[AVR] Target specific regression test causes virtual memory exhaustion

[Georg-Johann Lay]

Senthil Kumar Selvaraj schrieb:
> On a 64 bit machine, executing
> 
> $ make check RUNTESTFLAGS="avr-torture.exp=builtins-1.c --target_board=atxmega128a1"
> 
> causes virtual memory allocation failure and/or large scale machine
> slowdown, with cc1 using up gobs (>35G) virtual memory.
> 
> I tracked this down to
> 
> void delay_4 (void)  { __builtin_avr_delay_cycles (-1ul); }
> 
> In avr_expand_delay_cycles, the operand is converted into a
> HOST_WIDE_UINT, which on a 64 bit machine is 0xFFFFFFFFFFFFFFFF. The
> range checks therefore get bypassed and the while(cycles >= 2) loop near
> the end keeps generating nops, exhausting memory.
> 
> Given that avr_init_builtins declares delay_cycles builtin to take
> take an unsigned long (which I guess is 4 bytes for the AVR target),
> should the code be changed to consider only the lower 4 bytes? Or did I
> do something wrong?
> 
> Regards
> Senthil


Please file a bug report.

Thanks, Johann