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.

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)