linux/arch/x86/math-emu/fpu_etc.c
Ingo Molnar 3d0d14f983 x86: lindent arch/i386/math-emu
lindent these files:
                                       errors   lines of code   errors/KLOC
 arch/x86/math-emu/                      2236            9424         237.2
 arch/x86/math-emu/                       128            8706          14.7

no other changes. No code changed:

   text    data     bss     dec     hex filename
   5589802  612739 3833856 10036397         9924ad vmlinux.before
   5589802  612739 3833856 10036397         9924ad vmlinux.after

the intent of this patch is to ease the automated tracking of kernel
code quality - it's just much easier for us to maintain it if every file
in arch/x86 is supposed to be clean.

NOTE: it is a known problem of lindent that it causes some style damage
of its own, but it's a safe tool (well, except for the gcc array range
initializers extension), so we did the bulk of the changes via lindent,
and did the manual fixups in a followup patch.

the resulting math-emu code has been tested by Thomas Gleixner on a real
386 DX CPU as well, and it works fine.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:11 +01:00

131 lines
3.1 KiB
C

/*---------------------------------------------------------------------------+
| fpu_etc.c |
| |
| Implement a few FPU instructions. |
| |
| Copyright (C) 1992,1993,1994,1997 |
| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
| Australia. E-mail billm@suburbia.net |
| |
| |
+---------------------------------------------------------------------------*/
#include "fpu_system.h"
#include "exception.h"
#include "fpu_emu.h"
#include "status_w.h"
#include "reg_constant.h"
static void fchs(FPU_REG * st0_ptr, u_char st0tag)
{
if (st0tag ^ TAG_Empty) {
signbyte(st0_ptr) ^= SIGN_NEG;
clear_C1();
} else
FPU_stack_underflow();
}
static void fabs(FPU_REG * st0_ptr, u_char st0tag)
{
if (st0tag ^ TAG_Empty) {
setpositive(st0_ptr);
clear_C1();
} else
FPU_stack_underflow();
}
static void ftst_(FPU_REG * st0_ptr, u_char st0tag)
{
switch (st0tag) {
case TAG_Zero:
setcc(SW_C3);
break;
case TAG_Valid:
if (getsign(st0_ptr) == SIGN_POS)
setcc(0);
else
setcc(SW_C0);
break;
case TAG_Special:
switch (FPU_Special(st0_ptr)) {
case TW_Denormal:
if (getsign(st0_ptr) == SIGN_POS)
setcc(0);
else
setcc(SW_C0);
if (denormal_operand() < 0) {
#ifdef PECULIAR_486
/* This is weird! */
if (getsign(st0_ptr) == SIGN_POS)
setcc(SW_C3);
#endif /* PECULIAR_486 */
return;
}
break;
case TW_NaN:
setcc(SW_C0 | SW_C2 | SW_C3); /* Operand is not comparable */
EXCEPTION(EX_Invalid);
break;
case TW_Infinity:
if (getsign(st0_ptr) == SIGN_POS)
setcc(0);
else
setcc(SW_C0);
break;
default:
setcc(SW_C0 | SW_C2 | SW_C3); /* Operand is not comparable */
EXCEPTION(EX_INTERNAL | 0x14);
break;
}
break;
case TAG_Empty:
setcc(SW_C0 | SW_C2 | SW_C3);
EXCEPTION(EX_StackUnder);
break;
}
}
static void fxam(FPU_REG * st0_ptr, u_char st0tag)
{
int c = 0;
switch (st0tag) {
case TAG_Empty:
c = SW_C3 | SW_C0;
break;
case TAG_Zero:
c = SW_C3;
break;
case TAG_Valid:
c = SW_C2;
break;
case TAG_Special:
switch (FPU_Special(st0_ptr)) {
case TW_Denormal:
c = SW_C2 | SW_C3; /* Denormal */
break;
case TW_NaN:
/* We also use NaN for unsupported types. */
if ((st0_ptr->sigh & 0x80000000)
&& (exponent(st0_ptr) == EXP_OVER))
c = SW_C0;
break;
case TW_Infinity:
c = SW_C2 | SW_C0;
break;
}
}
if (getsign(st0_ptr) == SIGN_NEG)
c |= SW_C1;
setcc(c);
}
static FUNC_ST0 const fp_etc_table[] = {
fchs, fabs, (FUNC_ST0) FPU_illegal, (FUNC_ST0) FPU_illegal,
ftst_, fxam, (FUNC_ST0) FPU_illegal, (FUNC_ST0) FPU_illegal
};
void FPU_etc(void)
{
(fp_etc_table[FPU_rm]) (&st(0), FPU_gettag0());
}