Reorganisation of the source tree

Most of the other users of the fptools build system have migrated to
Cabal, and with the move to darcs we can now flatten the source tree
without losing history, so here goes.

The main change is that the ghc/ subdir is gone, and most of what it
contained is now at the top level.  The build system now makes no
pretense at being multi-project, it is just the GHC build system.

No doubt this will break many things, and there will be a period of
instability while we fix the dependencies.  A straightforward build
should work, but I haven't yet fixed binary/source distributions.
Changes to the Building Guide will follow, too.

1 files changed, 136 insertions, 0 deletions

diff --git a/rts/gmp/mpn/generic/jacbase.c b/rts/gmp/mpn/generic/jacbase.c
new file mode 100644
index 0000000000..dd437f1ac1
--- /dev/null
+++ b/rts/gmp/mpn/generic/jacbase.c
@@ -0,0 +1,136 @@
+/* mpn_jacobi_base -- limb/limb Jacobi symbol with restricted arguments.
+
+   THIS INTERFACE IS PRELIMINARY AND MIGHT DISAPPEAR OR BE SUBJECT TO
+   INCOMPATIBLE CHANGES IN A FUTURE RELEASE OF GMP. */
+
+/*
+Copyright (C) 1999, 2000 Free Software Foundation, Inc.
+
+This file is part of the GNU MP Library.
+
+The GNU MP Library is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or (at your
+option) any later version.
+
+The GNU MP 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 Lesser General Public
+License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with the GNU MP 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.  */
+
+#include "gmp.h"
+#include "gmp-impl.h"
+#include "longlong.h"
+
+
+#if COUNT_TRAILING_ZEROS_TIME <= 7
+/* If count_trailing_zeros is fast, use it.
+   K7 at 7 cycles and P6 at 2 are good here.  K6 at 12-27 and P5 at 18-42
+   are not.  The default 15 in longlong.h is meant to mean not good here.  */
+
+#define PROCESS_TWOS_ANY                                \
+  {                                                     \
+    mp_limb_t  twos;                                    \
+    count_trailing_zeros (twos, a);                     \
+    result_bit1 ^= JACOBI_TWOS_U_BIT1 (twos, b);        \
+    a >>= twos;                                         \
+  }
+
+#define PROCESS_TWOS_EVEN  PROCESS_TWOS_ANY
+
+#else
+/* Use a loop instead.  With "a" uniformly distributed there will usually be
+   only a few trailing zeros.
+
+   Unfortunately the branch for the while loop here will be on a 50/50
+   chance of a 1 or 0, which is bad for branch prediction.  */
+
+#define PROCESS_TWOS_EVEN               \
+  {                                     \
+    int  two;                           \
+    two = JACOBI_TWO_U_BIT1 (b);        \
+    do                                  \
+      {                                 \
+        a >>= 1;                        \
+        result_bit1 ^= two;             \
+        ASSERT (a != 0);                \
+      }                                 \
+    while ((a & 1) == 0);               \
+  }
+
+#define PROCESS_TWOS_ANY        \
+  if ((a & 1) == 0)             \
+    PROCESS_TWOS_EVEN;
+
+#endif
+
+
+/* Calculate the value of the Jacobi symbol (a/b) of two mp_limb_t's, but
+   with a restricted range of inputs accepted, namely b>1, b odd, and a<=b.
+
+   The initial result_bit1 is taken as a parameter for the convenience of
+   mpz_kronecker_zi_ui() et al.  The sign changes both here and in those
+   routines accumulate nicely in bit 1, see the JACOBI macros.
+
+   The return value here is the normal +1, 0, or -1.  Note that +1 and -1
+   have bit 1 in the "BIT1" sense, which could be useful if the caller is
+   accumulating it into some extended calculation.
+
+   Duplicating the loop body to avoid the MP_LIMB_T_SWAP(a,b) would be
+   possible, but a couple of tests suggest it's not a significant speedup,
+   and may even be a slowdown, so what's here is good enough for now.
+
+   Future: The code doesn't demand a<=b actually, so maybe this could be
+   relaxed.  All the places this is used currently call with a<=b though.  */
+
+int
+#if __STDC__
+mpn_jacobi_base (mp_limb_t a, mp_limb_t b, int result_bit1)
+#else
+mpn_jacobi_base (a, b, result_bit1)
+     mp_limb_t a;
+     mp_limb_t b;
+     int       result_bit1;
+#endif
+{
+  ASSERT (b & 1);  /* b odd */
+  ASSERT (b != 1);
+  ASSERT (a <= b);
+
+  if (a == 0)
+    return 0;
+
+  PROCESS_TWOS_ANY;
+  if (a == 1)
+    goto done;
+
+  for (;;)
+    {
+      result_bit1 ^= JACOBI_RECIP_UU_BIT1 (a, b);
+      MP_LIMB_T_SWAP (a, b);
+
+      do
+	{
+          /* working on (a/b), a,b odd, a>=b */
+          ASSERT (a & 1);
+          ASSERT (b & 1);
+          ASSERT (a >= b);
+
+	  if ((a -= b) == 0)
+	    return 0;
+
+          PROCESS_TWOS_EVEN;
+	  if (a == 1)
+	    goto done;
+	}
+      while (a >= b);
+    }
+
+ done:
+  return JACOBI_BIT1_TO_PN (result_bit1);
+}