llvm dev - Oct 2011 - [LLVMdev] [LLVM, llvm-diff] Question about FunctionDifferenceEngine and DiffConsumer::printValue

Hi all.
I found next code when switch instruction differs:

Engine.logf("right switch has extra case %r") << CaseValue;

Where CaseValue is a ConstantInt object. Looking how logf works I found 
that it invokes DiffConsumer::printValue method for CaseValue. And here 
I found that CaseValue itself will never printed. On first look how 
DiffConsumer::printValue works it seems that for all constants "object 
numbering" should be printed:

out << '%' << ctxt.RNumbering[V]; // V = CaseValue in our
case.
                                   // RNumbering is instance of 
DenseMap<Value*,unsigned>.

Then I look into DiffConsumer.cpp, ComputeNumbering method that fills 
RNumbering and LNumbering. Well, numbering computed for function 
arguments, basic blocks and instructions only.

It means that for Constants "%0" will be printed always. If so, I 
propose to add case for constants in DiffConsumer::printValue method, 
that will print constant itself.

Regards,
Stepan.

On Oct 28, 2011, at 2:00 AM, Stepan Dyatkovskiy wrote:
> I found next code when switch instruction differs:
> 
> Engine.logf("right switch has extra case %r") << CaseValue;
> 
> Where CaseValue is a ConstantInt object. Looking how logf works I found 
> that it invokes DiffConsumer::printValue method for CaseValue. And here 
> I found that CaseValue itself will never printed. On first look how 
> DiffConsumer::printValue works it seems that for all constants "object
> numbering" should be printed:
> 
> out << '%' << ctxt.RNumbering[V]; // V = CaseValue in
our case.
>                                   // RNumbering is instance of 
> DenseMap<Value*,unsigned>.
> 
> Then I look into DiffConsumer.cpp, ComputeNumbering method that fills 
> RNumbering and LNumbering. Well, numbering computed for function 
> arguments, basic blocks and instructions only.
> 
> It means that for Constants "%0" will be printed always. If so, I
> propose to add case for constants in DiffConsumer::printValue method, 
> that will print constant itself.
Patches welcome!

John.

Hi,

Please find the attached patch for review.

-Stepan.

John McCall wrote:
> On Oct 28, 2011, at 2:00 AM, Stepan Dyatkovskiy wrote:
>> I found next code when switch instruction differs:
>>
>> Engine.logf("right switch has extra case %r")<< 
CaseValue;
>>
>> Where CaseValue is a ConstantInt object. Looking how logf works I found
>> that it invokes DiffConsumer::printValue method for CaseValue. And here
>> I found that CaseValue itself will never printed. On first look how
>> DiffConsumer::printValue works it seems that for all constants
"object
>> numbering" should be printed:
>>
>> out<<  '%'<<  ctxt.RNumbering[V]; // V = CaseValue
in our case.
>>                                    // RNumbering is instance of
>> DenseMap<Value*,unsigned>.
>>
>> Then I look into DiffConsumer.cpp, ComputeNumbering method that fills
>> RNumbering and LNumbering. Well, numbering computed for function
>> arguments, basic blocks and instructions only.
>>
>> It means that for Constants "%0" will be printed always. If
so, I
>> propose to add case for constants in DiffConsumer::printValue method,
>> that will print constant itself.
>
> Patches welcome!
>
> John.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: diffeng.patch
Type: text/x-patch
Size: 957 bytes
Desc: not available
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20111031/d9301cc0/attachment.bin>