[PATCH] D80034: [Local] Do not ignore zexts in salvageDebugInfo, PR45923

[Adrian Prantl via Phabricator via llvm-commits]

aprantl added inline comments.


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Comment at: llvm/test/Transforms/InstCombine/cast-mul-select.ll:178
 ; DBGINFO-LABEL: @foo(
-; DBGINFO-NEXT:  call void @llvm.dbg.value(metadata i1 %b
+; DBGINFO-NEXT:  call void @llvm.dbg.value(metadata i1 %b, {{.*}} !DIExpression(DW_OP_LLVM_convert, 1, DW_ATE_unsigned, DW_OP_LLVM_convert, 8, DW_ATE_unsigned, DW_OP_stack_value))
 ; DBGINFO-NEXT:  ret i1 %b
----------------
I have not thought about the exact semantics, but I'm wondering if it would be possible to contract a sequence on DW_OP_convert operations in the backend in DwarfExpression.cpp to have a smaller encoding? I guess this would be easier if we distinguished between extending and truncating a value in our IR. Perhaps we'd need to introduce DW_OP_LLVM_zext & friends?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D80034/new/

https://reviews.llvm.org/D80034