/* SPDX-License-Identifier: GPL-2.0 */
|
/*---------------------------------------------------------------------------+
|
| 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 {
|
unsigned long lsw;
|
unsigned long midw;
|
unsigned long msw;
|
} Xsig;
|
|
asmlinkage void mul64(unsigned long long const *a, unsigned long long const *b,
|
unsigned long long *result);
|
asmlinkage void polynomial_Xsig(Xsig *, const unsigned long long *x,
|
const unsigned long long terms[], const int n);
|
|
asmlinkage void mul32_Xsig(Xsig *, const unsigned long mult);
|
asmlinkage void mul64_Xsig(Xsig *, const unsigned long long *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(Xsig *x1, const Xsig *x2, const Xsig *dest);
|
|
/* Macro to extract the most significant 32 bits from a long long */
|
#define LL_MSW(x) (((unsigned long *)&x)[1])
|
|
/* Macro to initialize an Xsig struct */
|
#define MK_XSIG(a,b,c) { c, b, a }
|
|
/* Macro to access the 8 ms bytes of an Xsig as a long long */
|
#define XSIG_LL(x) (*(unsigned long long *)&x.midw)
|
|
/*
|
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. */
|
/* Some versions of gcc make it difficult to stop eax from being clobbered.
|
Merely specifying that it is used doesn't work...
|
*/
|
static inline unsigned long mul_32_32(const unsigned long arg1,
|
const unsigned long arg2)
|
{
|
int retval;
|
asm volatile ("mull %2; movl %%edx,%%eax":"=a" (retval)
|
:"0"(arg1), "g"(arg2)
|
:"dx");
|
return retval;
|
}
|
|
/* 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)
|
{
|
asm volatile ("movl %1,%%edi; movl %2,%%esi;\n"
|
"movl (%%esi),%%eax; addl %%eax,(%%edi);\n"
|
"movl 4(%%esi),%%eax; adcl %%eax,4(%%edi);\n"
|
"movl 8(%%esi),%%eax; adcl %%eax,8(%%edi);\n":"=g"
|
(*dest):"g"(dest), "g"(x2)
|
:"ax", "si", "di");
|
}
|
|
/* Add the 12 byte Xsig x2 to Xsig dest, adjust exp if overflow occurs. */
|
/* 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! */
|
static inline void add_two_Xsig(Xsig *dest, const Xsig *x2, long int *exp)
|
{
|
asm volatile ("movl %2,%%ecx; movl %3,%%esi;\n"
|
"movl (%%esi),%%eax; addl %%eax,(%%ecx);\n"
|
"movl 4(%%esi),%%eax; adcl %%eax,4(%%ecx);\n"
|
"movl 8(%%esi),%%eax; adcl %%eax,8(%%ecx);\n"
|
"jnc 0f;\n"
|
"rcrl 8(%%ecx); rcrl 4(%%ecx); rcrl (%%ecx)\n"
|
"movl %4,%%ecx; incl (%%ecx)\n"
|
"movl $1,%%eax; jmp 1f;\n"
|
"0: xorl %%eax,%%eax;\n" "1:\n":"=g" (*exp), "=g"(*dest)
|
:"g"(dest), "g"(x2), "g"(exp)
|
:"cx", "si", "ax");
|
}
|
|
/* Negate (subtract from 1.0) the 12 byte Xsig */
|
/* This is faster in a loop on my 386 than using the "neg" instruction. */
|
static inline void negate_Xsig(Xsig *x)
|
{
|
asm volatile ("movl %1,%%esi;\n"
|
"xorl %%ecx,%%ecx;\n"
|
"movl %%ecx,%%eax; subl (%%esi),%%eax; movl %%eax,(%%esi);\n"
|
"movl %%ecx,%%eax; sbbl 4(%%esi),%%eax; movl %%eax,4(%%esi);\n"
|
"movl %%ecx,%%eax; sbbl 8(%%esi),%%eax; movl %%eax,8(%%esi);\n":"=g"
|
(*x):"g"(x):"si", "ax", "cx");
|
}
|
|
#endif /* _POLY_H */
|
