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, 36 insertions, 0 deletions

diff --git a/lib/VMCore/Verifier.cpp b/lib/VMCore/Verifier.cpp
index 9ec2edf..905e9a2 100644
--- a/lib/VMCore/Verifier.cpp
+++ b/lib/VMCore/Verifier.cpp
@@ -288,6 +288,8 @@ namespace {
     void visitUserOp1(Instruction &I);
     void visitUserOp2(Instruction &I) { visitUserOp1(I); }
     void visitIntrinsicFunctionCall(Intrinsic::ID ID, CallInst &CI);
+    void visitAtomicCmpXchgInst(AtomicCmpXchgInst &CXI);
+    void visitAtomicRMWInst(AtomicRMWInst &RMWI);
     void visitFenceInst(FenceInst &FI);
     void visitAllocaInst(AllocaInst &AI);
     void visitExtractValueInst(ExtractValueInst &EVI);
@@ -1327,6 +1329,40 @@ void Verifier::visitAllocaInst(AllocaInst &AI) {
   visitInstruction(AI);
 }
 
+void Verifier::visitAtomicCmpXchgInst(AtomicCmpXchgInst &CXI) {
+  Assert1(CXI.getOrdering() != NotAtomic,
+          "cmpxchg instructions must be atomic.", &CXI);
+  Assert1(CXI.getOrdering() != Unordered,
+          "cmpxchg instructions cannot be unordered.", &CXI);
+  PointerType *PTy = dyn_cast<PointerType>(CXI.getOperand(0)->getType());
+  Assert1(PTy, "First cmpxchg operand must be a pointer.", &CXI);
+  Type *ElTy = PTy->getElementType();
+  Assert2(ElTy == CXI.getOperand(1)->getType(),
+          "Expected value type does not match pointer operand type!",
+          &CXI, ElTy);
+  Assert2(ElTy == CXI.getOperand(2)->getType(),
+          "Stored value type does not match pointer operand type!",
+          &CXI, ElTy);
+  visitInstruction(CXI);
+}
+
+void Verifier::visitAtomicRMWInst(AtomicRMWInst &RMWI) {
+  Assert1(RMWI.getOrdering() != NotAtomic,
+          "atomicrmw instructions must be atomic.", &RMWI);
+  Assert1(RMWI.getOrdering() != Unordered,
+          "atomicrmw instructions cannot be unordered.", &RMWI);
+  PointerType *PTy = dyn_cast<PointerType>(RMWI.getOperand(0)->getType());
+  Assert1(PTy, "First atomicrmw operand must be a pointer.", &RMWI);
+  Type *ElTy = PTy->getElementType();
+  Assert2(ElTy == RMWI.getOperand(1)->getType(),
+          "Argument value type does not match pointer operand type!",
+          &RMWI, ElTy);
+  Assert1(AtomicRMWInst::FIRST_BINOP <= RMWI.getOperation() &&
+          RMWI.getOperation() <= AtomicRMWInst::LAST_BINOP,
+          "Invalid binary operation!", &RMWI);
+  visitInstruction(RMWI);
+}
+
 void Verifier::visitFenceInst(FenceInst &FI) {
   const AtomicOrdering Ordering = FI.getOrdering();
   Assert1(Ordering == Acquire || Ordering == Release ||