[LLVMdev] Opinions Wanted: New asm Comments

Chris Lattner clattner at apple.com
Mon Jul 11 21:09:28 PDT 2011

On Jul 11, 2011, at 2:48 PM, David Greene wrote:

> I have a patch I'd like to commit that adds commentary to asm files
> about which TableGen pattern generated a particular instruction.  The
> output looks like this:
> 	cvtpd2ps	%xmm0, %xmm0    # source.c:39
>                                        #  Src: (intrinsic_wo_chain:v4f32 927:iPTR, VR128:v2f64:$src)
>                                        #  Dst: (Int_CVTPD2PSrr:v4f32 VR128:v2f64:$src)
> This is enormously helpful when trying to track down codegen bugs but
> clutters the asm file pretty badly for "ordinary" users.
> Right now I have this under control of a separate -asm-pattern flag.
> All other asm commentary is controlled by -asm-verbose.
> Is a new flag appropriate for this or should I just put it under
> -asm-verbose with everything else?  If we want a new flag, does anyone
> have a spelling they'd recommend?  I'm not particularly fond of
> -asm-pattern but it was the best concise name my uncreative brain could
> conjur up.

How do you plan to implement this?  This is a compiler-hacker-only feature, can it be protected fully in !NDEBUG code?


More information about the llvm-dev mailing list