1 files changed, 85 insertions, 0 deletions
diff --git a/contrib/llvm-project/llvm/lib/Transforms/IPO/InferFunctionAttrs.cpp b/contrib/llvm-project/llvm/lib/Transforms/IPO/InferFunctionAttrs.cpp
new file mode 100644
index 000000000000..685f8f7d7a00
--- /dev/null
+++ b/contrib/llvm-project/llvm/lib/Transforms/IPO/InferFunctionAttrs.cpp
@@ -0,0 +1,85 @@
+//===- InferFunctionAttrs.cpp - Infer implicit function attributes --------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/IPO/InferFunctionAttrs.h"
+#include "llvm/Analysis/TargetLibraryInfo.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/InitializePasses.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/Utils/BuildLibCalls.h"
+using namespace llvm;
+
+#define DEBUG_TYPE "inferattrs"
+
+static bool inferAllPrototypeAttributes(
+    Module &M, function_ref<TargetLibraryInfo &(Function &)> GetTLI) {
+  bool Changed = false;
+
+  for (Function &F : M.functions())
+    // We only infer things using the prototype and the name; we don't need
+    // definitions.
+    if (F.isDeclaration() && !F.hasOptNone())
+      Changed |= inferLibFuncAttributes(F, GetTLI(F));
+
+  return Changed;
+}
+
+PreservedAnalyses InferFunctionAttrsPass::run(Module &M,
+                                              ModuleAnalysisManager &AM) {
+  FunctionAnalysisManager &FAM =
+      AM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
+  auto GetTLI = [&FAM](Function &F) -> TargetLibraryInfo & {
+    return FAM.getResult<TargetLibraryAnalysis>(F);
+  };
+
+  if (!inferAllPrototypeAttributes(M, GetTLI))
+    // If we didn't infer anything, preserve all analyses.
+    return PreservedAnalyses::all();
+
+  // Otherwise, we may have changed fundamental function attributes, so clear
+  // out all the passes.
+  return PreservedAnalyses::none();
+}
+
+namespace {
+struct InferFunctionAttrsLegacyPass : public ModulePass {
+  static char ID; // Pass identification, replacement for typeid
+  InferFunctionAttrsLegacyPass() : ModulePass(ID) {
+    initializeInferFunctionAttrsLegacyPassPass(
+        *PassRegistry::getPassRegistry());
+  }
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.addRequired<TargetLibraryInfoWrapperPass>();
+  }
+
+  bool runOnModule(Module &M) override {
+    if (skipModule(M))
+      return false;
+
+    auto GetTLI = [this](Function &F) -> TargetLibraryInfo & {
+      return this->getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(F);
+    };
+    return inferAllPrototypeAttributes(M, GetTLI);
+  }
+};
+}
+
+char InferFunctionAttrsLegacyPass::ID = 0;
+INITIALIZE_PASS_BEGIN(InferFunctionAttrsLegacyPass, "inferattrs",
+                      "Infer set function attributes", false, false)
+INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
+INITIALIZE_PASS_END(InferFunctionAttrsLegacyPass, "inferattrs",
+                    "Infer set function attributes", false, false)
+
+Pass *llvm::createInferFunctionAttrsLegacyPass() {
+  return new InferFunctionAttrsLegacyPass();
+}