[llvm-dev] [RFC][ThinLTO] llvm-dis ThinLTO summary dump format

[Peter Collingbourne via llvm-dev]

On Fri, Jun 2, 2017 at 12:29 PM, Teresa Johnson <tejohnson at google.com>
wrote:

> On Fri, Jun 2, 2017 at 12:18 PM, Peter Collingbourne via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
>> Why do we need a custom dumping format for the summary? Since we already
>> need the YAML format anyway, wouldn't it be better to extend that to cover
>> the entire summary?
>>
>
> IMO it is useful/convenient to be able to see the summary in the llvm-dis
> output.
>

There are two things:
1) the format of the summary
2) where to add the dumper
I'm not too concerned about 2 (I wouldn't add it to llvm-dis, but rather as
a subcommand to llvm-lto2, but I don't have a strong opinion about that).

So that leaves the text based summary format. We need a format that is
easily parseable so that we can test components that manipulate summaries
in isolation. That is what the YAML format is. Why add a second format that
is not parseable?

Peter

Teresa
>
>
>> Peter
>>
>> On Fri, Jun 2, 2017 at 8:46 AM, Charles Saternos via llvm-dev <
>> llvm-dev at lists.llvm.org> wrote:
>>
>>> Hey all,
>>>
>>> Below is the proposed format for the dump of the ThinLTO module summary
>>> in the llvm-dis utility:
>>>
>>> > ../build/bin/llvm-dis t.o && cat t.o.ll
>>> ; ModuleID = '2.o'
>>> source_filename = "2.ll"
>>> target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
>>> target triple = "x86_64-unknown-linux-gnu"
>>>
>>> @X = constant i32 42, section "foo", align 4
>>>
>>> @a = weak alias i32, i32* @X
>>>
>>> define void @afun() {
>>>   %1 = load i32, i32* @a
>>>   ret void
>>> }
>>>
>>> define void @testtest() {
>>>   tail call void @boop()
>>>   ret void
>>> }
>>>
>>> declare void @boop()
>>>
>>> ; Module summary:
>>> ;  testtest (External linkage)
>>> ;    Function (2 instructions)
>>> ;    Calls: boop
>>> ;  X (External linkage)
>>> ;    Global Variable
>>> ;  afun (External linkage)
>>> ;    Function (2 instructions)
>>> ;    Refs:
>>> ;      a
>>> ;  a (Weak any linkage)
>>> ;    Alias (aliasee X)
>>>
>>> I've implemented the above format in the llvm-dis utility, since there
>>> currently isn't really a way of getting ThinLTO summaries in a
>>> human-readable format.
>>>
>>> Let me know what you think of this format, and what information you
>>> think should be added/removed.
>>>
>>> Thanks,
>>> Charles
>>>
>>>
>>> _______________________________________________
>>> LLVM Developers mailing list
>>> llvm-dev at lists.llvm.org
>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>>
>>>
>>
>>
>> --
>> --
>> Peter
>>
>> _______________________________________________
>> LLVM Developers mailing list
>> llvm-dev at lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>
>>
>
>
> --
> Teresa Johnson |  Software Engineer |  tejohnson at google.com |
> 408-460-2413 <(408)%20460-2413>
>



-- 
-- 
Peter
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