Imported Upstream version 5.18.0.167

Former-commit-id: 289509151e0fee68a1b591a20c9f109c3c789d3a

external/llvm/lib/Transforms/Scalar/ConstantProp.cpp

@@ -1,104 +0,0 @@
-//===- ConstantProp.cpp - Code to perform Simple Constant Propagation -----===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements constant propagation and merging:
-//
-// Specifically, this:
-//   * Converts instructions like "add int 1, 2" into 3
-//
-// Notice that:
-//   * This pass has a habit of making definitions be dead.  It is a good idea
-//     to run a DIE pass sometime after running this pass.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/ADT/Statistic.h"
-#include "llvm/Analysis/ConstantFolding.h"
-#include "llvm/Analysis/TargetLibraryInfo.h"
-#include "llvm/IR/Constant.h"
-#include "llvm/IR/InstIterator.h"
-#include "llvm/IR/Instruction.h"
-#include "llvm/Pass.h"
-#include "llvm/Transforms/Scalar.h"
-#include "llvm/Transforms/Utils/Local.h"
-#include <set>
-using namespace llvm;
-
-#define DEBUG_TYPE "constprop"
-
-STATISTIC(NumInstKilled, "Number of instructions killed");
-
-namespace {
-  struct ConstantPropagation : public FunctionPass {
-    static char ID; // Pass identification, replacement for typeid
-    ConstantPropagation() : FunctionPass(ID) {
-      initializeConstantPropagationPass(*PassRegistry::getPassRegistry());
-    }
-
-    bool runOnFunction(Function &F) override;
-
-    void getAnalysisUsage(AnalysisUsage &AU) const override {
-      AU.setPreservesCFG();
-      AU.addRequired<TargetLibraryInfoWrapperPass>();
-    }
-  };
-}
-
-char ConstantPropagation::ID = 0;
-INITIALIZE_PASS_BEGIN(ConstantPropagation, "constprop",
-                "Simple constant propagation", false, false)
-INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
-INITIALIZE_PASS_END(ConstantPropagation, "constprop",
-                "Simple constant propagation", false, false)
-
-FunctionPass *llvm::createConstantPropagationPass() {
-  return new ConstantPropagation();
-}
-
-bool ConstantPropagation::runOnFunction(Function &F) {
-  if (skipFunction(F))
-    return false;
-
-  // Initialize the worklist to all of the instructions ready to process...
-  std::set<Instruction*> WorkList;
-  for (Instruction &I: instructions(&F))
-    WorkList.insert(&I);
-
-  bool Changed = false;
-  const DataLayout &DL = F.getParent()->getDataLayout();
-  TargetLibraryInfo *TLI =
-      &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
-
-  while (!WorkList.empty()) {
-    Instruction *I = *WorkList.begin();
-    WorkList.erase(WorkList.begin());    // Get an element from the worklist...
-
-    if (!I->use_empty())                 // Don't muck with dead instructions...
-      if (Constant *C = ConstantFoldInstruction(I, DL, TLI)) {
-        // Add all of the users of this instruction to the worklist, they might
-        // be constant propagatable now...
-        for (User *U : I->users())
-          WorkList.insert(cast<Instruction>(U));
-
-        // Replace all of the uses of a variable with uses of the constant.
-        I->replaceAllUsesWith(C);
-
-        // Remove the dead instruction.
-        WorkList.erase(I);
-        if (isInstructionTriviallyDead(I, TLI)) {
-          I->eraseFromParent();
-          ++NumInstKilled;
-        }
-
-        // We made a change to the function...
-        Changed = true;
-      }
-  }
-  return Changed;
-}