there!
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6 ** I would appreciate receiving any updates/patches/changes that anyone
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7 ** makes, and am willing to be the repository for said changes (am I
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8 ** making a big mistake?).
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11 ** Pipeline Associates, Inc.
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12 ** pipeline!phw@motown.com or
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13 ** sun!pipeline!phw or
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14 ** uunet!motown!pipeline!phw
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18 ** $Id: fsmul.c 3513 2004-10-01 14:49:51Z vrokas $
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21 /* (c)2000/2001: hacked a little by johan.knol@iduna.nl for sdcc */
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31 /* multiply two floats */
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32 float __fsmul (float a1, float a2) _FS_REENTRANT
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34 FS_STATIC volatile union float_long fl1, fl2;
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35 unsigned long result;
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42 if (!fl1.l || !fl2.l)
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45 /* compute sign and exponent */
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46 sign = SIGN (fl1.l) ^ SIGN (fl2.l);
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47 exp = EXP (fl1.l) - EXCESS;
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50 fl1.l = MANT (fl1.l);
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51 fl2.l = MANT (fl2.l);
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53 /* the multiply is done as one 16x16 multiply and two 16x8 multiples */
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54 result = (fl1.l >> 8) * (fl2.l >> 8);
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55 result += ((fl1.l & (unsigned long) 0xFF) * (fl2.l >> 8)) >> 8;
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56 result += ((fl2.l & (unsigned long) 0xFF) * (fl1.l >> 8)) >> 8;
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58 if (0 != (result & SIGNBIT))
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74 /* pack up and go home */
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76 fl1.l = (sign ? SIGNBIT : 0) | 0x7F800000;
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80 fl1.l = PACK (sign ? SIGNBIT : 0 , exp, result);
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