1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /*---------------------------------------------------------------------------+ |
3 | | poly.h | |
4 | | | |
5 | | Header file for the FPU-emu poly*.c source files. | |
6 | | | |
7 | | Copyright (C) 1994,1999 | |
8 | | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, | |
9 | | Australia. E-mail billm@melbpc.org.au | |
10 | | | |
11 | | Declarations and definitions for functions operating on Xsig (12-byte | |
12 | | extended-significand) quantities. | |
13 | | | |
14 | +---------------------------------------------------------------------------*/ |
15 | |
16 | #ifndef _POLY_H |
17 | #define _POLY_H |
18 | |
19 | /* This 12-byte structure is used to improve the accuracy of computation |
20 | of transcendental functions. |
21 | Intended to be used to get results better than 8-byte computation |
22 | allows. 9-byte would probably be sufficient. |
23 | */ |
24 | typedef struct { |
25 | unsigned long lsw; |
26 | unsigned long midw; |
27 | unsigned long msw; |
28 | } Xsig; |
29 | |
30 | asmlinkage void mul64(unsigned long long const *a, unsigned long long const *b, |
31 | unsigned long long *result); |
32 | asmlinkage void polynomial_Xsig(Xsig *, const unsigned long long *x, |
33 | const unsigned long long terms[], const int n); |
34 | |
35 | asmlinkage void mul32_Xsig(Xsig *, const unsigned long mult); |
36 | asmlinkage void mul64_Xsig(Xsig *, const unsigned long long *mult); |
37 | asmlinkage void mul_Xsig_Xsig(Xsig *dest, const Xsig *mult); |
38 | |
39 | asmlinkage void shr_Xsig(Xsig *, const int n); |
40 | asmlinkage int round_Xsig(Xsig *); |
41 | asmlinkage int norm_Xsig(Xsig *); |
42 | asmlinkage void div_Xsig(Xsig *x1, const Xsig *x2, const Xsig *dest); |
43 | |
44 | /* Macro to extract the most significant 32 bits from a long long */ |
45 | #define LL_MSW(x) (((unsigned long *)&x)[1]) |
46 | |
47 | /* Macro to initialize an Xsig struct */ |
48 | #define MK_XSIG(a,b,c) { c, b, a } |
49 | |
50 | /* Macro to access the 8 ms bytes of an Xsig as a long long */ |
51 | #define XSIG_LL(x) (*(unsigned long long *)&x.midw) |
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 | */ |
63 | static 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" :"=a" (retval) |
68 | :"0" (arg1), "g" (arg2) |
69 | :"dx" ); |
70 | return retval; |
71 | } |
72 | |
73 | /* Add the 12 byte Xsig x2 to Xsig dest, with no checks for overflow. */ |
74 | static inline void add_Xsig_Xsig(Xsig *dest, const Xsig *x2) |
75 | { |
76 | asm volatile ("movl %1,%%edi; movl %2,%%esi;\n" |
77 | "movl (%%esi),%%eax; addl %%eax,(%%edi);\n" |
78 | "movl 4(%%esi),%%eax; adcl %%eax,4(%%edi);\n" |
79 | "movl 8(%%esi),%%eax; adcl %%eax,8(%%edi);\n" :"=g" |
80 | (*dest):"g" (dest), "g" (x2) |
81 | :"ax" , "si" , "di" ); |
82 | } |
83 | |
84 | /* Add the 12 byte Xsig x2 to Xsig dest, adjust exp if overflow occurs. */ |
85 | /* Note: the constraints in the asm statement didn't always work properly |
86 | with gcc 2.5.8. Changing from using edi to using ecx got around the |
87 | problem, but keep fingers crossed! */ |
88 | static inline void add_two_Xsig(Xsig *dest, const Xsig *x2, long int *exp) |
89 | { |
90 | asm volatile ("movl %2,%%ecx; movl %3,%%esi;\n" |
91 | "movl (%%esi),%%eax; addl %%eax,(%%ecx);\n" |
92 | "movl 4(%%esi),%%eax; adcl %%eax,4(%%ecx);\n" |
93 | "movl 8(%%esi),%%eax; adcl %%eax,8(%%ecx);\n" |
94 | "jnc 0f;\n" |
95 | "rcrl 8(%%ecx); rcrl 4(%%ecx); rcrl (%%ecx)\n" |
96 | "movl %4,%%ecx; incl (%%ecx)\n" |
97 | "movl $1,%%eax; jmp 1f;\n" |
98 | "0: xorl %%eax,%%eax;\n" "1:\n" :"=g" (*exp), "=g" (*dest) |
99 | :"g" (dest), "g" (x2), "g" (exp) |
100 | :"cx" , "si" , "ax" ); |
101 | } |
102 | |
103 | /* Negate (subtract from 1.0) the 12 byte Xsig */ |
104 | /* This is faster in a loop on my 386 than using the "neg" instruction. */ |
105 | static inline void negate_Xsig(Xsig *x) |
106 | { |
107 | asm volatile ("movl %1,%%esi;\n" |
108 | "xorl %%ecx,%%ecx;\n" |
109 | "movl %%ecx,%%eax; subl (%%esi),%%eax; movl %%eax,(%%esi);\n" |
110 | "movl %%ecx,%%eax; sbbl 4(%%esi),%%eax; movl %%eax,4(%%esi);\n" |
111 | "movl %%ecx,%%eax; sbbl 8(%%esi),%%eax; movl %%eax,8(%%esi);\n" :"=g" |
112 | (*x):"g" (x):"si" , "ax" , "cx" ); |
113 | } |
114 | |
115 | #endif /* _POLY_H */ |
116 | |