Add libgmp 6.2.0 to third_party
Don't build it yet. That will come in the next review.
Change-Id: Idf3266558165e5ab45f4a41c98cc8c838c8244d5
diff --git a/third_party/gmp/mpq/div.c b/third_party/gmp/mpq/div.c
new file mode 100644
index 0000000..3bd9726
--- /dev/null
+++ b/third_party/gmp/mpq/div.c
@@ -0,0 +1,133 @@
+/* mpq_div -- divide two rational numbers.
+
+Copyright 1991, 1994-1996, 2000, 2001, 2015, 2018 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"
+
+
+void
+mpq_div (mpq_ptr quot, mpq_srcptr op1, mpq_srcptr op2)
+{
+ mpz_t gcd1, gcd2;
+ mpz_t tmp1, tmp2;
+ mp_size_t op1_size;
+ mp_size_t op2_size;
+ mp_size_t alloc;
+ TMP_DECL;
+
+ op2_size = SIZ(NUM(op2));
+
+ if (UNLIKELY (op2_size == 0))
+ DIVIDE_BY_ZERO;
+
+ if (UNLIKELY (quot == op2))
+ {
+ if (UNLIKELY (op1 == op2))
+ {
+ mpq_set_ui (quot, 1, 1);
+ return;
+ }
+
+ /* We checked for op1 == op2: we are not in the x=x/x case.
+ We compute x=y/x by computing x=inv(x)*y */
+ MPN_PTR_SWAP (PTR(NUM(quot)), ALLOC(NUM(quot)),
+ PTR(DEN(quot)), ALLOC(DEN(quot)));
+ if (op2_size > 0)
+ {
+ SIZ(NUM(quot)) = SIZ(DEN(quot));
+ SIZ(DEN(quot)) = op2_size;
+ }
+ else
+ {
+ SIZ(NUM(quot)) = - SIZ(DEN(quot));
+ SIZ(DEN(quot)) = - op2_size;
+ }
+ mpq_mul (quot, quot, op1);
+ return;
+ }
+
+ op1_size = ABSIZ(NUM(op1));
+
+ if (op1_size == 0)
+ {
+ /* We special case this to simplify allocation logic; gcd(0,x) = x
+ is a singular case for the allocations. */
+ SIZ(NUM(quot)) = 0;
+ MPZ_NEWALLOC (DEN(quot), 1)[0] = 1;
+ SIZ(DEN(quot)) = 1;
+ return;
+ }
+
+ op2_size = ABS(op2_size);
+
+ TMP_MARK;
+
+ alloc = MIN (op1_size, op2_size);
+ MPZ_TMP_INIT (gcd1, alloc);
+
+ alloc = MAX (op1_size, op2_size);
+ MPZ_TMP_INIT (tmp1, alloc);
+
+ op2_size = SIZ(DEN(op2));
+ op1_size = SIZ(DEN(op1));
+
+ alloc = MIN (op1_size, op2_size);
+ MPZ_TMP_INIT (gcd2, alloc);
+
+ alloc = MAX (op1_size, op2_size);
+ MPZ_TMP_INIT (tmp2, alloc);
+
+ /* QUOT might be identical to OP1, so don't store the result there
+ until we are finished with the input operand. We can overwrite
+ the numerator of QUOT when we are finished with the numerator of
+ OP1. */
+
+ mpz_gcd (gcd1, NUM(op1), NUM(op2));
+ mpz_gcd (gcd2, DEN(op2), DEN(op1));
+
+ mpz_divexact_gcd (tmp1, NUM(op1), gcd1);
+ mpz_divexact_gcd (tmp2, DEN(op2), gcd2);
+
+ mpz_mul (NUM(quot), tmp1, tmp2);
+
+ mpz_divexact_gcd (tmp1, NUM(op2), gcd1);
+ mpz_divexact_gcd (tmp2, DEN(op1), gcd2);
+
+ mpz_mul (DEN(quot), tmp1, tmp2);
+
+ /* Keep the denominator positive. */
+ if (SIZ(DEN(quot)) < 0)
+ {
+ SIZ(DEN(quot)) = -SIZ(DEN(quot));
+ SIZ(NUM(quot)) = -SIZ(NUM(quot));
+ }
+
+ TMP_FREE;
+}