llvm dev - Jun 2007 - [LLVMdev] hacked up llvm-gcc bootstraps on linux-x86_64

Bugs 1519 and 1521 currently prevent a clean bootstrap on Linux
x86_64. I was able to hack it to work :-)

The attached patch includes two parts. One is a tentative fix bug
1519: just set LastFieldStartsAtNonByteBoundry in
allFieldsAreNotBitFields.

The other one is a plain hack. llvm-gcc and gcc disagree on how to
pass some structures, so stage2 gcc fails to use the libcpp compiled
by gcc. So I just copied a function form libcpp to gcc itself :-)

Cheers,
Rafael
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On Jun 21, 2007, at 3:01 PM, Chris Lattner wrote:
> On Thu, 21 Jun 2007, [UTF-8] Rafael Esp?ndola wrote:
>> Bugs 1519 and 1521 currently prevent a clean bootstrap on Linux
>> x86_64. I was able to hack it to work :-)
>>
>> The attached patch includes two parts. One is a tentative fix bug
>> 1519: just set LastFieldStartsAtNonByteBoundry in
>> allFieldsAreNotBitFields.
>
> Cool, I'll let Duncan or Devang comment on this patch, it looks simple
> enough, but they are the experts on the code.
This patch is ok. I'm building llvm-gcc right now. I'll apply this  
chunk after build finishes.

-
Devang

On Thu, 21 Jun 2007, [UTF-8] Rafael Esp?ndola wrote:
> Bugs 1519 and 1521 currently prevent a clean bootstrap on Linux
> x86_64. I was able to hack it to work :-)
>
> The attached patch includes two parts. One is a tentative fix bug
> 1519: just set LastFieldStartsAtNonByteBoundry in
> allFieldsAreNotBitFields.
Cool, I'll let Duncan or Devang comment on this patch, it looks simple 
enough, but they are the experts on the code.
> The other one is a plain hack. llvm-gcc and gcc disagree on how to
> pass some structures, so stage2 gcc fails to use the libcpp compiled
> by gcc. So I just copied a function form libcpp to gcc itself :-)
I'm not opposed to this as a short-term hack.  Do you think we should 
commit it until PR1521 is resolved?

-Chris

-- 
http://nondot.org/sabre/
http://llvm.org/

On Thu, 21 Jun 2007, [UTF-8] Rafael Esp?ndola wrote:
> The other one is a plain hack. llvm-gcc and gcc disagree on how to
> pass some structures, so stage2 gcc fails to use the libcpp compiled
> by gcc. So I just copied a function form libcpp to gcc itself :-)
I went back and forth on this one, but eventually decided that that 
ability to bootstrap llvm-gcc on a major platform is more important than 
avoiding a (very cute and well crafted) little hack.  I checked in the 
patch, we can revert it when the real fix for PR1521 is done.

I also wrote a detailed description of the proposed fix for PR1521 in the 
bug if anyone is interested.  The fix would dramatically improve codegen 
quality for structs passed by value (e.g. structs with vectors in them, 
complex numbers, etc), in addition to fixing the correctness problem.

-Chris

-- 
http://nondot.org/sabre/
http://llvm.org/