xref: /openbmc/u-boot/arch/nios2/lib/longlong.h (revision 6b7c0f5e)
1 /* longlong.h -- definitions for mixed size 32/64 bit arithmetic.
2    Copyright (C) 1991, 1992, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2004,
3    2005  Free Software Foundation, Inc.
4 
5    This definition file is free software; you can redistribute it
6    and/or modify it under the terms of the GNU General Public
7    License as published by the Free Software Foundation; either
8    version 2, or (at your option) any later version.
9 
10    This definition file is distributed in the hope that it will be
11    useful, but WITHOUT ANY WARRANTY; without even the implied
12    warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
13    See the GNU General Public License for more details.
14 
15    You should have received a copy of the GNU General Public License
16    along with this program; if not, write to the Free Software
17    Foundation, Inc., 51 Franklin Street, Fifth Floor,
18    Boston, MA 02110-1301, USA.  */
19 
20 /* You have to define the following before including this file:
21 
22    UWtype -- An unsigned type, default type for operations (typically a "word")
23    UHWtype -- An unsigned type, at least half the size of UWtype.
24    UDWtype -- An unsigned type, at least twice as large a UWtype
25    W_TYPE_SIZE -- size in bits of UWtype
26 
27    UQItype -- Unsigned 8 bit type.
28    SItype, USItype -- Signed and unsigned 32 bit types.
29    DItype, UDItype -- Signed and unsigned 64 bit types.
30 
31    On a 32 bit machine UWtype should typically be USItype;
32    on a 64 bit machine, UWtype should typically be UDItype.  */
33 
34 #define __BITS4 (W_TYPE_SIZE / 4)
35 #define __ll_B ((UWtype) 1 << (W_TYPE_SIZE / 2))
36 #define __ll_lowpart(t) ((UWtype) (t) & (__ll_B - 1))
37 #define __ll_highpart(t) ((UWtype) (t) >> (W_TYPE_SIZE / 2))
38 
39 #ifndef W_TYPE_SIZE
40 #define W_TYPE_SIZE	32
41 #define UWtype		USItype
42 #define UHWtype		USItype
43 #define UDWtype		UDItype
44 #endif
45 
46 extern const UQItype __clz_tab[256];
47 
48 /* Define auxiliary asm macros.
49 
50    1) umul_ppmm(high_prod, low_prod, multiplier, multiplicand) multiplies two
51    UWtype integers MULTIPLIER and MULTIPLICAND, and generates a two UWtype
52    word product in HIGH_PROD and LOW_PROD.
53 
54    2) __umulsidi3(a,b) multiplies two UWtype integers A and B, and returns a
55    UDWtype product.  This is just a variant of umul_ppmm.
56 
57    3) udiv_qrnnd(quotient, remainder, high_numerator, low_numerator,
58    denominator) divides a UDWtype, composed by the UWtype integers
59    HIGH_NUMERATOR and LOW_NUMERATOR, by DENOMINATOR and places the quotient
60    in QUOTIENT and the remainder in REMAINDER.  HIGH_NUMERATOR must be less
61    than DENOMINATOR for correct operation.  If, in addition, the most
62    significant bit of DENOMINATOR must be 1, then the pre-processor symbol
63    UDIV_NEEDS_NORMALIZATION is defined to 1.
64 
65    4) sdiv_qrnnd(quotient, remainder, high_numerator, low_numerator,
66    denominator).  Like udiv_qrnnd but the numbers are signed.  The quotient
67    is rounded towards 0.
68 
69    5) count_leading_zeros(count, x) counts the number of zero-bits from the
70    msb to the first nonzero bit in the UWtype X.  This is the number of
71    steps X needs to be shifted left to set the msb.  Undefined for X == 0,
72    unless the symbol COUNT_LEADING_ZEROS_0 is defined to some value.
73 
74    6) count_trailing_zeros(count, x) like count_leading_zeros, but counts
75    from the least significant end.
76 
77    7) add_ssaaaa(high_sum, low_sum, high_addend_1, low_addend_1,
78    high_addend_2, low_addend_2) adds two UWtype integers, composed by
79    HIGH_ADDEND_1 and LOW_ADDEND_1, and HIGH_ADDEND_2 and LOW_ADDEND_2
80    respectively.  The result is placed in HIGH_SUM and LOW_SUM.  Overflow
81    (i.e. carry out) is not stored anywhere, and is lost.
82 
83    8) sub_ddmmss(high_difference, low_difference, high_minuend, low_minuend,
84    high_subtrahend, low_subtrahend) subtracts two two-word UWtype integers,
85    composed by HIGH_MINUEND_1 and LOW_MINUEND_1, and HIGH_SUBTRAHEND_2 and
86    LOW_SUBTRAHEND_2 respectively.  The result is placed in HIGH_DIFFERENCE
87    and LOW_DIFFERENCE.  Overflow (i.e. carry out) is not stored anywhere,
88    and is lost.
89 
90    If any of these macros are left undefined for a particular CPU,
91    C macros are used.  */
92 
93 /* The CPUs come in alphabetical order below.
94 
95    Please add support for more CPUs here, or improve the current support
96    for the CPUs below!
97    (E.g. WE32100, IBM360.)  */
98 
99 /* Snipped per CPU support */
100 
101 /* If this machine has no inline assembler, use C macros.  */
102 
103 #if !defined (add_ssaaaa)
104 #define add_ssaaaa(sh, sl, ah, al, bh, bl) \
105   do {									\
106     UWtype __x;								\
107     __x = (al) + (bl);							\
108     (sh) = (ah) + (bh) + (__x < (al));					\
109     (sl) = __x;								\
110   } while (0)
111 #endif
112 
113 #if !defined (sub_ddmmss)
114 #define sub_ddmmss(sh, sl, ah, al, bh, bl) \
115   do {									\
116     UWtype __x;								\
117     __x = (al) - (bl);							\
118     (sh) = (ah) - (bh) - (__x > (al));					\
119     (sl) = __x;								\
120   } while (0)
121 #endif
122 
123 /* If we lack umul_ppmm but have smul_ppmm, define umul_ppmm in terms of
124    smul_ppmm.  */
125 #if !defined (umul_ppmm) && defined (smul_ppmm)
126 #define umul_ppmm(w1, w0, u, v)						\
127   do {									\
128     UWtype __w1;							\
129     UWtype __xm0 = (u), __xm1 = (v);					\
130     smul_ppmm (__w1, w0, __xm0, __xm1);					\
131     (w1) = __w1 + (-(__xm0 >> (W_TYPE_SIZE - 1)) & __xm1)		\
132 		+ (-(__xm1 >> (W_TYPE_SIZE - 1)) & __xm0);		\
133   } while (0)
134 #endif
135 
136 /* If we still don't have umul_ppmm, define it using plain C.  */
137 #if !defined (umul_ppmm)
138 #define umul_ppmm(w1, w0, u, v)						\
139   do {									\
140     UWtype __x0, __x1, __x2, __x3;					\
141     UHWtype __ul, __vl, __uh, __vh;					\
142 									\
143     __ul = __ll_lowpart (u);						\
144     __uh = __ll_highpart (u);						\
145     __vl = __ll_lowpart (v);						\
146     __vh = __ll_highpart (v);						\
147 									\
148     __x0 = (UWtype) __ul * __vl;					\
149     __x1 = (UWtype) __ul * __vh;					\
150     __x2 = (UWtype) __uh * __vl;					\
151     __x3 = (UWtype) __uh * __vh;					\
152 									\
153     __x1 += __ll_highpart (__x0);/* this can't give carry */		\
154     __x1 += __x2;		/* but this indeed can */		\
155     if (__x1 < __x2)		/* did we get it? */			\
156       __x3 += __ll_B;		/* yes, add it in the proper pos.  */	\
157 									\
158     (w1) = __x3 + __ll_highpart (__x1);					\
159     (w0) = __ll_lowpart (__x1) * __ll_B + __ll_lowpart (__x0);		\
160   } while (0)
161 #endif
162 
163 #if !defined (__umulsidi3)
164 #define __umulsidi3(u, v) \
165   ({DWunion __w;							\
166     umul_ppmm (__w.s.high, __w.s.low, u, v);				\
167     __w.ll; })
168 #endif
169 
170 /* Define this unconditionally, so it can be used for debugging.  */
171 #define __udiv_qrnnd_c(q, r, n1, n0, d) \
172   do {									\
173     UWtype __d1, __d0, __q1, __q0;					\
174     UWtype __r1, __r0, __m;						\
175     __d1 = __ll_highpart (d);						\
176     __d0 = __ll_lowpart (d);						\
177 									\
178     __r1 = (n1) % __d1;							\
179     __q1 = (n1) / __d1;							\
180     __m = (UWtype) __q1 * __d0;						\
181     __r1 = __r1 * __ll_B | __ll_highpart (n0);				\
182     if (__r1 < __m)							\
183       {									\
184 	__q1--, __r1 += (d);						\
185 	if (__r1 >= (d)) /* i.e. we didn't get carry when adding to __r1 */\
186 	  if (__r1 < __m)						\
187 	    __q1--, __r1 += (d);					\
188       }									\
189     __r1 -= __m;							\
190 									\
191     __r0 = __r1 % __d1;							\
192     __q0 = __r1 / __d1;							\
193     __m = (UWtype) __q0 * __d0;						\
194     __r0 = __r0 * __ll_B | __ll_lowpart (n0);				\
195     if (__r0 < __m)							\
196       {									\
197 	__q0--, __r0 += (d);						\
198 	if (__r0 >= (d))						\
199 	  if (__r0 < __m)						\
200 	    __q0--, __r0 += (d);					\
201       }									\
202     __r0 -= __m;							\
203 									\
204     (q) = (UWtype) __q1 * __ll_B | __q0;				\
205     (r) = __r0;								\
206   } while (0)
207 
208 /* If the processor has no udiv_qrnnd but sdiv_qrnnd, go through
209    __udiv_w_sdiv (defined in libgcc or elsewhere).  */
210 #if !defined (udiv_qrnnd) && defined (sdiv_qrnnd)
211 #define udiv_qrnnd(q, r, nh, nl, d) \
212   do {									\
213     USItype __r;							\
214     (q) = __udiv_w_sdiv (&__r, nh, nl, d);				\
215     (r) = __r;								\
216   } while (0)
217 #endif
218 
219 /* If udiv_qrnnd was not defined for this processor, use __udiv_qrnnd_c.  */
220 #if !defined (udiv_qrnnd)
221 #define UDIV_NEEDS_NORMALIZATION 1
222 #define udiv_qrnnd __udiv_qrnnd_c
223 #endif
224 
225 #if !defined (count_leading_zeros)
226 #define count_leading_zeros(count, x) \
227   do {									\
228     UWtype __xr = (x);							\
229     UWtype __a;								\
230 									\
231     if (W_TYPE_SIZE <= 32)						\
232       {									\
233 	__a = __xr < ((UWtype)1<<2*__BITS4)				\
234 	  ? (__xr < ((UWtype)1<<__BITS4) ? 0 : __BITS4)			\
235 	  : (__xr < ((UWtype)1<<3*__BITS4) ?  2*__BITS4 : 3*__BITS4);	\
236       }									\
237     else								\
238       {									\
239 	for (__a = W_TYPE_SIZE - 8; __a > 0; __a -= 8)			\
240 	  if (((__xr >> __a) & 0xff) != 0)				\
241 	    break;							\
242       }									\
243 									\
244     (count) = W_TYPE_SIZE - (__clz_tab[__xr >> __a] + __a);		\
245   } while (0)
246 #define COUNT_LEADING_ZEROS_0 W_TYPE_SIZE
247 #endif
248 
249 #if !defined (count_trailing_zeros)
250 /* Define count_trailing_zeros using count_leading_zeros.  The latter might be
251    defined in asm, but if it is not, the C version above is good enough.  */
252 #define count_trailing_zeros(count, x) \
253   do {									\
254     UWtype __ctz_x = (x);						\
255     UWtype __ctz_c;							\
256     count_leading_zeros (__ctz_c, __ctz_x & -__ctz_x);			\
257     (count) = W_TYPE_SIZE - 1 - __ctz_c;				\
258   } while (0)
259 #endif
260 
261 #ifndef UDIV_NEEDS_NORMALIZATION
262 #define UDIV_NEEDS_NORMALIZATION 0
263 #endif
264