linux/arch/x86/math-emu/fpu_aux.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

187 lines
4.1 KiB
C

/*---------------------------------------------------------------------------+
| fpu_aux.c |
| |
| Code to implement some of the FPU auxiliary 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 "control_w.h"
static void fnop(void)
{
}
static void fclex(void)
{
partial_status &=
~(SW_Backward | SW_Summary | SW_Stack_Fault | SW_Precision |
SW_Underflow | SW_Overflow | SW_Zero_Div | SW_Denorm_Op |
SW_Invalid);
no_ip_update = 1;
}
/* Needs to be externally visible */
void finit(void)
{
control_word = 0x037f;
partial_status = 0;
top = 0; /* We don't keep top in the status word internally. */
fpu_tag_word = 0xffff;
/* The behaviour is different from that detailed in
Section 15.1.6 of the Intel manual */
operand_address.offset = 0;
operand_address.selector = 0;
instruction_address.offset = 0;
instruction_address.selector = 0;
instruction_address.opcode = 0;
no_ip_update = 1;
}
/*
* These are nops on the i387..
*/
#define feni fnop
#define fdisi fnop
#define fsetpm fnop
static FUNC const finit_table[] = {
feni, fdisi, fclex, finit,
fsetpm, FPU_illegal, FPU_illegal, FPU_illegal
};
void finit_(void)
{
(finit_table[FPU_rm]) ();
}
static void fstsw_ax(void)
{
*(short *)&FPU_EAX = status_word();
no_ip_update = 1;
}
static FUNC const fstsw_table[] = {
fstsw_ax, FPU_illegal, FPU_illegal, FPU_illegal,
FPU_illegal, FPU_illegal, FPU_illegal, FPU_illegal
};
void fstsw_(void)
{
(fstsw_table[FPU_rm]) ();
}
static FUNC const fp_nop_table[] = {
fnop, FPU_illegal, FPU_illegal, FPU_illegal,
FPU_illegal, FPU_illegal, FPU_illegal, FPU_illegal
};
void fp_nop(void)
{
(fp_nop_table[FPU_rm]) ();
}
void fld_i_(void)
{
FPU_REG *st_new_ptr;
int i;
u_char tag;
if (STACK_OVERFLOW) {
FPU_stack_overflow();
return;
}
/* fld st(i) */
i = FPU_rm;
if (NOT_EMPTY(i)) {
reg_copy(&st(i), st_new_ptr);
tag = FPU_gettagi(i);
push();
FPU_settag0(tag);
} else {
if (control_word & CW_Invalid) {
/* The masked response */
FPU_stack_underflow();
} else
EXCEPTION(EX_StackUnder);
}
}
void fxch_i(void)
{
/* fxch st(i) */
FPU_REG t;
int i = FPU_rm;
FPU_REG *st0_ptr = &st(0), *sti_ptr = &st(i);
long tag_word = fpu_tag_word;
int regnr = top & 7, regnri = ((regnr + i) & 7);
u_char st0_tag = (tag_word >> (regnr * 2)) & 3;
u_char sti_tag = (tag_word >> (regnri * 2)) & 3;
if (st0_tag == TAG_Empty) {
if (sti_tag == TAG_Empty) {
FPU_stack_underflow();
FPU_stack_underflow_i(i);
return;
}
if (control_word & CW_Invalid) {
/* Masked response */
FPU_copy_to_reg0(sti_ptr, sti_tag);
}
FPU_stack_underflow_i(i);
return;
}
if (sti_tag == TAG_Empty) {
if (control_word & CW_Invalid) {
/* Masked response */
FPU_copy_to_regi(st0_ptr, st0_tag, i);
}
FPU_stack_underflow();
return;
}
clear_C1();
reg_copy(st0_ptr, &t);
reg_copy(sti_ptr, st0_ptr);
reg_copy(&t, sti_ptr);
tag_word &= ~(3 << (regnr * 2)) & ~(3 << (regnri * 2));
tag_word |= (sti_tag << (regnr * 2)) | (st0_tag << (regnri * 2));
fpu_tag_word = tag_word;
}
void ffree_(void)
{
/* ffree st(i) */
FPU_settagi(FPU_rm, TAG_Empty);
}
void ffreep(void)
{
/* ffree st(i) + pop - unofficial code */
FPU_settagi(FPU_rm, TAG_Empty);
FPU_pop();
}
void fst_i_(void)
{
/* fst st(i) */
FPU_copy_to_regi(&st(0), FPU_gettag0(), FPU_rm);
}
void fstp_i(void)
{
/* fstp st(i) */
FPU_copy_to_regi(&st(0), FPU_gettag0(), FPU_rm);
FPU_pop();
}