From ac0d3a625a5f0e2f81522b7d6d7ca6a6c3f158e2 Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Tue, 15 Mar 2016 23:19:01 +0100 Subject: Fix bug in libzahl_msb_nz_* and optimise and simplify libzahl_realloc MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- src/allocator.c | 20 +++++++------------- src/internals.h | 8 ++++---- 2 files changed, 11 insertions(+), 17 deletions(-) diff --git a/src/allocator.c b/src/allocator.c index 7737046..80668f1 100644 --- a/src/allocator.c +++ b/src/allocator.c @@ -5,21 +5,15 @@ void libzahl_realloc(z_t a, size_t need) { - size_t i, x; + size_t i, new_size = 1; zahl_char_t *new; - /* Find n such that n is a minimal power of 2 ≥ need. */ - if (likely((need & (~need + 1)) != need)) { - need |= need >> 1; - need |= need >> 2; - need |= need >> 4; - for (i = sizeof(need), x = 8; (i >>= 1); x <<= 1) - need |= need >> x; - need += 1; + new_size <<= i = libzahl_msb_nz_zu(need); + if (likely(new_size != need)) { + i += 1; + new_size <<= 1; } - i = libzahl_msb_nz_zu(need); - if (likely(libzahl_pool_n[i])) { libzahl_pool_n[i]--; new = libzahl_pool[i][libzahl_pool_n[i]]; @@ -27,12 +21,12 @@ libzahl_realloc(z_t a, size_t need) zfree(a); a->chars = new; } else { - a->chars = realloc(a->chars, need * sizeof(zahl_char_t)); + a->chars = realloc(a->chars, new_size * sizeof(zahl_char_t)); if (unlikely(!a->chars)) { if (!errno) /* sigh... */ errno = ENOMEM; libzahl_failure(errno); } } - a->alloced = need; + a->alloced = new_size; } diff --git a/src/internals.h b/src/internals.h index da8ce0c..a9d9af5 100644 --- a/src/internals.h +++ b/src/internals.h @@ -150,15 +150,15 @@ zmemset(zahl_char_t *a, register zahl_char_t v, register size_t n) #endif #if defined(__GNUC__) || defined(__clang__) -# define libzahl_msb_nz_lu(x) (8 * sizeof(unsigned long int) - (size_t)__builtin_clzl(x)); -# define libzahl_msb_nz_llu(x) (8 * sizeof(unsigned long long int) - (size_t)__builtin_clzll(x)); +# define libzahl_msb_nz_lu(x) (8 * sizeof(unsigned long int) - 1 - (size_t)__builtin_clzl(x)) +# define libzahl_msb_nz_llu(x) (8 * sizeof(unsigned long long int) - 1 - (size_t)__builtin_clzll(x)) #else static inline size_t libzahl_msb_nz_lu(unsigned long int x) { size_t r = 0; for (; x; x >>= 1, r++); - return r; + return r - 1; } static inline size_t @@ -166,7 +166,7 @@ libzahl_msb_nz_llu(unsigned long long int x) { size_t r = 0; for (; x; x >>= 1, r++); - return r; + return r - 1; } #endif -- cgit v1.2.3-70-g09d2