aboutsummaryrefslogtreecommitdiff
path: root/soft-fp/op-1.h
diff options
context:
space:
mode:
authorUlrich Drepper <drepper@redhat.com>1999-12-29 18:11:48 +0000
committerUlrich Drepper <drepper@redhat.com>1999-12-29 18:11:48 +0000
commitd876f5327985eac3bf3109e9429febc8a8954ff5 (patch)
tree2ab0233054876a59507ff2ef9652ef81b1317991 /soft-fp/op-1.h
parentdbbbaf53352501384c57512e2251c9d7169388af (diff)
downloadglibc-d876f5327985eac3bf3109e9429febc8a8954ff5.zip
glibc-d876f5327985eac3bf3109e9429febc8a8954ff5.tar.gz
glibc-d876f5327985eac3bf3109e9429febc8a8954ff5.tar.bz2
Update.
1999-12-29 Ulrich Drepper <drepper@cygnus.com> * soft-fp/*: Tons of new files to implement floating-point arithmetic in software. Contributed by Richard Henderson, Jakub Jelinek and others.
Diffstat (limited to 'soft-fp/op-1.h')
-rw-r--r--soft-fp/op-1.h297
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)