Refactor bigint functions and add remaining helpers

A second variant of the mpz-based iterator is added, and both functions
are moved into a new 'mpz' module, removing 'iterations' and the common
pszip.h header.

These iterators have been updated to have all (de)allocation performed
externally as to reduce overhead / boost performance.  Related helper
functions have also been added to this module.

Signed-off-by: Malfurious <m@lfurio.us>

1 files changed, 0 insertions, 40 deletions

diff --git a/iterations.c b/iterations.c
deleted file mode 100644
index 517bcaa..0000000
--- a/iterations.c
+++ /dev/null
@@ -1,40 +0,0 @@
-#include "pszip.h"
-
-/*
- * Bit hack source:
- * https://graphics.stanford.edu/~seander/bithacks.html#NextBitPermutation
- */
-
-void pszip_iterate_bithack01(mpz_t w, const mpz_t v)
-{
-    mpz_t vmo, t, tpo, ct, nct, act, actmo;
-    mp_limb_t *actmo_l;
-    size_t actmo_s;
-
-    mpz_inits(vmo, t, tpo, ct, nct, act, actmo, 0);
-
-    /* Gets v's least significant 0 bits set to 1.
-     * t = v | (v - 1); */
-    mpz_sub_ui(vmo, v, 1);
-    mpz_ior(t, v, vmo);
-
-    /* Next set to 1 the most significant bit to change,
-     * set to 0 the least significant ones, and add the necessary 1 bits.
-     * w = (t + 1) | (((~t & -~t) - 1) >> (__builtin_ctz(v) + 1));
-     * __builtin_ctz(v) -> mpz_scan1(v, 0) */
-    mpz_add_ui(tpo, t, 1);
-    mpz_com(ct, t);
-    mpz_neg(nct, ct);
-    mpz_and(act, ct, nct);
-    mpz_sub_ui(actmo, act, 1);
-
-    /* the bitshift requires obtaining direct memory access */
-    actmo_s = mpz_size(actmo);
-    actmo_l = mpz_limbs_modify(actmo, actmo_s);
-    mpn_rshift(actmo_l, actmo_l, actmo_s, (mpz_scan1(v, 0) + 1));
-    mpz_limbs_finish(actmo, actmo_s);
-
-    mpz_ior(w, tpo, actmo);
-
-    mpz_clears(vmo, t, tpo, ct, nct, act, actmo, 0);
-}