explain that r12 is the stack pointer reg
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25336 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/IA64/IA64ISelDAGToDAG.cpp b/lib/Target/IA64/IA64ISelDAGToDAG.cpp
index f8827ea..f819465 100644
--- a/lib/Target/IA64/IA64ISelDAGToDAG.cpp
+++ b/lib/Target/IA64/IA64ISelDAGToDAG.cpp
@@ -450,37 +450,6 @@
case ISD::SREM:
case ISD::UREM: return SelectDIV(Op);
- case ISD::DYNAMIC_STACKALLOC: {
- if (!isa<ConstantSDNode>(N->getOperand(2)) ||
- cast<ConstantSDNode>(N->getOperand(2))->getValue() != 0) {
- std::cerr << "Cannot allocate stack object with greater alignment than"
- << " the stack alignment yet!";
- abort();
- }
-
- SDOperand Chain = Select(N->getOperand(0));
- SDOperand Amt = Select(N->getOperand(1));
- SDOperand Reg = CurDAG->getRegister(IA64::r12, MVT::i64);
- SDOperand Val = CurDAG->getCopyFromReg(Chain, IA64::r12, MVT::i64);
- Chain = Val.getValue(1);
-
- // Subtract the amount (guaranteed to be a multiple of the stack alignment)
- // from the stack pointer, giving us the result pointer.
- SDOperand Result = Select(CurDAG->getNode(ISD::SUB, MVT::i64, Val, Amt));
-
- // Copy this result back into r12.
- Chain = CurDAG->getNode(ISD::CopyToReg, MVT::Other, Chain, Reg, Result);
-
- // Copy this result back out of r12 to make sure we're not using the stack
- // space without decrementing the stack pointer.
- Result = CurDAG->getCopyFromReg(Chain, IA64::r12, MVT::i64);
-
- // Finally, replace the DYNAMIC_STACKALLOC with the copyfromreg.
- CodeGenMap[Op.getValue(0)] = Result;
- CodeGenMap[Op.getValue(1)] = Result.getValue(1);
- return SDOperand(Result.Val, Op.ResNo);
- }
-
case ISD::ConstantFP: {
SDOperand Chain = CurDAG->getEntryNode(); // this is a constant, so..
@@ -501,7 +470,8 @@
CurDAG->getTargetFrameIndex(FI, MVT::i64));
}
- case ISD::ConstantPool: {
+ case ISD::ConstantPool: { // TODO: nuke the constant pool
+ // (ia64 doesn't need one)
Constant *C = cast<ConstantPoolSDNode>(N)->get();
SDOperand CPI = CurDAG->getTargetConstantPool(C, MVT::i64);
return CurDAG->getTargetNode(IA64::ADDL_GA, MVT::i64, // ?