[LLVMdev] [PATCH] Support asm comment output
clattner at apple.com
Mon Jul 13 13:49:23 PDT 2009
On Jul 13, 2009, at 1:34 PM, David Greene wrote:
> On Monday 13 July 2009 13:29, David Greene wrote:
>> I forgot about the LLVM instruction information. That's something
>> can't be synthesized by the asmprinter. Again, we only emit some
>> of this
>> with special debug flags so we don't carry the original IR around in
>> comments all the time. :)
> If the FI question can be answered (how do we know it's a spill slot)?
I just responded separately.
> Then the above is the only use I think we don't have a long-term
> answer for.
> I don't see how asmprinter can synthesize this information.
I agree, but our isel currently doesn't propagate this in any other
way either. Lets just defer this issue for now.
> Line numbers are still a problem because we need to propagate the
> from LLVM IR to MachineInstrs and there's currently no DebugLoc
> in LLVM IR Instructions. I'll take a look at the existing DebugLoc
> and see if
> we can put our LLVM IR line number info there instead of printing it
> comments early.
Just generate stoppoints like llvm-gcc.
> If it's any comfort, we've been running with this MachineInstr for a
> very long time and done multiple public releases. We always go
> asm to do our x86 compiles and no one has ever complained about
> time or memory usage in this area (legalize is actually our biggest
> And we compile HUGE source files containing very large functions.
We care most about -O0 compile times, which generally don't use
legalize or selection dags at all, and use the local register allocator.
More information about the llvm-dev