Bug #72715 character set code endianness dependent on CPU type rather than endianness of CP
Submitted: 21 May 2014 22:39 Modified: 22 May 2014 8:00
Reporter: Stewart Smith Email Updates:
Status: Verified Impact on me:
Category:MySQL Server: Charsets Severity:S3 (Non-critical)
Version:5.6.17 OS:Any
Assigned to: CPU Architecture:Any

[21 May 2014 22:39] Stewart Smith
The PowerLinux Migration Toolkit helped find this gem in include/m_ctype.h

  On i386 we store Unicode->CS conversion tables for
  some character sets using Big-endian order,
  to copy two bytes at onces.
  This gives some performance improvement.
#ifdef __i386__
#define MB2(x)                (((x) >> 8) + (((x) & 0xFF) << 8))
#define MY_PUT_MB2(s, code)   { *((uint16*)(s))= (code); }
#define MB2(x)                (x)
#define MY_PUT_MB2(s, code)   { (s)[0]= code >> 8; (s)[1]= code & 0xFF; }

Which needs some analysis as to the validity on both non-x86 and especially on POWER BE and LE (maybe also MIPS/MIPSel).

How to repeat:
Code analysis.

Suggested fix:
think carefully.. hopefully I'll investigate further and provide further insight/a patch... but if somebody else gets to it first, yay!

I'm mostly filing the bug to keep track of this issue.
[22 May 2014 8:00] MySQL Verification Team
Hello Stewart,

Thank you for the bug report.