[Bug target/65261] [5 Regression] bootstrap-ubsan ppc64le: gcc/libcpp/lex.c:552:30: runtime error: load of misaligned address 0x01002172dfc6 for type 'const uchar', which requires 16 byte alignment

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65261

--- Comment #3 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
Author: trippels
Date: Wed Mar  4 17:28:56 2015
New Revision: 221190

URL: https://gcc.gnu.org/viewcvs?rev=221190&root=gcc&view=rev
Log:
Fix PR65261

Running bootstrap-ubsan on ppc64le shows many instances of:

  libcpp/lex.c:552:30: runtime error: load of misaligned address
  0x01001f31d37a for type 'const uchar', which requires 16 byte alignment

But the unaligned vector loads are intended in this case, because they
are preferable to forced-alignment on POWER8. So just silence the ubsan
errors.

2015-03-02  Markus Trippelsdorf  <mar...@trippelsdorf.de>

include/
    PR target/65261
    * ansidecl.h (ATTRIBUTE_NO_SANITIZE_UNDEFINED): New macro.

libcpp/
    PR target/65261
    * lex.c (search_line_fast): Silence ubsan errors.

Modified:
    trunk/include/ChangeLog
    trunk/include/ansidecl.h
    trunk/libcpp/ChangeLog
    trunk/libcpp/lex.c