[BPF] Avoid repeated map lookups (NFC) (#129820)

Author: kazutakahirata

llvm/lib/Target/BPF/BTFDebug.cpp

@@ -1542,17 +1542,12 @@ bool BTFDebug::InstLower(const MachineInstr *MI, MCInst &OutMI) {
       const GlobalValue *GVal = MO.getGlobal();
       auto *GVar = dyn_cast<GlobalVariable>(GVal);
       if (GVar) {
-        // Emit "mov ri, <imm>"
-        int64_t Imm;
-        uint32_t Reloc;
-        if (GVar->hasAttribute(BPFCoreSharedInfo::AmaAttr) ||
-            GVar->hasAttribute(BPFCoreSharedInfo::TypeIdAttr)) {
-          Imm = PatchImms[GVar].first;
-          Reloc = PatchImms[GVar].second;
-        } else {
+        if (!GVar->hasAttribute(BPFCoreSharedInfo::AmaAttr) &&
+            !GVar->hasAttribute(BPFCoreSharedInfo::TypeIdAttr))
           return false;
-        }
 
+        // Emit "mov ri, <imm>"
+        auto [Imm, Reloc] = PatchImms[GVar];
         if (Reloc == BTF::ENUM_VALUE_EXISTENCE || Reloc == BTF::ENUM_VALUE ||
             Reloc == BTF::BTF_TYPE_ID_LOCAL || Reloc == BTF::BTF_TYPE_ID_REMOTE)
           OutMI.setOpcode(BPF::LD_imm64);