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<div>I was trying to run the simplify CFG Pass in LLVM , and delete an unreachable basic block ("continuation" below ) after running one of my own IR transforms , but I keep getting the </div>
<div>error -</div>
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<div><b>While deleting: i8* %g</b></div>
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<div><b>Use still stuck around after Def is destroyed: store i8 0, i8* %g</b></div>
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<div>I am well aware of what that means, but isn't the whole purpose of the "simplifyCFGPass" to delete the unreachable basic blocks for us ? Why must it then throw this error ? I would assume it should simply be able to manage all the use-def dependencies
and delete the instructions in the unreachable "continuation" basic block below.</div>
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<div><b>Following is the relevant IR </b></div>
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<div> entry:</div>
<div> %a3 = alloca i32</div>
<div> store i32 %a, i32* %a3</div>
<div> %a4 = load i32, i32* %a3 </div>
<div> %ifcond = icmp ne i32 %a4, 0</div>
<div> br i1 %ifcond, label %then, label %else</div>
<div> </div>
<div> </div>
<div> then: ; preds = %entry</div>
<div> %gclone1 = alloca i32</div>
<div> store i32 0, i32* %gclone1</div>
<div> ret i5 0</div>
<div> </div>
<div> else: ; preds = %entry</div>
<div> %gclone4 = alloca i64</div>
<div> store i64 0, i64* %gclone4</div>
<div> ret i5 0</div>
<div> </div>
<div> continuation: ; No predecessors!</div>
<div> %iftmp = phi i32 [ 32, %then ], [ 64, %else ], !range !0</div>
<div> %datasize = alloca i32</div>
<div> store i32 %iftmp, i32* %datasize</div>
<div> </div>
<div> %g = alloca i8<span style="color: rgb(255, 0, 0);"> ---------------------> Issue</span></div>
<div> store i8 0, i8* %g <span style="color: rgb(255, 0, 0);">---------------------> Issue</span></div>
<div> ret i5 0</div>
<div> }</div>
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<div><b>Can someone please explain why this error crops up ? Isn't the API supposed to handle this ?</b></div>
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<div>Thanks,</div>
<div>Malhar</div>
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