[llvm] [BasicBlockUtils] Remove redundant llvm.dbg instructions after blocks to reduce compile time (PR #89069)

[Florian Hahn via llvm-commits]

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@@ -0,0 +1,45 @@
+; RUN: opt < %s -S -passes=loop-unroll | FileCheck %s
+
+define i64 @d(i1 %tobool.not, i32 %add, i64 %conv23) {
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %for.body, %entry
+  ; There should be only one "llvm.dbg.vale" after loop unrolling
+  ; CHECK: tail call void @llvm.dbg.value(metadata i32 0, metadata !13, metadata !DIExpression()), !dbg !17
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fhahn wrote:

Better to just check for `call void @llvm.dbg.value`, as otherwise the test would be unnecessary brittle, e.g. needing updating if the metadata numbering slightly changes

https://github.com/llvm/llvm-project/pull/89069