1/*---------------------------------------------------------------------------+ 2 | poly.h | 3 | | 4 | Header file for the FPU-emu poly*.c source files. | 5 | | 6 | Copyright (C) 1994,1999 | 7 | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, | 8 | Australia. E-mail billm@melbpc.org.au | 9 | | 10 | Declarations and definitions for functions operating on Xsig (12-byte | 11 | extended-significand) quantities. | 12 | | 13 +---------------------------------------------------------------------------*/ 14 15#ifndef _POLY_H 16#define _POLY_H 17 18/* This 12-byte structure is used to improve the accuracy of computation 19 of transcendental functions. 20 Intended to be used to get results better than 8-byte computation 21 allows. 9-byte would probably be sufficient. 22 */ 23typedef struct { 24 unsigned long lsw; 25 unsigned long midw; 26 unsigned long msw; 27} Xsig; 28 29asmlinkage void mul64(unsigned long long const *a, unsigned long long const *b, 30 unsigned long long *result); 31asmlinkage void polynomial_Xsig(Xsig *, const unsigned long long *x, 32 const unsigned long long terms[], const int n); 33 34asmlinkage void mul32_Xsig(Xsig *, const unsigned long mult); 35asmlinkage void mul64_Xsig(Xsig *, const unsigned long long *mult); 36asmlinkage void mul_Xsig_Xsig(Xsig *dest, const Xsig *mult); 37 38asmlinkage void shr_Xsig(Xsig *, const int n); 39asmlinkage int round_Xsig(Xsig *); 40asmlinkage int norm_Xsig(Xsig *); 41asmlinkage void div_Xsig(Xsig *x1, const Xsig *x2, const Xsig *dest); 42 43/* Macro to extract the most significant 32 bits from a long long */ 44#define LL_MSW(x) (((unsigned long *)&x)[1]) 45 46/* Macro to initialize an Xsig struct */ 47#define MK_XSIG(a,b,c) { c, b, a } 48 49/* Macro to access the 8 ms bytes of an Xsig as a long long */ 50#define XSIG_LL(x) (*(unsigned long long *)&x.midw) 51 52 53/* 54 Need to run gcc with optimizations on to get these to 55 actually be in-line. 56 */ 57 58/* Multiply two fixed-point 32 bit numbers, producing a 32 bit result. 59 The answer is the ms word of the product. */ 60/* Some versions of gcc make it difficult to stop eax from being clobbered. 61 Merely specifying that it is used doesn't work... 62 */ 63static inline unsigned long mul_32_32(const unsigned long arg1, 64 const unsigned long arg2) 65{ 66 int retval; 67 asm volatile ("mull %2; movl %%edx,%%eax" \ 68 :"=a" (retval) \ 69 :"0" (arg1), "g" (arg2) \ 70 :"dx"); 71 return retval; 72} 73 74 75/* Add the 12 byte Xsig x2 to Xsig dest, with no checks for overflow. */ 76static inline void add_Xsig_Xsig(Xsig *dest, const Xsig *x2) 77{ 78 asm volatile ("movl %1,%%edi; movl %2,%%esi;\n" 79 "movl (%%esi),%%eax; addl %%eax,(%%edi);\n" 80 "movl 4(%%esi),%%eax; adcl %%eax,4(%%edi);\n" 81 "movl 8(%%esi),%%eax; adcl %%eax,8(%%edi);\n" 82 :"=g" (*dest):"g" (dest), "g" (x2) 83 :"ax","si","di"); 84} 85 86 87/* Add the 12 byte Xsig x2 to Xsig dest, adjust exp if overflow occurs. */ 88/* Note: the constraints in the asm statement didn't always work properly 89 with gcc 2.5.8. Changing from using edi to using ecx got around the 90 problem, but keep fingers crossed! */ 91static inline void add_two_Xsig(Xsig *dest, const Xsig *x2, long int *exp) 92{ 93 asm volatile ("movl %2,%%ecx; movl %3,%%esi;\n" 94 "movl (%%esi),%%eax; addl %%eax,(%%ecx);\n" 95 "movl 4(%%esi),%%eax; adcl %%eax,4(%%ecx);\n" 96 "movl 8(%%esi),%%eax; adcl %%eax,8(%%ecx);\n" 97 "jnc 0f;\n" 98 "rcrl 8(%%ecx); rcrl 4(%%ecx); rcrl (%%ecx)\n" 99 "movl %4,%%ecx; incl (%%ecx)\n" 100 "movl $1,%%eax; jmp 1f;\n" 101 "0: xorl %%eax,%%eax;\n" 102 "1:\n" 103 :"=g" (*exp), "=g" (*dest) 104 :"g" (dest), "g" (x2), "g" (exp) 105 :"cx","si","ax"); 106} 107 108 109/* Negate (subtract from 1.0) the 12 byte Xsig */ 110/* This is faster in a loop on my 386 than using the "neg" instruction. */ 111static inline void negate_Xsig(Xsig *x) 112{ 113 asm volatile("movl %1,%%esi;\n" 114 "xorl %%ecx,%%ecx;\n" 115 "movl %%ecx,%%eax; subl (%%esi),%%eax; movl %%eax,(%%esi);\n" 116 "movl %%ecx,%%eax; sbbl 4(%%esi),%%eax; movl %%eax,4(%%esi);\n" 117 "movl %%ecx,%%eax; sbbl 8(%%esi),%%eax; movl %%eax,8(%%esi);\n" 118 :"=g" (*x):"g" (x):"si","ax","cx"); 119} 120 121#endif /* _POLY_H */ 122