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- /*---------------------------------------------------------------------------+
- | poly.h |
- | |
- | Header file for the FPU-emu poly*.c source files. |
- | |
- | Copyright (C) 1994 |
- | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
- | Australia. E-mail billm@vaxc.cc.monash.edu.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. */
- extern inline void mul_32_32(const unsigned long arg1,
- const unsigned long arg2,
- unsigned long *out)
- {
- asm volatile ("movl %1,%%eax; mull %2; movl %%edx,%0" \
- :"=g" (*out) \
- :"g" (arg1), "g" (arg2) \
- :"ax","dx");
- }
-
-
- /* Add the 12 byte Xsig x2 to Xsig dest, with no checks for overflow. */
- extern inline void add_Xsig_Xsig(Xsig *dest, const Xsig *x2)
- {
- 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");
- }
-
-
- /* 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! */
- extern inline int add_two_Xsig(Xsig *dest, const Xsig *x2, long int *exp)
- {
- 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");
- }
-
-
- /* Negate (subtract from 1.0) the 12 byte Xsig */
- /* This is faster in a loop on my 386 than using the "neg" instruction. */
- extern inline void negate_Xsig(Xsig *x)
- {
- 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 _POLY_H
-