Bochs/bochs/fpu/poly.h
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

218 lines
6.3 KiB
C

/*---------------------------------------------------------------------------+
| poly.h |
| |
| Header file for the FPU-emu poly*.c source files. |
| |
| Copyright (C) 1994,1999 |
| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
| Australia. E-mail billm@melbpc.org.au |
| |
| Declarations and definitions for functions operating on Xsig (12-byte |
| extended-significand) quantities. |
| |
+---------------------------------------------------------------------------*/
#ifndef _POLY_H
#define _POLY_H
/* This 12-byte structure is used to improve the accuracy of computation
of transcendental functions.
Intended to be used to get results better than 8-byte computation
allows. 9-byte would probably be sufficient.
*/
typedef struct {
#ifdef EMU_BIG_ENDIAN
u32 msw;
u32 midw;
u32 lsw;
#else
u32 lsw;
u32 midw;
u32 msw;
#endif
} GCC_ATTRIBUTE((packed)) Xsig;
asmlinkage void mul64(u64 const *a, u64 const *b,
u64 *result);
asmlinkage void polynomial_Xsig(Xsig *, const u64 *x,
const u64 terms[], const int n);
asmlinkage void mul32_Xsig(Xsig *, const u32 mult);
asmlinkage void mul64_Xsig(Xsig *, const u64 *mult);
asmlinkage void mul_Xsig_Xsig(Xsig *dest, const Xsig *mult);
asmlinkage void shr_Xsig(Xsig *, const int n);
asmlinkage int round_Xsig(Xsig *);
asmlinkage int norm_Xsig(Xsig *);
asmlinkage void div_Xsig(const Xsig *x1, const Xsig *x2, Xsig *dest);
/* Macro to extract the most significant 32 bits from a 64bit quantity */
#ifdef EMU_BIG_ENDIAN
#define LL_MSW(x) (((u32 *)&x)[0])
#else
#define LL_MSW(x) (((u32 *)&x)[1])
#endif
/* Macro to initialize an Xsig struct */
#ifdef EMU_BIG_ENDIAN
#define MK_XSIG(a,b,c) { a, b, c }
#else
#define MK_XSIG(a,b,c) { c, b, a }
#endif
/* Macro to access the 8 ms bytes of an Xsig as a 64bit quantity */
#ifdef EMU_BIG_ENDIAN
#define XSIG_LL(x) (*(u64 *)&x.msw)
#else
#define XSIG_LL(x) (*(u64 *)&x.midw)
#endif
/*
Need to run gcc with optimizations on to get these to
actually be in-line.
*/
/* Multiply two fixed-point 32 bit numbers, producing a 32 bit result.
The answer is the ms word of the product.
bbd: this and all other inline functions in this file used to be
declared extern inline. But if the compiler does not inline the function,
each .c declares its own external symbol for the function, leading to
symbol conflicts. static inline seems to be safe in either case.
*/
static inline u32 mul_32_32(const u32 arg1, const u32 arg2)
{
#ifdef NO_ASSEMBLER
return (((u64)arg1) * arg2) >> 32;
#else
/* Some versions of gcc make it difficult to stop eax from being clobbered.
Merely specifying that it is used doesn't work...
*/
int retval;
asm volatile ("mull %2; movl %%edx,%%eax" \
:"=a" (retval) \
:"0" (arg1), "g" (arg2) \
:"dx");
return retval;
#endif
}
/* Add the 12 byte Xsig x2 to Xsig dest, with no checks for overflow. */
static inline void add_Xsig_Xsig(Xsig *dest, const Xsig *x2)
{
#ifdef NO_ASSEMBLER
dest->lsw += x2->lsw;
if ( dest->lsw < x2->lsw )
{
dest->midw ++;
if ( dest->midw == 0 )
dest->msw ++;
}
dest->midw += x2->midw;
if ( dest->midw < x2->midw )
{
dest->msw ++;
}
dest->msw += x2->msw;
#else
asm volatile ("movl %1,%%edi; movl %2,%%esi;
movl (%%esi),%%eax; addl %%eax,(%%edi);
movl 4(%%esi),%%eax; adcl %%eax,4(%%edi);
movl 8(%%esi),%%eax; adcl %%eax,8(%%edi);"
:"=g" (*dest):"g" (dest), "g" (x2)
:"ax","si","di");
#endif
}
/* Add the 12 byte Xsig x2 to Xsig dest, adjust exp if overflow occurs. */
static inline void add_two_Xsig(Xsig *dest, const Xsig *x2, s32 *exp)
{
#ifdef NO_ASSEMBLER
int ovfl = 0;
dest->lsw += x2->lsw;
if ( dest->lsw < x2->lsw )
{
dest->midw ++;
if ( dest->midw == 0 )
{
dest->msw ++;
if ( dest->msw == 0 )
ovfl = 1;
}
}
dest->midw += x2->midw;
if ( dest->midw < x2->midw )
{
dest->msw ++;
if ( dest->msw == 0 )
ovfl = 1;
}
dest->msw += x2->msw;
if ( dest->msw < x2->msw )
ovfl = 1;
if ( ovfl )
{
(*exp) ++;
dest->lsw >>= 1;
if ( dest->midw & 1 )
dest->lsw |= 0x80000000;
dest->midw >>= 1;
if ( dest->msw & 1 )
dest->midw |= 0x80000000;
dest->msw >>= 1;
dest->msw |= 0x80000000;
}
#else
/* Note: the constraints in the asm statement didn't always work properly
with gcc 2.5.8. Changing from using edi to using ecx got around the
problem, but keep fingers crossed! */
asm volatile ("movl %2,%%ecx; movl %3,%%esi;
movl (%%esi),%%eax; addl %%eax,(%%ecx);
movl 4(%%esi),%%eax; adcl %%eax,4(%%ecx);
movl 8(%%esi),%%eax; adcl %%eax,8(%%ecx);
jnc 0f;
rcrl 8(%%ecx); rcrl 4(%%ecx); rcrl (%%ecx)
movl %4,%%ecx; incl (%%ecx)
movl $1,%%eax; jmp 1f;
0: xorl %%eax,%%eax;
1:"
:"=g" (*exp), "=g" (*dest)
:"g" (dest), "g" (x2), "g" (exp)
:"cx","si","ax");
#endif
}
/* Negate the 12 byte Xsig */
static inline void negate_Xsig(Xsig *x)
{
#ifdef NO_ASSEMBLER
x->lsw = ~x->lsw;
x->midw = ~x->midw;
x->msw = ~x->msw;
x->lsw ++;
if ( x->lsw == 0 )
{
x->midw ++;
if ( x->midw == 0 )
x->msw ++;
}
#else
/* Negate (subtract from 1.0) the 12 byte Xsig */
/* This is faster in a loop on my 386 than using the "neg" instruction. */
asm volatile("movl %1,%%esi; "
"xorl %%ecx,%%ecx; "
"movl %%ecx,%%eax; subl (%%esi),%%eax; movl %%eax,(%%esi); "
"movl %%ecx,%%eax; sbbl 4(%%esi),%%eax; movl %%eax,4(%%esi); "
"movl %%ecx,%%eax; sbbl 8(%%esi),%%eax; movl %%eax,8(%%esi); "
:"=g" (*x):"g" (x):"si","ax","cx");
#endif
}
#endif /* _POLY_H */