Merge "Update prebuilt Clang to r353983." into p9.0HEADp9.0-backupp9.0

1 files changed, 458 insertions, 0 deletions

diff --git a/clang-r353983/include/llvm/IR/Statepoint.h b/clang-r353983/include/llvm/IR/Statepoint.h
new file mode 100644
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+++ b/clang-r353983/include/llvm/IR/Statepoint.h
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+//===- llvm/IR/Statepoint.h - gc.statepoint utilities -----------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains utility functions and a wrapper class analogous to
+// CallBase for accessing the fields of gc.statepoint, gc.relocate,
+// gc.result intrinsics; and some general utilities helpful when dealing with
+// gc.statepoint.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_IR_STATEPOINT_H
+#define LLVM_IR_STATEPOINT_H
+
+#include "llvm/ADT/Optional.h"
+#include "llvm/ADT/iterator_range.h"
+#include "llvm/IR/Attributes.h"
+#include "llvm/IR/BasicBlock.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/Instruction.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Intrinsics.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/MathExtras.h"
+#include <cassert>
+#include <cstddef>
+#include <cstdint>
+#include <vector>
+
+namespace llvm {
+
+/// The statepoint intrinsic accepts a set of flags as its third argument.
+/// Valid values come out of this set.
+enum class StatepointFlags {
+  None = 0,
+  GCTransition = 1, ///< Indicates that this statepoint is a transition from
+                    ///< GC-aware code to code that is not GC-aware.
+  /// Mark the deopt arguments associated with the statepoint as only being
+  /// "live-in". By default, deopt arguments are "live-through".  "live-through"
+  /// requires that they the value be live on entry, on exit, and at any point
+  /// during the call.  "live-in" only requires the value be available at the
+  /// start of the call.  In particular, "live-in" values can be placed in
+  /// unused argument registers or other non-callee saved registers.
+  DeoptLiveIn = 2,
+
+  MaskAll = 3 ///< A bitmask that includes all valid flags.
+};
+
+class GCRelocateInst;
+class GCResultInst;
+
+bool isStatepoint(const CallBase *Call);
+bool isStatepoint(const Value *V);
+bool isStatepoint(const Value &V);
+
+bool isGCRelocate(const CallBase *Call);
+bool isGCRelocate(const Value *V);
+
+bool isGCResult(const CallBase *Call);
+bool isGCResult(const Value *V);
+
+/// A wrapper around a GC intrinsic call, this provides most of the actual
+/// functionality for Statepoint and ImmutableStatepoint.  It is
+/// templatized to allow easily specializing of const and non-const
+/// concrete subtypes.
+template <typename FunTy, typename InstructionTy, typename ValueTy,
+          typename CallBaseTy>
+class StatepointBase {
+  CallBaseTy *StatepointCall;
+
+protected:
+  explicit StatepointBase(InstructionTy *I) {
+    if (isStatepoint(I)) {
+      StatepointCall = cast<CallBaseTy>(I);
+    }
+  }
+
+  explicit StatepointBase(CallBaseTy *Call) {
+    if (isStatepoint(Call))
+      StatepointCall = Call;
+  }
+
+public:
+  using arg_iterator = typename CallBaseTy::const_op_iterator;
+
+  enum {
+    IDPos = 0,
+    NumPatchBytesPos = 1,
+    CalledFunctionPos = 2,
+    NumCallArgsPos = 3,
+    FlagsPos = 4,
+    CallArgsBeginPos = 5,
+  };
+
+  void *operator new(size_t, unsigned) = delete;
+  void *operator new(size_t s) = delete;
+
+  explicit operator bool() const {
+    // We do not assign non-statepoint call instructions to StatepointCall.
+    return (bool)StatepointCall;
+  }
+
+  /// Return the underlying call instruction.
+  CallBaseTy *getCall() const {
+    assert(*this && "check validity first!");
+    return StatepointCall;
+  }
+
+  uint64_t getFlags() const {
+    return cast<ConstantInt>(getCall()->getArgOperand(FlagsPos))
+        ->getZExtValue();
+  }
+
+  /// Return the ID associated with this statepoint.
+  uint64_t getID() const {
+    const Value *IDVal = getCall()->getArgOperand(IDPos);
+    return cast<ConstantInt>(IDVal)->getZExtValue();
+  }
+
+  /// Return the number of patchable bytes associated with this statepoint.
+  uint32_t getNumPatchBytes() const {
+    const Value *NumPatchBytesVal = getCall()->getArgOperand(NumPatchBytesPos);
+    uint64_t NumPatchBytes =
+      cast<ConstantInt>(NumPatchBytesVal)->getZExtValue();
+    assert(isInt<32>(NumPatchBytes) && "should fit in 32 bits!");
+    return NumPatchBytes;
+  }
+
+  /// Return the value actually being called or invoked.
+  ValueTy *getCalledValue() const {
+    return getCall()->getArgOperand(CalledFunctionPos);
+  }
+
+  // FIXME: Migrate users of this to `getCall` and remove it.
+  InstructionTy *getInstruction() const { return getCall(); }
+
+  /// Return the function being called if this is a direct call, otherwise
+  /// return null (if it's an indirect call).
+  FunTy *getCalledFunction() const {
+    return dyn_cast<Function>(getCalledValue());
+  }
+
+  /// Return the caller function for this statepoint.
+  FunTy *getCaller() const { return getCall()->getCaller(); }
+
+  /// Determine if the statepoint cannot unwind.
+  bool doesNotThrow() const {
+    Function *F = getCalledFunction();
+    return getCall()->doesNotThrow() || (F ? F->doesNotThrow() : false);
+  }
+
+  /// Return the type of the value returned by the call underlying the
+  /// statepoint.
+  Type *getActualReturnType() const {
+    auto *FTy = cast<FunctionType>(
+        cast<PointerType>(getCalledValue()->getType())->getElementType());
+    return FTy->getReturnType();
+  }
+
+  /// Number of arguments to be passed to the actual callee.
+  int getNumCallArgs() const {
+    const Value *NumCallArgsVal = getCall()->getArgOperand(NumCallArgsPos);
+    return cast<ConstantInt>(NumCallArgsVal)->getZExtValue();
+  }
+
+  size_t arg_size() const { return getNumCallArgs(); }
+  arg_iterator arg_begin() const {
+    assert(CallArgsBeginPos <= (int)getCall()->arg_size());
+    return getCall()->arg_begin() + CallArgsBeginPos;
+  }
+  arg_iterator arg_end() const {
+    auto I = arg_begin() + arg_size();
+    assert((getCall()->arg_end() - I) >= 0);
+    return I;
+  }
+
+  ValueTy *getArgument(unsigned Index) {
+    assert(Index < arg_size() && "out of bounds!");
+    return *(arg_begin() + Index);
+  }
+
+  /// range adapter for call arguments
+  iterator_range<arg_iterator> call_args() const {
+    return make_range(arg_begin(), arg_end());
+  }
+
+  /// Return true if the call or the callee has the given attribute.
+  bool paramHasAttr(unsigned i, Attribute::AttrKind A) const {
+    Function *F = getCalledFunction();
+    return getCall()->paramHasAttr(i + CallArgsBeginPos, A) ||
+           (F ? F->getAttributes().hasAttribute(i, A) : false);
+  }
+
+  /// Number of GC transition args.
+  int getNumTotalGCTransitionArgs() const {
+    const Value *NumGCTransitionArgs = *arg_end();
+    return cast<ConstantInt>(NumGCTransitionArgs)->getZExtValue();
+  }
+  arg_iterator gc_transition_args_begin() const {
+    auto I = arg_end() + 1;
+    assert((getCall()->arg_end() - I) >= 0);
+    return I;
+  }
+  arg_iterator gc_transition_args_end() const {
+    auto I = gc_transition_args_begin() + getNumTotalGCTransitionArgs();
+    assert((getCall()->arg_end() - I) >= 0);
+    return I;
+  }
+
+  /// range adapter for GC transition arguments
+  iterator_range<arg_iterator> gc_transition_args() const {
+    return make_range(gc_transition_args_begin(), gc_transition_args_end());
+  }
+
+  /// Number of additional arguments excluding those intended
+  /// for garbage collection.
+  int getNumTotalVMSArgs() const {
+    const Value *NumVMSArgs = *gc_transition_args_end();
+    return cast<ConstantInt>(NumVMSArgs)->getZExtValue();
+  }
+
+  arg_iterator deopt_begin() const {
+    auto I = gc_transition_args_end() + 1;
+    assert((getCall()->arg_end() - I) >= 0);
+    return I;
+  }
+  arg_iterator deopt_end() const {
+    auto I = deopt_begin() + getNumTotalVMSArgs();
+    assert((getCall()->arg_end() - I) >= 0);
+    return I;
+  }
+
+  /// range adapter for vm state arguments
+  iterator_range<arg_iterator> deopt_operands() const {
+    return make_range(deopt_begin(), deopt_end());
+  }
+
+  arg_iterator gc_args_begin() const { return deopt_end(); }
+  arg_iterator gc_args_end() const { return getCall()->arg_end(); }
+
+  unsigned gcArgsStartIdx() const {
+    return gc_args_begin() - getCall()->op_begin();
+  }
+
+  /// range adapter for gc arguments
+  iterator_range<arg_iterator> gc_args() const {
+    return make_range(gc_args_begin(), gc_args_end());
+  }
+
+  /// Get list of all gc reloactes linked to this statepoint
+  /// May contain several relocations for the same base/derived pair.
+  /// For example this could happen due to relocations on unwinding
+  /// path of invoke.
+  std::vector<const GCRelocateInst *> getRelocates() const;
+
+  /// Get the experimental_gc_result call tied to this statepoint.  Can be
+  /// nullptr if there isn't a gc_result tied to this statepoint.  Guaranteed to
+  /// be a CallInst if non-null.
+  const GCResultInst *getGCResult() const {
+    for (auto *U : getInstruction()->users())
+      if (auto *GRI = dyn_cast<GCResultInst>(U))
+        return GRI;
+    return nullptr;
+  }
+
+#ifndef NDEBUG
+  /// Asserts if this statepoint is malformed.  Common cases for failure
+  /// include incorrect length prefixes for variable length sections or
+  /// illegal values for parameters.
+  void verify() {
+    assert(getNumCallArgs() >= 0 &&
+           "number of arguments to actually callee can't be negative");
+
+    // The internal asserts in the iterator accessors do the rest.
+    (void)arg_begin();
+    (void)arg_end();
+    (void)gc_transition_args_begin();
+    (void)gc_transition_args_end();
+    (void)deopt_begin();
+    (void)deopt_end();
+    (void)gc_args_begin();
+    (void)gc_args_end();
+  }
+#endif
+};
+
+/// A specialization of it's base class for read only access
+/// to a gc.statepoint.
+class ImmutableStatepoint
+    : public StatepointBase<const Function, const Instruction, const Value,
+                            const CallBase> {
+  using Base = StatepointBase<const Function, const Instruction, const Value,
+                              const CallBase>;
+
+public:
+  explicit ImmutableStatepoint(const Instruction *I) : Base(I) {}
+  explicit ImmutableStatepoint(const CallBase *Call) : Base(Call) {}
+};
+
+/// A specialization of it's base class for read-write access
+/// to a gc.statepoint.
+class Statepoint
+    : public StatepointBase<Function, Instruction, Value, CallBase> {
+  using Base = StatepointBase<Function, Instruction, Value, CallBase>;
+
+public:
+  explicit Statepoint(Instruction *I) : Base(I) {}
+  explicit Statepoint(CallBase *Call) : Base(Call) {}
+};
+
+/// Common base class for representing values projected from a statepoint.
+/// Currently, the only projections available are gc.result and gc.relocate.
+class GCProjectionInst : public IntrinsicInst {
+public:
+  static bool classof(const IntrinsicInst *I) {
+    return I->getIntrinsicID() == Intrinsic::experimental_gc_relocate ||
+      I->getIntrinsicID() == Intrinsic::experimental_gc_result;
+  }
+
+  static bool classof(const Value *V) {
+    return isa<IntrinsicInst>(V) && classof(cast<IntrinsicInst>(V));
+  }
+
+  /// Return true if this relocate is tied to the invoke statepoint.
+  /// This includes relocates which are on the unwinding path.
+  bool isTiedToInvoke() const {
+    const Value *Token = getArgOperand(0);
+
+    return isa<LandingPadInst>(Token) || isa<InvokeInst>(Token);
+  }
+
+  /// The statepoint with which this gc.relocate is associated.
+  const CallBase *getStatepoint() const {
+    const Value *Token = getArgOperand(0);
+
+    // This takes care both of relocates for call statepoints and relocates
+    // on normal path of invoke statepoint.
+    if (!isa<LandingPadInst>(Token)) {
+      assert(isStatepoint(Token));
+      return cast<CallBase>(Token);
+    }
+
+    // This relocate is on exceptional path of an invoke statepoint
+    const BasicBlock *InvokeBB =
+        cast<Instruction>(Token)->getParent()->getUniquePredecessor();
+
+    assert(InvokeBB && "safepoints should have unique landingpads");
+    assert(InvokeBB->getTerminator() &&
+           "safepoint block should be well formed");
+    assert(isStatepoint(InvokeBB->getTerminator()));
+
+    return cast<CallBase>(InvokeBB->getTerminator());
+  }
+};
+
+/// Represents calls to the gc.relocate intrinsic.
+class GCRelocateInst : public GCProjectionInst {
+public:
+  static bool classof(const IntrinsicInst *I) {
+    return I->getIntrinsicID() == Intrinsic::experimental_gc_relocate;
+  }
+
+  static bool classof(const Value *V) {
+    return isa<IntrinsicInst>(V) && classof(cast<IntrinsicInst>(V));
+  }
+
+  /// The index into the associate statepoint's argument list
+  /// which contains the base pointer of the pointer whose
+  /// relocation this gc.relocate describes.
+  unsigned getBasePtrIndex() const {
+    return cast<ConstantInt>(getArgOperand(1))->getZExtValue();
+  }
+
+  /// The index into the associate statepoint's argument list which
+  /// contains the pointer whose relocation this gc.relocate describes.
+  unsigned getDerivedPtrIndex() const {
+    return cast<ConstantInt>(getArgOperand(2))->getZExtValue();
+  }
+
+  Value *getBasePtr() const {
+    return *(getStatepoint()->arg_begin() + getBasePtrIndex());
+  }
+
+  Value *getDerivedPtr() const {
+    return *(getStatepoint()->arg_begin() + getDerivedPtrIndex());
+  }
+};
+
+/// Represents calls to the gc.result intrinsic.
+class GCResultInst : public GCProjectionInst {
+public:
+  static bool classof(const IntrinsicInst *I) {
+    return I->getIntrinsicID() == Intrinsic::experimental_gc_result;
+  }
+
+  static bool classof(const Value *V) {
+    return isa<IntrinsicInst>(V) && classof(cast<IntrinsicInst>(V));
+  }
+};
+
+template <typename FunTy, typename InstructionTy, typename ValueTy,
+          typename CallBaseTy>
+std::vector<const GCRelocateInst *>
+StatepointBase<FunTy, InstructionTy, ValueTy, CallBaseTy>::getRelocates()
+    const {
+  std::vector<const GCRelocateInst *> Result;
+
+  // Search for relocated pointers.  Note that working backwards from the
+  // gc_relocates ensures that we only get pairs which are actually relocated
+  // and used after the statepoint.
+  for (const User *U : StatepointCall->users())
+    if (auto *Relocate = dyn_cast<GCRelocateInst>(U))
+      Result.push_back(Relocate);
+
+  auto *StatepointInvoke = dyn_cast<InvokeInst>(StatepointCall);
+  if (!StatepointInvoke)
+    return Result;
+
+  // We need to scan thorough exceptional relocations if it is invoke statepoint
+  LandingPadInst *LandingPad = StatepointInvoke->getLandingPadInst();
+
+  // Search for gc relocates that are attached to this landingpad.
+  for (const User *LandingPadUser : LandingPad->users()) {
+    if (auto *Relocate = dyn_cast<GCRelocateInst>(LandingPadUser))
+      Result.push_back(Relocate);
+  }
+  return Result;
+}
+
+/// Call sites that get wrapped by a gc.statepoint (currently only in
+/// RewriteStatepointsForGC and potentially in other passes in the future) can
+/// have attributes that describe properties of gc.statepoint call they will be
+/// eventually be wrapped in.  This struct is used represent such directives.
+struct StatepointDirectives {
+  Optional<uint32_t> NumPatchBytes;
+  Optional<uint64_t> StatepointID;
+
+  static const uint64_t DefaultStatepointID = 0xABCDEF00;
+  static const uint64_t DeoptBundleStatepointID = 0xABCDEF0F;
+};
+
+/// Parse out statepoint directives from the function attributes present in \p
+/// AS.
+StatepointDirectives parseStatepointDirectivesFromAttrs(AttributeList AS);
+
+/// Return \c true if the \p Attr is an attribute that is a statepoint
+/// directive.
+bool isStatepointDirectiveAttr(Attribute Attr);
+
+} // end namespace llvm
+
+#endif // LLVM_IR_STATEPOINT_H