LangRef and basic memory-representation/reading/writing for 'cmpxchg' and

'atomicrmw' instructions, which allow representing all the current atomic
rmw intrinsics.

The allowed operands for these instructions are heavily restricted at the
moment; we can probably loosen it a bit, but supporting general
first-class types (where it makes sense) might get a bit complicated,
given how SelectionDAG works.

As an initial cut, these operations do not support specifying an alignment,
but it would be possible to add if we think it's useful. Specifying an
alignment lower than the natural alignment would be essentially
impossible to support on anything other than x86, but specifying a greater
alignment would be possible.  I can't think of any useful optimizations which
would use that information, but maybe someone else has ideas.

Optimizer/codegen support coming soon.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136404 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 111 insertions, 0 deletions

diff --git a/lib/VMCore/Instructions.cpp b/lib/VMCore/Instructions.cpp
index 9fdff0773a..abee7b741a 100644
--- a/lib/VMCore/Instructions.cpp
+++ b/lib/VMCore/Instructions.cpp
@@ -1106,6 +1106,101 @@ void StoreInst::setAlignment(unsigned Align) {
 }
 
 //===----------------------------------------------------------------------===//
+//                       AtomicCmpXchgInst Implementation
+//===----------------------------------------------------------------------===//
+
+void AtomicCmpXchgInst::Init(Value *Ptr, Value *Cmp, Value *NewVal,
+                             AtomicOrdering Ordering,
+                             SynchronizationScope SynchScope) {
+  Op<0>() = Ptr;
+  Op<1>() = Cmp;
+  Op<2>() = NewVal;
+  setOrdering(Ordering);
+  setSynchScope(SynchScope);
+
+  assert(getOperand(0) && getOperand(1) && getOperand(2) &&
+         "All operands must be non-null!");
+  assert(getOperand(0)->getType()->isPointerTy() &&
+         "Ptr must have pointer type!");
+  assert(getOperand(1)->getType() ==
+                 cast<PointerType>(getOperand(0)->getType())->getElementType()
+         && "Ptr must be a pointer to Cmp type!");
+  assert(getOperand(2)->getType() ==
+                 cast<PointerType>(getOperand(0)->getType())->getElementType()
+         && "Ptr must be a pointer to NewVal type!");
+  assert(Ordering != NotAtomic &&
+         "AtomicCmpXchg instructions must be atomic!");
+}
+
+AtomicCmpXchgInst::AtomicCmpXchgInst(Value *Ptr, Value *Cmp, Value *NewVal,
+                                     AtomicOrdering Ordering,
+                                     SynchronizationScope SynchScope,
+                                     Instruction *InsertBefore)
+  : Instruction(Cmp->getType(), AtomicCmpXchg,
+                OperandTraits<AtomicCmpXchgInst>::op_begin(this),
+                OperandTraits<AtomicCmpXchgInst>::operands(this),
+                InsertBefore) {
+  Init(Ptr, Cmp, NewVal, Ordering, SynchScope);
+}
+
+AtomicCmpXchgInst::AtomicCmpXchgInst(Value *Ptr, Value *Cmp, Value *NewVal,
+                                     AtomicOrdering Ordering,
+                                     SynchronizationScope SynchScope,
+                                     BasicBlock *InsertAtEnd)
+  : Instruction(Cmp->getType(), AtomicCmpXchg,
+                OperandTraits<AtomicCmpXchgInst>::op_begin(this),
+                OperandTraits<AtomicCmpXchgInst>::operands(this),
+                InsertAtEnd) {
+  Init(Ptr, Cmp, NewVal, Ordering, SynchScope);
+}
+ 
+//===----------------------------------------------------------------------===//
+//                       AtomicRMWInst Implementation
+//===----------------------------------------------------------------------===//
+
+void AtomicRMWInst::Init(BinOp Operation, Value *Ptr, Value *Val,
+                         AtomicOrdering Ordering,
+                         SynchronizationScope SynchScope) {
+  Op<0>() = Ptr;
+  Op<1>() = Val;
+  setOperation(Operation);
+  setOrdering(Ordering);
+  setSynchScope(SynchScope);
+
+  assert(getOperand(0) && getOperand(1) &&
+         "All operands must be non-null!");
+  assert(getOperand(0)->getType()->isPointerTy() &&
+         "Ptr must have pointer type!");
+  assert(getOperand(1)->getType() ==
+         cast<PointerType>(getOperand(0)->getType())->getElementType()
+         && "Ptr must be a pointer to Val type!");
+  assert(Ordering != NotAtomic &&
+         "AtomicRMW instructions must be atomic!");
+}
+
+AtomicRMWInst::AtomicRMWInst(BinOp Operation, Value *Ptr, Value *Val,
+                             AtomicOrdering Ordering,
+                             SynchronizationScope SynchScope,
+                             Instruction *InsertBefore)
+  : Instruction(Val->getType(), AtomicRMW,
+                OperandTraits<AtomicRMWInst>::op_begin(this),
+                OperandTraits<AtomicRMWInst>::operands(this),
+                InsertBefore) {
+  Init(Operation, Ptr, Val, Ordering, SynchScope);
+}
+
+AtomicRMWInst::AtomicRMWInst(BinOp Operation, Value *Ptr, Value *Val,
+                             AtomicOrdering Ordering,
+                             SynchronizationScope SynchScope,
+                             BasicBlock *InsertAtEnd)
+  : Instruction(Val->getType(), AtomicRMW,
+                OperandTraits<AtomicRMWInst>::op_begin(this),
+                OperandTraits<AtomicRMWInst>::operands(this),
+                InsertAtEnd) {
+  Init(Operation, Ptr, Val, Ordering, SynchScope);
+}
+
+//===----------------------------------------------------------------------===//
 //                       FenceInst Implementation
 //===----------------------------------------------------------------------===//
 
@@ -3148,6 +3243,22 @@ StoreInst *StoreInst::clone_impl() const {
                        isVolatile(), getAlignment());
 }
 
+AtomicCmpXchgInst *AtomicCmpXchgInst::clone_impl() const {
+  AtomicCmpXchgInst *Result =
+    new AtomicCmpXchgInst(getOperand(0), getOperand(1), getOperand(2),
+                          getOrdering(), getSynchScope());
+  Result->setVolatile(isVolatile());
+  return Result;
+}
+
+AtomicRMWInst *AtomicRMWInst::clone_impl() const {
+  AtomicRMWInst *Result =
+    new AtomicRMWInst(getOperation(),getOperand(0), getOperand(1),
+                      getOrdering(), getSynchScope());
+  Result->setVolatile(isVolatile());
+  return Result;
+}
+
 FenceInst *FenceInst::clone_impl() const {
   return new FenceInst(getContext(), getOrdering(), getSynchScope());
 }