Bochs/bochs/fpu/reg_constant.c
Bryce Denney f850a6df1f These changes are from "portable1" patch.
- put /*comments symbols*/ around any chars after #endif.  Other compilers
  do not get it.
- fix cases in which a pointer is cast to a 32-bit int, then back to a
  pointer.  This breaks on a machine with 64-bit pointers.  Examples:
  FPU_sub arg 2 and FPU_div arg 2.  The int->ptr->int conversions are
  now done more safely by macros REGNO2PTR and PTR2INT.
- use GCC_ATTRIBUTE macro instead of __attribute__.  For compilers that
  do not support __attribute__, the macro can be defined to be nothing.
- in fpu_entry.c, arg1 of FPU_load_int32 is (s32*), but the calls to
  it cast their data to (u32*).
- if compiler does NOT inline functions in poly.h, the "extern inline"
  setting caused duplicate symbols to be created.  Changed them to
  "static inline" so that the mul_32_32 from different .c files do not
  conflict.
- implemented setcc so that it doesn't use curly brackets inside parens
- comment out sigcontext structure definition, which conflicts with
  non-linux or non-intel operating systems.  It's not used by bochs anyway.
2001-04-10 01:43:09 +00:00

120 lines
3.8 KiB
C

/*---------------------------------------------------------------------------+
| reg_constant.c |
| |
| All of the constant FPU_REGs |
| |
| 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 "fpu_emu.h"
#include "status_w.h"
#include "reg_constant.h"
#include "control_w.h"
FPU_REG const CONST_1 = MAKE_REG(POS, 0, 0x00000000, 0x80000000);
FPU_REG const CONST_2 = MAKE_REG(POS, 1, 0x00000000, 0x80000000);
FPU_REG const CONST_HALF = MAKE_REG(POS, -1, 0x00000000, 0x80000000);
FPU_REG const CONST_L2T = MAKE_REG(POS, 1, 0xcd1b8afe, 0xd49a784b);
FPU_REG const CONST_L2E = MAKE_REG(POS, 0, 0x5c17f0bc, 0xb8aa3b29);
FPU_REG const CONST_PI = MAKE_REG(POS, 1, 0x2168c235, 0xc90fdaa2);
// bbd: make CONST_PI2 non-const so that you can write "&CONST_PI2" when
// calling a function. Otherwise you get const warnings. Surely there's
// a better way.
FPU_REG CONST_PI2 = MAKE_REG(POS, 0, 0x2168c235, 0xc90fdaa2);
FPU_REG const CONST_PI4 = MAKE_REG(POS, -1, 0x2168c235, 0xc90fdaa2);
FPU_REG const CONST_LG2 = MAKE_REG(POS, -2, 0xfbcff799, 0x9a209a84);
FPU_REG const CONST_LN2 = MAKE_REG(POS, -1, 0xd1cf79ac, 0xb17217f7);
/* Extra bits to take pi/2 to more than 128 bits precision. */
FPU_REG const CONST_PI2extra = MAKE_REG(NEG, -66,
0xfc8f8cbb, 0xece675d1);
/* Only the sign (and tag) is used in internal zeroes */
FPU_REG const CONST_Z = MAKE_REG(POS, EXP_UNDER, 0x0, 0x0);
/* Only the sign and significand (and tag) are used in internal NaNs */
/* The 80486 never generates one of these
FPU_REG const CONST_SNAN = MAKE_REG(POS, EXP_OVER, 0x00000001, 0x80000000);
*/
/* This is the real indefinite QNaN */
FPU_REG const CONST_QNaN = MAKE_REG(NEG, EXP_OVER, 0x00000000, 0xC0000000);
/* Only the sign (and tag) is used in internal infinities */
FPU_REG const CONST_INF = MAKE_REG(POS, EXP_OVER, 0x00000000, 0x80000000);
static void fld_const(FPU_REG const *c, int adj, u_char tag)
{
FPU_REG *st_new_ptr;
if ( STACK_OVERFLOW )
{
FPU_stack_overflow();
return;
}
push();
reg_copy(c, st_new_ptr);
st_new_ptr->sigl += adj; /* For all our fldxxx constants, we don't need to
borrow or carry. */
FPU_settag0(tag);
clear_C1();
}
/* A fast way to find out whether x is one of RC_DOWN or RC_CHOP
(and not one of RC_RND or RC_UP).
*/
#define DOWN_OR_CHOP(x) (x & RC_DOWN)
static void fld1(int rc)
{
fld_const(&CONST_1, 0, TAG_Valid);
}
static void fldl2t(int rc)
{
fld_const(&CONST_L2T, (rc == RC_UP) ? 1 : 0, TAG_Valid);
}
static void fldl2e(int rc)
{
fld_const(&CONST_L2E, DOWN_OR_CHOP(rc) ? -1 : 0, TAG_Valid);
}
static void fldpi(int rc)
{
fld_const(&CONST_PI, DOWN_OR_CHOP(rc) ? -1 : 0, TAG_Valid);
}
static void fldlg2(int rc)
{
fld_const(&CONST_LG2, DOWN_OR_CHOP(rc) ? -1 : 0, TAG_Valid);
}
static void fldln2(int rc)
{
fld_const(&CONST_LN2, DOWN_OR_CHOP(rc) ? -1 : 0, TAG_Valid);
}
static void fldz(int rc)
{
fld_const(&CONST_Z, 0, TAG_Zero);
}
typedef void (*FUNC_RC)(int);
static FUNC_RC constants_table[] = {
fld1, fldl2t, fldl2e, fldpi, fldlg2, fldln2, fldz, (FUNC_RC)FPU_illegal
};
void fconst(void)
{
(constants_table[FPU_rm])(control_word & CW_RC);
}