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fpc/rtl/inc/genmath.inc
peter e7c86006db * m68k updates merged
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{
$Id$
This file is part of the Free Pascal run time library.
Copyright (c) 1999-2001 by Several contributors
Generic mathemtical routines (on type real)
See the file COPYING.FPC, included in this distribution,
for details about the copyright.
This program 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.
**********************************************************************}
{*************************************************************************}
{ Credits }
{*************************************************************************}
{ Copyright Abandoned, 1987, Fred Fish }
{ }
{ This previously copyrighted work has been placed into the }
{ public domain by the author (Fred Fish) and may be freely used }
{ for any purpose, private or commercial. I would appreciate }
{ it, as a courtesy, if this notice is left in all copies and }
{ derivative works. Thank you, and enjoy... }
{ }
{ The author makes no warranty of any kind with respect to this }
{ product and explicitly disclaims any implied warranties of }
{ merchantability or fitness for any particular purpose. }
{-------------------------------------------------------------------------}
{ Copyright (c) 1992 Odent Jean Philippe }
{ }
{ The source can be modified as long as my name appears and some }
{ notes explaining the modifications done are included in the file. }
{-------------------------------------------------------------------------}
{ Copyright (c) 1997 Carl Eric Codere }
{-------------------------------------------------------------------------}
{$goto on}
type
TabCoef = array[0..6] of Real;
const
PIO2 = 1.57079632679489661923; { pi/2 }
PIO4 = 7.85398163397448309616E-1; { pi/4 }
SQRT2 = 1.41421356237309504880; { sqrt(2) }
SQRTH = 7.07106781186547524401E-1; { sqrt(2)/2 }
LOG2E = 1.4426950408889634073599; { 1/log(2) }
SQ2OPI = 7.9788456080286535587989E-1; { sqrt( 2/pi )}
LOGE2 = 6.93147180559945309417E-1; { log(2) }
LOGSQ2 = 3.46573590279972654709E-1; { log(2)/2 }
THPIO4 = 2.35619449019234492885; { 3*pi/4 }
TWOOPI = 6.36619772367581343075535E-1; { 2/pi }
lossth = 1.073741824e9;
MAXLOG = 8.8029691931113054295988E1; { log(2**127) }
MINLOG = -8.872283911167299960540E1; { log(2**-128) }
DP1 = 7.85398125648498535156E-1;
DP2 = 3.77489470793079817668E-8;
DP3 = 2.69515142907905952645E-15;
const sincof : TabCoef = (
1.58962301576546568060E-10,
-2.50507477628578072866E-8,
2.75573136213857245213E-6,
-1.98412698295895385996E-4,
8.33333333332211858878E-3,
-1.66666666666666307295E-1, 0);
coscof : TabCoef = (
-1.13585365213876817300E-11,
2.08757008419747316778E-9,
-2.75573141792967388112E-7,
2.48015872888517045348E-5,
-1.38888888888730564116E-3,
4.16666666666665929218E-2, 0);
{$ifndef FPC_SYSTEM_HAS_TRUNC}
type
float32 = longint;
{$ifdef ENDIAN_LITTLE}
float64 = packed record
low: longint;
high: longint;
end;
{$else}
float64 = packed record
high: longint;
low: longint;
end;
{$endif}
flag = byte;
Function extractFloat64Frac0(a: float64): longint;
Begin
extractFloat64Frac0 := a.high and $000FFFFF;
End;
Function extractFloat64Frac1(a: float64): longint;
Begin
extractFloat64Frac1 := a.low;
End;
Function extractFloat64Exp(a: float64): smallint;
Begin
extractFloat64Exp:= ( a.high shr 20 ) AND $7FF;
End;
Function extractFloat64Sign(a: float64) : flag;
Begin
extractFloat64Sign := a.high shr 31;
End;
Procedure
shortShift64Left(
a0:longint; a1:longint; count:smallint; VAR z0Ptr:longint; VAR z1Ptr:longint );
Begin
z1Ptr := a1 shl count;
if count = 0 then
z0Ptr := a0
else
z0Ptr := ( a0 shl count ) OR ( a1 shr ( ( - count ) AND 31 ) );
End;
function float64_to_int32_round_to_zero(a: float64 ): longint;
Var
aSign: flag;
aExp, shiftCount: smallint;
aSig0, aSig1, absZ, aSigExtra: longint;
z: smallint;
label invalid;
Begin
aSig1 := extractFloat64Frac1( a );
aSig0 := extractFloat64Frac0( a );
aExp := extractFloat64Exp( a );
aSign := extractFloat64Sign( a );
shiftCount := aExp - $413;
if ( 0 <= shiftCount ) then
Begin
if ( $41E < aExp ) then
Begin
if ( ( aExp = $7FF ) AND (( aSig0 OR aSig1 )<>0) ) then
aSign := 0;
goto invalid;
End;
shortShift64Left(
aSig0 OR $00100000, aSig1, shiftCount, absZ, aSigExtra );
End
else
Begin
if ( aExp < $3FF ) then
Begin
float64_to_int32_round_to_zero := 0;
exit;
End;
aSig0 := aSig0 or $00100000;
aSigExtra := ( aSig0 shl ( shiftCount and 31 ) ) OR aSig1;
absZ := aSig0 shr ( - shiftCount );
End;
if aSign <> 0 then
z := - absZ
else
z := absZ;
if ( (( aSign xor flag( z < 0 )) <> 0) AND (z<>0) ) then
Begin
invalid:
RunError(207);
exit;
End;
float64_to_int32_round_to_zero := z;
End;
Function ExtractFloat32Frac(a : Float32) : longint;
Begin
ExtractFloat32Frac := A AND $007FFFFF;
End;
Function extractFloat32Exp( a: float32 ): smallint;
Begin
extractFloat32Exp := (a shr 23) AND $FF;
End;
Function extractFloat32Sign( a: float32 ): Flag;
Begin
extractFloat32Sign := a shr 31;
End;
Function float32_to_int32_round_to_zero( a: Float32 ): longint;
Var
aSign : flag;
aExp, shiftCount : smallint;
aSig : longint;
z : longint;
Begin
aSig := extractFloat32Frac( a );
aExp := extractFloat32Exp( a );
aSign := extractFloat32Sign( a );
shiftCount := aExp - $9E;
if ( 0 <= shiftCount ) then
Begin
if ( a <> $CF000000 ) then
Begin
if ( (aSign=0) or ( ( aExp = $FF ) and (aSig<>0) ) ) then
Begin
RunError(207);
exit;
end;
End;
RunError(207);
exit;
End
else
if ( aExp <= $7E ) then
Begin
float32_to_int32_round_to_zero := 0;
exit;
End;
aSig := ( aSig or $00800000 ) shl 8;
z := aSig shr ( - shiftCount );
if ( aSign<>0 ) then z := - z;
float32_to_int32_round_to_zero := z;
End;
function trunc(d : real) : longint;[internconst:in_const_trunc];
var
l: longint;
f32 : float32;
f64 : float64;
Begin
{ in emulation mode the real is equal to a single }
{ otherwise in fpu mode, it is equal to a double }
{ extended is not supported yet. }
if sizeof(D) > 8 then
RunError(255);
if sizeof(D)=8 then
begin
move(d,f64,sizeof(f64));
trunc:=float64_to_int32_round_to_zero(f64);
end
else
begin
move(d,f32,sizeof(f32));
trunc:=float32_to_int32_round_to_zero(f32);
end;
end;
{$endif}
{$ifndef FPC_SYSTEM_HAS_INT}
function int(d : real) : real;[internconst:in_const_int];
begin
{ this will be correct since real = single in the case of }
{ the motorola version of the compiler... }
int:=real(trunc(d));
end;
{$endif}
{$ifndef FPC_SYSTEM_HAS_ABS}
function abs(d : Real) : Real;[internconst:in_const_abs];
begin
if( d < 0.0 ) then
abs := -d
else
abs := d ;
end;
{$endif}
function frexp(x:Real; var e:Integer ):Real;
{* frexp() extracts the exponent from x. It returns an integer *}
{* power of two to expnt and the significand between 0.5 and 1 *}
{* to y. Thus x = y * 2**expn. *}
begin
e :=0;
if (abs(x)<0.5) then
While (abs(x)<0.5) do
begin
x := x*2;
Dec(e);
end
else
While (abs(x)>1) do
begin
x := x/2;
Inc(e);
end;
frexp := x;
end;
function ldexp( x: Real; N: Integer):Real;
{* ldexp() multiplies x by 2**n. *}
var r : Real;
begin
R := 1;
if N>0 then
while N>0 do
begin
R:=R*2;
Dec(N);
end
else
while N<0 do
begin
R:=R/2;
Inc(N);
end;
ldexp := x * R;
end;
function polevl(var x:Real; var Coef:TabCoef; N:Integer):Real;
{*****************************************************************}
{ Evaluate polynomial }
{*****************************************************************}
{ }
{ SYNOPSIS: }
{ }
{ int N; }
{ double x, y, coef[N+1], polevl[]; }
{ }
{ y = polevl( x, coef, N ); }
{ }
{ DESCRIPTION: }
{ }
{ Evaluates polynomial of degree N: }
{ }
{ 2 N }
{ y = C + C x + C x +...+ C x }
{ 0 1 2 N }
{ }
{ Coefficients are stored in reverse order: }
{ }
{ coef[0] = C , ..., coef[N] = C . }
{ N 0 }
{ }
{ The function p1evl() assumes that coef[N] = 1.0 and is }
{ omitted from the array. Its calling arguments are }
{ otherwise the same as polevl(). }
{ }
{ SPEED: }
{ }
{ In the interest of speed, there are no checks for out }
{ of bounds arithmetic. This routine is used by most of }
{ the functions in the library. Depending on available }
{ equipment features, the user may wish to rewrite the }
{ program in microcode or assembly language. }
{*****************************************************************}
var ans : Real;
i : Integer;
begin
ans := Coef[0];
for i:=1 to N do
ans := ans * x + Coef[i];
polevl:=ans;
end;
function p1evl(var x:Real; var Coef:TabCoef; N:Integer):Real;
{ }
{ Evaluate polynomial when coefficient of x is 1.0. }
{ Otherwise same as polevl. }
{ }
var
ans : Real;
i : Integer;
begin
ans := x + Coef[0];
for i:=1 to N-1 do
ans := ans * x + Coef[i];
p1evl := ans;
end;
{$ifndef FPC_SYSTEM_HAS_SQR}
function sqr(d : Real) : Real;[internconst:in_const_sqr];
begin
sqr := d*d;
end;
{$endif}
{$ifndef FPC_SYSTEM_HAS_PI}
function pi : Real;[internconst:in_const_pi];
begin
pi := 3.1415926535897932385;
end;
{$endif}
{$ifndef FPC_SYSTEM_HAS_SQRT}
function sqrt(d:Real):Real;[internconst:in_const_sqrt];
{*****************************************************************}
{ Square root }
{*****************************************************************}
{ }
{ SYNOPSIS: }
{ }
{ double x, y, sqrt(); }
{ }
{ y = sqrt( x ); }
{ }
{ DESCRIPTION: }
{ }
{ Returns the square root of x. }
{ }
{ Range reduction involves isolating the power of two of the }
{ argument and using a polynomial approximation to obtain }
{ a rough value for the square root. Then Heron's iteration }
{ is used three times to converge to an accurate value. }
{*****************************************************************}
var e : Integer;
w,z : Real;
begin
if( d <= 0.0 ) then
begin
if( d < 0.0 ) then
RunError(207);
sqrt := 0.0;
end
else
begin
w := d;
{ separate exponent and significand }
z := frexp( d, e );
{ approximate square root of number between 0.5 and 1 }
{ relative error of approximation = 7.47e-3 }
d := 4.173075996388649989089E-1 + 5.9016206709064458299663E-1 * z;
{ adjust for odd powers of 2 }
if odd(e) then
d := d*SQRT2;
{ re-insert exponent }
d := ldexp( d, (e div 2) );
{ Newton iterations: }
d := 0.5*(d + w/d);
d := 0.5*(d + w/d);
d := 0.5*(d + w/d);
d := 0.5*(d + w/d);
d := 0.5*(d + w/d);
d := 0.5*(d + w/d);
sqrt := d;
end;
end;
{$endif}
{$ifndef FPC_SYSTEM_HAS_EXP}
function Exp(d:Real):Real;[internconst:in_const_exp];
{*****************************************************************}
{ Exponential Function }
{*****************************************************************}
{ }
{ SYNOPSIS: }
{ }
{ double x, y, exp(); }
{ }
{ y = exp( x ); }
{ }
{ DESCRIPTION: }
{ }
{ Returns e (2.71828...) raised to the x power. }
{ }
{ Range reduction is accomplished by separating the argument }
{ into an integer k and fraction f such that }
{ }
{ x k f }
{ e = 2 e. }
{ }
{ A Pade' form of degree 2/3 is used to approximate exp(f)- 1 }
{ in the basic range [-0.5 ln 2, 0.5 ln 2]. }
{*****************************************************************}
const P : TabCoef = (
1.26183092834458542160E-4,
3.02996887658430129200E-2,
1.00000000000000000000E0, 0, 0, 0, 0);
Q : TabCoef = (
3.00227947279887615146E-6,
2.52453653553222894311E-3,
2.27266044198352679519E-1,
2.00000000000000000005E0, 0 ,0 ,0);
C1 = 6.9335937500000000000E-1;
C2 = 2.1219444005469058277E-4;
var n : Integer;
px, qx, xx : Real;
begin
if( d > MAXLOG) then
RunError(205)
else
if( d < MINLOG ) then
begin
Runerror(205);
end
else
begin
{ Express e**x = e**g 2**n }
{ = e**g e**( n loge(2) ) }
{ = e**( g + n loge(2) ) }
px := d * LOG2E;
qx := Trunc( px + 0.5 ); { Trunc() truncates toward -infinity. }
n := Trunc(qx);
d := d - qx * C1;
d := d + qx * C2;
{ rational approximation for exponential }
{ of the fractional part: }
{ e**x - 1 = 2x P(x**2)/( Q(x**2) - P(x**2) ) }
xx := d * d;
px := d * polevl( xx, P, 2 );
d := px/( polevl( xx, Q, 3 ) - px );
d := ldexp( d, 1 );
d := d + 1.0;
d := ldexp( d, n );
Exp := d;
end;
end;
{$endif}
{$ifndef FPC_SYSTEM_HAS_ROUND}
function Round(d: Real): longint;[internconst:in_const_round];
var
fr: Real;
tr: Real;
Begin
fr := Frac(d);
tr := Trunc(d);
if fr > 0.5 then
Round:=Trunc(d)+1
else
if fr < 0.5 then
Round:=Trunc(d)
else { fr = 0.5 }
{ check sign to decide ... }
{ as in Turbo Pascal... }
if d >= 0.0 then
Round := Trunc(d)+1
else
Round := Trunc(d);
end;
{$endif}
{$ifndef FPC_SYSTEM_HAS_LN}
function Ln(d:Real):Real;[internconst:in_const_ln];
{*****************************************************************}
{ Natural Logarithm }
{*****************************************************************}
{ }
{ SYNOPSIS: }
{ }
{ double x, y, log(); }
{ }
{ y = ln( x ); }
{ }
{ DESCRIPTION: }
{ }
{ Returns the base e (2.718...) logarithm of x. }
{ }
{ The argument is separated into its exponent and fractional }
{ parts. If the exponent is between -1 and +1, the logarithm }
{ of the fraction is approximated by }
{ }
{ log(1+x) = x - 0.5 x**2 + x**3 P(x)/Q(x). }
{ }
{ Otherwise, setting z = 2(x-1)/x+1), }
{ }
{ log(x) = z + z**3 P(z)/Q(z). }
{ }
{*****************************************************************}
const P : TabCoef = (
{ Coefficients for log(1+x) = x - x**2/2 + x**3 P(x)/Q(x)
1/sqrt(2) <= x < sqrt(2) }
4.58482948458143443514E-5,
4.98531067254050724270E-1,
6.56312093769992875930E0,
2.97877425097986925891E1,
6.06127134467767258030E1,
5.67349287391754285487E1,
1.98892446572874072159E1);
Q : TabCoef = (
1.50314182634250003249E1,
8.27410449222435217021E1,
2.20664384982121929218E2,
3.07254189979530058263E2,
2.14955586696422947765E2,
5.96677339718622216300E1, 0);
{ Coefficients for log(x) = z + z**3 P(z)/Q(z),
where z = 2(x-1)/(x+1)
1/sqrt(2) <= x < sqrt(2) }
R : TabCoef = (
-7.89580278884799154124E-1,
1.63866645699558079767E1,
-6.41409952958715622951E1, 0, 0, 0, 0);
S : TabCoef = (
-3.56722798256324312549E1,
3.12093766372244180303E2,
-7.69691943550460008604E2, 0, 0, 0, 0);
var e : Integer;
z, y : Real;
Label Ldone;
begin
if( d <= 0.0 ) then
RunError(207);
d := frexp( d, e );
{ logarithm using log(x) = z + z**3 P(z)/Q(z),
where z = 2(x-1)/x+1) }
if( (e > 2) or (e < -2) ) then
begin
if( d < SQRTH ) then
begin
{ 2( 2x-1 )/( 2x+1 ) }
Dec(e, 1);
z := d - 0.5;
y := 0.5 * z + 0.5;
end
else
begin
{ 2 (x-1)/(x+1) }
z := d - 0.5;
z := z - 0.5;
y := 0.5 * d + 0.5;
end;
d := z / y;
{ /* rational form */ }
z := d*d;
z := d + d * ( z * polevl( z, R, 2 ) / p1evl( z, S, 3 ) );
goto ldone;
end;
{ logarithm using log(1+x) = x - .5x**2 + x**3 P(x)/Q(x) }
if( d < SQRTH ) then
begin
Dec(e, 1);
d := ldexp( d, 1 ) - 1.0; { 2x - 1 }
end
else
d := d - 1.0;
{ rational form }
z := d*d;
y := d * ( z * polevl( d, P, 6 ) / p1evl( d, Q, 6 ) );
y := y - ldexp( z, -1 ); { y - 0.5 * z }
z := d + y;
ldone:
{ recombine with exponent term }
if( e <> 0 ) then
begin
y := e;
z := z - y * 2.121944400546905827679e-4;
z := z + y * 0.693359375;
end;
Ln:= z;
end;
{$endif}
{$ifndef FPC_SYSTEM_HAS_SIN}
function Sin(d:Real):Real;[internconst:in_const_sin];
{*****************************************************************}
{ Circular Sine }
{*****************************************************************}
{ }
{ SYNOPSIS: }
{ }
{ double x, y, sin(); }
{ }
{ y = sin( x ); }
{ }
{ DESCRIPTION: }
{ }
{ Range reduction is into intervals of pi/4. The reduction }
{ error is nearly eliminated by contriving an extended }
{ precision modular arithmetic. }
{ }
{ Two polynomial approximating functions are employed. }
{ Between 0 and pi/4 the sine is approximated by }
{ x + x**3 P(x**2). }
{ Between pi/4 and pi/2 the cosine is represented as }
{ 1 - x**2 Q(x**2). }
{*****************************************************************}
var y, z, zz : Real;
j, sign : Integer;
begin
{ make argument positive but save the sign }
sign := 1;
if( d < 0 ) then
begin
d := -d;
sign := -1;
end;
{ above this value, approximate towards 0 }
if( d > lossth ) then
begin
sin := 0.0;
exit;
end;
y := Trunc( d/PIO4 ); { integer part of x/PIO4 }
{ strip high bits of integer part to prevent integer overflow }
z := ldexp( y, -4 );
z := Trunc(z); { integer part of y/8 }
z := y - ldexp( z, 4 ); { y - 16 * (y/16) }
j := Trunc(z); { convert to integer for tests on the phase angle }
{ map zeros to origin }
if odd( j ) then
begin
inc(j);
y := y + 1.0;
end;
j := j and 7; { octant modulo 360 degrees }
{ reflect in x axis }
if( j > 3) then
begin
sign := -sign;
dec(j, 4);
end;
{ Extended precision modular arithmetic }
z := ((d - y * DP1) - y * DP2) - y * DP3;
zz := z * z;
if( (j=1) or (j=2) ) then
y := 1.0 - ldexp(zz,-1) + zz * zz * polevl( zz, coscof, 5 )
else
{ y = z + z * (zz * polevl( zz, sincof, 5 )); }
y := z + z * z * z * polevl( zz, sincof, 5 );
if(sign < 0) then
y := -y;
sin := y;
end;
{$endif}
{$ifndef FPC_SYSTEM_HAS_COS}
function Cos(d:Real):Real;[internconst:in_const_cos];
{*****************************************************************}
{ Circular cosine }
{*****************************************************************}
{ }
{ Circular cosine }
{ }
{ SYNOPSIS: }
{ }
{ double x, y, cos(); }
{ }
{ y = cos( x ); }
{ }
{ DESCRIPTION: }
{ }
{ Range reduction is into intervals of pi/4. The reduction }
{ error is nearly eliminated by contriving an extended }
{ precision modular arithmetic. }
{ }
{ Two polynomial approximating functions are employed. }
{ Between 0 and pi/4 the cosine is approximated by }
{ 1 - x**2 Q(x**2). }
{ Between pi/4 and pi/2 the sine is represented as }
{ x + x**3 P(x**2). }
{*****************************************************************}
var y, z, zz : Real;
j, sign : Integer;
i : LongInt;
begin
{ make argument positive }
sign := 1;
if( d < 0 ) then
d := -d;
{ above this value, round towards zero }
if( d > lossth ) then
begin
cos := 0.0;
exit;
end;
y := Trunc( d/PIO4 );
z := ldexp( y, -4 );
z := Trunc(z); { integer part of y/8 }
z := y - ldexp( z, 4 ); { y - 16 * (y/16) }
{ integer and fractional part modulo one octant }
i := Trunc(z);
if odd( i ) then { map zeros to origin }
begin
inc(i);
y := y + 1.0;
end;
j := i and 07;
if( j > 3) then
begin
dec(j,4);
sign := -sign;
end;
if( j > 1 ) then
sign := -sign;
{ Extended precision modular arithmetic }
z := ((d - y * DP1) - y * DP2) - y * DP3;
zz := z * z;
if( (j=1) or (j=2) ) then
{ y = z + z * (zz * polevl( zz, sincof, 5 )); }
y := z + z * z * z * polevl( zz, sincof, 5 )
else
y := 1.0 - ldexp(zz,-1) + zz * zz * polevl( zz, coscof, 5 );
if(sign < 0) then
y := -y;
cos := y ;
end;
{$endif}
{$ifndef FPC_SYSTEM_HAS_ARCTAN}
function ArcTan(d:Real):Real;[internconst:in_const_arctan];
{*****************************************************************}
{ Inverse circular tangent (arctangent) }
{*****************************************************************}
{ }
{ SYNOPSIS: }
{ }
{ double x, y, atan(); }
{ }
{ y = atan( x ); }
{ }
{ DESCRIPTION: }
{ }
{ Returns radian angle between -pi/2 and +pi/2 whose tangent }
{ is x. }
{ }
{ Range reduction is from four intervals into the interval }
{ from zero to tan( pi/8 ). The approximant uses a rational }
{ function of degree 3/4 of the form x + x**3 P(x)/Q(x). }
{*****************************************************************}
const P : TabCoef = (
-8.40980878064499716001E-1,
-8.83860837023772394279E0,
-2.18476213081316705724E1,
-1.48307050340438946993E1, 0, 0, 0);
Q : TabCoef = (
1.54974124675307267552E1,
6.27906555762653017263E1,
9.22381329856214406485E1,
4.44921151021319438465E1, 0, 0, 0);
{ tan( 3*pi/8 ) }
T3P8 = 2.41421356237309504880;
{ tan( pi/8 ) }
TP8 = 0.41421356237309504880;
var y,z : Real;
Sign : Integer;
begin
{ make argument positive and save the sign }
sign := 1;
if( d < 0.0 ) then
begin
sign := -1;
d := -d;
end;
{ range reduction }
if( d > T3P8 ) then
begin
y := PIO2;
d := -( 1.0/d );
end
else if( d > TP8 ) then
begin
y := PIO4;
d := (d-1.0)/(d+1.0);
end
else
y := 0.0;
{ rational form in x**2 }
z := d * d;
y := y + ( polevl( z, P, 3 ) / p1evl( z, Q, 4 ) ) * z * d + d;
if( sign < 0 ) then
y := -y;
Arctan := y;
end;
{$endif}
{$ifndef FPC_SYSTEM_HAS_FRAC}
function frac(d : Real) : Real;[internconst:in_const_frac];
begin
frac := d - Int(d);
end;
{$endif}
{$ifndef FPC_SYSTEM_HAS_POWER}
function power(bas,expo : real) : real;
begin
if bas=0.0 then
begin
if expo<>0.0 then
power:=0.0
else
HandleError(207);
end
else if expo=0.0 then
power:=1
else
{ bas < 0 is not allowed }
if bas<0.0 then
handleerror(207)
else
power:=exp(ln(bas)*expo);
end;
function power(bas,expo : longint) : longint;
begin
if bas=0 then
begin
if expo<>0 then
power:=0
else
HandleError(207);
end
else if expo=0 then
power:=1
else
begin
if bas<0 then
begin
if odd(expo) then
power:=-round(exp(ln(-bas)*expo))
else
power:=round(exp(ln(-bas)*expo));
end
else
power:=round(exp(ln(bas)*expo));
end;
end;
{$endif}
{
$Log$
Revision 1.2 2001-07-30 21:38:55 peter
* m68k updates merged
Revision 1.1.2.1 2001/07/29 23:58:16 carl
+ generic version of mathematical routines (taken from m68k directory)
}
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