commit 5e77b994435be4bef66ff596bf931e1fff97a77c
parent c018cebc38c37370ab6c89d19694587edf7d0d0e
Author: Mattias Andrée <maandree@kth.se>
Date: Sat, 12 Mar 2016 20:22:11 +0100
64-bit chars out-perform 32-bit chars on almost all operations, and on all expensive operations
Signed-off-by: Mattias Andrée <maandree@kth.se>
Diffstat:
5 files changed, 17 insertions(+), 23 deletions(-)
diff --git a/src/internals.h b/src/internals.h
@@ -5,9 +5,9 @@
#include <stdlib.h>
#include <errno.h>
-#define BITS_PER_CHAR 32
-#define LB_BITS_PER_CHAR 5
-#define ZAHL_CHAR_MAX UINT32_MAX
+#define BITS_PER_CHAR 64
+#define LB_BITS_PER_CHAR 6
+#define ZAHL_CHAR_MAX UINT64_MAX
#define FLOOR_BITS_TO_CHARS(bits) ((bits) >> LB_BITS_PER_CHAR)
#define CEILING_BITS_TO_CHARS(bits) (((bits) + (BITS_PER_CHAR - 1)) >> LB_BITS_PER_CHAR)
diff --git a/src/zsets.c b/src/zsets.c
@@ -41,9 +41,6 @@ zsets(z_t a, const char *str)
if (!temp)
continue;
libzahl_tmp_str_num->chars[0] = (zahl_char_t)temp;
- temp >>= BITS_PER_CHAR;
- libzahl_tmp_str_num->chars[1] = (zahl_char_t)temp;
- libzahl_tmp_str_num->used = 1 + !!temp;
zadd(a, a, libzahl_tmp_str_num);
}
}
diff --git a/src/zsetu.c b/src/zsetu.c
@@ -13,9 +13,6 @@ zsetu(z_t a, unsigned long long int b)
}
ENSURE_SIZE(a, SIZE_MULTIPLE(b, *(a->chars)));
SET_SIGNUM(a, 1);
- a->used = 0;
- while (b) {
- a->chars[a->used++] = (zahl_char_t)b;
- b >>= BITS_PER_CHAR;
- }
+ a->chars[0] = (zahl_char_t)b;
+ a->used = 1;
}
diff --git a/src/zstr.c b/src/zstr.c
@@ -6,16 +6,16 @@
#define num libzahl_tmp_str_num
#define rem libzahl_tmp_str_rem
-/* All 9 you see here is derived from that 10⁹ is the largest
- * power of than < 2³², and 32 is the number of bits in
- * zahl_char_t. If zahl_char_t is chanced, the value 9, and
- * the cast to unsigned long must be changed accordingly. */
+/* All 19 you see here is derived from that 10¹⁹ is the largest
+ * power of than < 2⁶⁴, and 64 is the number of bits in
+ * zahl_char_t. If zahl_char_t is chanced, the value 19, and
+ * the cast to unsigned long long must be changed accordingly. */
char *
zstr(z_t a, char *b)
{
- char buf[9 + 1];
+ char buf[19 + 1];
size_t n, len;
char overridden = 0;
int neg;
@@ -44,17 +44,17 @@ zstr(z_t a, char *b)
b[0] = '-';
b += neg;
n -= neg;
- n = n > 9 ? (n - 9) : 0;
+ n = n > 19 ? (n - 19) : 0;
for (;;) {
- zdivmod(num, rem, num, libzahl_const_1e9);
+ zdivmod(num, rem, num, libzahl_const_1e19);
if (!zzero(num)) {
- sprintf(b + n, "%09lu", zzero(rem) ? 0UL : (unsigned long)(rem->chars[0]));
- b[n + 9] = overridden;
+ sprintf(b + n, "%019llu", zzero(rem) ? 0ULL : (unsigned long long)(rem->chars[0]));
+ b[n + 19] = overridden;
overridden = b[n];
- n = n > 9 ? (n - 9) : 0;
+ n = n > 19 ? (n - 19) : 0;
} else {
- len = (size_t)sprintf(buf, "%lu", (unsigned long)(rem->chars[0]));
+ len = (size_t)sprintf(buf, "%llu", (unsigned long long)(rem->chars[0]));
if (overridden)
buf[len] = b[n + len];
memcpy(b + n, buf, len + 1);
diff --git a/zahl.h b/zahl.h
@@ -11,7 +11,7 @@
/* You should pretend like this typedef does not exist. */
-typedef uint32_t zahl_char_t;
+typedef uint64_t zahl_char_t;
/* This structure should be considered opaque. */
typedef struct {
