lilium-voyager/code/asm/ftola.c
Zack Middleton 2e3312676e Fix Elite Force rounding for SnapVector
Make QVM convertion of float to long use round to nearest instead of
round toward zero. This fixes EF's SnapVector. Though native libs will
still need to fix SnapVector in the game code itself.

Side note: this changes rounding in the renderer too.
2015-07-09 18:44:07 -05:00

113 lines
2.3 KiB
C

/*
===========================================================================
Copyright (C) 2011 Thilo Schulz <thilo@tjps.eu>
This file is part of Quake III Arena source code.
Quake III Arena source code 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.
Quake III Arena source code 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 Quake III Arena source code; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
===========================================================================
*/
#include "qasm-inline.h"
// Make Elite Force use round to nearest instead of round toward zero
#ifdef ELITEFORCE
static const unsigned short fpucw = 0x007F;
#else
static const unsigned short fpucw = 0x0C7F;
#endif
/*
* GNU inline asm ftol conversion functions using SSE or FPU
*/
long qftolsse(float f)
{
long retval;
__asm__ volatile
(
#ifdef ELITEFORCE
"cvtss2si %1, %0\n"
#else
"cvttss2si %1, %0\n"
#endif
: "=r" (retval)
: "x" (f)
);
return retval;
}
int qvmftolsse(void)
{
int retval;
__asm__ volatile
(
"movss (" EDI ", " EBX ", 4), %%xmm0\n"
#ifdef ELITEFORCE
"cvtss2si %%xmm0, %0\n"
#else
"cvttss2si %%xmm0, %0\n"
#endif
: "=r" (retval)
:
: "%xmm0"
);
return retval;
}
long qftolx87(float f)
{
long retval;
unsigned short oldcw = 0;
__asm__ volatile
(
"fnstcw %2\n"
"fldcw %3\n"
"flds %1\n"
"fistpl %1\n"
"fldcw %2\n"
"mov %1, %0\n"
: "=r" (retval)
: "m" (f), "m" (oldcw), "m" (fpucw)
);
return retval;
}
int qvmftolx87(void)
{
int retval;
unsigned short oldcw = 0;
__asm__ volatile
(
"fnstcw %1\n"
"fldcw %2\n"
"flds (" EDI ", " EBX ", 4)\n"
"fistpl (" EDI ", " EBX ", 4)\n"
"fldcw %1\n"
"mov (" EDI ", " EBX ", 4), %0\n"
: "=r" (retval)
: "m" (oldcw), "m" (fpucw)
);
return retval;
}