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, 414 insertions, 0 deletions

diff --git a/rts/gmp/mpn/generic/gcd.c b/rts/gmp/mpn/generic/gcd.c
new file mode 100644
index 0000000000..059e219a06
--- /dev/null
+++ b/rts/gmp/mpn/generic/gcd.c
@@ -0,0 +1,414 @@
+/* mpn/gcd.c: mpn_gcd for gcd of two odd integers.
+
+Copyright (C) 1991, 1993, 1994, 1995, 1996, 1997, 1998, 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. */
+
+/* Integer greatest common divisor of two unsigned integers, using
+   the accelerated algorithm (see reference below).
+
+   mp_size_t mpn_gcd (up, usize, vp, vsize).
+
+   Preconditions [U = (up, usize) and V = (vp, vsize)]:
+
+   1.  V is odd.
+   2.  numbits(U) >= numbits(V).
+
+   Both U and V are destroyed by the operation.  The result is left at vp,
+   and its size is returned.
+
+   Ken Weber (kweber@mat.ufrgs.br, kweber@mcs.kent.edu)
+
+   Funding for this work has been partially provided by Conselho Nacional
+   de Desenvolvimento Cienti'fico e Tecnolo'gico (CNPq) do Brazil, Grant
+   301314194-2, and was done while I was a visiting reseacher in the Instituto
+   de Matema'tica at Universidade Federal do Rio Grande do Sul (UFRGS).
+
+   Refer to
+	K. Weber, The accelerated integer GCD algorithm, ACM Transactions on
+	Mathematical Software, v. 21 (March), 1995, pp. 111-122.  */
+
+#include "gmp.h"
+#include "gmp-impl.h"
+#include "longlong.h"
+
+/* If MIN (usize, vsize) >= GCD_ACCEL_THRESHOLD, then the accelerated
+   algorithm is used, otherwise the binary algorithm is used.  This may be
+   adjusted for different architectures.  */
+#ifndef GCD_ACCEL_THRESHOLD
+#define GCD_ACCEL_THRESHOLD 5
+#endif
+
+/* When U and V differ in size by more than BMOD_THRESHOLD, the accelerated
+   algorithm reduces using the bmod operation.  Otherwise, the k-ary reduction
+   is used.  0 <= BMOD_THRESHOLD < BITS_PER_MP_LIMB.  */
+enum
+  {
+    BMOD_THRESHOLD = BITS_PER_MP_LIMB/2
+  };
+
+
+/* Use binary algorithm to compute V <-- GCD (V, U) for usize, vsize == 2.
+   Both U and V must be odd.  */
+static __gmp_inline mp_size_t
+#if __STDC__
+gcd_2 (mp_ptr vp, mp_srcptr up)
+#else
+gcd_2 (vp, up)
+     mp_ptr vp;
+     mp_srcptr up;
+#endif
+{
+  mp_limb_t u0, u1, v0, v1;
+  mp_size_t vsize;
+
+  u0 = up[0], u1 = up[1], v0 = vp[0], v1 = vp[1];
+
+  while (u1 != v1 && u0 != v0)
+    {
+      unsigned long int r;
+      if (u1 > v1)
+	{
+	  u1 -= v1 + (u0 < v0), u0 -= v0;
+	  count_trailing_zeros (r, u0);
+	  u0 = u1 << (BITS_PER_MP_LIMB - r) | u0 >> r;
+	  u1 >>= r;
+	}
+      else  /* u1 < v1.  */
+	{
+	  v1 -= u1 + (v0 < u0), v0 -= u0;
+	  count_trailing_zeros (r, v0);
+	  v0 = v1 << (BITS_PER_MP_LIMB - r) | v0 >> r;
+	  v1 >>= r;
+	}
+    }
+
+  vp[0] = v0, vp[1] = v1, vsize = 1 + (v1 != 0);
+
+  /* If U == V == GCD, done.  Otherwise, compute GCD (V, |U - V|).  */
+  if (u1 == v1 && u0 == v0)
+    return vsize;
+
+  v0 = (u0 == v0) ? (u1 > v1) ? u1-v1 : v1-u1 : (u0 > v0) ? u0-v0 : v0-u0;
+  vp[0] = mpn_gcd_1 (vp, vsize, v0);
+
+  return 1;
+}
+
+/* The function find_a finds 0 < N < 2^BITS_PER_MP_LIMB such that there exists
+   0 < |D| < 2^BITS_PER_MP_LIMB, and N == D * C mod 2^(2*BITS_PER_MP_LIMB).
+   In the reference article, D was computed along with N, but it is better to
+   compute D separately as D <-- N / C mod 2^(BITS_PER_MP_LIMB + 1), treating
+   the result as a twos' complement signed integer.
+
+   Initialize N1 to C mod 2^(2*BITS_PER_MP_LIMB).  According to the reference
+   article, N2 should be initialized to 2^(2*BITS_PER_MP_LIMB), but we use
+   2^(2*BITS_PER_MP_LIMB) - N1 to start the calculations within double
+   precision.  If N2 > N1 initially, the first iteration of the while loop
+   will swap them.  In all other situations, N1 >= N2 is maintained.  */
+
+static
+#if ! defined (__i386__)
+__gmp_inline			/* don't inline this for the x86 */
+#endif
+mp_limb_t
+#if __STDC__
+find_a (mp_srcptr cp)
+#else
+find_a (cp)
+     mp_srcptr cp;
+#endif
+{
+  unsigned long int leading_zero_bits = 0;
+
+  mp_limb_t n1_l = cp[0];	/* N1 == n1_h * 2^BITS_PER_MP_LIMB + n1_l.  */
+  mp_limb_t n1_h = cp[1];
+
+  mp_limb_t n2_l = -n1_l;	/* N2 == n2_h * 2^BITS_PER_MP_LIMB + n2_l.  */
+  mp_limb_t n2_h = ~n1_h;
+
+  /* Main loop.  */
+  while (n2_h)			/* While N2 >= 2^BITS_PER_MP_LIMB.  */
+    {
+      /* N1 <-- N1 % N2.  */
+      if ((MP_LIMB_T_HIGHBIT >> leading_zero_bits & n2_h) == 0)
+	{
+	  unsigned long int i;
+	  count_leading_zeros (i, n2_h);
+	  i -= leading_zero_bits, leading_zero_bits += i;
+	  n2_h = n2_h<<i | n2_l>>(BITS_PER_MP_LIMB - i), n2_l <<= i;
+	  do
+	    {
+	      if (n1_h > n2_h || (n1_h == n2_h && n1_l >= n2_l))
+		n1_h -= n2_h + (n1_l < n2_l), n1_l -= n2_l;
+	      n2_l = n2_l>>1 | n2_h<<(BITS_PER_MP_LIMB - 1), n2_h >>= 1;
+	      i -= 1;
+	    }
+	  while (i);
+	}
+      if (n1_h > n2_h || (n1_h == n2_h && n1_l >= n2_l))
+	n1_h -= n2_h + (n1_l < n2_l), n1_l -= n2_l;
+
+      MP_LIMB_T_SWAP (n1_h, n2_h);
+      MP_LIMB_T_SWAP (n1_l, n2_l);
+    }
+
+  return n2_l;
+}
+
+mp_size_t
+#if __STDC__
+mpn_gcd (mp_ptr gp, mp_ptr up, mp_size_t usize, mp_ptr vp, mp_size_t vsize)
+#else
+mpn_gcd (gp, up, usize, vp, vsize)
+     mp_ptr gp;
+     mp_ptr up;
+     mp_size_t usize;
+     mp_ptr vp;
+     mp_size_t vsize;
+#endif
+{
+  mp_ptr orig_vp = vp;
+  mp_size_t orig_vsize = vsize;
+  int binary_gcd_ctr;		/* Number of times binary gcd will execute.  */
+  TMP_DECL (marker);
+
+  TMP_MARK (marker);
+
+  /* Use accelerated algorithm if vsize is over GCD_ACCEL_THRESHOLD.
+     Two EXTRA limbs for U and V are required for kary reduction.  */
+  if (vsize >= GCD_ACCEL_THRESHOLD)
+    {
+      unsigned long int vbitsize, d;
+      mp_ptr orig_up = up;
+      mp_size_t orig_usize = usize;
+      mp_ptr anchor_up = (mp_ptr) TMP_ALLOC ((usize + 2) * BYTES_PER_MP_LIMB);
+
+      MPN_COPY (anchor_up, orig_up, usize);
+      up = anchor_up;
+
+      count_leading_zeros (d, up[usize-1]);
+      d = usize * BITS_PER_MP_LIMB - d;
+      count_leading_zeros (vbitsize, vp[vsize-1]);
+      vbitsize = vsize * BITS_PER_MP_LIMB - vbitsize;
+      d = d - vbitsize + 1;
+
+      /* Use bmod reduction to quickly discover whether V divides U.  */
+      up[usize++] = 0;				/* Insert leading zero.  */
+      mpn_bdivmod (up, up, usize, vp, vsize, d);
+
+      /* Now skip U/V mod 2^d and any low zero limbs.  */
+      d /= BITS_PER_MP_LIMB, up += d, usize -= d;
+      while (usize != 0 && up[0] == 0)
+	up++, usize--;
+
+      if (usize == 0)				/* GCD == ORIG_V.  */
+	goto done;
+
+      vp = (mp_ptr) TMP_ALLOC ((vsize + 2) * BYTES_PER_MP_LIMB);
+      MPN_COPY (vp, orig_vp, vsize);
+
+      do					/* Main loop.  */
+	{
+          /* mpn_com_n can't be used here because anchor_up and up may
+             partially overlap */
+	  if (up[usize-1] & MP_LIMB_T_HIGHBIT)  /* U < 0; take twos' compl. */
+	    {
+	      mp_size_t i;
+	      anchor_up[0] = -up[0];
+	      for (i = 1; i < usize; i++)
+		anchor_up[i] = ~up[i];
+	      up = anchor_up;
+	    }
+
+	  MPN_NORMALIZE_NOT_ZERO (up, usize);
+
+	  if ((up[0] & 1) == 0)			/* Result even; remove twos. */
+	    {
+	      unsigned int r;
+	      count_trailing_zeros (r, up[0]);
+	      mpn_rshift (anchor_up, up, usize, r);
+	      usize -= (anchor_up[usize-1] == 0);
+	    }
+	  else if (anchor_up != up)
+	    MPN_COPY_INCR (anchor_up, up, usize);
+
+	  MPN_PTR_SWAP (anchor_up,usize, vp,vsize);
+	  up = anchor_up;
+
+	  if (vsize <= 2)		/* Kary can't handle < 2 limbs and  */
+	    break;			/* isn't efficient for == 2 limbs.  */
+
+	  d = vbitsize;
+	  count_leading_zeros (vbitsize, vp[vsize-1]);
+	  vbitsize = vsize * BITS_PER_MP_LIMB - vbitsize;
+	  d = d - vbitsize + 1;
+
+	  if (d > BMOD_THRESHOLD)	/* Bmod reduction.  */
+	    {
+	      up[usize++] = 0;
+	      mpn_bdivmod (up, up, usize, vp, vsize, d);
+	      d /= BITS_PER_MP_LIMB, up += d, usize -= d;
+	    }
+	  else				/* Kary reduction.  */
+	    {
+	      mp_limb_t bp[2], cp[2];
+
+	      /* C <-- V/U mod 2^(2*BITS_PER_MP_LIMB).  */
+              {
+                mp_limb_t u_inv, hi, lo;
+                modlimb_invert (u_inv, up[0]);
+                cp[0] = vp[0] * u_inv;
+                umul_ppmm (hi, lo, cp[0], up[0]);
+                cp[1] = (vp[1] - hi - cp[0] * up[1]) * u_inv;
+              }
+
+	      /* U <-- find_a (C)  *  U.  */
+	      up[usize] = mpn_mul_1 (up, up, usize, find_a (cp));
+	      usize++;
+
+	      /* B <-- A/C == U/V mod 2^(BITS_PER_MP_LIMB + 1).
+		  bp[0] <-- U/V mod 2^BITS_PER_MP_LIMB and
+		  bp[1] <-- ( (U - bp[0] * V)/2^BITS_PER_MP_LIMB ) / V mod 2
+
+                 Like V/U above, but simplified because only the low bit of
+                 bp[1] is wanted. */
+              {
+                mp_limb_t  v_inv, hi, lo;
+                modlimb_invert (v_inv, vp[0]);
+                bp[0] = up[0] * v_inv;
+                umul_ppmm (hi, lo, bp[0], vp[0]);
+                bp[1] = (up[1] + hi + (bp[0]&vp[1])) & 1;
+              }
+
+	      up[usize++] = 0;
+	      if (bp[1])	/* B < 0: U <-- U + (-B)  * V.  */
+		{
+		   mp_limb_t c = mpn_addmul_1 (up, vp, vsize, -bp[0]);
+		   mpn_add_1 (up + vsize, up + vsize, usize - vsize, c);
+		}
+	      else		/* B >= 0:  U <-- U - B * V.  */
+		{
+		  mp_limb_t b = mpn_submul_1 (up, vp, vsize, bp[0]);
+		  mpn_sub_1 (up + vsize, up + vsize, usize - vsize, b);
+		}
+
+	      up += 2, usize -= 2;  /* At least two low limbs are zero.  */
+	    }
+
+	  /* Must remove low zero limbs before complementing.  */
+	  while (usize != 0 && up[0] == 0)
+	    up++, usize--;
+	}
+      while (usize);
+
+      /* Compute GCD (ORIG_V, GCD (ORIG_U, V)).  Binary will execute twice.  */
+      up = orig_up, usize = orig_usize;
+      binary_gcd_ctr = 2;
+    }
+  else
+    binary_gcd_ctr = 1;
+
+  /* Finish up with the binary algorithm.  Executes once or twice.  */
+  for ( ; binary_gcd_ctr--; up = orig_vp, usize = orig_vsize)
+    {
+      if (usize > 2)		/* First make U close to V in size.  */
+	{
+	  unsigned long int vbitsize, d;
+	  count_leading_zeros (d, up[usize-1]);
+	  d = usize * BITS_PER_MP_LIMB - d;
+	  count_leading_zeros (vbitsize, vp[vsize-1]);
+	  vbitsize = vsize * BITS_PER_MP_LIMB - vbitsize;
+	  d = d - vbitsize - 1;
+	  if (d != -(unsigned long int)1 && d > 2)
+	    {
+	      mpn_bdivmod (up, up, usize, vp, vsize, d);  /* Result > 0.  */
+	      d /= (unsigned long int)BITS_PER_MP_LIMB, up += d, usize -= d;
+	    }
+	}
+
+      /* Start binary GCD.  */
+      do
+	{
+	  mp_size_t zeros;
+
+	  /* Make sure U is odd.  */
+	  MPN_NORMALIZE (up, usize);
+	  while (up[0] == 0)
+	    up += 1, usize -= 1;
+	  if ((up[0] & 1) == 0)
+	    {
+	      unsigned int r;
+	      count_trailing_zeros (r, up[0]);
+	      mpn_rshift (up, up, usize, r);
+	      usize -= (up[usize-1] == 0);
+	    }
+
+	  /* Keep usize >= vsize.  */
+	  if (usize < vsize)
+	    MPN_PTR_SWAP (up, usize, vp, vsize);
+
+	  if (usize <= 2)				/* Double precision. */
+	    {
+	      if (vsize == 1)
+		vp[0] = mpn_gcd_1 (up, usize, vp[0]);
+	      else
+		vsize = gcd_2 (vp, up);
+	      break;					/* Binary GCD done.  */
+	    }
+
+	  /* Count number of low zero limbs of U - V.  */
+	  for (zeros = 0; up[zeros] == vp[zeros] && ++zeros != vsize; )
+	    continue;
+
+	  /* If U < V, swap U and V; in any case, subtract V from U.  */
+	  if (zeros == vsize)				/* Subtract done.  */
+	    up += zeros, usize -= zeros;
+	  else if (usize == vsize)
+	    {
+	      mp_size_t size = vsize;
+	      do
+		size--;
+	      while (up[size] == vp[size]);
+	      if (up[size] < vp[size])			/* usize == vsize.  */
+		MP_PTR_SWAP (up, vp);
+	      up += zeros, usize = size + 1 - zeros;
+	      mpn_sub_n (up, up, vp + zeros, usize);
+	    }
+	  else
+	    {
+	      mp_size_t size = vsize - zeros;
+	      up += zeros, usize -= zeros;
+	      if (mpn_sub_n (up, up, vp + zeros, size))
+		{
+		  while (up[size] == 0)			/* Propagate borrow. */
+		    up[size++] = -(mp_limb_t)1;
+		  up[size] -= 1;
+		}
+	    }
+	}
+      while (usize);					/* End binary GCD.  */
+    }
+
+done:
+  if (vp != gp)
+    MPN_COPY (gp, vp, vsize);
+  TMP_FREE (marker);
+  return vsize;
+}