[clang] [llvm] CodeGen: Add LibcallLoweringInfo analysis pass (PR #168622)

[Matt Arsenault via llvm-commits]

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@@ -73,6 +77,70 @@ class LibcallLoweringInfo {
   }
 };
 
+/// Record a mapping from subtarget to LibcallLoweringInfo.
+class LibcallLoweringModuleAnalysisResult {
+private:
+  using LibcallLoweringMap =
+      DenseMap<const TargetSubtargetInfo *, LibcallLoweringInfo>;
+  mutable LibcallLoweringMap LoweringMap;
+  const RTLIB::RuntimeLibcallsInfo *RTLCI = nullptr;
+
+public:
+  LibcallLoweringModuleAnalysisResult() = default;
+  LibcallLoweringModuleAnalysisResult(RTLIB::RuntimeLibcallsInfo &RTLCI)
+      : RTLCI(&RTLCI) {}
+
+  void init(const RTLIB::RuntimeLibcallsInfo *RT) { RTLCI = RT; }
+
+  void clear() {
+    RTLCI = nullptr;
+    LoweringMap.clear();
+  }
+
+  LLVM_ABI bool invalidate(Module &, const PreservedAnalyses &,
+                           ModuleAnalysisManager::Invalidator &);
+
+  const LibcallLoweringInfo &
+  getLibcallLowering(const TargetSubtargetInfo &Subtarget) const {
+    return LoweringMap.try_emplace(&Subtarget, *RTLCI, Subtarget).first->second;
+  }
+};
+
+class LibcallLoweringModuleAnalysis
+    : public AnalysisInfoMixin<LibcallLoweringModuleAnalysis> {
+private:
+  friend AnalysisInfoMixin<LibcallLoweringModuleAnalysis>;
+  LLVM_ABI static AnalysisKey Key;
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arsenm wrote:

Copied from TargetLibraryAnalysis 

https://github.com/llvm/llvm-project/pull/168622