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authorPaul Eggert <eggert@cs.ucla.edu>2015-07-21 22:50:29 -0700
committerPaul Eggert <eggert@cs.ucla.edu>2015-08-18 10:00:57 -0700
commit5542236837c5c41435f8282ec92799f480c36f18 (patch)
tree9379c73ad00dc1ffea986464bbf96634f3a7fd5f /string/strchr.c
parent1814df5b02b9c359052c2048a1d2d617b406a17a (diff)
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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/strchr.c')
-rw-r--r--string/strchr.c9
1 files changed, 2 insertions, 7 deletions
diff --git a/string/strchr.c b/string/strchr.c
index 5f900750a3..f13b2b3d94 100644
--- a/string/strchr.c
+++ b/string/strchr.c
@@ -60,13 +60,8 @@ strchr (const char *s, int 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.  */
-  switch (sizeof (longword))
-    {
-    case 4: magic_bits = 0x7efefeffL; break;
-    case 8: magic_bits = ((0x7efefefeL << 16) << 16) | 0xfefefeffL; break;
-    default:
-      abort ();
-    }
+  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);