[llvm] [LLVM] remove redundant uses of dyn_cast (NFC) (PR #189105)

[Nikita Popov via llvm-commits]

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@@ -7655,7 +7655,7 @@ static bool isARMMCExpr(MCParsedAsmOperand &MCOp) {
   const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(Op.getImm());
   if (CE)
     return false;
-  const MCExpr *E = dyn_cast<MCExpr>(Op.getImm());
+  const MCExpr *E = Op.getImm();
   if (!E)
     return false;
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nikic wrote:

Previously this was checking for an (impossible) dyn_cast failure, so I think it the null check should be dropped.

https://github.com/llvm/llvm-project/pull/189105