Index: lib/Analysis/PHITransAddr.cpp =================================================================== --- lib/Analysis/PHITransAddr.cpp +++ lib/Analysis/PHITransAddr.cpp @@ -374,9 +374,10 @@ if (!Tmp.PHITranslateValue(CurBB, PredBB, &DT, /*MustDominate=*/true)) return Tmp.getAddr(); - // If we don't have an available version of this value, it must be an - // instruction. - Instruction *Inst = cast(InVal); + // We don't need to PHI translate values which aren't instructions. + auto *Inst = dyn_cast(InVal); + if (!Inst) + return nullptr; // Handle cast of PHI translatable value. if (CastInst *Cast = dyn_cast(Inst)) { Index: test/Transforms/GVN/pr24397.ll =================================================================== --- /dev/null +++ test/Transforms/GVN/pr24397.ll @@ -0,0 +1,18 @@ +; RUN: opt -basicaa -gvn -disable-output < %s + +target triple = "x86_64-unknown-linux-gnu" + +define i64 @foo(i64** %arrayidx) { +entry: + %p = load i64*, i64** %arrayidx, align 8 + %cmpnull = icmp eq i64* %p, null + br label %BB2 + +entry2: ; No predecessors! + br label %BB2 + +BB2: ; preds = %entry2, %entry + %bc = bitcast i64** %arrayidx to i64* + %load = load i64, i64* %bc, align 8 + ret i64 %load +}