freepascal.compiler/rtl/i8086/basemath.inc

{
    This file is part of the Free Pascal run time library.
    Copyright (c) 1999-2003 by Florian Klaempfl
    member of the Free Pascal development team

    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.

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

function GetRoundMode: TFPURoundingMode;
begin
  Result := TFPURoundingMode((Get8087CW shr 10) and 3);
end;


function SetRoundMode(const RoundMode: TFPURoundingMode): TFPURoundingMode;
var
  CtlWord: Word;
begin
  softfloat_rounding_mode:=RoundMode;
  CtlWord := Get8087CW;
  Set8087CW((CtlWord and $F3FF) or (Ord(RoundMode) shl 10));
{  if has_sse_support then
    SetSSECSR((GetSSECSR and $ffff9fff) or (dword(RoundMode) shl 13));}
  Result := TFPURoundingMode((CtlWord shr 10) and 3);
end;

function GetPrecisionMode: TFPUPrecisionMode;
begin
  Result := TFPUPrecisionMode((Get8087CW shr 8) and 3);
end;

function SetPrecisionMode(const Precision: TFPUPrecisionMode): TFPUPrecisionMode;
var
  CtlWord: Word;
begin
  CtlWord := Get8087CW;
  Set8087CW((CtlWord and $FCFF) or (Ord(Precision) shl 8));
  Result := TFPUPrecisionMode((CtlWord shr 8) and 3);
end;

function GetExceptionMask: TFPUExceptionMask;
begin
  Result := TFPUExceptionMask(Byte(Get8087CW and $3F));
end;

function SetExceptionMask(const Mask: TFPUExceptionMask): TFPUExceptionMask;
var
  CtlWord: Word;
begin
  CtlWord := Get8087CW;
  Set8087CW( (CtlWord and $FFC0) or Byte(Mask) );
{  if has_sse_support then
    SetSSECSR((GetSSECSR and $ffffe07f) or (dword(Mask) shl 7));}
  Result := TFPUExceptionMask(Byte(CtlWord and $3F));
end;

procedure ClearExceptions(RaisePending: Boolean);assembler;
asm
  cmp byte RaisePending, 0
  je @Lclear
  fwait
@Lclear:
  fnclex
end;