[llvm-commits] [llvm] r48521 - in /llvm/trunk: include/llvm/CodeGen/LiveVariables.h lib/CodeGen/LiveVariables.cpp test/CodeGen/PowerPC/2008-03-18-RegScavengerAssert.ll test/CodeGen/X86/x86-64-ret0.ll

[Chris Lattner]

On Mar 24, 2008, at 6:41 PM, Evan Cheng wrote:

>> How about using reg_iterators to do this?  I assume this only applies
>> to vregs.  If you walk the use_iterator list for the register, you  
>> can
>> very efficiently discard uses in other blocks (check User- 
>> >getparent()
>> == MBB).  Any uses within the same block are either a) in phi nodes,
>> in which case they are above the instruction or b) users later in the
>> block.
>
> No, this applies to physical registers only.
>
> We need def / use information for physical registers and MI to
> distance from top of MBB mapping to quickly determine this property.
> This is not *yet* showing up to be a compile time issue, so I am
> ignoring it for now.
>
> Isn't Owen going to do something about LiveVariables? Can I volunteer
> Own to own this problem? :-)

Sure you can volunteer him; lets see how much he fights back!  What do  
you say Owen? :)

-Chris