diff options
Diffstat (limited to 'arch/i386/math-emu/fpu_aux.c')
| -rw-r--r-- | arch/i386/math-emu/fpu_aux.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/arch/i386/math-emu/fpu_aux.c b/arch/i386/math-emu/fpu_aux.c new file mode 100644 index 00000000000..20886cfb9f7 --- /dev/null +++ b/arch/i386/math-emu/fpu_aux.c @@ -0,0 +1,204 @@ +/*---------------------------------------------------------------------------+ + | 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(); +} + |