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| author | Ulrich Drepper <drepper@redhat.com> | 1998-11-13 13:21:56 +0000 |
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| committer | Ulrich Drepper <drepper@redhat.com> | 1998-11-13 13:21:56 +0000 |
| commit | 7f2a1e3cf8077faa2c5de78f081890302a4c8362 (patch) | |
| tree | fe02a7b2be425a9609d7bc3ffddc72b5efd54f1b /libio | |
| parent | 2dc9c8cd694ef6c72c631e33ff2eb2c3d412dfe8 (diff) | |
| download | glibc-7f2a1e3cf8077faa2c5de78f081890302a4c8362.tar.gz glibc-7f2a1e3cf8077faa2c5de78f081890302a4c8362.tar.xz glibc-7f2a1e3cf8077faa2c5de78f081890302a4c8362.zip | |
Correct and improve fread_unlocked and fwrite_unlocked optimizations.
Diffstat (limited to 'libio')
| -rw-r--r-- | libio/bits/stdio.h | 39 |
1 files changed, 27 insertions, 12 deletions
diff --git a/libio/bits/stdio.h b/libio/bits/stdio.h index f47749e1d6..a3e3d6fc8d 100644 --- a/libio/bits/stdio.h +++ b/libio/bits/stdio.h @@ -127,32 +127,47 @@ ferror_unlocked (FILE *__stream) __THROW #if defined __USE_MISC && defined __GNUC__ && defined __OPTIMIZE__ /* Perform some simple optimizations. */ # define fread_unlocked(ptr, size, n, stream) \ - (__extension__ ((__builtin_constant_p (size) && __builtin_constant_p (n) \ + (__extension__ ((((__builtin_constant_p (size) \ + && ((size) == 0 || __builtin_constant_p (n))) \ + || (__builtin_constant_p (n) && (n) == 0)) \ && (size_t) ((size) * (n)) <= 8) \ ? ({ char *__ptr = (char *) (ptr); \ FILE *__stream = (stream); \ - int __c; \ - size_t __cnt = (size) * (n); \ - while (__cnt-- > 0) \ + size_t __size = (size); \ + size_t __n = (n); \ + size_t __readres = __n; \ + size_t __cnt = __size * __n + 1; \ + while (--__cnt > 0) \ { \ - __c = _IO_getc_unlocked (__stream); \ + int __c = _IO_getc_unlocked (__stream); \ if (__c == EOF) \ - break; \ + { \ + __readres = (__size * __n - __cnt) / __size; \ + break; \ + } \ *__ptr++ = __c; \ } \ - ((size_t) ((size) * (n)) - __cnt) / (size); }) \ + __readres; }) \ : fread_unlocked (ptr, size, n, stream))) # define fwrite_unlocked(ptr, size, n, stream) \ - (__extension__ ((__builtin_constant_p (size) && __builtin_constant_p (n) \ + (__extension__ ((((__builtin_constant_p (size) \ + && ((size) == 0 || __builtin_constant_p (n))) \ + || (__builtin_constant_p (n) && (n) == 0)) \ && (size_t) ((size) * (n)) <= 8) \ ? ({ const char *__ptr = (const char *) (ptr); \ FILE *__stream = (stream); \ - size_t __cnt = (size) * (n); \ - while (__cnt-- > 0) \ + size_t __size = (size); \ + size_t __n = (n); \ + size_t __writeres = __n; \ + size_t __cnt = __size * __n + 1; \ + while (--__cnt > 0) \ if (_IO_putc_unlocked (*__ptr++, __stream) == EOF) \ - break; \ - ((size_t) ((size) * (n)) - __cnt) / (size); }) \ + { \ + __writeres = (__size * __n - __cnt) / __size; \ + break; \ + } \ + __writeres; }) \ : fwrite_unlocked (ptr, size, n, stream))) #endif |