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Diffstat (limited to 'soft-fp/op-1.h')
| -rw-r--r-- | soft-fp/op-1.h | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/soft-fp/op-1.h b/soft-fp/op-1.h new file mode 100644 index 0000000..48bf4ce --- /dev/null +++ b/soft-fp/op-1.h @@ -0,0 +1,297 @@ +/* Software floating-point emulation. + Basic one-word fraction declaration and manipulation. + Copyright (C) 1997,1998,1999 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Richard Henderson (rth@cygnus.com), + Jakub Jelinek (jj@ultra.linux.cz), + David S. Miller (davem@redhat.com) and + Peter Maydell (pmaydell@chiark.greenend.org.uk). + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If + not, write to the Free Software Foundation, Inc., + 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +#define _FP_FRAC_DECL_1(X) _FP_W_TYPE X##_f +#define _FP_FRAC_COPY_1(D,S) (D##_f = S##_f) +#define _FP_FRAC_SET_1(X,I) (X##_f = I) +#define _FP_FRAC_HIGH_1(X) (X##_f) +#define _FP_FRAC_LOW_1(X) (X##_f) +#define _FP_FRAC_WORD_1(X,w) (X##_f) + +#define _FP_FRAC_ADDI_1(X,I) (X##_f += I) +#define _FP_FRAC_SLL_1(X,N) \ + do { \ + if (__builtin_constant_p(N) && (N) == 1) \ + X##_f += X##_f; \ + else \ + X##_f <<= (N); \ + } while (0) +#define _FP_FRAC_SRL_1(X,N) (X##_f >>= N) + +/* Right shift with sticky-lsb. */ +#define _FP_FRAC_SRS_1(X,N,sz) __FP_FRAC_SRS_1(X##_f, N, sz) + +#define __FP_FRAC_SRS_1(X,N,sz) \ + (X = (X >> (N) | (__builtin_constant_p(N) && (N) == 1 \ + ? X & 1 : (X << (_FP_W_TYPE_SIZE - (N))) != 0))) + +#define _FP_FRAC_ADD_1(R,X,Y) (R##_f = X##_f + Y##_f) +#define _FP_FRAC_SUB_1(R,X,Y) (R##_f = X##_f - Y##_f) +#define _FP_FRAC_DEC_1(X,Y) (X##_f -= Y##_f) +#define _FP_FRAC_CLZ_1(z, X) __FP_CLZ(z, X##_f) + +/* Predicates */ +#define _FP_FRAC_NEGP_1(X) ((_FP_WS_TYPE)X##_f < 0) +#define _FP_FRAC_ZEROP_1(X) (X##_f == 0) +#define _FP_FRAC_OVERP_1(fs,X) (X##_f & _FP_OVERFLOW_##fs) +#define _FP_FRAC_EQ_1(X, Y) (X##_f == Y##_f) +#define _FP_FRAC_GE_1(X, Y) (X##_f >= Y##_f) +#define _FP_FRAC_GT_1(X, Y) (X##_f > Y##_f) + +#define _FP_ZEROFRAC_1 0 +#define _FP_MINFRAC_1 1 +#define _FP_MAXFRAC_1 (~(_FP_WS_TYPE)0) + +/* + * Unpack the raw bits of a native fp value. Do not classify or + * normalize the data. + */ + +#define _FP_UNPACK_RAW_1(fs, X, val) \ + do { \ + union _FP_UNION_##fs _flo; _flo.flt = (val); \ + \ + X##_f = _flo.bits.frac; \ + X##_e = _flo.bits.exp; \ + X##_s = _flo.bits.sign; \ + } while (0) + +#define _FP_UNPACK_RAW_1_P(fs, X, val) \ + do { \ + union _FP_UNION_##fs *_flo = \ + (union _FP_UNION_##fs *)(val); \ + \ + X##_f = _flo->bits.frac; \ + X##_e = _flo->bits.exp; \ + X##_s = _flo->bits.sign; \ + } while (0) + +/* + * Repack the raw bits of a native fp value. + */ + +#define _FP_PACK_RAW_1(fs, val, X) \ + do { \ + union _FP_UNION_##fs _flo; \ + \ + _flo.bits.frac = X##_f; \ + _flo.bits.exp = X##_e; \ + _flo.bits.sign = X##_s; \ + \ + (val) = _flo.flt; \ + } while (0) + +#define _FP_PACK_RAW_1_P(fs, val, X) \ + do { \ + union _FP_UNION_##fs *_flo = \ + (union _FP_UNION_##fs *)(val); \ + \ + _flo->bits.frac = X##_f; \ + _flo->bits.exp = X##_e; \ + _flo->bits.sign = X##_s; \ + } while (0) + + +/* + * Multiplication algorithms: + */ + +/* Basic. Assuming the host word size is >= 2*FRACBITS, we can do the + multiplication immediately. */ + +#define _FP_MUL_MEAT_1_imm(wfracbits, R, X, Y) \ + do { \ + R##_f = X##_f * Y##_f; \ + /* Normalize since we know where the msb of the multiplicands \ + were (bit B), we know that the msb of the of the product is \ + at either 2B or 2B-1. */ \ + _FP_FRAC_SRS_1(R, wfracbits-1, 2*wfracbits); \ + } while (0) + +/* Given a 1W * 1W => 2W primitive, do the extended multiplication. */ + +#define _FP_MUL_MEAT_1_wide(wfracbits, R, X, Y, doit) \ + do { \ + _FP_W_TYPE _Z_f0, _Z_f1; \ + doit(_Z_f1, _Z_f0, X##_f, Y##_f); \ + /* Normalize since we know where the msb of the multiplicands \ + were (bit B), we know that the msb of the of the product is \ + at either 2B or 2B-1. */ \ + _FP_FRAC_SRS_2(_Z, wfracbits-1, 2*wfracbits); \ + R##_f = _Z_f0; \ + } while (0) + +/* Finally, a simple widening multiply algorithm. What fun! */ + +#define _FP_MUL_MEAT_1_hard(wfracbits, R, X, Y) \ + do { \ + _FP_W_TYPE _xh, _xl, _yh, _yl, _z_f0, _z_f1, _a_f0, _a_f1; \ + \ + /* split the words in half */ \ + _xh = X##_f >> (_FP_W_TYPE_SIZE/2); \ + _xl = X##_f & (((_FP_W_TYPE)1 << (_FP_W_TYPE_SIZE/2)) - 1); \ + _yh = Y##_f >> (_FP_W_TYPE_SIZE/2); \ + _yl = Y##_f & (((_FP_W_TYPE)1 << (_FP_W_TYPE_SIZE/2)) - 1); \ + \ + /* multiply the pieces */ \ + _z_f0 = _xl * _yl; \ + _a_f0 = _xh * _yl; \ + _a_f1 = _xl * _yh; \ + _z_f1 = _xh * _yh; \ + \ + /* reassemble into two full words */ \ + if ((_a_f0 += _a_f1) < _a_f1) \ + _z_f1 += (_FP_W_TYPE)1 << (_FP_W_TYPE_SIZE/2); \ + _a_f1 = _a_f0 >> (_FP_W_TYPE_SIZE/2); \ + _a_f0 = _a_f0 << (_FP_W_TYPE_SIZE/2); \ + _FP_FRAC_ADD_2(_z, _z, _a); \ + \ + /* normalize */ \ + _FP_FRAC_SRS_2(_z, wfracbits - 1, 2*wfracbits); \ + R##_f = _z_f0; \ + } while (0) + + +/* + * Division algorithms: + */ + +/* Basic. Assuming the host word size is >= 2*FRACBITS, we can do the + division immediately. Give this macro either _FP_DIV_HELP_imm for + C primitives or _FP_DIV_HELP_ldiv for the ISO function. Which you + choose will depend on what the compiler does with divrem4. */ + +#define _FP_DIV_MEAT_1_imm(fs, R, X, Y, doit) \ + do { \ + _FP_W_TYPE _q, _r; \ + X##_f <<= (X##_f < Y##_f \ + ? R##_e--, _FP_WFRACBITS_##fs \ + : _FP_WFRACBITS_##fs - 1); \ + doit(_q, _r, X##_f, Y##_f); \ + R##_f = _q | (_r != 0); \ + } while (0) + +/* GCC's longlong.h defines a 2W / 1W => (1W,1W) primitive udiv_qrnnd + that may be useful in this situation. This first is for a primitive + that requires normalization, the second for one that does not. Look + for UDIV_NEEDS_NORMALIZATION to tell which your machine needs. */ + +#define _FP_DIV_MEAT_1_udiv_norm(fs, R, X, Y) \ + do { \ + _FP_W_TYPE _nh, _nl, _q, _r; \ + \ + /* Normalize Y -- i.e. make the most significant bit set. */ \ + Y##_f <<= _FP_WFRACXBITS_##fs - 1; \ + \ + /* Shift X op correspondingly high, that is, up one full word. */ \ + if (X##_f <= Y##_f) \ + { \ + _nl = 0; \ + _nh = X##_f; \ + } \ + else \ + { \ + R##_e++; \ + _nl = X##_f << (_FP_W_TYPE_SIZE-1); \ + _nh = X##_f >> 1; \ + } \ + \ + udiv_qrnnd(_q, _r, _nh, _nl, Y##_f); \ + R##_f = _q | (_r != 0); \ + } while (0) + +#define _FP_DIV_MEAT_1_udiv(fs, R, X, Y) \ + do { \ + _FP_W_TYPE _nh, _nl, _q, _r; \ + if (X##_f < Y##_f) \ + { \ + R##_e--; \ + _nl = X##_f << _FP_WFRACBITS_##fs; \ + _nh = X##_f >> _FP_WFRACXBITS_##fs; \ + } \ + else \ + { \ + _nl = X##_f << (_FP_WFRACBITS_##fs - 1); \ + _nh = X##_f >> (_FP_WFRACXBITS_##fs + 1); \ + } \ + udiv_qrnnd(_q, _r, _nh, _nl, Y##_f); \ + R##_f = _q | (_r != 0); \ + } while (0) + + +/* + * Square root algorithms: + * We have just one right now, maybe Newton approximation + * should be added for those machines where division is fast. + */ + +#define _FP_SQRT_MEAT_1(R, S, T, X, q) \ + do { \ + while (q != _FP_WORK_ROUND) \ + { \ + T##_f = S##_f + q; \ + if (T##_f <= X##_f) \ + { \ + S##_f = T##_f + q; \ + X##_f -= T##_f; \ + R##_f += q; \ + } \ + _FP_FRAC_SLL_1(X, 1); \ + q >>= 1; \ + } \ + if (X##_f) \ + { \ + if (S##_f < X##_f) \ + R##_f |= _FP_WORK_ROUND; \ + R##_f |= _FP_WORK_STICKY; \ + } \ + } while (0) + +/* + * Assembly/disassembly for converting to/from integral types. + * No shifting or overflow handled here. + */ + +#define _FP_FRAC_ASSEMBLE_1(r, X, rsize) (r = X##_f) +#define _FP_FRAC_DISASSEMBLE_1(X, r, rsize) (X##_f = r) + + +/* + * Convert FP values between word sizes + */ + +#define _FP_FRAC_CONV_1_1(dfs, sfs, D, S) \ + do { \ + D##_f = S##_f; \ + if (_FP_WFRACBITS_##sfs > _FP_WFRACBITS_##dfs) \ + { \ + if (S##_c != FP_CLS_NAN) \ + _FP_FRAC_SRS_1(D, (_FP_WFRACBITS_##sfs-_FP_WFRACBITS_##dfs), \ + _FP_WFRACBITS_##sfs); \ + else \ + _FP_FRAC_SRL_1(D, (_FP_WFRACBITS_##sfs-_FP_WFRACBITS_##dfs)); \ + } \ + else \ + D##_f <<= _FP_WFRACBITS_##dfs - _FP_WFRACBITS_##sfs; \ + } while (0) |