Imported Upstream version 5.18.0.167

Former-commit-id: 289509151e0fee68a1b591a20c9f109c3c789d3a

external/llvm/lib/Target/Hexagon/HexagonOptimizeSZextends.cpp

@@ -1,148 +0,0 @@
-//===- HexagonOptimizeSZextends.cpp - Remove unnecessary argument extends -===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// Pass that removes sign extends for function parameters. These parameters
-// are already sign extended by the caller per Hexagon's ABI
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/CodeGen/StackProtector.h"
-#include "llvm/IR/Function.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/IntrinsicInst.h"
-#include "llvm/Pass.h"
-#include "llvm/Transforms/Scalar.h"
-
-#include "Hexagon.h"
-
-using namespace llvm;
-
-namespace llvm {
-  FunctionPass *createHexagonOptimizeSZextends();
-  void initializeHexagonOptimizeSZextendsPass(PassRegistry&);
-}
-
-namespace {
-  struct HexagonOptimizeSZextends : public FunctionPass {
-  public:
-    static char ID;
-    HexagonOptimizeSZextends() : FunctionPass(ID) {
-      initializeHexagonOptimizeSZextendsPass(*PassRegistry::getPassRegistry());
-    }
-    bool runOnFunction(Function &F) override;
-
-    StringRef getPassName() const override { return "Remove sign extends"; }
-
-    void getAnalysisUsage(AnalysisUsage &AU) const override {
-      AU.addPreserved<StackProtector>();
-      FunctionPass::getAnalysisUsage(AU);
-    }
-
-    bool intrinsicAlreadySextended(Intrinsic::ID IntID);
-  };
-}
-
-char HexagonOptimizeSZextends::ID = 0;
-
-INITIALIZE_PASS(HexagonOptimizeSZextends, "reargs",
-                "Remove Sign and Zero Extends for Args", false, false)
-
-bool HexagonOptimizeSZextends::intrinsicAlreadySextended(Intrinsic::ID IntID) {
-  switch(IntID) {
-    case llvm::Intrinsic::hexagon_A2_addh_l16_sat_ll:
-      return true;
-    default:
-      break;
-  }
-  return false;
-}
-
-bool HexagonOptimizeSZextends::runOnFunction(Function &F) {
-  if (skipFunction(F))
-    return false;
-
-  unsigned Idx = 1;
-  // Try to optimize sign extends in formal parameters. It's relying on
-  // callee already sign extending the values. I'm not sure if our ABI
-  // requires callee to sign extend though.
-  for (auto &Arg : F.args()) {
-    if (F.getAttributes().hasAttribute(Idx, Attribute::SExt)) {
-      if (!isa<PointerType>(Arg.getType())) {
-        for (auto UI = Arg.use_begin(); UI != Arg.use_end();) {
-          if (isa<SExtInst>(*UI)) {
-            Instruction* Use = cast<Instruction>(*UI);
-            SExtInst* SI = new SExtInst(&Arg, Use->getType());
-            assert (EVT::getEVT(SI->getType()) ==
-                    (EVT::getEVT(Use->getType())));
-            ++UI;
-            Use->replaceAllUsesWith(SI);
-            Instruction* First = &F.getEntryBlock().front();
-            SI->insertBefore(First);
-            Use->eraseFromParent();
-          } else {
-            ++UI;
-          }
-        }
-      }
-    }
-    ++Idx;
-  }
-
-  // Try to remove redundant sext operations on Hexagon. The hardware
-  // already sign extends many 16 bit intrinsic operations to 32 bits.
-  // For example:
-  // %34 = tail call i32 @llvm.hexagon.A2.addh.l16.sat.ll(i32 %x, i32 %y)
-  // %sext233 = shl i32 %34, 16
-  // %conv52 = ashr exact i32 %sext233, 16
-  for (auto &B : F) {
-    for (auto &I : B) {
-      // Look for arithmetic shift right by 16.
-      BinaryOperator *Ashr = dyn_cast<BinaryOperator>(&I);
-      if (!(Ashr && Ashr->getOpcode() == Instruction::AShr))
-        continue;
-      Value *AshrOp1 = Ashr->getOperand(1);
-      ConstantInt *C = dyn_cast<ConstantInt>(AshrOp1);
-      // Right shifted by 16.
-      if (!(C && C->getSExtValue() == 16))
-        continue;
-
-      // The first operand of Ashr comes from logical shift left.
-      Instruction *Shl = dyn_cast<Instruction>(Ashr->getOperand(0));
-      if (!(Shl && Shl->getOpcode() == Instruction::Shl))
-        continue;
-      Value *Intr = Shl->getOperand(0);
-      Value *ShlOp1 = Shl->getOperand(1);
-      C = dyn_cast<ConstantInt>(ShlOp1);
-      // Left shifted by 16.
-      if (!(C && C->getSExtValue() == 16))
-        continue;
-
-      // The first operand of Shl comes from an intrinsic.
-      if (IntrinsicInst *I = dyn_cast<IntrinsicInst>(Intr)) {
-        if (!intrinsicAlreadySextended(I->getIntrinsicID()))
-          continue;
-        // All is well. Replace all uses of AShr with I.
-        for (auto UI = Ashr->user_begin(), UE = Ashr->user_end();
-             UI != UE; ++UI) {
-          const Use &TheUse = UI.getUse();
-          if (Instruction *J = dyn_cast<Instruction>(TheUse.getUser())) {
-            J->replaceUsesOfWith(Ashr, I);
-          }
-        }
-      }
-    }
-  }
-
-  return true;
-}
-
-
-FunctionPass *llvm::createHexagonOptimizeSZextends() {
-  return new HexagonOptimizeSZextends();
-}