sqr.c, mul.c: in the naive algorithm, redo computations with exact exponents

   in more cases; corrects bug for test
   + - 10 0b1e-1073741824 10 0  100 0b1@-536870912  100 0b1@-536870913 N N
   (not yet added to sqr.dat)


git-svn-id: svn://scm.gforge.inria.fr/svn/mpc/trunk@1134 211d60ee-9f03-0410-a15a-8952a2c7a4e4

2 files changed, 7 insertions, 9 deletions

diff --git a/src/mul.c b/src/mul.c
index a85fa84..6d64329 100644
--- a/src/mul.c
+++ b/src/mul.c
@@ -1,6 +1,6 @@
 /* mpc_mul -- Multiply two complex numbers
 
-Copyright (C) 2002, 2004, 2005, 2008, 2009, 2010, 2011 INRIA
+Copyright (C) 2002, 2004, 2005, 2008, 2009, 2010, 2011, 2012 INRIA
 
 This file is part of GNU MPC.
 
@@ -201,10 +201,9 @@ mpfr_fmma (mpfr_ptr z, mpfr_srcptr a, mpfr_srcptr b, mpfr_srcptr c,
       mpfr_set_si (z, (mpfr_signbit (z) ? -1 : 1), GMP_RNDN);
       inex = mpfr_mul_2ui (z, z, mpfr_get_emax (), rnd);
    }
-   else if (mpfr_nan_p (z) || (mpfr_zero_p (u) && mpfr_zero_p (v))) {
-      /* In the first case, u and v are infinities with opposite signs.
-         In the second case, u and v are zeroes; their sum may be 0 or the
-         least representable number, with a sign to be determined.
+   else if (mpfr_inf_p (u) || mpfr_inf_p (v)
+            || mpfr_zero_p (u) || mpfr_zero_p (v)) {
+      /* There is at least one over- or underflow.
          Redo the computations with mpz_t exponents */
       mpfr_exp_t ea, eb, ec, ed;
       mpz_t eu, ev;
diff --git a/src/sqr.c b/src/sqr.c
index 47a3f7e..b5be792 100644
--- a/src/sqr.c
+++ b/src/sqr.c
@@ -58,10 +58,9 @@ mpfr_fmma (mpfr_ptr z, mpfr_srcptr a, mpfr_srcptr b, mpfr_srcptr c,
       mpfr_set_si (z, (mpfr_signbit (z) ? -1 : 1), GMP_RNDN);
       inex = mpfr_mul_2ui (z, z, mpfr_get_emax (), rnd);
    }
-   else if (mpfr_nan_p (z) || (mpfr_zero_p (u) && mpfr_zero_p (v))) {
-      /* In the first case, u and v are infinities with opposite signs.
-         In the second case, u and v are zeroes; their sum may be 0 or the
-         least representable number, with a sign to be determined.
+   else if (mpfr_inf_p (u) || mpfr_inf_p (v)
+            || mpfr_zero_p (u) || mpfr_zero_p (v)) {
+      /* There is at least one over- or underflow.
          Redo the computations with mpz_t exponents */
       mpfr_exp_t ea, eb, ec, ed;
       mpz_t eu, ev;