[llvm] [ISelDAG] Salvage debug info at isel by referring to frame indices. (PR #109126)

[Orlando Cazalet-Hyams via llvm-commits]

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@@ -0,0 +1,85 @@
+; RUN: llc -march=sparc -O1 %s -o - | FileCheck %s
+
+; Debug info salvaging in isel means we should see a location for this variable.
+
+; CHECK-LABEL: a:
+; CHECK:    !DEBUG_VALUE: a:d <- [DW_OP_plus_uconst 98, DW_OP_plus_uconst 3, DW_OP_stack_value] $o6
+
+define dso_local zeroext i16 @a() local_unnamed_addr #0 !dbg !7 {
+entry:
+  %b = alloca [6 x i8], align 1, !DIAssignID !24
+    #dbg_assign(i1 undef, !14, !DIExpression(), !24, ptr %b, !DIExpression(), !25)
+  call void @llvm.lifetime.start.p0(i64 6, ptr nonnull %b) #2, !dbg !26
+  %arrayidx = getelementptr inbounds [6 x i8], ptr %b, i32 0, i32 undef, !dbg !27
+  store i8 4, ptr %arrayidx, align 1, !dbg !28, !tbaa !29
+  %arrayidx1 = getelementptr inbounds i8, ptr %b, i32 3, !dbg !32
+    #dbg_value(ptr %arrayidx1, !22, !DIExpression(), !25)
+  %0 = load i8, ptr %arrayidx1, align 1, !dbg !33, !tbaa !29
+  %tobool.not = icmp eq i8 %0, 0, !dbg !35
+  br i1 %tobool.not, label %if.end, label %for.cond, !dbg !36
+
+for.cond:                                         ; preds = %entry, %for.cond
+  br label %for.cond, !dbg !37, !llvm.loop !40
+
+if.end:                                           ; preds = %entry
+  call void @llvm.lifetime.end.p0(i64 6, ptr nonnull %b) #2, !dbg !44
+  ret i16 undef, !dbg !44
+}
+
+declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1
+
+declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1
+
+attributes #0 = { nofree noinline norecurse nosync nounwind memory(none) "no-builtins" "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
+attributes #1 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+attributes #2 = { nounwind }
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OCHyams wrote:

Please can you remove the attributes that aren't needed for the test?

https://github.com/llvm/llvm-project/pull/109126