Multiple changes:

1)  Compile test with -O0, it takes too long otherwise.

2)  Add error codes: ZERROR_0_POW_0, ZERROR_0_DIV_0, ZERROR_DIV_0, ZERROR_NEGATIVE.

3)  Add workaround for a bug in clang (src/allocator.c).

4)  Cleanups.

5)  Minor optimisations.

6)  Add inclusion guard for zahl.h.

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 34 insertions, 14 deletions

diff --git a/src/allocator.c b/src/allocator.c
index 33c8677..41ce9ed 100644
--- a/src/allocator.c
+++ b/src/allocator.c
@@ -1,27 +1,47 @@
 /* See LICENSE file for copyright and license details. */
 #include "internals.h"
+#include <stdio.h>
+
+
+/* Find r such that r is a minimal power of 2 ≥ n. */
+#define NEXT_2POW(n)\
+	do if (likely((n & (~n + 1)) != n)) {\
+		size_t x;\
+		n |= n >> 1;\
+		n |= n >> 2;\
+		n |= n >> 4;\
+		for (i = sizeof(n), x = 8; i; i >>= 1, x <<= 1)\
+			n |= n >> x;\
+		n += 1;\
+	} while (0)
+
+
+#if defined(__clang__)
+static inline __attribute__((optnone)) size_t
+clang_warkaround_next_2pow(size_t need)
+{
+	size_t i;
+	NEXT_2POW(need);
+	return need;
+}
+#endif
 
 
 void
 libzahl_realloc(z_t a, size_t need)
 {
-	size_t i, x;
+	size_t i;
 	zahl_char_t *new;
 
-	/* Find n such that n is a minimal power of 2 ≥ need. */
-	if ((need & (~need + 1)) != need) {
-		need |= need >> 1;
-		need |= need >> 2;
-		need |= need >> 4;
-		for (i = sizeof(need), x = 8; i; i >>= 1, x <<= 1)
-			need |= need >> x;
-		need += 1;
-	}
+#if defined(__clang__)
+	need = clang_warkaround_next_2pow(need);
+#else
+	NEXT_2POW(need);
+#endif
 
-	for (i = 0, x = need; x; x >>= 1)
-		i += 1;
+	i = libzahl_msb_nz_zu(need);
 
-	if (libzahl_pool_n[i]) {
+	if (likely(libzahl_pool_n[i])) {
 		libzahl_pool_n[i]--;
 		new = libzahl_pool[i][libzahl_pool_n[i]];
 		zmemcpy(new, a->chars, a->alloced);
@@ -32,7 +52,7 @@ libzahl_realloc(z_t a, size_t need)
 		if (!a->chars) {
 			if (!errno) /* sigh... */
 				errno = ENOMEM;
-			FAILURE(errno);
+			libzahl_failure(errno);
 		}
 	}
 	a->alloced = need;