linux/arch/ppc/math-emu/op-4.h
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

298 lines
13 KiB
C

/*
* Basic four-word fraction declaration and manipulation.
*
* When adding quadword support for 32 bit machines, we need
* to be a little careful as double multiply uses some of these
* macros: (in op-2.h)
* _FP_MUL_MEAT_2_wide() uses _FP_FRAC_DECL_4, _FP_FRAC_WORD_4,
* _FP_FRAC_ADD_4, _FP_FRAC_SRS_4
* _FP_MUL_MEAT_2_gmp() uses _FP_FRAC_SRS_4 (and should use
* _FP_FRAC_DECL_4: it appears to be broken and is not used
* anywhere anyway. )
*
* I've now fixed all the macros that were here from the sparc64 code.
* [*none* of the shift macros were correct!] -- PMM 02/1998
*
* The only quadword stuff that remains to be coded is:
* 1) the conversion to/from ints, which requires
* that we check (in op-common.h) that the following do the right thing
* for quadwords: _FP_TO_INT(Q,4,r,X,rsz,rsg), _FP_FROM_INT(Q,4,X,r,rs,rt)
* 2) multiply, divide and sqrt, which require:
* _FP_MUL_MEAT_4_*(R,X,Y), _FP_DIV_MEAT_4_*(R,X,Y), _FP_SQRT_MEAT_4(R,S,T,X,q),
* This also needs _FP_MUL_MEAT_Q and _FP_DIV_MEAT_Q to be defined to
* some suitable _FP_MUL_MEAT_4_* macros in sfp-machine.h.
* [we're free to choose whatever FP_MUL_MEAT_4_* macros we need for
* these; they are used nowhere else. ]
*/
#define _FP_FRAC_DECL_4(X) _FP_W_TYPE X##_f[4]
#define _FP_FRAC_COPY_4(D,S) \
(D##_f[0] = S##_f[0], D##_f[1] = S##_f[1], \
D##_f[2] = S##_f[2], D##_f[3] = S##_f[3])
/* The _FP_FRAC_SET_n(X,I) macro is intended for use with another
* macro such as _FP_ZEROFRAC_n which returns n comma separated values.
* The result is that we get an expansion of __FP_FRAC_SET_n(X,I0,I1,I2,I3)
* which just assigns the In values to the array X##_f[].
* This is why the number of parameters doesn't appear to match
* at first glance... -- PMM
*/
#define _FP_FRAC_SET_4(X,I) __FP_FRAC_SET_4(X, I)
#define _FP_FRAC_HIGH_4(X) (X##_f[3])
#define _FP_FRAC_LOW_4(X) (X##_f[0])
#define _FP_FRAC_WORD_4(X,w) (X##_f[w])
#define _FP_FRAC_SLL_4(X,N) \
do { \
_FP_I_TYPE _up, _down, _skip, _i; \
_skip = (N) / _FP_W_TYPE_SIZE; \
_up = (N) % _FP_W_TYPE_SIZE; \
_down = _FP_W_TYPE_SIZE - _up; \
for (_i = 3; _i > _skip; --_i) \
X##_f[_i] = X##_f[_i-_skip] << _up | X##_f[_i-_skip-1] >> _down; \
/* bugfixed: was X##_f[_i] <<= _up; -- PMM 02/1998 */ \
X##_f[_i] = X##_f[0] << _up; \
for (--_i; _i >= 0; --_i) \
X##_f[_i] = 0; \
} while (0)
/* This one was broken too */
#define _FP_FRAC_SRL_4(X,N) \
do { \
_FP_I_TYPE _up, _down, _skip, _i; \
_skip = (N) / _FP_W_TYPE_SIZE; \
_down = (N) % _FP_W_TYPE_SIZE; \
_up = _FP_W_TYPE_SIZE - _down; \
for (_i = 0; _i < 3-_skip; ++_i) \
X##_f[_i] = X##_f[_i+_skip] >> _down | X##_f[_i+_skip+1] << _up; \
X##_f[_i] = X##_f[3] >> _down; \
for (++_i; _i < 4; ++_i) \
X##_f[_i] = 0; \
} while (0)
/* Right shift with sticky-lsb.
* What this actually means is that we do a standard right-shift,
* but that if any of the bits that fall off the right hand side
* were one then we always set the LSbit.
*/
#define _FP_FRAC_SRS_4(X,N,size) \
do { \
_FP_I_TYPE _up, _down, _skip, _i; \
_FP_W_TYPE _s; \
_skip = (N) / _FP_W_TYPE_SIZE; \
_down = (N) % _FP_W_TYPE_SIZE; \
_up = _FP_W_TYPE_SIZE - _down; \
for (_s = _i = 0; _i < _skip; ++_i) \
_s |= X##_f[_i]; \
_s |= X##_f[_i] << _up; \
/* s is now != 0 if we want to set the LSbit */ \
for (_i = 0; _i < 3-_skip; ++_i) \
X##_f[_i] = X##_f[_i+_skip] >> _down | X##_f[_i+_skip+1] << _up; \
X##_f[_i] = X##_f[3] >> _down; \
for (++_i; _i < 4; ++_i) \
X##_f[_i] = 0; \
/* don't fix the LSB until the very end when we're sure f[0] is stable */ \
X##_f[0] |= (_s != 0); \
} while (0)
#define _FP_FRAC_ADD_4(R,X,Y) \
__FP_FRAC_ADD_4(R##_f[3], R##_f[2], R##_f[1], R##_f[0], \
X##_f[3], X##_f[2], X##_f[1], X##_f[0], \
Y##_f[3], Y##_f[2], Y##_f[1], Y##_f[0])
#define _FP_FRAC_SUB_4(R,X,Y) \
__FP_FRAC_SUB_4(R##_f[3], R##_f[2], R##_f[1], R##_f[0], \
X##_f[3], X##_f[2], X##_f[1], X##_f[0], \
Y##_f[3], Y##_f[2], Y##_f[1], Y##_f[0])
#define _FP_FRAC_ADDI_4(X,I) \
__FP_FRAC_ADDI_4(X##_f[3], X##_f[2], X##_f[1], X##_f[0], I)
#define _FP_ZEROFRAC_4 0,0,0,0
#define _FP_MINFRAC_4 0,0,0,1
#define _FP_FRAC_ZEROP_4(X) ((X##_f[0] | X##_f[1] | X##_f[2] | X##_f[3]) == 0)
#define _FP_FRAC_NEGP_4(X) ((_FP_WS_TYPE)X##_f[3] < 0)
#define _FP_FRAC_OVERP_4(fs,X) (X##_f[0] & _FP_OVERFLOW_##fs)
#define _FP_FRAC_EQ_4(X,Y) \
(X##_f[0] == Y##_f[0] && X##_f[1] == Y##_f[1] \
&& X##_f[2] == Y##_f[2] && X##_f[3] == Y##_f[3])
#define _FP_FRAC_GT_4(X,Y) \
(X##_f[3] > Y##_f[3] || \
(X##_f[3] == Y##_f[3] && (X##_f[2] > Y##_f[2] || \
(X##_f[2] == Y##_f[2] && (X##_f[1] > Y##_f[1] || \
(X##_f[1] == Y##_f[1] && X##_f[0] > Y##_f[0]) \
)) \
)) \
)
#define _FP_FRAC_GE_4(X,Y) \
(X##_f[3] > Y##_f[3] || \
(X##_f[3] == Y##_f[3] && (X##_f[2] > Y##_f[2] || \
(X##_f[2] == Y##_f[2] && (X##_f[1] > Y##_f[1] || \
(X##_f[1] == Y##_f[1] && X##_f[0] >= Y##_f[0]) \
)) \
)) \
)
#define _FP_FRAC_CLZ_4(R,X) \
do { \
if (X##_f[3]) \
{ \
__FP_CLZ(R,X##_f[3]); \
} \
else if (X##_f[2]) \
{ \
__FP_CLZ(R,X##_f[2]); \
R += _FP_W_TYPE_SIZE; \
} \
else if (X##_f[1]) \
{ \
__FP_CLZ(R,X##_f[2]); \
R += _FP_W_TYPE_SIZE*2; \
} \
else \
{ \
__FP_CLZ(R,X##_f[0]); \
R += _FP_W_TYPE_SIZE*3; \
} \
} while(0)
#define _FP_UNPACK_RAW_4(fs, X, val) \
do { \
union _FP_UNION_##fs _flo; _flo.flt = (val); \
X##_f[0] = _flo.bits.frac0; \
X##_f[1] = _flo.bits.frac1; \
X##_f[2] = _flo.bits.frac2; \
X##_f[3] = _flo.bits.frac3; \
X##_e = _flo.bits.exp; \
X##_s = _flo.bits.sign; \
} while (0)
#define _FP_PACK_RAW_4(fs, val, X) \
do { \
union _FP_UNION_##fs _flo; \
_flo.bits.frac0 = X##_f[0]; \
_flo.bits.frac1 = X##_f[1]; \
_flo.bits.frac2 = X##_f[2]; \
_flo.bits.frac3 = X##_f[3]; \
_flo.bits.exp = X##_e; \
_flo.bits.sign = X##_s; \
(val) = _flo.flt; \
} while (0)
/*
* Internals
*/
#define __FP_FRAC_SET_4(X,I3,I2,I1,I0) \
(X##_f[3] = I3, X##_f[2] = I2, X##_f[1] = I1, X##_f[0] = I0)
#ifndef __FP_FRAC_ADD_4
#define __FP_FRAC_ADD_4(r3,r2,r1,r0,x3,x2,x1,x0,y3,y2,y1,y0) \
(r0 = x0 + y0, \
r1 = x1 + y1 + (r0 < x0), \
r2 = x2 + y2 + (r1 < x1), \
r3 = x3 + y3 + (r2 < x2))
#endif
#ifndef __FP_FRAC_SUB_4
#define __FP_FRAC_SUB_4(r3,r2,r1,r0,x3,x2,x1,x0,y3,y2,y1,y0) \
(r0 = x0 - y0, \
r1 = x1 - y1 - (r0 > x0), \
r2 = x2 - y2 - (r1 > x1), \
r3 = x3 - y3 - (r2 > x2))
#endif
#ifndef __FP_FRAC_ADDI_4
/* I always wanted to be a lisp programmer :-> */
#define __FP_FRAC_ADDI_4(x3,x2,x1,x0,i) \
(x3 += ((x2 += ((x1 += ((x0 += i) < x0)) < x1) < x2)))
#endif
/* Convert FP values between word sizes. This appears to be more
* complicated than I'd have expected it to be, so these might be
* wrong... These macros are in any case somewhat bogus because they
* use information about what various FRAC_n variables look like
* internally [eg, that 2 word vars are X_f0 and x_f1]. But so do
* the ones in op-2.h and op-1.h.
*/
#define _FP_FRAC_CONV_1_4(dfs, sfs, D, S) \
do { \
_FP_FRAC_SRS_4(S, (_FP_WFRACBITS_##sfs - _FP_WFRACBITS_##dfs), \
_FP_WFRACBITS_##sfs); \
D##_f = S##_f[0]; \
} while (0)
#define _FP_FRAC_CONV_2_4(dfs, sfs, D, S) \
do { \
_FP_FRAC_SRS_4(S, (_FP_WFRACBITS_##sfs - _FP_WFRACBITS_##dfs), \
_FP_WFRACBITS_##sfs); \
D##_f0 = S##_f[0]; \
D##_f1 = S##_f[1]; \
} while (0)
/* Assembly/disassembly for converting to/from integral types.
* No shifting or overflow handled here.
*/
/* Put the FP value X into r, which is an integer of size rsize. */
#define _FP_FRAC_ASSEMBLE_4(r, X, rsize) \
do { \
if (rsize <= _FP_W_TYPE_SIZE) \
r = X##_f[0]; \
else if (rsize <= 2*_FP_W_TYPE_SIZE) \
{ \
r = X##_f[1]; \
r <<= _FP_W_TYPE_SIZE; \
r += X##_f[0]; \
} \
else \
{ \
/* I'm feeling lazy so we deal with int == 3words (implausible)*/ \
/* and int == 4words as a single case. */ \
r = X##_f[3]; \
r <<= _FP_W_TYPE_SIZE; \
r += X##_f[2]; \
r <<= _FP_W_TYPE_SIZE; \
r += X##_f[1]; \
r <<= _FP_W_TYPE_SIZE; \
r += X##_f[0]; \
} \
} while (0)
/* "No disassemble Number Five!" */
/* move an integer of size rsize into X's fractional part. We rely on
* the _f[] array consisting of words of size _FP_W_TYPE_SIZE to avoid
* having to mask the values we store into it.
*/
#define _FP_FRAC_DISASSEMBLE_4(X, r, rsize) \
do { \
X##_f[0] = r; \
X##_f[1] = (rsize <= _FP_W_TYPE_SIZE ? 0 : r >> _FP_W_TYPE_SIZE); \
X##_f[2] = (rsize <= 2*_FP_W_TYPE_SIZE ? 0 : r >> 2*_FP_W_TYPE_SIZE); \
X##_f[3] = (rsize <= 3*_FP_W_TYPE_SIZE ? 0 : r >> 3*_FP_W_TYPE_SIZE); \
} while (0)
#define _FP_FRAC_CONV_4_1(dfs, sfs, D, S) \
do { \
D##_f[0] = S##_f; \
D##_f[1] = D##_f[2] = D##_f[3] = 0; \
_FP_FRAC_SLL_4(D, (_FP_WFRACBITS_##dfs - _FP_WFRACBITS_##sfs)); \
} while (0)
#define _FP_FRAC_CONV_4_2(dfs, sfs, D, S) \
do { \
D##_f[0] = S##_f0; \
D##_f[1] = S##_f1; \
D##_f[2] = D##_f[3] = 0; \
_FP_FRAC_SLL_4(D, (_FP_WFRACBITS_##dfs - _FP_WFRACBITS_##sfs)); \
} while (0)
/* FIXME! This has to be written */
#define _FP_SQRT_MEAT_4(R, S, T, X, q)