1 files changed, 80 insertions, 0 deletions
diff --git a/mpc/src/mul_i.c b/mpc/src/mul_i.c
new file mode 100644
index 0000000000..591b0c6d7f
--- /dev/null
+++ b/mpc/src/mul_i.c
@@ -0,0 +1,80 @@
+/* mpc_mul_i -- Multiply a complex number by plus or minus i.
+
+Copyright (C) 2005, 2009, 2010, 2011 INRIA
+
+This file is part of GNU MPC.
+
+GNU MPC 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 3 of the License, or (at your
+option) any later version.
+
+GNU MPC 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 this program. If not, see http://www.gnu.org/licenses/ .
+*/
+
+#include "mpc-impl.h"
+
+int
+mpc_mul_i (mpc_ptr a, mpc_srcptr b, int sign, mpc_rnd_t rnd)
+/* if sign is >= 0, multiply by i, otherwise by -i */
+{
+  int   inex_re, inex_im;
+  mpfr_t tmp;
+
+  /* Treat the most probable case of compatible precisions first */
+  if (     MPC_PREC_RE (b) == MPC_PREC_IM (a)
+        && MPC_PREC_IM (b) == MPC_PREC_RE (a))
+  {
+     if (a == b)
+        mpfr_swap (mpc_realref (a), mpc_imagref (a));
+     else
+     {
+        mpfr_set (mpc_realref (a), mpc_imagref (b), GMP_RNDN);
+        mpfr_set (mpc_imagref (a), mpc_realref (b), GMP_RNDN);
+     }
+     if (sign >= 0)
+        MPFR_CHANGE_SIGN (mpc_realref (a));
+     else
+        MPFR_CHANGE_SIGN (mpc_imagref (a));
+     inex_re = 0;
+     inex_im = 0;
+  }
+  else
+  {
+     if (a == b)
+     {
+        mpfr_init2 (tmp, MPC_PREC_RE (a));
+        if (sign >= 0)
+        {
+           inex_re = mpfr_neg (tmp, mpc_imagref (b), MPC_RND_RE (rnd));
+           inex_im = mpfr_set (mpc_imagref (a), mpc_realref (b), MPC_RND_IM (rnd));
+        }
+        else
+        {
+           inex_re = mpfr_set (tmp, mpc_imagref (b), MPC_RND_RE (rnd));
+           inex_im = mpfr_neg (mpc_imagref (a), mpc_realref (b), MPC_RND_IM (rnd));
+        }
+        mpfr_clear (mpc_realref (a));
+        mpc_realref (a)[0] = tmp [0];
+     }
+     else
+        if (sign >= 0)
+        {
+           inex_re = mpfr_neg (mpc_realref (a), mpc_imagref (b), MPC_RND_RE (rnd));
+           inex_im = mpfr_set (mpc_imagref (a), mpc_realref (b), MPC_RND_IM (rnd));
+        }
+        else
+        {
+           inex_re = mpfr_set (mpc_realref (a), mpc_imagref (b), MPC_RND_RE (rnd));
+           inex_im = mpfr_neg (mpc_imagref (a), mpc_realref (b), MPC_RND_IM (rnd));
+        }
+  }
+
+  return MPC_INEX(inex_re, inex_im);
+}