+/// \brief Add a stack map intrinsic call's live variable operands to a stackmap
+/// or patchpoint target node's operand list.
+///
+/// Constants are converted to TargetConstants purely as an optimization to
+/// avoid constant materialization and register allocation.
+///
+/// FrameIndex operands are converted to TargetFrameIndex so that ISEL does not
+/// generate addess computation nodes, and so ExpandISelPseudo can convert the
+/// TargetFrameIndex into a DirectMemRefOp StackMap location. This avoids
+/// address materialization and register allocation, but may also be required
+/// for correctness. If a StackMap (or PatchPoint) intrinsic directly uses an
+/// alloca in the entry block, then the runtime may assume that the alloca's
+/// StackMap location can be read immediately after compilation and that the
+/// location is valid at any point during execution (this is similar to the
+/// assumption made by the llvm.gcroot intrinsic). If the alloca's location were
+/// only available in a register, then the runtime would need to trap when
+/// execution reaches the StackMap in order to read the alloca's location.
+static void addStackMapLiveVars(const CallInst &CI, unsigned StartIdx,
+ SmallVectorImpl<SDValue> &Ops,
+ SelectionDAGBuilder &Builder) {
+ for (unsigned i = StartIdx, e = CI.getNumArgOperands(); i != e; ++i) {
+ SDValue OpVal = Builder.getValue(CI.getArgOperand(i));
+ if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(OpVal)) {
+ Ops.push_back(
+ Builder.DAG.getTargetConstant(StackMaps::ConstantOp, MVT::i64));
+ Ops.push_back(
+ Builder.DAG.getTargetConstant(C->getSExtValue(), MVT::i64));
+ } else if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(OpVal)) {
+ const TargetLowering &TLI = Builder.DAG.getTargetLoweringInfo();
+ Ops.push_back(
+ Builder.DAG.getTargetFrameIndex(FI->getIndex(), TLI.getPointerTy()));
+ } else
+ Ops.push_back(OpVal);
+ }
+}
+