Edit File: op-1.h
/* 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. */ #ifndef __MATH_EMU_OP_1_H__ #define __MATH_EMU_OP_1_H__ #define _FP_FRAC_DECL_1(X) _FP_W_TYPE X##_f=0 #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_CLEAR_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, _y; \ \ /* Normalize Y -- i.e. make the most significant bit set. */ \ _y = Y##_f << _FP_WFRACXBITS_##fs; \ \ /* Shift X op correspondingly high, that is, up one full word. */ \ if (X##_f < Y##_f) \ { \ R##_e--; \ _nl = 0; \ _nh = X##_f; \ } \ else \ { \ _nl = X##_f << (_FP_W_TYPE_SIZE - 1); \ _nh = X##_f >> 1; \ } \ \ udiv_qrnnd(_q, _r, _nh, _nl, _y); \ 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) #endif /* __MATH_EMU_OP_1_H__ */