quakeforge/libs/util/sys_ia32.S

/*
	sys_ia32.S

	Intel 32-bit assembly language dependent routines.

	Copyright (C) 1996-1997  Id Software, Inc.

	This program is free software; you can redistribute it and/or
	modify it under the terms of the GNU General Public License
	as published by the Free Software Foundation; either version 2
	of the License, or (at your option) any later version.

	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.

	See the GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to:

		Free Software Foundation, Inc.
		59 Temple Place - Suite 330
		Boston, MA  02111-1307, USA

	$Id$
*/

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include "asm_i386.h"


#ifdef USE_INTEL_ASM

#ifdef WIN32
# undef PIC		//no such thing in win32
#endif

	.data

	.align	4
fpenv:
	.long	0, 0, 0, 0, 0, 0, 0, 0

#ifdef PIC
#define got_base(n)										\
	call	.Lpic##n									;\
.Lpic##n:												;\
	popl	%edx										;\
	addl	$C(_GLOBAL_OFFSET_TABLE_)+[.-.Lpic##n],%edx

#define got_var(v) v@GOT(%edx)
#else
#define got_base(n)
#define got_var(v) v
#endif

	.text

.globl C(MaskExceptions)
#ifdef PIC
	.type	C(MaskExceptions),@function
#endif
C(MaskExceptions):
	got_base(1)
	fnstenv	got_var(fpenv)
	orl		$0x3F,got_var(fpenv)
	fldenv	got_var(fpenv)

	ret

#if 0
.globl C(unmaskexceptions)
C(unmaskexceptions):
	fnstenv	got_var(fpenv)
	andl		$0xFFFFFFE0,got_var(fpenv)
	fldenv	got_var(fpenv)

	ret
#endif

	.data

	.align	4
.globl	ceil_cw, single_cw, full_cw, cw, pushed_cw
ceil_cw:	.long	0
single_cw:	.long	0
full_cw:	.long	0
cw:			.long	0
pushed_cw:	.long	0

	.text

.globl C(Sys_LowFPPrecision)
C(Sys_LowFPPrecision):
	fldcw	got_var(single_cw)

	ret

.globl C(Sys_HighFPPrecision)
C(Sys_HighFPPrecision):
	fldcw	got_var(full_cw)

	ret

.globl C(Sys_PushFPCW_SetHigh)
C(Sys_PushFPCW_SetHigh):
	fnstcw	got_var(pushed_cw)
	fldcw	got_var(full_cw)

	ret

.globl C(Sys_PopFPCW)
C(Sys_PopFPCW):
	fldcw	got_var(pushed_cw)

	ret

.globl C(Sys_SetFPCW)
C(Sys_SetFPCW):
	fnstcw	got_var(cw)
	movl	got_var(cw),%eax
	andb	$0xF0,%ah
	orb		$0x03,%ah	// round mode, 64-bit precision
	movl	%eax,got_var(full_cw)

	andb	$0xF0,%ah
	orb		$0x0C,%ah	// chop mode, single precision
	movl	%eax,got_var(single_cw)

	andb	$0xF0,%ah
	orb		$0x08,%ah	// ceil mode, single precision
	movl	%eax,got_var(ceil_cw)

	ret
#endif /* USE_INTEL_ASM */