[Bug middle-end/23369] [4.0.x regression] Generates wrong code for funcptr comparison

[dave at hiauly1 dot hia dot nrc dot ca]

------- Additional Comments From dave at hiauly1 dot hia dot nrc dot ca  2005-08-13 21:46 -------
Subject: Re:  [4.0.x regression] Generates wrong code for funcptr comparison

> Bah, while this is probably going to happen for hppa-linux, it'snever going to happen for hppa-hpux.  GCC's treatment of functionpointers here is just WRONG.There are a couple of issues.  The most serious is the following:We have the following code from __pthread_sigaction in the .i file:   if (old == ((__sighandler_t) 1) || old == ((__sighandler_t) 0) || old == ((__sighandler_t) -1))     __sighandler[sig].old = (arch_sighandler_t) act->__sigaction_handler.sa_handler;This is what the above turns into in the tree dump filebug321785.c.t02.original:          if ((void (*<T2bd>) (int)) old - 2B > -4B)            {              __sighandler[sig].old = (void (*<T431>) (int, struct sigcontext *)) act->__sigaction_handler.sa_handler;            }I don't believe that the transformation is valid.  Also, it not validC to do relational comparisons where one of the operands is a functionpointer.  See 6.5.8 (2).do_compare_and_jump doesn't check code before canonicalizing functionpointer!
 s.!
>    I think we need an assert in do_compare_and_jump to catchinvalid function pointer comparisons.

Yuck.  I used Konqueror to add this comment and it totally botched up
the white space ;(

Dave


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23369