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Subject: [Bug rtl-optimization/64294] invalid code, zero check gets optimized away
Date: Fri, 12 Dec 2014 22:54:00 -0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64294

--- Comment #2 from Sebastian Andrzej Siewior <gcc at breakpoint dot cc> ---
It seems exit(0) is dropped with -O1 -ftree-vrp.

(In reply to Andreas Schwab from comment #1)
> This condition is true if backsize == 0:

Ehm, yes. The Code is:
--
printf("bufsz: %u backsize: %d\n", bufsz, backsize);
if(!CLI_ISCONTAINED(buf, bufsz, ddst, backsize) || !CLI_ISCONTAINED(buf, bufsz,
ddst+backbytes, back size)) {
      free(usects);
      return 1;
}
asm volatile("labele:");
--
So I would expect that it leaves the function but I see a segfault in the while
loop later on and according the printf, backsize was 0.