CydandClaude Fable 5
63312e07f9
- BORLAND/: Borland C++ 4.52 (chosen over 4.5 by byte-match: CODE/RP/CW32.LIB
is identical to 4.52's install lib). BCC32/TLINK32/TLIB/MAKE run natively on
Win11; CODE/BT/OPT.MAK is the shipped BTL4OPT.EXE's exact flag recipe
(extender = Borland PowerPack DPMI32, not Phar Lap TNT).
- restoration/source410/: the literal 1995-form reconstruction of the missing
BT game source (never mixed into CODE/). Round 1-3 state:
* 6 of 10 surviving original TUs COMPILE CLEAN under the period toolchain
(BTMSSN, BTCNSL, BTSCNRL, BTTEAM, BTL4MODE, BTL4ARND) - first builds
since 1996.
* BT_L4/BTL4APP.CPP pilot reconstruction: 12/12 functions, Fail() lands on
its binary-recorded line 400 exactly.
* BT/BTCNSL.HPP: console wire IDs recovered from the binary's ctors
(Killed=9, Damaged=10, ScoreUpdate=13, DeathWithoutHonor=15 [T1];
TeamScore=12 flagged [T4]).
* MUNGA/: 8 engine-header backfills back-dated from the BT412 WinTesla tree
(VDATA numbering decomp-verified; AUDREND's OpenAL-era virtual removed -
the period compiler is the drift detector).
* Tooling: backdate.py (WinTesla->1995 header transform), compile410.sh
(per-TU verification sweep under authentic OPT.MAK flags).
* README: corrected roadmap - MECH.HPP is the capstone grown with the mech
TU reconstructions; BTREG.CPP green = the header-family milestone.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
134 lines
3.1 KiB
Plaintext
134 lines
3.1 KiB
Plaintext
/*------------------------------------------------------------------------
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* filename - tanhl.cas
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*
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* function(s)
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* tanhl - long double hyperbolic tangent function
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*-----------------------------------------------------------------------*/
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/*
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* C/C++ Run Time Library - Version 6.5
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*
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* Copyright (c) 1987, 1994 by Borland International
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* All Rights Reserved.
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*
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*/
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#pragma inline
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#include <asmrules.h>
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#include <_math.h>
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#include <math.h>
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/*--------------------------------------------------------------------------*
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Name tanhl - long double hyperbolic tangent function
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Usage long double tanhl(long double x);
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Prototype in math.h
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Description tanhl calculates the hyperbolic tangent of the input.
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Return value tanhl returns the hyperbolic tangent of the input value.
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For large arguments (magnitude greater than 32) the result
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will be +1.0 or -1.0.
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*---------------------------------------------------------------------------*/
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/*
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Algorithm.
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The usual formula is:
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tanhl(x) = (exp(x) - exp(-x))/(exp(x) + exp(-x))/
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but there is a loss of precision in using this formula directly near 0.
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Since tanhl(-x) = -tanhl(x), compute tanhl(|x|) and adjust the sign later.
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If 0 <= x < 2^-33, return x.
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If x >= 32 return 1.
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If x >= .17325, use
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y = exp(x)
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tanhl(x) = (y - 1/y)/(y + 1/y)
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If 2^-33 <= x < .17325, use
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y = exp(2x) - 1
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sinh(x) = y/(2 + y)
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where special chip functions are used to get exp(2x)-1 accurately.
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*/
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long double _FARFUNC tanhl (long double x)
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{
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asm FLD LONGDOUBLE (x)
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asm sub dh, dh
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asm mov cx, x [8]
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asm shl cx, 1
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asm rcr dh, 1 /* DH = sign */
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asm cmp cx, 8008h
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asm FABS
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asm ja tanhl_extreme
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asm cmp cx, 7FF8h
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asm jb tanhl_small
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#ifdef _Windows
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_f87_Exp();
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#else
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asm _FAST_ (_FEXP_) /* Exp (x) */
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#endif
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asm FLD1
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asm FDIV st, st(1) /* Exp (-x) */
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/*
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tanhl = sinh / cosh = (exp(x) - exp(-x)) / (exp(x) + exp(-x))
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*/
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asm FLD st(1)
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asm FSUB st, st(1)
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asm FXCH
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asm FADD st, st(2)
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asm FDIVP st(1), st
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asm FSTP st(1)
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tanhl_end:
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/* change sign if original argument was negative */
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asm or dh, dh
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asm jns tanhl_end2
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asm FCHS
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tanhl_end2:
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#pragma noretval
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return;
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/*
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tanhl is asymptotic to -1 for negative arguments and +1 for positives.
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It approaches very fast, with exponentially increasing accuracy,
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so it is 1.0 for IEEE accuracy when |x| > 23.
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*/
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tanhl_extreme:
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asm FSTP st(0) /* pop stack */
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asm FLD1
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goto tanhl_end;
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tanhl_small:
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asm cmp cx, 7FBCh
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asm jb tanhl_end
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asm FLD1
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asm FXCH
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asm FSCALE
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asm FLDL2E
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asm FMUL
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asm F2XM1
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/* TOS = y = exp(2x) - 1 */
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asm FXCH
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asm FLD1
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asm FADD
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asm FADD st(0),st(1)
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/* stack = 2+y,y */
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asm FDIV
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goto tanhl_end;
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}
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