1 files changed, 0 insertions, 283 deletions
diff --git a/contrib/llvm/lib/Target/X86/X86AtomicExpandPass.cpp b/contrib/llvm/lib/Target/X86/X86AtomicExpandPass.cpp
deleted file mode 100644
index 3dcadb1..0000000
--- a/contrib/llvm/lib/Target/X86/X86AtomicExpandPass.cpp
+++ /dev/null
@@ -1,283 +0,0 @@
-//===-- X86AtomicExpandPass.cpp - Expand illegal atomic instructions --0---===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file contains a pass (at IR level) to replace atomic instructions which
-// cannot be implemented as a single instruction with cmpxchg-based loops.
-//
-//===----------------------------------------------------------------------===//
-
-#include "X86.h"
-#include "X86TargetMachine.h"
-#include "llvm/CodeGen/Passes.h"
-#include "llvm/IR/Function.h"
-#include "llvm/IR/IRBuilder.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/Intrinsics.h"
-#include "llvm/IR/Module.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Target/TargetLowering.h"
-#include "llvm/Target/TargetMachine.h"
-using namespace llvm;
-
-#define DEBUG_TYPE "x86-atomic-expand"
-
-namespace {
-  class X86AtomicExpandPass : public FunctionPass {
-    const X86TargetMachine *TM;
-  public:
-    static char ID; // Pass identification, replacement for typeid
-    explicit X86AtomicExpandPass(const X86TargetMachine *TM)
-      : FunctionPass(ID), TM(TM) {}
-
-    bool runOnFunction(Function &F) override;
-    bool expandAtomicInsts(Function &F);
-
-    bool needsCmpXchgNb(Type *MemType);
-
-    /// There are four kinds of atomic operations. Two never need expanding:
-    /// cmpxchg is what we expand the others *to*, and loads are easily handled
-    /// by ISelLowering. Atomicrmw and store can need expanding in some
-    /// circumstances.
-    bool shouldExpand(Instruction *Inst);
-
-    /// 128-bit atomic stores (64-bit on i686) need to be implemented in terms
-    /// of trivial cmpxchg16b loops. A simple store isn't necessarily atomic.
-    bool shouldExpandStore(StoreInst *SI);
-
-    /// Only some atomicrmw instructions need expanding -- some operations
-    /// (e.g. max) have absolutely no architectural support; some (e.g. or) have
-    /// limited support but can't return the previous value; some (e.g. add)
-    /// have complete support in the instruction set.
-    ///
-    /// Also, naturally, 128-bit operations always need to be expanded.
-    bool shouldExpandAtomicRMW(AtomicRMWInst *AI);
-
-    bool expandAtomicRMW(AtomicRMWInst *AI);
-    bool expandAtomicStore(StoreInst *SI);
-  };
-}
-
-char X86AtomicExpandPass::ID = 0;
-
-FunctionPass *llvm::createX86AtomicExpandPass(const X86TargetMachine *TM) {
-  return new X86AtomicExpandPass(TM);
-}
-
-bool X86AtomicExpandPass::runOnFunction(Function &F) {
-  SmallVector<Instruction *, 1> AtomicInsts;
-
-  // Changing control-flow while iterating through it is a bad idea, so gather a
-  // list of all atomic instructions before we start.
-  for (BasicBlock &BB : F)
-    for (Instruction &Inst : BB) {
-      if (isa<AtomicRMWInst>(&Inst) ||
-          (isa<StoreInst>(&Inst) && cast<StoreInst>(&Inst)->isAtomic()))
-        AtomicInsts.push_back(&Inst);
-    }
-
-  bool MadeChange = false;
-  for (Instruction *Inst : AtomicInsts) {
-    if (!shouldExpand(Inst))
-      continue;
-
-    if (AtomicRMWInst *AI = dyn_cast<AtomicRMWInst>(Inst))
-      MadeChange |= expandAtomicRMW(AI);
-    if (StoreInst *SI = dyn_cast<StoreInst>(Inst))
-      MadeChange |= expandAtomicStore(SI);
-
-    assert(MadeChange && "Atomic inst not expanded when it should be?");
-    Inst->eraseFromParent();
-  }
-
-  return MadeChange;
-}
-
-/// Returns true if the operand type is 1 step up from the native width, and
-/// the corresponding cmpxchg8b or cmpxchg16b instruction is available
-/// (otherwise we leave them alone to become __sync_fetch_and_... calls).
-bool X86AtomicExpandPass::needsCmpXchgNb(llvm::Type *MemType) {
-  const X86Subtarget &Subtarget = TM->getSubtarget<X86Subtarget>();
-  unsigned OpWidth = MemType->getPrimitiveSizeInBits();
-
-  if (OpWidth == 64)
-    return !Subtarget.is64Bit();  // FIXME this should be Subtarget.hasCmpxchg8b
-  if (OpWidth == 128)
-    return Subtarget.hasCmpxchg16b();
-
-  return false;
-}
-
-bool X86AtomicExpandPass::shouldExpandAtomicRMW(AtomicRMWInst *AI) {
-  const X86Subtarget &Subtarget = TM->getSubtarget<X86Subtarget>();
-  unsigned NativeWidth = Subtarget.is64Bit() ? 64 : 32;
-
-  if (needsCmpXchgNb(AI->getType()))
-    return true;
-
-  if (AI->getType()->getPrimitiveSizeInBits() > NativeWidth)
-    return false;
-
-  AtomicRMWInst::BinOp Op = AI->getOperation();
-  switch (Op) {
-  default:
-    llvm_unreachable("Unknown atomic operation");
-  case AtomicRMWInst::Xchg:
-  case AtomicRMWInst::Add:
-  case AtomicRMWInst::Sub:
-    // It's better to use xadd, xsub or xchg for these in all cases.
-    return false;
-  case AtomicRMWInst::Or:
-  case AtomicRMWInst::And:
-  case AtomicRMWInst::Xor:
-    // If the atomicrmw's result isn't actually used, we can just add a "lock"
-    // prefix to a normal instruction for these operations.
-    return !AI->use_empty();
-  case AtomicRMWInst::Nand:
-  case AtomicRMWInst::Max:
-  case AtomicRMWInst::Min:
-  case AtomicRMWInst::UMax:
-  case AtomicRMWInst::UMin:
-    // These always require a non-trivial set of data operations on x86. We must
-    // use a cmpxchg loop.
-    return true;
-  }
-}
-
-bool X86AtomicExpandPass::shouldExpandStore(StoreInst *SI) {
-  if (needsCmpXchgNb(SI->getValueOperand()->getType()))
-    return true;
-
-  return false;
-}
-
-bool X86AtomicExpandPass::shouldExpand(Instruction *Inst) {
-  if (AtomicRMWInst *AI = dyn_cast<AtomicRMWInst>(Inst))
-    return shouldExpandAtomicRMW(AI);
-  if (StoreInst *SI = dyn_cast<StoreInst>(Inst))
-    return shouldExpandStore(SI);
-  return false;
-}
-
-/// Emit IR to implement the given atomicrmw operation on values in registers,
-/// returning the new value.
-static Value *performAtomicOp(AtomicRMWInst::BinOp Op, IRBuilder<> &Builder,
-                              Value *Loaded, Value *Inc) {
-  Value *NewVal;
-  switch (Op) {
-  case AtomicRMWInst::Xchg:
-    return Inc;
-  case AtomicRMWInst::Add:
-    return Builder.CreateAdd(Loaded, Inc, "new");
-  case AtomicRMWInst::Sub:
-    return Builder.CreateSub(Loaded, Inc, "new");
-  case AtomicRMWInst::And:
-    return Builder.CreateAnd(Loaded, Inc, "new");
-  case AtomicRMWInst::Nand:
-    return Builder.CreateNot(Builder.CreateAnd(Loaded, Inc), "new");
-  case AtomicRMWInst::Or:
-    return Builder.CreateOr(Loaded, Inc, "new");
-  case AtomicRMWInst::Xor:
-    return Builder.CreateXor(Loaded, Inc, "new");
-  case AtomicRMWInst::Max:
-    NewVal = Builder.CreateICmpSGT(Loaded, Inc);
-    return Builder.CreateSelect(NewVal, Loaded, Inc, "new");
-  case AtomicRMWInst::Min:
-    NewVal = Builder.CreateICmpSLE(Loaded, Inc);
-    return Builder.CreateSelect(NewVal, Loaded, Inc, "new");
-  case AtomicRMWInst::UMax:
-    NewVal = Builder.CreateICmpUGT(Loaded, Inc);
-    return  Builder.CreateSelect(NewVal, Loaded, Inc, "new");
-  case AtomicRMWInst::UMin:
-    NewVal = Builder.CreateICmpULE(Loaded, Inc);
-    return Builder.CreateSelect(NewVal, Loaded, Inc, "new");
-  default:
-    break;
-  }
-  llvm_unreachable("Unknown atomic op");
-}
-
-bool X86AtomicExpandPass::expandAtomicRMW(AtomicRMWInst *AI) {
-  AtomicOrdering Order =
-      AI->getOrdering() == Unordered ? Monotonic : AI->getOrdering();
-  Value *Addr = AI->getPointerOperand();
-  BasicBlock *BB = AI->getParent();
-  Function *F = BB->getParent();
-  LLVMContext &Ctx = F->getContext();
-
-  // Given: atomicrmw some_op iN* %addr, iN %incr ordering
-  //
-  // The standard expansion we produce is:
-  //     [...]
-  //     %init_loaded = load atomic iN* %addr
-  //     br label %loop
-  // loop:
-  //     %loaded = phi iN [ %init_loaded, %entry ], [ %new_loaded, %loop ]
-  //     %new = some_op iN %loaded, %incr
-  //     %pair = cmpxchg iN* %addr, iN %loaded, iN %new
-  //     %new_loaded = extractvalue { iN, i1 } %pair, 0
-  //     %success = extractvalue { iN, i1 } %pair, 1
-  //     br i1 %success, label %atomicrmw.end, label %loop
-  // atomicrmw.end:
-  //     [...]
-  BasicBlock *ExitBB = BB->splitBasicBlock(AI, "atomicrmw.end");
-  BasicBlock *LoopBB =  BasicBlock::Create(Ctx, "atomicrmw.start", F, ExitBB);
-
-  // This grabs the DebugLoc from AI.
-  IRBuilder<> Builder(AI);
-
-  // The split call above "helpfully" added a branch at the end of BB (to the
-  // wrong place), but we want a load. It's easiest to just remove
-  // the branch entirely.
-  std::prev(BB->end())->eraseFromParent();
-  Builder.SetInsertPoint(BB);
-  LoadInst *InitLoaded = Builder.CreateLoad(Addr);
-  InitLoaded->setAlignment(AI->getType()->getPrimitiveSizeInBits());
-  Builder.CreateBr(LoopBB);
-
-  // Start the main loop block now that we've taken care of the preliminaries.
-  Builder.SetInsertPoint(LoopBB);
-  PHINode *Loaded = Builder.CreatePHI(AI->getType(), 2, "loaded");
-  Loaded->addIncoming(InitLoaded, BB);
-
-  Value *NewVal =
-      performAtomicOp(AI->getOperation(), Builder, Loaded, AI->getValOperand());
-
-  Value *Pair = Builder.CreateAtomicCmpXchg(
-      Addr, Loaded, NewVal, Order,
-      AtomicCmpXchgInst::getStrongestFailureOrdering(Order));
-  Value *NewLoaded = Builder.CreateExtractValue(Pair, 0, "newloaded");
-  Loaded->addIncoming(NewLoaded, LoopBB);
-
-  Value *Success = Builder.CreateExtractValue(Pair, 1, "success");
-  Builder.CreateCondBr(Success, ExitBB, LoopBB);
-
-  AI->replaceAllUsesWith(NewLoaded);
-
-  return true;
-}
-
-bool X86AtomicExpandPass::expandAtomicStore(StoreInst *SI) {
-  // An atomic store might need cmpxchg16b (or 8b on x86) to execute. Express
-  // this in terms of the usual expansion to "atomicrmw xchg".
-  IRBuilder<> Builder(SI);
-  AtomicOrdering Order =
-      SI->getOrdering() == Unordered ? Monotonic : SI->getOrdering();
-  AtomicRMWInst *AI =
-      Builder.CreateAtomicRMW(AtomicRMWInst::Xchg, SI->getPointerOperand(),
-                              SI->getValueOperand(), Order);
-
-  // Now we have an appropriate swap instruction, lower it as usual.
-  if (shouldExpandAtomicRMW(AI)) {
-    expandAtomicRMW(AI);
-    AI->eraseFromParent();
-    return true;
-  }
-
-  return AI;
-}