[PATCH] D102917: [LiveDebugVariables] Stop trimming locations of non-inlined vars

[Djordje Todorovic via Phabricator via llvm-commits]

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The D35953 <https://reviews.llvm.org/D35953>, D62650 <https://reviews.llvm.org/D62650> and D73691 <https://reviews.llvm.org/D73691> introduced trimming of variables locations in `LiveDebugVariables` pass, since there are some cases where after the `virtregrewrite` we have exploded number of `DBG_VALUEs` created for some inlined variables. As it looks, all problematic cases were regarding inlined variables, so it seems reasonable to stop trimming the location ranges for non-inlined variables. It has very good impact on the llvm-locstats report.

By using GDB 7.11 compiled with `-g -O2` as test bed, the numbers looks as follows:

(before this patch)

  $ llvm-locstats ./gdb/gdb
   ================================================
              Debug Location Statistics
   ================================================
       cov%           samples         percentage(~)
   -----------------------------------------------
     0%                 2621                2%
     (0%,10%)           5675                5%
     [10%,20%)          5050                4%
     [20%,30%)          4997                4%
     [30%,40%)          4527                4%
     [40%,50%)          4237                4%
     [50%,60%)          4679                4%
     [60%,70%)          4737                4%
     [70%,80%)          5656                5%
     [80%,90%)          6481                6%
     [90%,100%)        12957               12%
     100%              41014               39%
   ================================================
   -the number of debug variables processed: 102631
   -PC ranges covered: 56%
   -----------------------------------------------
    -total availability: 86%
   ================================================

(after applying this patch)

  $ llvm-locstats ./gdb/gdb
   ================================================
              Debug Location Statistics
   ================================================
       cov%           samples         percentage(~)
   -----------------------------------------------
     0%                 2620                2%
     (0%,10%)           5628                5%
     [10%,20%)          4972                4%
     [20%,30%)          4862                4%
     [30%,40%)          4431                4%
     [40%,50%)          4109                4%
     [50%,60%)          4539                4%
     [60%,70%)          4625                4%
     [70%,80%)          5517                5%
     [80%,90%)          6232                6%
     [90%,100%)        10154                9%
     100%              44942               43%
   ================================================
   -the number of debug variables processed: 102631
   -PC ranges covered: 57%
   -----------------------------------------------
   -total availability: 86%
   ================================================


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D102917

Files:
  llvm/lib/CodeGen/LiveDebugVariables.cpp
  llvm/test/CodeGen/AMDGPU/ptr-arg-dbg-value.ll
  llvm/test/CodeGen/PowerPC/non-debug-mi-search-frspxsrsp.ll
  llvm/test/DebugInfo/MIR/Mips/livedebugvars-stop-trimming-loc.mir
  llvm/test/DebugInfo/X86/dbg-addr-dse.ll

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