simplify switch case with return

Author: optimisan

llvm/lib/CodeGen/RegAllocEvictionAdvisor.cpp

@@ -147,26 +147,25 @@ RegAllocEvictionAdvisorAnalysis::run(MachineFunction &MF,
 
 template <>
 Pass *llvm::callDefaultCtor<RegAllocEvictionAdvisorAnalysisLegacy>() {
- Pass *Ret = nullptr;
  switch (Mode) {
  case RegAllocEvictionAdvisorAnalysisLegacy::AdvisorMode::Default:
  return new DefaultEvictionAdvisorAnalysisLegacy(/*NotAsRequested=*/false);
- case RegAllocEvictionAdvisorAnalysisLegacy::AdvisorMode::Release:
- Ret = createReleaseModeAdvisorAnalysisLegacy();
+ case RegAllocEvictionAdvisorAnalysisLegacy::AdvisorMode::Release: {
+ Pass *Ret = createReleaseModeAdvisorAnalysisLegacy();
  // release mode advisor may not be supported
- if (!Ret)
- Ret = new DefaultEvictionAdvisorAnalysisLegacy(/*NotAsRequested=*/true);
- break;
+ if (Ret)
+ return Ret;
+ return new DefaultEvictionAdvisorAnalysisLegacy(/*NotAsRequested=*/true);
+ }
  case RegAllocEvictionAdvisorAnalysisLegacy::AdvisorMode::Development:
 #if defined(LLVM_HAVE_TFLITE)
- Ret = createDevelopmentModeAdvisorAnalysisLegacy();
+ return createDevelopmentModeAdvisorAnalysisLegacy();
 #else
- Ret = new DefaultEvictionAdvisorAnalysisLegacy(/*NotAsRequested=*/true);
+ return new DefaultEvictionAdvisorAnalysisLegacy(/*NotAsRequested=*/true);
 #endif
- break;
  }
-
- return Ret;
+ llvm_unreachable("unexpected advisor mode");
+ return nullptr;
 }
 
 StringRef RegAllocEvictionAdvisorAnalysisLegacy::getPassName() const {