[PATCH] D98439: [NFC][Inliner] Debugging support to print funtion size after each inlining.

Thu Mar 11 11:52:48 PST 2021

hoy added inline comments.

================
Comment at: llvm/lib/Transforms/IPO/Inliner.cpp:842

+      LLVM_DEBUG(dbgs() << "    Function size: " << F.getInstructionCount()
+                        << "\n");
----------------
hoy wrote:
> wenlei wrote:
> > We have debug prints for negative decision, but not positive decision, so we may end up with a bunch of "function size: ..". Would it be more helpful to say "Function size: X after inlining Y" or something like that?
> We actually have debug prints for positive decision. With the size printing, the debug log now looks like
> 
> 
> ```
> 
> Inlining calls in: _ZN11opentracing2v24util6detail10dispatcherIRN8facebook7tracing11opentracing12_GLOBAL__N_112ValueVisitorENS0_5ValueENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEJDnPKcNS1_17recursive_wrapperISt6vectorISA_SaISA_EEEENSJ_ISt13unordered_mapISG_SA_St4hashISG_ESt8equal_toISG_ESaISt4pairIKSG_SA_EEEEEEE11apply_constERKSA_S9_
>     Function size: 11
>     Inlining (cost=always): always inline attribute, Call:   %4 = call zeroext i1 @_ZNK11opentracing2v24util7variantIJbdlmNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEDnPKcNS1_17recursive_wrapperISt6vectorINS0_5ValueESaISD_EEEENSB_ISt13unordered_mapIS8_SD_St4hashIS8_ESt8equal_toIS8_ESaISt4pairIKS8_SD_EEEEEEE2isIDnEEbv(%"class.opentracing::v2::util::variant"* nonnull %3), !dbg !35441
>     Function size: 13
>     Inlining (cost=always): always inline attribute, Call:   %8 = call dereferenceable(8) i8** @_ZNK11opentracing2v24util7variantIJbdlmNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEDnPKcNS1_17recursive_wrapperISt6vectorINS0_5ValueESaISD_EEEENSB_ISt13unordered_mapIS8_SD_St4hashIS8_ESt8equal_toIS8_ESaISt4pairIKS8_SD_EEEEEEE3getIDnLPv0EEERKT_v(%"class.opentracing::v2::util::variant"* nonnull %3), !dbg !35458
>     Function size: 26
>     Inlining (cost=-35, threshold=375), Call:   %20 = call dereferenceable(8) i8** @_ZN11opentracing2v24util6detail9unwrapperIDnE11apply_constERKDn(i8** nonnull dereferenceable(8) %19), !dbg !35486
>     Function size: 25
>     Inlining (cost=-15020, threshold=375), Call:   call fastcc void @_ZNK8facebook7tracing11opentracing12_GLOBAL__N_112ValueVisitorclIDnEENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEET_(%"class.std::__cxx11::basic_string"* noalias %0), !dbg !35501
>     Function size: 31
>     Inlining (cost=-30, threshold=375), Call:   call fastcc void @_ZSt7forwardIRN8facebook7tracing11opentracing12_GLOBAL__N_112ValueVisitorEEOT_RNSt16remove_referenceIS6_E4typeE() #26, !dbg !35617
>     Function size: 30
> ```
> 
Well, I think you are right. I was looking at an older version and it had debug prints for positive decision there.

Repository:
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  https://reviews.llvm.org/D98439/new/

https://reviews.llvm.org/D98439