[Bug tree-optimization/52285] [4.7 Regression] libgcrypt _gcry_burn_stack slowdown

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52285

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.7.0

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-02-16 18:39:57 UTC ---
This is also a libgcrypt bug, because clearly if it wants to burn some portion
of the stack (assuming for security reasons), then
1) if it doesn't prevent tail recursion or tail call to itself, it doesn't do
what it is trying to do, in particular it keeps overwriting with zeros the same
portion of memory over and over
2) even if it isn't tail recursion/call optimized, on most targets it will
still leave gaps on the stack not overwritten
So, all in all, quite questionable way of burning cycles in the crypto library.