Re: [avr-llvm-devel] Regression tests

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No, im using a completely standard version of clang.

On Mon, Apr 30, 2012 at 9:01 PM, Borja Ferrer <bor...@gm...> wrote:

> Nice to see you around Eric :)
>
> Indeed, things are getting zero extended and then truncated back, there
> are two things going on here. First is that I'm getting things converted to
> i16 instead of i32, did you patch clang? I'll have to check if the target
> patch stuff of clang is right. Second is that I dont have the zeroext
> attribute and that's my fault because it's a patch for clang that I haven't
> commited.
>
> The type promotion is something in the C standard and because sizeof(int)
> is bigger than a register things get a bit nasty, but it's valid code.
>
>
> 2012/4/30 Nicklas Bo Jensen <nbj...@gm...>
>
>> I'm using clang.
>>
>> define zeroext i8 @add() nounwind uwtable {
>>   %a = alloca i8, align 1
>>   %b = alloca i8, align 1
>>   store i8 5, i8* %a, align 1
>>   store i8 7, i8* %b, align 1
>>   %1 = load i8* %a, align 1
>>   %2 = zext i8 %1 to i32
>>   %3 = load i8* %b, align 1
>>   %4 = zext i8 %3 to i32
>>   %5 = add nsw i32 %2, %4
>>   %6 = trunc i32 %5 to i8
>>   ret i8 %6
>> }
>>
>> On Mon, Apr 30, 2012 at 8:22 PM, Borja Ferrer <bor...@gm...>wrote:
>>
>>> I see what's going here, our version is doing a 16bit addition and then
>>> truncating it back to 8bits. Are you using clang or dragonegg for the
>>> frontend? And can you post the llvm asm?
>>> Also, no need to test imm+imm, only reg+imm and reg+reg will do, the
>>> other will be constant folded.
>>>
>>> Ah, you'll need svn commit access, John or Eric could you do it?
>>>
>>>
>>> 2012/4/30 Nicklas Bo Jensen <nbj...@gm...>
>>>
>>>> On Mon, Apr 30, 2012 at 12:33 AM, Borja Ferrer <bor...@gm...>
>>>>  wrote:
>>>>
>>>>> It should be similar to what other backends do, in this case we should
>>>>> test adding with 2 regs and then with immediates values, and repeat this
>>>>> for each value type (i8, i16, i32 and i64). Checking the instruction itself
>>>>> is enough, no need to check for registers aswell, that will come in other
>>>>> tests. But when testing with imm values we should check that the imm value
>>>>> is correctly generated, so in this case ignore the reg, but check that the
>>>>> imm field is valid.
>>>>>
>>>>
>>>> Ok, makes sense. I will work on creating the tests.
>>>>
>>>>
>>>>> And what do you mean in that you get different code between gcc and
>>>>> llvm?
>>>>
>>>>
>>>> Basically if I compile:
>>>>
>>>> unsigned char add()
>>>> {
>>>>   unsigned char a,b;
>>>>   a = 5;
>>>>   b = 7;
>>>>   return a+b;
>>>> }
>>>>
>>>>
>>>> with avr-gcc part of the resulting assembler is:
>>>> ldi r24,lo8(5)
>>>>  std Y+1,r24
>>>> ldi r24,lo8(7)
>>>> std Y+2,r24
>>>> ldd r25,Y+1
>>>>  ldd r24,Y+2
>>>> add r24,r25
>>>>
>>>> with clang+avr-llvm part of the resulting assembler is:
>>>>  ldi r24, 5
>>>> std Y+2, r24
>>>> ldi r24, 7
>>>>  std Y+1, r24
>>>> ldd r24, Y+2
>>>>  adiw r25:r24, 7
>>>> andi r24, 255
>>>>  andi r25, 0
>>>>
>>>> So they use different approaches(add and adiw) to solve the same
>>>> problem.
>>>>
>>>> Thanks
>>>> Nicklas
>>>>
>>>> 2012/4/29 Nicklas Bo Jensen <nbj...@gm...>
>>>>>
>>>>>> Sure. Just wanted to actually compile the code before writing tests.
>>>>>>
>>>>>> Got how the test framework works and added a very small test that is
>>>>>> working perfectly.
>>>>>>
>>>>>> How detailed should the test be? Should it check the generated
>>>>>> assembly fully or just the main parts, e.g. the addition itself? For an
>>>>>> addition the avr-llvm version is quite different from the avr-gcc version.
>>>>>>
>>>>>> Thanks,
>>>>>> Nicklas
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Sun, Apr 29, 2012 at 8:07 PM, Borja Ferrer <bor...@gm...>wrote:
>>>>>>
>>>>>>> The problem here is that I've represented register pairs as r29:r28
>>>>>>> while the assembler only wants the low register of the pair, that's why
>>>>>>> you're getting that error but you're doing it right.
>>>>>>>
>>>>>>> But the way of writing regression tests in llvm is different to what
>>>>>>> you're doing. Those tests in SVN are going away once we start writing the
>>>>>>> new ones.
>>>>>>>
>>>>>>> Read this: http://llvm.org/docs/TestingGuide.html
>>>>>>> and then go to
>>>>>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/ and
>>>>>>> choose any target you wish (say msp430 since it's the most similar one to
>>>>>>> us) to see how real tests look like.
>>>>>>>
>>>>>>> Basically, you have to write a test in llvm assembly, and then with
>>>>>>> CHECK you write the avr assembly that should be emitted, if it matches then
>>>>>>> the test passes otherwise it fails. You can avoid writing the llvm assembly
>>>>>>> by writing the test in C and then translate it to llvm assembly with clang.
>>>>>>>
>>>>>>> Try writing a small test for add using the llvm testing
>>>>>>> infrastructure and then run it with llvm to see if it passes.
>>>>>>> It's very important that you write the expected output assembly
>>>>>>> right, otherwise we'll generate wrong code to make the test pass, but since
>>>>>>> tests are quite small it's easy to get it right.
>>>>>>>
>>>>>>>
>>>>>>> 2012/4/29 Nicklas Bo Jensen <nbj...@gm...>
>>>>>>>
>>>>>>>> Hi,
>>>>>>>>
>>>>>>>> I have successfully been able to compile your testcases
>>>>>>>> (/avr-llvm/testcases/*.ll) to something looking like valid avr assembler.
>>>>>>>>
>>>>>>>> How should I test/simulate the assembler? I get errors when trying
>>>>>>>> to simulate the generated assembler in AVRStudio. Perhaps they use a
>>>>>>>> different assembler?
>>>>>>>>
>>>>>>>> For one test, add1.ll I cannot process it using avr-as. I have done:
>>>>>>>>
>>>>>>>> ../../build/Debug+Asserts/bin/llc --march=avr add1.ll -o add1.s
>>>>>>>> avr-as -mmcu=atmega168 add1.s
>>>>>>>>
>>>>>>>>
>>>>>>>> and get the error:
>>>>>>>>
>>>>>>>> asm.s: Assembler messages:
>>>>>>>> asm.s:12: Error: register r24, r26, r28 or r30 required
>>>>>>>> asm.s:12: Error: `,' required
>>>>>>>> asm.s:12: Error: garbage at end of line
>>>>>>>> asm.s:24: Error: register r24, r26, r28 or r30 required
>>>>>>>> asm.s:24: Error: `,' required
>>>>>>>> asm.s:24: Error: garbage at end of line
>>>>>>>>
>>>>>>>>
>>>>>>>> Am I doing something wrong? I have included the assembler.
>>>>>>>>
>>>>>>>> Thanks,
>>>>>>>> Nicklas
>>>>>>>>
>>>>>>>> On Sun, Apr 29, 2012 at 7:23 PM, Borja Ferrer <
>>>>>>>> bor...@gm...> wrote:
>>>>>>>>
>>>>>>>>> Hello Neil I'm replying you in this thread, i dont know why I
>>>>>>>>> didn't receive your mail, i had to look in SF to read it.
>>>>>>>>>
>>>>>>>>> Anyways, first try to build the backend so you can play a bit with
>>>>>>>>> it to get familiar with its code. Try compiling some C code to generate avr
>>>>>>>>> assembly.
>>>>>>>>>
>>>>>>>>> 2012/4/23 Nicklas Bo Jensen <nbj...@gm...>
>>>>>>>>>
>>>>>>>>>> Hi,
>>>>>>>>>>
>>>>>>>>>> I'll be happy to contribute, after I have fixed my issues getting
>>>>>>>>>> avr-llvm to compile in the first place.
>>>>>>>>>>
>>>>>>>>>> BR,
>>>>>>>>>> Nicklas
>>>>>>>>>>
>>>>>>>>>> On Sun, Apr 22, 2012 at 7:26 PM, Borja Ferrer <
>>>>>>>>>> bor...@gm...> wrote:
>>>>>>>>>>
>>>>>>>>>>> I think it's time to stop adding more features until we cover
>>>>>>>>>>> what is currently implemented with regression tests. Otherwise the further
>>>>>>>>>>> we go the harder will be to cover everything up, from now on it's going to
>>>>>>>>>>> be easier to go in parallel.
>>>>>>>>>>> In the past emails I've seen people interested in helping out
>>>>>>>>>>> with this, it's a good way of starting with some development becuase it's
>>>>>>>>>>> an easy task to do and it helps to understand how llvm works, so anybody
>>>>>>>>>>> interested check in here so I know if I'm going to have any help at all or
>>>>>>>>>>> I have to do it myself.
>>>>>>>>>>>
>>>>>>>>>>> So if there's some help available we can plan in this thread
>>>>>>>>>>> what needs to get covered and how to do it, I'll wait a few days for any
>>>>>>>>>>> replies.
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> ------------------------------------------------------------------------------
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>>>>>>>>>>> http://p.sf.net/sfu/Boundary-d2dvs2
>>>>>>>>>>> _______________________________________________
>>>>>>>>>>> avr-llvm-devel mailing list
>>>>>>>>>>> avr...@li...
>>>>>>>>>>> https://lists.sourceforge.net/lists/listinfo/avr-llvm-devel
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
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>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>

Re: [avr-llvm-devel] Regression tests

This is the AVR port of LLVM.

Re: [avr-llvm-devel] Regression tests