[llvm-commits] [llvm] r97475 - /llvm/trunk/utils/TableGen/DAGISelEmitter.cpp

[Török Edwin]

On 03/01/2010 11:16 PM, Chris Lattner wrote:
> On Mar 1, 2010, at 1:12 PM, Jakob Stoklund Olesen wrote:
> 
>>> Time to build X86ISelDAGToDAG.o:
>>> Old: 67.147u 2.060s 1:09.78
>>> New:  4.234u 0.387s 0:04.77
>> Nice!
>>
>> How does runtime performance compare?
> 
> It currently generates identical selections to the old isel.  It's compile time performance is basically the same as the old one, I have a few minor optimizations to go, but even when it's done it won't be significantly faster than the old one.  One of the nice things about this is that PreprocessRMW in the X86 backend is going to die, we might be the ability to write patterns in .td file for nodes with multiple results, etc.
> 

The build-time and code-size wins are amazing!

X86ISelDAGToDAG is something thats always given me troubles during build
(especially on slow buildbots, or older gccs that needed gigabytes of
memory for that thing).

Best regards,
--Edwin