Return correct value for nextprime with negative arg on GMP < 4.3

dvarrazzo · Apr 22, 2011 · 9f24053 · 9f24053
1 parent cb40b00
commit 9f24053
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Showing 2 changed files with 23 additions and 1 deletion.
diff --git a/src/pmpz_arith.c b/src/pmpz_arith.c
@@ -66,7 +66,6 @@ PGMP_PG_FUNCTION(pmpz_ ## op) \
 PMPZ_UN(neg,    PMPZ_NO_CHECK)
 PMPZ_UN(abs,    PMPZ_NO_CHECK)
 PMPZ_UN(sqrt,   PMPZ_CHECK_NONEG)
-PMPZ_UN(nextprime,  PMPZ_NO_CHECK)
 PMPZ_UN(com,    PMPZ_NO_CHECK)
 
 

diff --git a/src/pmpz_theor.c b/src/pmpz_theor.c
@@ -39,6 +39,29 @@ PGMP_PG_FUNCTION(pmpz_probab_prime_p)
     PG_RETURN_INT32(mpz_probab_prime_p(z1, reps));
 }
 
+PGMP_PG_FUNCTION(pmpz_nextprime)
+{
+    const mpz_t     z1;
+    mpz_t           zf;
+
+    PGMP_GETARG_MPZ(z1, 0);
+
+    mpz_init(zf);
+
+#if __GMP_MP_RELEASE < 40300
+    if (UNLIKELY(mpz_sgn(z1) < 0)) {
+        mpz_set_ui(zf, 2);
+    }
+    else
+#endif
+    {
+        mpz_nextprime(zf, z1);
+    }
+
+    PGMP_RETURN_MPZ(zf);
+}
+
+
 PGMP_PG_FUNCTION(pmpz_gcdext)
 {
     const mpz_t     z1;