Some extra int64 functions.

[u/mdw/putty] / int64.c

diff --git a/int64.c b/int64.c
index b43feea..a466bdd 100644 (file)
--- a/int64.c
+++ b/int64.c
@@ -5,12 +5,12 @@
  */
 
 #include <assert.h>
+#include <string.h>
 
-typedef struct {
-    unsigned long hi, lo;
-} uint64, int64;
+#include "int64.h"
 
-uint64 uint64_div10(uint64 x, int *remainder) {
+uint64 uint64_div10(uint64 x, int *remainder)
+{
     uint64 y;
     int rem, r2;
     y.hi = x.hi / 10;
@@ -30,37 +30,101 @@ uint64 uint64_div10(uint64 x, int *remainder) {
     return y;
 }
 
-void uint64_decimal(uint64 x, char *buffer) {
+void uint64_decimal(uint64 x, char *buffer)
+{
     char buf[20];
     int start = 20;
     int d;
 
-    while (x.hi || x.lo) {
+    do {
        x = uint64_div10(x, &d);
        assert(start > 0);
        buf[--start] = d + '0';
-    }
+    } while (x.hi || x.lo);
 
-    memcpy(buffer, buf+start, sizeof(buf)-start);
-    buffer[sizeof(buf)-start] = '\0';
+    memcpy(buffer, buf + start, sizeof(buf) - start);
+    buffer[sizeof(buf) - start] = '\0';
 }
 
-uint64 uint64_make(unsigned long hi, unsigned long lo) {
+uint64 uint64_make(unsigned long hi, unsigned long lo)
+{
     uint64 y;
     y.hi = hi;
     y.lo = lo;
     return y;
 }
 
-uint64 uint64_add(uint64 x, uint64 y) {
+uint64 uint64_add(uint64 x, uint64 y)
+{
     x.lo += y.lo;
     x.hi += y.hi + (x.lo < y.lo ? 1 : 0);
     return x;
 }
 
-uint64 uint64_add32(uint64 x, unsigned long y) {
+uint64 uint64_add32(uint64 x, unsigned long y)
+{
     uint64 yy;
     yy.hi = 0;
     yy.lo = y;
     return uint64_add(x, yy);
 }
+
+int uint64_compare(uint64 x, uint64 y)
+{
+    if (x.hi != y.hi)
+       return x.hi < y.hi ? -1 : +1;
+    if (x.lo != y.lo)
+       return x.lo < y.lo ? -1 : +1;
+    return 0;
+}
+
+uint64 uint64_subtract(uint64 x, uint64 y)
+{
+    x.lo -= y.lo;
+    x.hi -= y.hi + (x.lo > ~y.lo ? 1 : 0);
+    return x;
+}
+
+double uint64_to_double(uint64 x)
+{
+    return (4294967296.0 * x.hi) + (double)x.lo;
+}
+
+uint64 uint64_shift_right(uint64 x, int shift)
+{
+    if (shift < 32) {
+       x.lo >>= shift;
+       x.lo |= (x.hi << (32-shift));
+       x.hi >>= shift;
+    } else {
+       x.lo = x.hi >> (shift-32);
+       x.hi = 0;
+    }
+    return x;
+}
+
+uint64 uint64_shift_left(uint64 x, int shift)
+{
+    if (shift < 32) {
+       x.hi <<= shift;
+       x.hi |= (x.lo >> (32-shift));
+       x.lo <<= shift;
+    } else {
+       x.hi = x.lo << (shift-32);
+       x.lo = 0;
+    }
+    return x;
+}
+
+uint64 uint64_from_decimal(char *str)
+{
+    uint64 ret;
+    ret.hi = ret.lo = 0;
+    while (*str >= '0' && *str <= '9') {
+       ret = uint64_add(uint64_shift_left(ret, 3),
+                        uint64_shift_left(ret, 1));
+       ret = uint64_add32(ret, *str - '0');
+       str++;
+    }
+    return ret;
+}