freepascal.compiler/rtl/x86_64/math.inc

{
    This file is part of the Free Pascal run time library.
    Copyright (c) 1999-2001 by the Free Pascal development team

    Implementation of mathematical routines (for extended type)

    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.

 **********************************************************************}

{****************************************************************************
                            FPU Control word
 ****************************************************************************}

    procedure Set8087CW(cw:word);assembler;
    asm
      movw cw,%ax
{$ifdef FPC_PIC}
      movq default8087cw@GOTPCREL(%rip),%rax
      movw %ax,(%rax)
      fnclex
      fldcw (%rax)
{$else FPC_PIC}
      movw %ax,default8087cw
      fnclex
      fldcw default8087cw
{$endif FPC_PIC}
    end;

    function Get8087CW:word;assembler;
    asm
      pushq $0
      fnstcw (%rsp)
      popq %rax
    end;

{****************************************************************************
                       EXTENDED data type routines
 ****************************************************************************}

    {$define FPC_SYSTEM_HAS_PI}
    function fpc_pi_real : ValReal;compilerproc;
    begin
      { Function is handled internal in the compiler }
      runerror(207);
      result:=0;
    end;
    {$define FPC_SYSTEM_HAS_ABS}
    function fpc_abs_real(d : ValReal) : ValReal;compilerproc;
    begin
      { Function is handled internal in the compiler }
      runerror(207);
      result:=0;
    end;
    {$define FPC_SYSTEM_HAS_SQR}
    function fpc_sqr_real(d : ValReal) : ValReal;compilerproc;
    begin
      { Function is handled internal in the compiler }
      runerror(207);
      result:=0;
    end;
    {$define FPC_SYSTEM_HAS_SQRT}
    function fpc_sqrt_real(d : ValReal) : ValReal;compilerproc;
    begin
      { Function is handled internal in the compiler }
      runerror(207);
      result:=0;
    end;
    {$define FPC_SYSTEM_HAS_ARCTAN}
    function fpc_arctan_real(d : ValReal) : ValReal;compilerproc;
    begin
      { Function is handled internal in the compiler }
      runerror(207);
      result:=0;
    end;
    {$define FPC_SYSTEM_HAS_LN}
    function fpc_ln_real(d : ValReal) : ValReal;compilerproc;
    begin
      { Function is handled internal in the compiler }
      runerror(207);
      result:=0;
    end;
    {$define FPC_SYSTEM_HAS_SIN}
    function fpc_sin_real(d : ValReal) : ValReal;compilerproc;
    begin
      { Function is handled internal in the compiler }
      runerror(207);
      result:=0;
    end;
    {$define FPC_SYSTEM_HAS_COS}
    function fpc_cos_real(d : ValReal) : ValReal;compilerproc;
    begin
      { Function is handled internal in the compiler }
      runerror(207);
      result:=0;
    end;

    {$define FPC_SYSTEM_HAS_EXP}
    function fpc_exp_real(d : ValReal) : ValReal;assembler;compilerproc;
       asm
            subq        $16,%rsp
            // comes from DJ GPP
            fldt        d
            fldl2e
            fmulp       %st,%st(1)
            fstcw       -2(%rbp)
            fstcw       -4(%rbp)
            andw        $0xf3ff,-4(%rbp)
            orw         $0x0400,-4(%rbp)
            fldcw       -4(%rbp)
            fld         %st(0)
            frndint
            fldcw       -2(%rbp)
            fxch        %st(1)
            fsub        %st(1),%st
            f2xm1
            fld1
            faddp       %st,%st(1)
            fscale
            fstp        %st(1)
      end;


    {$define FPC_SYSTEM_HAS_FRAC}
    function fpc_frac_real(d : ValReal) : ValReal;assembler;compilerproc;
      asm
            subq $16,%rsp
            fnstcw -4(%rbp)
            fwait
            movw -4(%rbp),%cx
            orw $0x0c3f,%cx
            movw %cx,-8(%rbp)
            fldcw -8(%rbp)
            fwait
            fldt d
            frndint
            fldt d
            fsub %st(1),%st
            fstp %st(1)
            fnclex
            fldcw -4(%rbp)
      end;


    {$define FPC_SYSTEM_HAS_INT}
    function fpc_int_real(d : ValReal) : ValReal;assembler;compilerproc;
      asm
            subq $16,%rsp
            fnstcw -4(%rbp)
            fwait
            movw -4(%rbp),%cx
            orw $0x0c3f,%cx
            movw %cx,-8(%rbp)
            fldcw -8(%rbp)
            fwait
            fldt d
            frndint
            fwait
            fldcw -4(%rbp)
      end;



    {$define FPC_SYSTEM_HAS_TRUNC}
    function fpc_trunc_real(d : ValReal) : int64;assembler;compilerproc;
      var
        oldcw,
        newcw : word;
        res   : int64;
      asm
        fnstcw oldcw
        fwait
        movw oldcw,%cx
        orw $0x0c3f,%cx
        movw %cx,newcw
        fldcw newcw
        fldt d
        fistpq res
        fwait
        movq res,%rax
        fldcw oldcw
      end;


    {$define FPC_SYSTEM_HAS_ROUND}
    function fpc_round_real(d : ValReal) : int64;assembler;compilerproc;
      var
        res   : int64;
      asm
        fldt d
        fistpq res
        fwait
        movq res,%rax
      end;


    {$define FPC_SYSTEM_HAS_POWER}
   function power(bas,expo : extended) : extended;
     begin
        if bas=0 then
          begin
            if expo<>0 then
              power:=0.0
            else
              HandleError(207);
          end
        else if expo=0 then
         power:=1
        else
        { bas < 0 is not allowed }
         if bas<0 then
          handleerror(207)
         else
          power:=exp(ln(bas)*expo);
     end;