llvm dev - Jul 2008 - [LLVMdev] gcc in c++

On Wed, Jul 2, 2008 at 7:00 PM, Mike Stump <mrs at apple.com>
wrote:
> On Jul 2, 2008, at 4:39 PM, Eli Friedman wrote:
>> Another perspective on this sort of issue, if you haven't seen it:
>> http://weblogs.mozillazine.org/roc/archives/2007/10/
>> tablua_fracta.html.
>
> If we apply their logic to llvm, we can dominate, if we just target 8
> cores.  :-)
That's not so far from the truth... a high-quality parallelized
LTO+codegen implementation would really set LLVM apart from other
current compilers.

-Eli

> On Wed, Jul 2, 2008 at 7:00 PM, Mike Stump <mrs at apple.com> wrote:
>> If we apply their logic to llvm, we can dominate, if we just target 8
>> cores.  :-)
Does this mean llvm can not dominate if llvm target 1 core machine  
also ?

On Thu, Jul 3, 2008 at 9:09 AM, Devang Patel <dpatel at apple.com>
wrote:
>> On Wed, Jul 2, 2008 at 7:00 PM, Mike Stump <mrs at apple.com>
wrote:
>>> If we apply their logic to llvm, we can dominate, if we just target
8
>>> cores.  :-)
>
> Does this mean llvm can not dominate if llvm target 1 core machine
> also ?
Making an optimizer/code generator parallel is fundamentally a lot
easier than making a browser parallel because the problems parallelize
a lot more naturally.  There are essentially two chunks of code in the
llvm pipeline that take up large amounts of time: the optimization
passes and the code generator.  I think parallelizing both of these is
feasible with conventional parallelism techniques, with very little
penalty for the single-core case.

That said, that wasn't the point I was trying to make by linking to
that blog post; I was really trying to point in the direction of
building new programming tools with LLVM.  Parallelizing a web-browser
to many cores involves much more difficult issues.

-Eli