Port bellard/quickjs "dtoa library" commits

Added new dtoa library to print and parse float64 numbers. It is necessary to fix corner cases (e.g. radix != 10) and to have correct behavior regardless of the libc implementation.

Port of:
bellard/quickjs@9936606
bellard/quickjs@dbbca3d

Includes alternative fix for bellard/quickjs@638ec8c from 0191aea

Co-authored-by: Fabrice Bellard <fabrice@bellard.org>
Co-authored-by: Ben Noordhuis <info@bnoordhuis.nl>

Author: 3 people

CMakeLists.txt

@@ -227,6 +227,7 @@ endmacro()
 
 set(qjs_sources
     cutils.c
+    dtoa.c
     libregexp.c
     libunicode.c
     quickjs.c

amalgam.js

@@ -2,6 +2,8 @@ import {loadFile, writeFile} from "qjs:std"
 
 const cutils_c = loadFile("cutils.c")
 const cutils_h = loadFile("cutils.h")
+const dtoa_c = loadFile("dtoa.c")
+const dtoa_h = loadFile("dtoa.h")
 const libregexp_c = loadFile("libregexp.c")
 const libregexp_h = loadFile("libregexp.h")
 const libregexp_opcode_h = loadFile("libregexp-opcode.h")
@@ -25,6 +27,7 @@ let source = "#if defined(QJS_BUILD_LIBC) && defined(__linux__) && !defined(_GNU
            + "#endif\n"
            + quickjs_c_atomics_h
            + cutils_h
+           + dtoa_h
            + list_h
            + libunicode_h // exports lre_is_id_start, used by libregexp.h
            + libregexp_h
@@ -33,6 +36,7 @@ let source = "#if defined(QJS_BUILD_LIBC) && defined(__linux__) && !defined(_GNU
            + quickjs_h
            + quickjs_c
            + cutils_c
+           + dtoa_c
            + libregexp_c
            + libunicode_c
            + xsum_c

cutils.c

@@ -586,258 +586,6 @@ size_t utf8_encode_buf16(char *dest, size_t dest_len, const uint16_t *src, size_
     return j;
 }
 
-/*--- integer to string conversions --*/
-
-/* All conversion functions:
-   - require a destination array `buf` of sufficient length
-   - write the string representation at the beginning of `buf`
-   - null terminate the string
-   - return the string length
- */
-
-/* 2 <= base <= 36 */
-char const digits36[36] = {
-    '0','1','2','3','4','5','6','7','8','9',
-    'a','b','c','d','e','f','g','h','i','j',
-    'k','l','m','n','o','p','q','r','s','t',
-    'u','v','w','x','y','z'
-};
-
-
-#define USE_SPECIAL_RADIX_10  1  // special case base 10 radix conversions
-#define USE_SINGLE_CASE_FAST  1  // special case single digit numbers
-
-/* using u32toa_shift variant */
-
-#define gen_digit(buf, c)  if (is_be()) \
-            buf = (buf >> 8) | ((uint64_t)(c) << ((sizeof(buf) - 1) * 8)); \
-        else \
-            buf = (buf << 8) | (c)
-
-static size_t u7toa_shift(char dest[minimum_length(8)], uint32_t n)
-{
-    size_t len = 1;
-    uint64_t buf = 0;
-    while (n >= 10) {
-        uint32_t quo = n % 10;
-        n /= 10;
-        gen_digit(buf, '0' + quo);
-        len++;
-    }
-    gen_digit(buf, '0' + n);
-    memcpy(dest, &buf, sizeof buf);
-    return len;
-}
-
-static size_t u07toa_shift(char dest[minimum_length(8)], uint32_t n, size_t len)
-{
-    size_t i;
-    dest += len;
-    dest[7] = '\0';
-    for (i = 7; i-- > 1;) {
-        uint32_t quo = n % 10;
-        n /= 10;
-        dest[i] = (char)('0' + quo);
-    }
-    dest[i] = (char)('0' + n);
-    return len + 7;
-}
-
-size_t u32toa(char buf[minimum_length(11)], uint32_t n)
-{
-#ifdef USE_SINGLE_CASE_FAST /* 10% */
-    if (n < 10) {
-        buf[0] = (char)('0' + n);
-        buf[1] = '\0';
-        return 1;
-    }
-#endif
-#define TEN_POW_7 10000000
-    if (n >= TEN_POW_7) {
-        uint32_t quo = n / TEN_POW_7;
-        n %= TEN_POW_7;
-        size_t len = u7toa_shift(buf, quo);
-        return u07toa_shift(buf, n, len);
-    }
-    return u7toa_shift(buf, n);
-}
-
-size_t u64toa(char buf[minimum_length(21)], uint64_t n)
-{
-    if (likely(n < 0x100000000))
-        return u32toa(buf, n);
-
-    size_t len;
-    if (n >= TEN_POW_7) {
-        uint64_t n1 = n / TEN_POW_7;
-        n %= TEN_POW_7;
-        if (n1 >= TEN_POW_7) {
-            uint32_t quo = n1 / TEN_POW_7;
-            n1 %= TEN_POW_7;
-            len = u7toa_shift(buf, quo);
-            len = u07toa_shift(buf, n1, len);
-        } else {
-            len = u7toa_shift(buf, n1);
-        }
-        return u07toa_shift(buf, n, len);
-    }
-    return u7toa_shift(buf, n);
-}
-
-size_t i32toa(char buf[minimum_length(12)], int32_t n)
-{
-    if (likely(n >= 0))
-        return u32toa(buf, n);
-
-    buf[0] = '-';
-    return 1 + u32toa(buf + 1, -(uint32_t)n);
-}
-
-size_t i64toa(char buf[minimum_length(22)], int64_t n)
-{
-    if (likely(n >= 0))
-        return u64toa(buf, n);
-
-    buf[0] = '-';
-    return 1 + u64toa(buf + 1, -(uint64_t)n);
-}
-
-/* using u32toa_radix_length variant */
-
-static uint8_t const radix_shift[64] = {
-    0, 0, 1, 0, 2, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0,
-    4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-};
-
-size_t u32toa_radix(char buf[minimum_length(33)], uint32_t n, unsigned base)
-{
-    int shift;
-
-#ifdef USE_SPECIAL_RADIX_10
-    if (likely(base == 10))
-        return u32toa(buf, n);
-#endif
-    if (n < base) {
-        buf[0] = digits36[n];
-        buf[1] = '\0';
-        return 1;
-    }
-    shift = radix_shift[base & 63];
-    if (shift) {
-        uint32_t mask = (1 << shift) - 1;
-        size_t len = (32 - clz32(n) + shift - 1) / shift;
-        size_t last = n & mask;
-        char *end = buf + len;
-        n >>= shift;
-        *end-- = '\0';
-        *end-- = digits36[last];
-        while (n >= base) {
-            size_t quo = n & mask;
-            n >>= shift;
-            *end-- = digits36[quo];
-        }
-        *end = digits36[n];
-        return len;
-    } else {
-        size_t len = 2;
-        size_t last = n % base;
-        n /= base;
-        uint32_t nbase = base;
-        while (n >= nbase) {
-            nbase *= base;
-            len++;
-        }
-        char *end = buf + len;
-        *end-- = '\0';
-        *end-- = digits36[last];
-        while (n >= base) {
-            size_t quo = n % base;
-            n /= base;
-            *end-- = digits36[quo];
-        }
-        *end = digits36[n];
-        return len;
-    }
-}
-
-size_t u64toa_radix(char buf[minimum_length(65)], uint64_t n, unsigned base)
-{
-    int shift;
-
-#ifdef USE_SPECIAL_RADIX_10
-    if (likely(base == 10))
-        return u64toa(buf, n);
-#endif
-    shift = radix_shift[base & 63];
-    if (shift) {
-        if (n < base) {
-            buf[0] = digits36[n];
-            buf[1] = '\0';
-            return 1;
-        }
-        uint64_t mask = (1 << shift) - 1;
-        size_t len = (64 - clz64(n) + shift - 1) / shift;
-        size_t last = n & mask;
-        char *end = buf + len;
-        n >>= shift;
-        *end-- = '\0';
-        *end-- = digits36[last];
-        while (n >= base) {
-            size_t quo = n & mask;
-            n >>= shift;
-            *end-- = digits36[quo];
-        }
-        *end = digits36[n];
-        return len;
-    } else {
-        if (likely(n < 0x100000000))
-            return u32toa_radix(buf, n, base);
-        size_t last = n % base;
-        n /= base;
-        uint64_t nbase = base;
-        size_t len = 2;
-        while (n >= nbase) {
-            nbase *= base;
-            len++;
-        }
-        char *end = buf + len;
-        *end-- = '\0';
-        *end-- = digits36[last];
-        while (n >= base) {
-            size_t quo = n % base;
-            n /= base;
-            *end-- = digits36[quo];
-        }
-        *end = digits36[n];
-        return len;
-    }
-}
-
-size_t i32toa_radix(char buf[minimum_length(34)], int32_t n, unsigned int base)
-{
-    if (likely(n >= 0))
-        return u32toa_radix(buf, n, base);
-
-    buf[0] = '-';
-    return 1 + u32toa_radix(buf + 1, -(uint32_t)n, base);
-}
-
-size_t i64toa_radix(char buf[minimum_length(66)], int64_t n, unsigned int base)
-{
-    if (likely(n >= 0))
-        return u64toa_radix(buf, n, base);
-
-    buf[0] = '-';
-    return 1 + u64toa_radix(buf + 1, -(uint64_t)n, base);
-}
-
-#undef gen_digit
-#undef TEN_POW_7
-#undef USE_SPECIAL_RADIX_10
-#undef USE_SINGLE_CASE_FAST
-
 /*---- sorting with opaque argument ----*/
 
 typedef void (*exchange_f)(void *a, void *b, size_t size);

cutils.h

@@ -543,16 +543,6 @@ static inline uint8_t to_upper_ascii(uint8_t c) {
     return c >= 'a' && c <= 'z' ? c - 'a' + 'A' : c;
 }
 
-extern char const digits36[36];
-size_t u32toa(char buf[minimum_length(11)], uint32_t n);
-size_t i32toa(char buf[minimum_length(12)], int32_t n);
-size_t u64toa(char buf[minimum_length(21)], uint64_t n);
-size_t i64toa(char buf[minimum_length(22)], int64_t n);
-size_t u32toa_radix(char buf[minimum_length(33)], uint32_t n, unsigned int base);
-size_t i32toa_radix(char buf[minimum_length(34)], int32_t n, unsigned base);
-size_t u64toa_radix(char buf[minimum_length(65)], uint64_t n, unsigned int base);
-size_t i64toa_radix(char buf[minimum_length(66)], int64_t n, unsigned int base);
-
 void rqsort(void *base, size_t nmemb, size_t size,
             int (*cmp)(const void *, const void *, void *),
             void *arg);