libzahl

commit a626bacf8e45af60727882250f9d3abeb15ff3cd
parent 851c70c8645fc73a7377996b27c79fa7948fe477
Author: Mattias Andrée <maandree@kth.se>
Date:   Wed,  2 Mar 2016 09:59:52 +0100

Add zsets and zstr

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

Diffstat:
M
man/zstr_length.3
 | 
2
+-
M
src/internals.h
 | 
10
+++++++++-
A
src/zsets.c
 | 
47
+++++++++++++++++++++++++++++++++++++++++++++++
M
src/zsetup.c
 | 
10
+++++++++-
A
src/zstr.c
 | 
61
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
M
src/zstr_length.c
 | 
2
+-
M
src/zunsetup.c
 | 
7
++++++-

7 files changed, 134 insertions(+), 5 deletions(-)
diff --git a/man/zstr_length.3 b/man/zstr_length.3
@@ -10,7 +10,7 @@ size_t zstr_length(z_t \fIa\fP, unsigned long long int\fIradix\fP);
 .SH DESCRIPTION
 .B zstr_length
 calculates the number of digits required to
-to represent the absolute value of
+to represent
 .I a
 in the selected
 .IR radix .
diff --git a/src/internals.h b/src/internals.h
@@ -12,11 +12,19 @@
 	X(libzahl_tmp_cmp)\
 	X(libzahl_tmp_str_num)\
 	X(libzahl_tmp_str_mag)\
-	X(libzahl_tmp_str_div)
+	X(libzahl_tmp_str_div)\
+	X(libzahl_tmp_str_rem)
+
+#define LIST_CONSTS\
+	X(libzahl_const_1e19, zsetu, 10000000000000000000ULL) /* The largest power of 10 < 2⁶⁴. */\
+	X(libzahl_const_1e9,  zsetu, 1000000000ULL)           /* The largest power of 10 < 2³². */
 
 #define X(x)  extern z_t x;
 LIST_TEMPS
 #undef X
+#define X(x, f, v)  extern z_t x;
+LIST_CONSTS
+#undef X
 
 extern jmp_buf libzahl_jmp_buf;
 extern int libzahl_set_up;
diff --git a/src/zsets.c b/src/zsets.c
@@ -0,0 +1,47 @@
+/* See LICENSE file for copyright and license details. */
+#include "internals"
+
+#include <errno.h>
+
+
+int
+zsets(z_t a, const char *str)
+{
+	unsigned long long int temp = 0;
+	int neg = (*str == '-');
+	const char *str_end;
+
+	str += neg || (*str == '+');
+
+	if (!*str) {
+		errno = EINVAL;
+		return -1;
+	}
+	for (str_end = str; *str_end; str_end++) {
+		if (!isdigit(*str_end)) {
+			errno = EINVAL;
+			return -1;
+		}
+	}
+
+	SET_SIGNUM(a, 0);
+
+	switch ((str_end - str) % 19) {
+		while (*str) {
+#define X(n)\
+			temp *= 10, temp += *str++ & 15;\
+		case n:
+		X(18) X(17) X(16) X(15) X(14) X(13) X(12) X(11) X(10)
+		X(9) X(8) X(7) X(6) X(5) X(4) X(3) X(2) X(1) X(0)
+#undef X
+			zmul(a, a, libzahl_const_1e19);
+			zsetu(libzahl_tmp_str_num, temp);
+			zadd(a, a, libzahl_tmp_str_num);
+			temp = 0;
+		}
+	}
+
+	if (neg)
+		SET_SIGNUM(a, -zsignum(a));
+	return 0;
+}
diff --git a/src/zsetup.c b/src/zsetup.c
@@ -4,6 +4,9 @@
 #define X(x)  z_t x;
 LIST_TEMPS
 #undef X
+#define X(x, f, v)  z_t x;
+LIST_CONSTS
+#undef X
 
 jmp_buf libzahl_jmp_buf;
 int libzahl_set_up = 0;
@@ -16,8 +19,13 @@ zsetup(jmp_buf env)
 
 	if (!libzahl_set_up) {
 		libzahl_set_up = 1;
-#define X(x)  zinit(zahl_tmp_##x);
+#define X(x)\
+		zinit(x);
 		LIST_TEMPS;
 #undef X
+#define X(x, f, v)\
+		zinit(x), f(x, v);
+		LIST_CONSTS;
+#undef X
 	}
 }
diff --git a/src/zstr.c b/src/zstr.c
@@ -0,0 +1,61 @@
+/* See LICENSE file for copyright and license details. */
+#include "internals"
+
+#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. */
+
+
+char *
+zstr(z_t a, char *b)
+{
+	size_t n;
+	char overridden;
+	int neg;
+
+	if (zzero(a)) {
+		if (!b) {
+			b = malloc(2);
+			if (!b)
+				FAILURE_JUMP();
+		}
+		b[0] = '0';
+		b[1] = 0;
+		return b;
+	}
+
+	n = zstr_length(a, 10);
+	if (!b) {
+		b = malloc(n + 1);
+		if (!b)
+			FAILURE_JUMP();
+	}
+
+	neg = zsignum(a) < 0;
+	zabs(num, a);
+	n -= neg;
+	n = n > 9 ? (n - 9) : 0;
+	b[0] = '-';
+	b += neg;
+	overridden = 0;
+
+	for (;;) {
+		zdivmod(num, rem, num, libzahl_const_1e9);
+		if (!zzero(num)) {
+			sprintf(b + n, "%09lu", (unsigned long)(rem->chars[0]));
+			b[n + 9] = overridden;
+			overridden = b[n + (9 - 1)];
+			n = n > 9 ? (n - 9) : 0;
+		} else {
+			n += sprintf(b + n, "%lu", (unsigned long)(rem->chars[0]));
+			b[n] = overridden;
+			break;
+		}
+	}
+
+	return b - neg;
+}
diff --git a/src/zstr_length.c b/src/zstr_length.c
@@ -24,5 +24,5 @@ zstr_length(z_t a, unsigned long long int radix)
 		size_total += size_temp;
 		zdiv(num, num, div);
 	}
-	return size_total;
+	return size_total + (zsignum(a) < 0);
 }
diff --git a/src/zunsetup.c b/src/zunsetup.c
@@ -7,8 +7,13 @@ zunsetup(jmp_buf env)
 {
 	if (libzahl_set_up) {
 		libzahl_set_up = 0;
-#define X(x)  zfree(zahl_tmp_##x);
+#define X(x)\
+		zfree(x);
 		LIST_TEMPS;
 #undef X
+#define X(x, f, v)\
+		zfree(x);
+		LIST_CONSTS;
+#undef X
 	}
 }