program FSINCOS_ ;

{$IFDEF WINDOWS} uses WinCrt ; {$ENDIF}

procedure _SinCos(var S, C : extended ; A : extended) ;
begin S := Sin(A) ; C := Cos(A) end {_SinCos} ;

{$IFDEF OLD}
{ Gives runtime fault/crash in BPW }
procedure FSinCos(var S, C : extended ; A : extended) ; assembler ;
asm  fld [A] ; db $CD,$35,$FB { >287: => fsincos; fpatan is CD35F3 } ;
  les di,[C] ; fstp es:tbyte ptr[di] ;
  les di,[S] ; fstp es:tbyte ptr[di] ;
  end {FSinCos} ;

function FTan(A : extended) : extended ; assembler ;
asm  fld [A] ; db $CD,$35,$FB ; FDIV  end {FTan} ;  (* OK? *)

function FCot(A : extended) : extended ; assembler ;
asm  fld [A] ; db $CD,$35,$FB ; FDIVR  end {FCot} ;  (* OK? *)

{$ELSE}
{ Gives compiler fault in Delphi - why ? }
procedure FSinCos(var S, C : extended ; A : extended) ; assembler ;
asm  fld [A] ; db $D9,$FB { >287: => fsincos; fpatan is D9F3 } ;
  les di,[C] ; fstp es:tbyte ptr[di] ;
  les di,[S] ; fstp es:tbyte ptr[di] ;
  end {FSinCos} ;

function FTan(A : extended) : extended ; assembler ;
asm  fld [A] ; db $D9,$FB ; FDIV  end {FTan} ;  (* OK? *)

function FCot(A : extended) : extended ; assembler ;
asm  fld [A] ; db $D9,$FB ; FDIVR  end {FCot} ;  (* OK? *)

{$ENDIF}

var P, Q, X, Y, R : extended ; K : shortint ;

BEGIN ;
Writeln('Radians   New FSin   Old Sin  Difference',
  {}          '    New FCos   Old Cos  Difference') ;
for k := -10 to +10 do begin R := 0.5*K ;
  FSinCos(P, Q, R) ; _SinCos(X, Y, R) ;
  Writeln(R:6:3,
    P:12:6, X:10:6, '':2, P-X:10, Q:12:6, Y:10:6, '':2, Q-Y:10) ;
  end ;
Write('<cr>') ; Readln ;
Writeln
  ('Radians      New FTan     Old Sin/Cos    Difference    Fractional') ;
for k := -10 to +10 do begin R := 0.5*K ;
  P := FTan(R) ; _SinCos(X, Y, R) ; X := X/Y ;
  Write(R:6:3, P:15:6, X:15:6, '':5, P-X:10) ;
  if X<>0.0 then Write('':4, (P-X)/X:10) ;
  Writeln end ;
Write('<cr>') ; Readln ;
Writeln
  ('Radians      New FCot     Old Cos/Sin    Difference    Fractional') ;
for k := -10 to +10 do if k=0 then Writeln(' 0.0') else begin
  R := 0.5*K ; P := FCot(R) ; _SinCos(X, Y, R) ; X := Y/X ;
  Write(R:6:3, P:15:6, X:15:6, '':5, P-X:10) ;
  if X<>0.0 then Write('':4, (P-X)/X:10) ;
  Writeln end ;
Write('<cr>') ; Readln ;
END.

N.B. The actual floating-point machine instructions are given as $CDhh.. ; 
AIUI, the CD is a software interrupt op-code which, when using a real FPU, 
is replaced by the appropriate value for an FPU op-code. 

The program seems OK in TP7 and BP7 (DOS & DPMI); 
"OLD" crashes in BPW (can break Windows);
Delphi 2 rejects "OLD" ("new"?) "fstp es:tbyte ptr[di]".
I don't know why.

www.merlyn.demon.co.uk   97/07/14, 98/10/19