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| author |   Paul Eggert <eggert@cs.ucla.edu> | 2015-07-21 22:50:29 -0700 |
|---|---|---|
| committer | Paul Eggert <eggert@cs.ucla.edu> | 2015-08-18 10:00:57 -0700 |
| commit | 5542236837c5c41435f8282ec92799f480c36f18 (patch) | |
| tree | 9379c73ad00dc1ffea986464bbf96634f3a7fd5f /string/rawmemchr.c | |
| parent | Define HAS_CPUID/HAS_I586/HAS_I686 from -march= (diff) | |
| download | glibc-5542236837c5c41435f8282ec92799f480c36f18.tar.gz glibc-5542236837c5c41435f8282ec92799f480c36f18.tar.bz2 glibc-5542236837c5c41435f8282ec92799f480c36f18.zip | |
Port the 0x7efe...feff pattern to GCC 6.
See Steve Ellcey's bug report in:
https://sourceware.org/ml/libc-alpha/2015-07/msg00673.html
* string/memrchr.c (MEMRCHR):
* string/rawmemchr.c (RAWMEMCHR):
* string/strchr.c (strchr):
* string/strchrnul.c (STRCHRNUL):
Rewrite code to avoid issues with signed shift overflow.
Diffstat (limited to 'string/rawmemchr.c')
| -rw-r--r-- | string/rawmemchr.c | 11 |
1 files changed, 2 insertions, 9 deletions
diff --git a/string/rawmemchr.c b/string/rawmemchr.c index 05b22be24e..228ca9d216 100644 --- a/string/rawmemchr.c +++ b/string/rawmemchr.c @@ -86,15 +86,8 @@ RAWMEMCHR (s, c_in) The 1-bits make sure that carries propagate to the next 0-bit. The 0-bits provide holes for carries to fall into. */ - - if (sizeof (longword) != 4 && sizeof (longword) != 8) - abort (); - -#if LONG_MAX <= LONG_MAX_32_BITS - magic_bits = 0x7efefeff; -#else - magic_bits = ((unsigned long int) 0x7efefefe << 32) | 0xfefefeff; -#endif + magic_bits = -1; + magic_bits = magic_bits / 0xff * 0xfe << 1 >> 1 | 1; /* Set up a longword, each of whose bytes is C. */ charmask = c | (c << 8); |