From e88b9f0e5cc50cab57a299dc7efe1a4eb385161d Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Mon, 19 Dec 2022 18:56:54 +0100 Subject: stdio-common: Convert vfprintf and related functions to buffers vfprintf is entangled with vfwprintf (of course), __printf_fp, __printf_fphex, __vstrfmon_l_internal, and the strfrom family of functions. The latter use the internal snprintf functionality, so vsnprintf is converted as well. The simples conversion is __printf_fphex, followed by __vstrfmon_l_internal and __printf_fp, and finally __vfprintf_internal and __vfwprintf_internal. __vsnprintf_internal and strfrom* are mostly consuming the new interfaces, so they are comparatively simple. __printf_fp is a public symbol, so the FILE *-based interface had to preserved. The __printf_fp rewrite does not change the actual binary-to-decimal conversion algorithm, and digits are still not emitted directly to the target buffer. However, the staging buffer now uses bytes instead of wide characters, and one buffer copy is eliminated. The changes are at least performance-neutral in my testing. Floating point printing and snprintf improved measurably, so that this Lua script for i=1,5000000 do print(i, i * math.pi) end runs about 5% faster for me. To preserve fprintf performance for a simple "%d" format, this commit has some logic changes under LABEL (unsigned_number) to avoid additional function calls. There are certainly some very easy performance improvements here: binary, octal and hexadecimal formatting can easily avoid the temporary work buffer (the number of digits can be computed ahead-of-time using one of the __builtin_clz* built-ins). Decimal formatting can use a specialized version of _itoa_word for base 10. The existing (inconsistent) width handling between strfmon and printf is preserved here. __print_fp_buffer_1 would have to use __translated_number_width to achieve ISO conformance for printf. Test expectations in libio/tst-vtables-common.c are adjusted because the internal staging buffer merges all virtual function calls into one. In general, stack buffer usage is greatly reduced, particularly for unbuffered input streams. __printf_fp can still use a large buffer in binary128 mode for %g, though. Reviewed-by: Adhemerval Zanella --- stdio-common/printf_fphex.c | 260 +++++++++++++++++++------------------------- 1 file changed, 109 insertions(+), 151 deletions(-) (limited to 'stdio-common/printf_fphex.c') diff --git a/stdio-common/printf_fphex.c b/stdio-common/printf_fphex.c index 5af380da62..1947faba8d 100644 --- a/stdio-common/printf_fphex.c +++ b/stdio-common/printf_fphex.c @@ -17,10 +17,12 @@ . */ #include +#include #include #include #include #include +#include #include #include #include @@ -30,6 +32,9 @@ #include #include #include +#include +#include +#include #if __HAVE_DISTINCT_FLOAT128 # include "ieee754_float128.h" @@ -39,58 +44,11 @@ IEEE854_FLOAT128_BIAS) #endif -/* #define NDEBUG 1*/ /* Undefine this for debugging assertions. */ -#include - -#include -#define PUT(f, s, n) _IO_sputn (f, s, n) -#define PAD(f, c, n) (wide ? _IO_wpadn (f, c, n) : _IO_padn (f, c, n)) -#undef putc -#define putc(c, f) (wide \ - ? (int)_IO_putwc_unlocked (c, f) : _IO_putc_unlocked (c, f)) - - -/* Macros for doing the actual output. */ - -#define outchar(ch) \ - do \ - { \ - const int outc = (ch); \ - if (putc (outc, fp) == EOF) \ - return -1; \ - ++done; \ - } while (0) - -#define PRINT(ptr, wptr, len) \ - do \ - { \ - size_t outlen = (len); \ - if (wide) \ - while (outlen-- > 0) \ - outchar (*wptr++); \ - else \ - while (outlen-- > 0) \ - outchar (*ptr++); \ - } while (0) - -#define PADN(ch, len) \ - do \ - { \ - if (PAD (fp, ch, len) != len) \ - return -1; \ - done += len; \ - } \ - while (0) - -#ifndef MIN -# define MIN(a,b) ((a)<(b)?(a):(b)) -#endif - - -int -__printf_fphex (FILE *fp, - const struct printf_info *info, - const void *const *args) +static void +__printf_fphex_buffer (struct __printf_buffer *buf, + const char *decimal, + const struct printf_info *info, + const void *const *args) { /* The floating-point value to output. */ union @@ -106,34 +64,19 @@ __printf_fphex (FILE *fp, /* This function always uses LC_NUMERIC. */ assert (info->extra == 0); - /* Locale-dependent representation of decimal point. Hexadecimal - formatting always using LC_NUMERIC (disregarding info->extra). */ - const char *decimal = _NL_CURRENT (LC_NUMERIC, DECIMAL_POINT); - wchar_t decimalwc = _NL_CURRENT_WORD (LC_NUMERIC, - _NL_NUMERIC_DECIMAL_POINT_WC); - - /* The decimal point character must never be zero. */ - assert (*decimal != '\0' && decimalwc != L'\0'); - /* "NaN" or "Inf" for the special cases. */ const char *special = NULL; - const wchar_t *wspecial = NULL; /* Buffer for the generated number string for the mantissa. The maximal size for the mantissa is 128 bits. */ char numbuf[32]; char *numstr; char *numend; - wchar_t wnumbuf[32]; - wchar_t *wnumstr; - wchar_t *wnumend; int negative; /* The maximal exponent of two in decimal notation has 5 digits. */ char expbuf[5]; char *expstr; - wchar_t wexpbuf[5]; - wchar_t *wexpstr; int expnegative; int exponent; @@ -149,12 +92,6 @@ __printf_fphex (FILE *fp, /* Width. */ int width = info->width; - /* Number of characters written. */ - int done = 0; - - /* Nonzero if this is output on a wide character stream. */ - int wide = info->wide; - #define PRINTF_FPHEX_FETCH(FLOAT, VAR) \ { \ (VAR) = *(const FLOAT *) args[0]; \ @@ -163,30 +100,18 @@ __printf_fphex (FILE *fp, if (isnan (VAR)) \ { \ if (isupper (info->spec)) \ - { \ - special = "NAN"; \ - wspecial = L"NAN"; \ - } \ + special = "NAN"; \ else \ - { \ - special = "nan"; \ - wspecial = L"nan"; \ - } \ + special = "nan"; \ } \ else \ { \ if (isinf (VAR)) \ { \ if (isupper (info->spec)) \ - { \ - special = "INF"; \ - wspecial = L"INF"; \ - } \ + special = "INF"; \ else \ - { \ - special = "inf"; \ - wspecial = L"inf"; \ - } \ + special = "inf"; \ } \ } \ negative = signbit (VAR); \ @@ -215,22 +140,22 @@ __printf_fphex (FILE *fp, --width; width -= 3; - if (!info->left && width > 0) - PADN (' ', width); + if (!info->left) + __printf_buffer_pad (buf, ' ', width); if (negative) - outchar ('-'); + __printf_buffer_putc (buf, '-'); else if (info->showsign) - outchar ('+'); + __printf_buffer_putc (buf, '+'); else if (info->space) - outchar (' '); + __printf_buffer_putc (buf, ' '); - PRINT (special, wspecial, 3); + __printf_buffer_puts (buf, special); - if (info->left && width > 0) - PADN (' ', width); + if (info->left) + __printf_buffer_pad (buf, ' ', width); - return done; + return; } #if __HAVE_DISTINCT_FLOAT128 @@ -252,26 +177,15 @@ __printf_fphex (FILE *fp, zero_mantissa = num == 0; if (sizeof (unsigned long int) > 6) - { - wnumstr = _itowa_word (num, wnumbuf + (sizeof wnumbuf) / sizeof (wchar_t), 16, - info->spec == 'A'); numstr = _itoa_word (num, numbuf + sizeof numbuf, 16, info->spec == 'A'); - } else - { - wnumstr = _itowa (num, wnumbuf + sizeof wnumbuf / sizeof (wchar_t), 16, - info->spec == 'A'); numstr = _itoa (num, numbuf + sizeof numbuf, 16, info->spec == 'A'); - } /* Fill with zeroes. */ - while (wnumstr > wnumbuf + (sizeof wnumbuf - 52) / sizeof (wchar_t)) - { - *--wnumstr = L'0'; - *--numstr = '0'; - } + while (numstr > numbuf + (sizeof numbuf - 13)) + *--numstr = '0'; leading = fpnum.dbl.ieee.exponent == 0 ? '0' : '1'; @@ -307,13 +221,9 @@ __printf_fphex (FILE *fp, /* Look for trailing zeroes. */ if (! zero_mantissa) { - wnumend = array_end (wnumbuf); numend = array_end (numbuf); - while (wnumend[-1] == L'0') - { - --wnumend; + while (numend[-1] == '0') --numend; - } bool do_round_away = false; @@ -352,7 +262,6 @@ __printf_fphex (FILE *fp, like in ASCII. This is true for the rest of GNU, too. */ if (ch == '9') { - wnumstr[cnt] = (wchar_t) info->spec; numstr[cnt] = info->spec; /* This is tricky, think about it! */ break; @@ -360,14 +269,10 @@ __printf_fphex (FILE *fp, else if (tolower (ch) < 'f') { ++numstr[cnt]; - ++wnumstr[cnt]; break; } else - { - numstr[cnt] = '0'; - wnumstr[cnt] = L'0'; - } + numstr[cnt] = '0'; } if (cnt < 0) { @@ -401,13 +306,10 @@ __printf_fphex (FILE *fp, if (precision == -1) precision = 0; numend = numstr; - wnumend = wnumstr; } /* Now we can compute the exponent string. */ expstr = _itoa_word (exponent, expbuf + sizeof expbuf, 10, 0); - wexpstr = _itowa_word (exponent, - wexpbuf + sizeof wexpbuf / sizeof (wchar_t), 10, 0); /* Now we have all information to compute the size. */ width -= ((negative || info->showsign || info->space) @@ -421,54 +323,110 @@ __printf_fphex (FILE *fp, A special case when the mantissa or the precision is zero and the `#' is not given. In this case we must not print the decimal point. */ if (precision > 0 || info->alt) - width -= wide ? 1 : strlen (decimal); + --width; - if (!info->left && info->pad != '0' && width > 0) - PADN (' ', width); + if (!info->left && info->pad != '0') + __printf_buffer_pad (buf, ' ', width); if (negative) - outchar ('-'); + __printf_buffer_putc (buf, '-'); else if (info->showsign) - outchar ('+'); + __printf_buffer_putc (buf, '+'); else if (info->space) - outchar (' '); + __printf_buffer_putc (buf, ' '); - outchar ('0'); + __printf_buffer_putc (buf, '0'); if ('X' - 'A' == 'x' - 'a') - outchar (info->spec + ('x' - 'a')); + __printf_buffer_putc (buf, info->spec + ('x' - 'a')); else - outchar (info->spec == 'A' ? 'X' : 'x'); + __printf_buffer_putc (buf, info->spec == 'A' ? 'X' : 'x'); - if (!info->left && info->pad == '0' && width > 0) - PADN ('0', width); + if (!info->left && info->pad == '0') + __printf_buffer_pad (buf, '0', width); - outchar (leading); + __printf_buffer_putc (buf, leading); if (precision > 0 || info->alt) - { - const wchar_t *wtmp = &decimalwc; - PRINT (decimal, wtmp, wide ? 1 : strlen (decimal)); - } + __printf_buffer_puts (buf, decimal); if (precision > 0) { ssize_t tofill = precision - (numend - numstr); - PRINT (numstr, wnumstr, MIN (numend - numstr, precision)); - if (tofill > 0) - PADN ('0', tofill); + __printf_buffer_write (buf, numstr, MIN (numend - numstr, precision)); + __printf_buffer_pad (buf, '0', tofill); } if ('P' - 'A' == 'p' - 'a') - outchar (info->spec + ('p' - 'a')); + __printf_buffer_putc (buf, info->spec + ('p' - 'a')); else - outchar (info->spec == 'A' ? 'P' : 'p'); + __printf_buffer_putc (buf, info->spec == 'A' ? 'P' : 'p'); + + __printf_buffer_putc (buf, expnegative ? '-' : '+'); + + __printf_buffer_write (buf, expstr, (expbuf + sizeof expbuf) - expstr); + + if (info->left && info->pad != '0') + __printf_buffer_pad (buf, info->pad, width); +} + +void +__printf_fphex_l_buffer (struct __printf_buffer *buf, locale_t loc, + const struct printf_info *info, + const void *const *args) +{ + __printf_fphex_buffer (buf, _nl_lookup (loc, LC_NUMERIC, DECIMAL_POINT), + info, args); +} - outchar (expnegative ? '-' : '+'); - PRINT (expstr, wexpstr, (expbuf + sizeof expbuf) - expstr); +/* The wide buffer version is implemented by translating the output of + the multibyte verison. */ - if (info->left && info->pad != '0' && width > 0) - PADN (info->pad, width); +struct __printf_buffer_fphex_to_wide +{ + struct __printf_buffer base; + wchar_t decimalwc; + struct __wprintf_buffer *next; + char untranslated[PRINTF_BUFFER_SIZE_DIGITS]; +}; + +/* Translate to wide characters, rewriting "." to the actual decimal + point. */ +void +__printf_buffer_flush_fphex_to_wide (struct __printf_buffer_fphex_to_wide *buf) +{ + /* No need to adjust buf->base.written, only buf->next->written matters. */ + for (char *p = buf->untranslated; p < buf->base.write_ptr; ++p) + { + /* wchar_t overlaps with char in the ASCII range. */ + wchar_t ch = *p; + if (ch == L'.') + ch = buf->decimalwc; + __wprintf_buffer_putc (buf->next, ch); + } - return done; + if (!__wprintf_buffer_has_failed (buf->next)) + buf->base.write_ptr = buf->untranslated; + else + __printf_buffer_mark_failed (&buf->base); +} + +void +__wprintf_fphex_l_buffer (struct __wprintf_buffer *next, locale_t loc, + const struct printf_info *info, + const void *const *args) +{ + struct __printf_buffer_fphex_to_wide buf; + __printf_buffer_init (&buf.base, buf.untranslated, sizeof (buf.untranslated), + __printf_buffer_mode_fphex_to_wide); + buf.decimalwc = _nl_lookup_word (loc, LC_NUMERIC, + _NL_NUMERIC_DECIMAL_POINT_WC); + buf.next = next; + __printf_fphex_buffer (&buf.base, ".", info, args); + if (__printf_buffer_has_failed (&buf.base)) + { + __wprintf_buffer_mark_failed (buf.next); + return; + } + __printf_buffer_flush_fphex_to_wide (&buf); } -- cgit 1.4.1