Add Chromium-only Blender WebEngine parity work

blender-5.2.0/extern/gmp-source/mpn/generic/mulmid.c

@@ -0,0 +1,255 @@
+/* mpn_mulmid -- middle product
+
+   Contributed by David Harvey.
+
+   THE FUNCTION IN THIS FILE IS INTERNAL WITH A MUTABLE INTERFACE.  IT IS ONLY
+   SAFE TO REACH IT THROUGH DOCUMENTED INTERFACES.  IN FACT, IT IS ALMOST
+   GUARANTEED THAT IT'LL CHANGE OR DISAPPEAR IN A FUTURE GNU MP RELEASE.
+
+Copyright 2011 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 either:
+
+  * the GNU Lesser General Public License as published by the Free
+    Software Foundation; either version 3 of the License, or (at your
+    option) any later version.
+
+or
+
+  * the GNU General Public License as published by the Free Software
+    Foundation; either version 2 of the License, or (at your option) any
+    later version.
+
+or both in parallel, as here.
+
+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 General Public License
+for more details.
+
+You should have received copies of the GNU General Public License and the
+GNU Lesser General Public License along with the GNU MP Library.  If not,
+see https://www.gnu.org/licenses/.  */
+
+
+#include "gmp-impl.h"
+
+
+#define CHUNK (200 + MULMID_TOOM42_THRESHOLD)
+
+
+void
+mpn_mulmid (mp_ptr rp,
+            mp_srcptr ap, mp_size_t an,
+            mp_srcptr bp, mp_size_t bn)
+{
+  mp_size_t rn, k;
+  mp_ptr scratch, temp;
+
+  ASSERT (an >= bn);
+  ASSERT (bn >= 1);
+  ASSERT (! MPN_OVERLAP_P (rp, an - bn + 3, ap, an));
+  ASSERT (! MPN_OVERLAP_P (rp, an - bn + 3, bp, bn));
+
+  if (bn < MULMID_TOOM42_THRESHOLD)
+    {
+      /* region not tall enough to make toom42 worthwhile for any portion */
+
+      if (an < CHUNK)
+	{
+	  /* region not too wide either, just call basecase directly */
+	  mpn_mulmid_basecase (rp, ap, an, bp, bn);
+	  return;
+	}
+
+      /* Region quite wide. For better locality, use basecase on chunks:
+
+	 AAABBBCC..
+	 .AAABBBCC.
+	 ..AAABBBCC
+      */
+
+      k = CHUNK - bn + 1;    /* number of diagonals per chunk */
+
+      /* first chunk (marked A in the above diagram) */
+      mpn_mulmid_basecase (rp, ap, CHUNK, bp, bn);
+
+      /* remaining chunks (B, C, etc) */
+      an -= k;
+
+      while (an >= CHUNK)
+	{
+	  mp_limb_t t0, t1, cy;
+	  ap += k, rp += k;
+	  t0 = rp[0], t1 = rp[1];
+	  mpn_mulmid_basecase (rp, ap, CHUNK, bp, bn);
+	  ADDC_LIMB (cy, rp[0], rp[0], t0);    /* add back saved limbs */
+	  MPN_INCR_U (rp + 1, k + 1, t1 + cy);
+	  an -= k;
+	}
+
+      if (an >= bn)
+	{
+	  /* last remaining chunk */
+	  mp_limb_t t0, t1, cy;
+	  ap += k, rp += k;
+	  t0 = rp[0], t1 = rp[1];
+	  mpn_mulmid_basecase (rp, ap, an, bp, bn);
+	  ADDC_LIMB (cy, rp[0], rp[0], t0);
+	  MPN_INCR_U (rp + 1, an - bn + 2, t1 + cy);
+	}
+
+      return;
+    }
+
+  /* region is tall enough for toom42 */
+
+  rn = an - bn + 1;
+
+  if (rn < MULMID_TOOM42_THRESHOLD)
+    {
+      /* region not wide enough to make toom42 worthwhile for any portion */
+
+      TMP_DECL;
+
+      if (bn < CHUNK)
+	{
+	  /* region not too tall either, just call basecase directly */
+	  mpn_mulmid_basecase (rp, ap, an, bp, bn);
+	  return;
+	}
+
+      /* Region quite tall. For better locality, use basecase on chunks:
+
+	 AAAAA....
+	 .AAAAA...
+	 ..BBBBB..
+	 ...BBBBB.
+	 ....CCCCC
+      */
+
+      TMP_MARK;
+
+      temp = TMP_ALLOC_LIMBS (rn + 2);
+
+      /* first chunk (marked A in the above diagram) */
+      bp += bn - CHUNK, an -= bn - CHUNK;
+      mpn_mulmid_basecase (rp, ap, an, bp, CHUNK);
+
+      /* remaining chunks (B, C, etc) */
+      bn -= CHUNK;
+
+      while (bn >= CHUNK)
+	{
+	  ap += CHUNK, bp -= CHUNK;
+	  mpn_mulmid_basecase (temp, ap, an, bp, CHUNK);
+	  mpn_add_n (rp, rp, temp, rn + 2);
+	  bn -= CHUNK;
+	}
+
+      if (bn)
+	{
+	  /* last remaining chunk */
+	  ap += CHUNK, bp -= bn;
+	  mpn_mulmid_basecase (temp, ap, rn + bn - 1, bp, bn);
+	  mpn_add_n (rp, rp, temp, rn + 2);
+	}
+
+      TMP_FREE;
+      return;
+    }
+
+  /* we're definitely going to use toom42 somewhere */
+
+  if (bn > rn)
+    {
+      /* slice region into chunks, use toom42 on all chunks except possibly
+	 the last:
+
+         AA....
+         .AA...
+         ..BB..
+         ...BB.
+         ....CC
+      */
+
+      TMP_DECL;
+      TMP_MARK;
+
+      temp = TMP_ALLOC_LIMBS (rn + 2 + mpn_toom42_mulmid_itch (rn));
+      scratch = temp + rn + 2;
+
+      /* first chunk (marked A in the above diagram) */
+      bp += bn - rn;
+      mpn_toom42_mulmid (rp, ap, bp, rn, scratch);
+
+      /* remaining chunks (B, C, etc) */
+      bn -= rn;
+
+      while (bn >= rn)
+        {
+          ap += rn, bp -= rn;
+	  mpn_toom42_mulmid (temp, ap, bp, rn, scratch);
+          mpn_add_n (rp, rp, temp, rn + 2);
+          bn -= rn;
+        }
+
+      if (bn)
+        {
+          /* last remaining chunk */
+          ap += rn, bp -= bn;
+	  mpn_mulmid (temp, ap, rn + bn - 1, bp, bn);
+          mpn_add_n (rp, rp, temp, rn + 2);
+        }
+
+      TMP_FREE;
+    }
+  else
+    {
+      /* slice region into chunks, use toom42 on all chunks except possibly
+	 the last:
+
+         AAABBBCC..
+         .AAABBBCC.
+         ..AAABBBCC
+      */
+
+      TMP_DECL;
+      TMP_MARK;
+
+      scratch = TMP_ALLOC_LIMBS (mpn_toom42_mulmid_itch (bn));
+
+      /* first chunk (marked A in the above diagram) */
+      mpn_toom42_mulmid (rp, ap, bp, bn, scratch);
+
+      /* remaining chunks (B, C, etc) */
+      rn -= bn;
+
+      while (rn >= bn)
+        {
+	  mp_limb_t t0, t1, cy;
+          ap += bn, rp += bn;
+          t0 = rp[0], t1 = rp[1];
+          mpn_toom42_mulmid (rp, ap, bp, bn, scratch);
+	  ADDC_LIMB (cy, rp[0], rp[0], t0);     /* add back saved limbs */
+	  MPN_INCR_U (rp + 1, bn + 1, t1 + cy);
+	  rn -= bn;
+        }
+
+      TMP_FREE;
+
+      if (rn)
+        {
+          /* last remaining chunk */
+	  mp_limb_t t0, t1, cy;
+          ap += bn, rp += bn;
+          t0 = rp[0], t1 = rp[1];
+          mpn_mulmid (rp, ap, rn + bn - 1, bp, bn);
+	  ADDC_LIMB (cy, rp[0], rp[0], t0);
+	  MPN_INCR_U (rp + 1, rn + 1, t1 + cy);
+        }
+    }
+}