libplatform-254.40.4.tar.gz

[apple/libplatform.git] / src / simple / string_io.c

diff --git a/src/simple/string_io.c b/src/simple/string_io.c
index 0c8c6375e811c945bcce09b7409a76ca15db76d6..2f7a22523d3ec41bdaa08ebf18f76dc5b5627cea 100644 (file)
--- a/src/simple/string_io.c
+++ b/src/simple/string_io.c
@@ -147,6 +147,41 @@ put_n(BUF *b, _esc_func esc, const char *str, ssize_t n)
                put_c(b, esc, *str++);
 }
 
+#if __LP64__ || defined(__arm64__)
+static unsigned long long
+udiv10(unsigned long long a, unsigned long long *rem)
+{
+       *rem = a % 10;
+       return a / 10;
+}
+#else
+unsigned long long
+udiv10(unsigned long long a, unsigned long long *rem_out)
+{
+       if (a <= UINT_MAX) {
+               *rem_out = (unsigned long long)((unsigned int)a % 10);
+               return (unsigned long long)((unsigned int)a / 10);
+       }
+
+       // The biggest multiple of 10 that dividend might contain
+       unsigned long long divisor  = 0xa000000000000000;
+       unsigned long long dividend = a;
+       unsigned long long quotient = 0;
+
+       while (divisor >= 0xa) {
+               quotient = quotient << 1;
+               if (dividend >= divisor) {
+                       dividend -= divisor;
+                       quotient += 1;
+               }
+               divisor = divisor >> 1;
+       }
+
+       *rem_out = dividend;
+       return quotient;
+}
+#endif
+
 /*
  * Output the signed decimal string representing the number in "in".  "width" is
  * the minimum field width, and "zero" is a boolean value, true for zero padding
@@ -160,6 +195,7 @@ dec(BUF *b, _esc_func esc, long long in, int width, int zero)
        ssize_t pad;
        int neg = 0;
        unsigned long long n = (unsigned long long)in;
+       unsigned long long rem;
 
        if(in < 0) {
                neg++;
@@ -169,8 +205,8 @@ dec(BUF *b, _esc_func esc, long long in, int width, int zero)
        *--cp = 0;
        if(n) {
                while(n) {
-                       *--cp = (n % 10) + '0';
-                       n /= 10;
+                       n = udiv10(n, &rem);
+                       *--cp = rem + '0';
                }
        } else
                *--cp = '0';
@@ -268,13 +304,14 @@ udec(BUF *b, _esc_func esc, unsigned long long n, int width, int zero)
 {
        char buf[32];
        char *cp = buf + sizeof(buf);
+       unsigned long long rem;
        ssize_t pad;
 
        *--cp = 0;
        if(n) {
                while(n) {
-                       *--cp = (n % 10) + '0';
-                       n /= 10;
+                       n = udiv10(n, &rem);
+                       *--cp = rem + '0';
                }
        } else
                *--cp = '0';