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page ,132 title 87trigh - hyperbolic trigonometric functions - SINH, COSH, TANH;*** ;87trigh.asm - hyperbolic trigonometric functions - SINH, COSH, TANH;; Copyright (c) 1984-2001, Microsoft Corporation. All rights reserved.;;Purpose:; Routines for SINH, COSH, TANH;;Revision History:;; 07/04/84 Greg Whitten; initial version;; 10/31/85 Jamie Bariteau; made _fFSINH and _fFCOSH public labels;; 10/30/87 Bill Johnston; Minor changes for new cmacros.;; 08/25/88 Bill Johnston; 386 version.;; 02/10/92 Georgios Papagiannakopoulos; NT port --used CHECKOVER for detection of overflow;;*******************************************************************************
.xlist include cruntime.inc include mrt386.inc include elem87.inc.list
.data
extrn _logemax:tbyteextrn _infinity:tbytestaticT _tanhmaxarg, 04003987E0C9996699000R
jmptab OP_SINH,4,<'sinh',0,0>,<0,0,0,0,0,0>,1 DNCPTR codeoffset fFSINH ; 0000 TOS Valid non-0 DNCPTR codeoffset _rttosnpop ; 0001 TOS 0 DNCPTR codeoffset _tosnan1 ; 0010 TOS NAN DNCPTR codeoffset _rtforsnhinf ; 0011 TOS Inf
jmptab OP_COSH,4,<'cosh',0,0>,<0,0,0,0,0,0>,1 DNCPTR codeoffset fFCOSH ; 0000 TOS Valid non-0 DNCPTR codeoffset _rtonenpop ; 0001 TOS 0 DNCPTR codeoffset _tosnan1 ; 0010 TOS NAN DNCPTR codeoffset _rtforcshinf ; 0011 TOS Inf
jmptab OP_TANH,4,<'tanh',0,0>,<0,0,0,0,0,0>,1 DNCPTR codeoffset fFTANH ; 0000 TOS Valid non-0 DNCPTR codeoffset _rttosnpop ; 0001 TOS 0 DNCPTR codeoffset _tosnan1 ; 0010 TOS NAN DNCPTR codeoffset _rtfortnhinf ; 0011 TOS Inf
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CODESEG
extrn _ffexpm1:nearextrn _rtchsifneg:nearextrn _rtindfnpop:nearextrn _rtinfnpop:nearextrn _rtonenpop:nearextrn _rttospop:nearextrn _rttosnpop:nearextrn _rttosnpopde:nearextrn _tosnan1:near
;----------------------------------------------------------;; HYPERBOLIC FUNCTIONS;;----------------------------------------------------------;; INPUTS - The argument is the stack top.; The sign of the argument is bit 2 of CL.;; OUTPUT - The result is the stack top;;----------------------------------------------------------
labelNP _fFSINH, PUBLIClab fFSINH mov DSF.ErrorType, CHECKOVER ; indicate possible overflow on exit call fFEXPH ; compute e^x for hyperbolics or bl, bl ; if e^x is infinite JSZ _rtforsnhlarge ; return as if x = affine infinity call ExpHypCopyInv ; TOS = e^(-x), NOS = e^x fsubp st(1), st(0) ; compute e^x - e^(-x) for hyperbolics jmp short SinhCoshReturn
lab fFTANH fld st(0) ; copy TOS fabs ; make TOS +ve fld [_tanhmaxarg] ; get largest arg, roughly ln(2)(55)/2 fcompp fstsw DSF.StatusWord fwait test CondCode, 041h ; if abs(arg) > XBIG (see tanh.h) JSNZ _rtfortnhlarge ; return as if x = affine infinity call fFEXPH ; compute e^x for hyperbolics or bl, bl ; if e^x is infinite JSZ _rtfortnhlarge ; return as if x = affine infinity fld st(0) ; copy TOS call ExpHypSum ; compute e^x + e^(-x) for hyperbolics fxch ; get copy of e^x call ExpHypCopyInv ; TOS = e^(-x), NOS = e^x fsubp st(1), st(0) ; compute e^x - e^(-x) for hyperbolics fdivrp st(1), st(0) ; now TOS = tanh(x) ret
labelNP _fFCOSH, PUBLIClab fFCOSH mov DSF.ErrorType, CHECKOVER ; indicate possible overflow on exit call fFEXPH ; compute e^x for hyperbolics or bl, bl ; if e^x is infinite JSZ _rtforcnhlarge ; return as if x = affine infinity call ExpHypSum ; compute e^x + e^(-x) for hyperbolics
lab SinhCoshReturn fld1 fchs fxch fscale ; divide result by 2 jmp _rttospop
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lab _rtforsnhinf fstp st(0) fld [_infinity] jmp _rtchsifneg ; change sign if argument -ve
lab _rtforcshinf fstp st(0) fld [_infinity] ret
lab infpositive ret
lab _rtforsnhlarge call _rtinfnpop ; TOS = infinity
lab chsifneg jmp _rtchsifneg ; change sign if argument -ve
lab _rtforcnhlarge jmp _rtinfnpop ; TOS = infinity
lab _rtfortnhlarge mov DSF.ErrorType, INEXACTlab _rtfortnhinf call _rtonenpop ; TOS = one jmp chsifneg ; change sign if argument -ve
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lab fFEXPH fldl2e fmul ; convert log base e to log base 2 xor rbx, rbx ; clear e^x, finite result flags call _ffexpm1 ; TOS = e^|x|-1 unscaled, NOS = scale not bl ; set finite result flag test CondCode, 1 ; if fraction > 0 (TOS > 0) JSZ ExpHypNoInvert ; bypass e^x-1 invert call ExpHypCopyInv ; TOS = e^(-x)-1, NOS = e^x-1 fxch fstp st(0) ; remove NOS
lab ExpHypNoInvert test dl, 040h ; if integer part was zero JSNZ ExpHypScaled ; bypass scaling to avoid bug not bh ; set e^x flag fld1 fadd ; TOS = e^x unscaled fscale ; now TOS = e^x
lab ExpHypScaled jmp _rttospop ; TOS = e^x-1 or e^x scaled
lab ExpHypSum call ExpHypCopyInv ; TOS = e^(-x), NOS = e^x fadd ; TOS = e^x + e^(-x) or bh, bh ; if e^x flag set JSNZ ExpHypSumReturn ; bypass e^x-1 adjust fld1 fadd st(1),st fadd ; add 2 to result
lab ExpHypSumReturn ret
lab ExpHypCopyInv fld st(0) ; TOS = e^x (or e^x-1) fld1 ; TOS = 1, NOS = e^x (or e^x-1) or bh, bh ; if e^x flag set JSNZ ExpHypCopyInvReturn ; bypass e^x-1 adjust fadd st, st(1) ; TOS = e^x, NOS = e^x-1 fchs ; TOS = -e^x, NOS = e^x-1 fxch ; TOS = e^x-1, NOS = -e^x
lab ExpHypCopyInvReturn fdivrp st(1), st(0) ; TOS = e^(-x) (or e^(-x)-1) ret
end
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