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/arch/ppc/math-emu/op-1.h

https://bitbucket.org/evzijst/gittest
C Header | 245 lines | 164 code | 35 blank | 46 comment | 28 complexity | 482862228956017d775e21db2936ae0f MD5 | raw file
  1/*
  2 * Basic one-word fraction declaration and manipulation.
  3 */
  4
  5#define _FP_FRAC_DECL_1(X)	_FP_W_TYPE X##_f
  6#define _FP_FRAC_COPY_1(D,S)	(D##_f = S##_f)
  7#define _FP_FRAC_SET_1(X,I)	(X##_f = I)
  8#define _FP_FRAC_HIGH_1(X)	(X##_f)
  9#define _FP_FRAC_LOW_1(X)	(X##_f)
 10#define _FP_FRAC_WORD_1(X,w)	(X##_f)
 11
 12#define _FP_FRAC_ADDI_1(X,I)	(X##_f += I)
 13#define _FP_FRAC_SLL_1(X,N)			\
 14  do {						\
 15    if (__builtin_constant_p(N) && (N) == 1)	\
 16      X##_f += X##_f;				\
 17    else					\
 18      X##_f <<= (N);				\
 19  } while (0)
 20#define _FP_FRAC_SRL_1(X,N)	(X##_f >>= N)
 21
 22/* Right shift with sticky-lsb.  */
 23#define _FP_FRAC_SRS_1(X,N,sz)	__FP_FRAC_SRS_1(X##_f, N, sz)
 24
 25#define __FP_FRAC_SRS_1(X,N,sz)						\
 26   (X = (X >> (N) | (__builtin_constant_p(N) && (N) == 1		\
 27		     ? X & 1 : (X << (_FP_W_TYPE_SIZE - (N))) != 0)))
 28
 29#define _FP_FRAC_ADD_1(R,X,Y)	(R##_f = X##_f + Y##_f)
 30#define _FP_FRAC_SUB_1(R,X,Y)	(R##_f = X##_f - Y##_f)
 31#define _FP_FRAC_CLZ_1(z, X)	__FP_CLZ(z, X##_f)
 32
 33/* Predicates */
 34#define _FP_FRAC_NEGP_1(X)	((_FP_WS_TYPE)X##_f < 0)
 35#define _FP_FRAC_ZEROP_1(X)	(X##_f == 0)
 36#define _FP_FRAC_OVERP_1(fs,X)	(X##_f & _FP_OVERFLOW_##fs)
 37#define _FP_FRAC_EQ_1(X, Y)	(X##_f == Y##_f)
 38#define _FP_FRAC_GE_1(X, Y)	(X##_f >= Y##_f)
 39#define _FP_FRAC_GT_1(X, Y)	(X##_f > Y##_f)
 40
 41#define _FP_ZEROFRAC_1		0
 42#define _FP_MINFRAC_1		1
 43
 44/*
 45 * Unpack the raw bits of a native fp value.  Do not classify or
 46 * normalize the data.
 47 */
 48
 49#define _FP_UNPACK_RAW_1(fs, X, val)				\
 50  do {								\
 51    union _FP_UNION_##fs _flo; _flo.flt = (val);		\
 52								\
 53    X##_f = _flo.bits.frac;					\
 54    X##_e = _flo.bits.exp;					\
 55    X##_s = _flo.bits.sign;					\
 56  } while (0)
 57
 58
 59/*
 60 * Repack the raw bits of a native fp value.
 61 */
 62
 63#define _FP_PACK_RAW_1(fs, val, X)				\
 64  do {								\
 65    union _FP_UNION_##fs _flo;					\
 66								\
 67    _flo.bits.frac = X##_f;					\
 68    _flo.bits.exp  = X##_e;					\
 69    _flo.bits.sign = X##_s;					\
 70								\
 71    (val) = _flo.flt;						\
 72  } while (0)
 73
 74
 75/*
 76 * Multiplication algorithms:
 77 */
 78
 79/* Basic.  Assuming the host word size is >= 2*FRACBITS, we can do the
 80   multiplication immediately.  */
 81
 82#define _FP_MUL_MEAT_1_imm(fs, R, X, Y)					\
 83  do {									\
 84    R##_f = X##_f * Y##_f;						\
 85    /* Normalize since we know where the msb of the multiplicands	\
 86       were (bit B), we know that the msb of the of the product is	\
 87       at either 2B or 2B-1.  */					\
 88    _FP_FRAC_SRS_1(R, _FP_WFRACBITS_##fs-1, 2*_FP_WFRACBITS_##fs);	\
 89  } while (0)
 90
 91/* Given a 1W * 1W => 2W primitive, do the extended multiplication.  */
 92
 93#define _FP_MUL_MEAT_1_wide(fs, R, X, Y, doit)				\
 94  do {									\
 95    _FP_W_TYPE _Z_f0, _Z_f1;						\
 96    doit(_Z_f1, _Z_f0, X##_f, Y##_f);					\
 97    /* Normalize since we know where the msb of the multiplicands	\
 98       were (bit B), we know that the msb of the of the product is	\
 99       at either 2B or 2B-1.  */					\
100    _FP_FRAC_SRS_2(_Z, _FP_WFRACBITS_##fs-1, 2*_FP_WFRACBITS_##fs);	\
101    R##_f = _Z_f0;							\
102  } while (0)
103
104/* Finally, a simple widening multiply algorithm.  What fun!  */
105
106#define _FP_MUL_MEAT_1_hard(fs, R, X, Y)				\
107  do {									\
108    _FP_W_TYPE _xh, _xl, _yh, _yl, _z_f0, _z_f1, _a_f0, _a_f1;		\
109									\
110    /* split the words in half */					\
111    _xh = X##_f >> (_FP_W_TYPE_SIZE/2);					\
112    _xl = X##_f & (((_FP_W_TYPE)1 << (_FP_W_TYPE_SIZE/2)) - 1);		\
113    _yh = Y##_f >> (_FP_W_TYPE_SIZE/2);					\
114    _yl = Y##_f & (((_FP_W_TYPE)1 << (_FP_W_TYPE_SIZE/2)) - 1);		\
115									\
116    /* multiply the pieces */						\
117    _z_f0 = _xl * _yl;							\
118    _a_f0 = _xh * _yl;							\
119    _a_f1 = _xl * _yh;							\
120    _z_f1 = _xh * _yh;							\
121									\
122    /* reassemble into two full words */				\
123    if ((_a_f0 += _a_f1) < _a_f1)					\
124      _z_f1 += (_FP_W_TYPE)1 << (_FP_W_TYPE_SIZE/2);			\
125    _a_f1 = _a_f0 >> (_FP_W_TYPE_SIZE/2);				\
126    _a_f0 = _a_f0 << (_FP_W_TYPE_SIZE/2);				\
127    _FP_FRAC_ADD_2(_z, _z, _a);						\
128									\
129    /* normalize */							\
130    _FP_FRAC_SRS_2(_z, _FP_WFRACBITS_##fs - 1, 2*_FP_WFRACBITS_##fs);	\
131    R##_f = _z_f0;							\
132  } while (0)
133
134
135/*
136 * Division algorithms:
137 */
138
139/* Basic.  Assuming the host word size is >= 2*FRACBITS, we can do the
140   division immediately.  Give this macro either _FP_DIV_HELP_imm for
141   C primitives or _FP_DIV_HELP_ldiv for the ISO function.  Which you
142   choose will depend on what the compiler does with divrem4.  */
143
144#define _FP_DIV_MEAT_1_imm(fs, R, X, Y, doit)		\
145  do {							\
146    _FP_W_TYPE _q, _r;					\
147    X##_f <<= (X##_f < Y##_f				\
148	       ? R##_e--, _FP_WFRACBITS_##fs		\
149	       : _FP_WFRACBITS_##fs - 1);		\
150    doit(_q, _r, X##_f, Y##_f);				\
151    R##_f = _q | (_r != 0);				\
152  } while (0)
153
154/* GCC's longlong.h defines a 2W / 1W => (1W,1W) primitive udiv_qrnnd
155   that may be useful in this situation.  This first is for a primitive
156   that requires normalization, the second for one that does not.  Look
157   for UDIV_NEEDS_NORMALIZATION to tell which your machine needs.  */
158
159#define _FP_DIV_MEAT_1_udiv_norm(fs, R, X, Y)				\
160  do {									\
161    _FP_W_TYPE _nh, _nl, _q, _r;					\
162									\
163    /* Normalize Y -- i.e. make the most significant bit set.  */	\
164    Y##_f <<= _FP_WFRACXBITS_##fs - 1;					\
165									\
166    /* Shift X op correspondingly high, that is, up one full word.  */	\
167    if (X##_f <= Y##_f)							\
168      {									\
169	_nl = 0;							\
170	_nh = X##_f;							\
171      }									\
172    else								\
173      {									\
174	R##_e++;							\
175	_nl = X##_f << (_FP_W_TYPE_SIZE-1);				\
176	_nh = X##_f >> 1;						\
177      }									\
178    									\
179    udiv_qrnnd(_q, _r, _nh, _nl, Y##_f);				\
180    R##_f = _q | (_r != 0);						\
181  } while (0)
182
183#define _FP_DIV_MEAT_1_udiv(fs, R, X, Y)		\
184  do {							\
185    _FP_W_TYPE _nh, _nl, _q, _r;			\
186    if (X##_f < Y##_f)					\
187      {							\
188	R##_e--;					\
189	_nl = X##_f << _FP_WFRACBITS_##fs;		\
190	_nh = X##_f >> _FP_WFRACXBITS_##fs;		\
191      }							\
192    else						\
193      {							\
194	_nl = X##_f << (_FP_WFRACBITS_##fs - 1);	\
195	_nh = X##_f >> (_FP_WFRACXBITS_##fs + 1);	\
196      }							\
197    udiv_qrnnd(_q, _r, _nh, _nl, Y##_f);		\
198    R##_f = _q | (_r != 0);				\
199  } while (0)
200
201
202/*
203 * Square root algorithms:
204 * We have just one right now, maybe Newton approximation
205 * should be added for those machines where division is fast.
206 */
207
208#define _FP_SQRT_MEAT_1(R, S, T, X, q)			\
209  do {							\
210    while (q)						\
211      {							\
212        T##_f = S##_f + q;				\
213        if (T##_f <= X##_f)				\
214          {						\
215            S##_f = T##_f + q;				\
216            X##_f -= T##_f;				\
217            R##_f += q;					\
218          }						\
219        _FP_FRAC_SLL_1(X, 1);				\
220        q >>= 1;					\
221      }							\
222  } while (0)
223
224/*
225 * Assembly/disassembly for converting to/from integral types.
226 * No shifting or overflow handled here.
227 */
228
229#define _FP_FRAC_ASSEMBLE_1(r, X, rsize)	(r = X##_f)
230#define _FP_FRAC_DISASSEMBLE_1(X, r, rsize)	(X##_f = r)
231
232
233/*
234 * Convert FP values between word sizes
235 */
236
237#define _FP_FRAC_CONV_1_1(dfs, sfs, D, S)				\
238  do {									\
239    D##_f = S##_f;							\
240    if (_FP_WFRACBITS_##sfs > _FP_WFRACBITS_##dfs)			\
241      _FP_FRAC_SRS_1(D, (_FP_WFRACBITS_##sfs-_FP_WFRACBITS_##dfs),	\
242		     _FP_WFRACBITS_##sfs);				\
243    else								\
244      D##_f <<= _FP_WFRACBITS_##dfs - _FP_WFRACBITS_##sfs;		\
245  } while (0)