180 lines
3.7 KiB
C
180 lines
3.7 KiB
C
/*---------------------------------------------------------------------------+
|
|
| fpu_aux.c |
|
|
| |
|
|
| Code to implement some of the FPU auxiliary instructions. |
|
|
| |
|
|
| Copyright (C) 1992,1993,1994 |
|
|
| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
|
|
| Australia. E-mail billm@vaxc.cc.monash.edu.au |
|
|
| |
|
|
| |
|
|
+---------------------------------------------------------------------------*/
|
|
|
|
#include "fpu_system.h"
|
|
#include "exception.h"
|
|
#include "fpu_emu.h"
|
|
#include "status_w.h"
|
|
#include "control_w.h"
|
|
|
|
|
|
|
|
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_NET_DATA_EFFECT;
|
|
FPU_entry_eip = ip_offset; /* We want no net effect */
|
|
}
|
|
|
|
/* Needs to be externally visible */
|
|
void finit()
|
|
{
|
|
int r;
|
|
control_word = 0x037f;
|
|
partial_status = 0;
|
|
top = 0; /* We don't keep top in the status word internally. */
|
|
for (r = 0; r < 8; r++)
|
|
{
|
|
regs[r].tag = TW_Empty;
|
|
}
|
|
/* The behaviour is different to that detailed in
|
|
Section 15.1.6 of the Intel manual */
|
|
data_operand_offset = 0;
|
|
operand_selector = 0;
|
|
NO_NET_DATA_EFFECT;
|
|
FPU_entry_op_cs = 0;
|
|
FPU_entry_eip = ip_offset = 0;
|
|
}
|
|
|
|
static FUNC const finit_table[] = {
|
|
Un_impl, Un_impl, fclex, finit,
|
|
Un_impl, FPU_illegal, FPU_illegal, FPU_illegal
|
|
};
|
|
|
|
void finit_()
|
|
{
|
|
(finit_table[FPU_rm])();
|
|
}
|
|
|
|
|
|
static void fstsw_ax(void)
|
|
{
|
|
*(short *) &FPU_EAX = status_word();
|
|
NO_NET_INSTR_EFFECT;
|
|
}
|
|
|
|
static FUNC const fstsw_table[] = {
|
|
fstsw_ax, FPU_illegal, FPU_illegal, FPU_illegal,
|
|
FPU_illegal, FPU_illegal, FPU_illegal, FPU_illegal
|
|
};
|
|
|
|
void fstsw_()
|
|
{
|
|
(fstsw_table[FPU_rm])();
|
|
}
|
|
|
|
|
|
|
|
static void fnop(void)
|
|
{
|
|
}
|
|
|
|
static FUNC const fp_nop_table[] = {
|
|
fnop, FPU_illegal, FPU_illegal, FPU_illegal,
|
|
FPU_illegal, FPU_illegal, FPU_illegal, FPU_illegal
|
|
};
|
|
|
|
void fp_nop()
|
|
{
|
|
(fp_nop_table[FPU_rm])();
|
|
}
|
|
|
|
|
|
void fld_i_()
|
|
{
|
|
FPU_REG *st_new_ptr;
|
|
|
|
if ( STACK_OVERFLOW )
|
|
{ stack_overflow(); return; }
|
|
|
|
/* fld st(i) */
|
|
if ( NOT_EMPTY(FPU_rm) )
|
|
{ reg_move(&st(FPU_rm), st_new_ptr); push(); }
|
|
else
|
|
{
|
|
if ( control_word & EX_Invalid )
|
|
{
|
|
/* The masked response */
|
|
push();
|
|
stack_underflow();
|
|
}
|
|
else
|
|
EXCEPTION(EX_StackUnder);
|
|
}
|
|
|
|
}
|
|
|
|
|
|
void fxch_i()
|
|
{
|
|
/* fxch st(i) */
|
|
FPU_REG t;
|
|
register FPU_REG *sti_ptr = &st(FPU_rm);
|
|
|
|
if ( FPU_st0_tag == TW_Empty )
|
|
{
|
|
if ( sti_ptr->tag == TW_Empty )
|
|
{
|
|
stack_underflow();
|
|
stack_underflow_i(FPU_rm);
|
|
return;
|
|
}
|
|
if ( control_word & CW_Invalid )
|
|
reg_move(sti_ptr, FPU_st0_ptr); /* Masked response */
|
|
stack_underflow_i(FPU_rm);
|
|
return;
|
|
}
|
|
if ( sti_ptr->tag == TW_Empty )
|
|
{
|
|
if ( control_word & CW_Invalid )
|
|
reg_move(FPU_st0_ptr, sti_ptr); /* Masked response */
|
|
stack_underflow();
|
|
return;
|
|
}
|
|
clear_C1();
|
|
reg_move(FPU_st0_ptr, &t);
|
|
reg_move(sti_ptr, FPU_st0_ptr);
|
|
reg_move(&t, sti_ptr);
|
|
}
|
|
|
|
|
|
void ffree_()
|
|
{
|
|
/* ffree st(i) */
|
|
st(FPU_rm).tag = TW_Empty;
|
|
}
|
|
|
|
|
|
void ffreep()
|
|
{
|
|
/* ffree st(i) + pop - unofficial code */
|
|
st(FPU_rm).tag = TW_Empty;
|
|
pop();
|
|
}
|
|
|
|
|
|
void fst_i_()
|
|
{
|
|
/* fst st(i) */
|
|
reg_move(FPU_st0_ptr, &st(FPU_rm));
|
|
}
|
|
|
|
|
|
void fstp_i()
|
|
{
|
|
/* fstp st(i) */
|
|
reg_move(FPU_st0_ptr, &st(FPU_rm));
|
|
pop();
|
|
}
|
|
|