Re: [PATCH, testsuite] Don't run SREC, IHEX and TEKHEX tests for MIPS N64.

[Pedro Alves <palves at redhat dot com>]

On 07/03/2013 08:22 PM, Luis Machado wrote:
> On 07/03/2013 12:05 PM, Pedro Alves wrote:
>> On 07/02/2013 07:50 PM, Luis Machado wrote:
>>> -
>>> -if {[istarget "spu*-*-*"]} then {
>>> -    # The internal address format used for the combined Cell/B.E.
>>> -    # debugger requires 64-bit.
>>> -    set is64bitonly "yes"
>>> -}
>>> -
>>
>> I'm not sure this equates to sizeof pointer == 64-bit.
>> This bit may need to be retained.  [Adding Ulrich].
> 
> Fair enough. Ulrich, let me know if the pointer check in the attached 
> patch doesn't make sense for Cell BE.
> 
>>
>>> +
>>> +    set sizeof_function_ptr [get_sizeof "void (*)(void)" 8]
>>> +    set sizeof_data_ptr [get_sizeof "void *" 8]
>>> +    if {${sizeof_function_ptr} != 4 && ${sizeof_data_ptr} != 4} then {
>>> +	set is64bitonly "yes"
>>> +    }
>>> +}
>>> +
>>
>> srec (etc.) is most used in small embedded targets (e.g., those
>> that include dsrec.o in the configure.tgt), consequently
>> that's where the test is most useful.  Such targets
>> are the most likely to have 16-bit pointers (< 4 bytes).
>> E.g., h8300, etc.  Looks like this ends up causing the tests to
>> be skipped there too.  IOW, a better check would be:
>>
>>     if {${sizeof_function_ptr} > 4 || ${sizeof_data_ptr} > 4} then {
>>
> 
> Ah, yes. This check is indeed better. Follows an updated patch that does 
> this.
> 
>> But, this change also means we have reduced routine-checking,
>> as most people test on x86_64.  I think we can do better.  The test
>> works fine on e.g., x86_64, because programs get linked to low (< 32-bit)
>> addresses by default.  That's the point of:
>>
>> if [istarget "alpha*-*-*"] then {
>>      # SREC etc cannot handle 64-bit addresses.  Force the test
>>      # program into the low 31 bits of the address space.
>>      lappend options "additional_flags=-Wl,-taso"
>> }
>>
>> (For MIPS N64, if you wanted, I guess you could do similarly
>>   to Alpha, and rebuild with:
>>
>>    lappend options "ldflags=-Wl,-Tdata=0x600000"
>>
>>   to force use of low addresses.)
>>
>> IOW, instead of checking for ABI pointer sizes, I think it'd
>> be better to test for the actual address size of one the
>> variables dumped.  That is, check that &intarray is < 32-bit.
>>
> 
> If lack of coverage for x86_64 running things on low addresses is a 
> problem, we can add an exception for x86_64, what do you think? Adding 
> these exceptions usually polute the testcases though.

But do you see a problem with checking whether "&intarray is < 32-bit" instead?

-- 
Pedro Alves