evan.cheng at apple.com
Wed Jul 18 11:34:01 PDT 2007
On Jul 13, 2007, at 11:43 AM, Fernando Magno Quintao Pereira wrote:
>> Why do you want to do this? Empty MBBs are valid, and it's probably
>> better to have your code handle them.
> Currently, that is the solution. I have a special treatment for empty
> basic blocks. I think the code would be more homogeneous if there
> were no
> empty basic blocks.
>> There is a NOP "instruction" on x86, equivalent to XCHG EAX, EAX.
> The problem with xchk EAX, EAX is that is uses registers, and it would
> add a small burden on the register allocator.
It won't. EAX is not an explicit operand. The register allocator
doesn't need to know it touches any register.
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu
More information about the llvm-dev