Add the PPC lfiwax instruction
This instruction is available on modern PPC64 CPUs, and is now used
to improve the SINT_TO_FP lowering (by eliminating the need for the
separate sign extension instruction and decreasing the amount of
needed stack space).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178446 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index bf31029..1226921 100644
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -4809,20 +4809,43 @@
// then lfd it and fcfid it.
MachineFunction &MF = DAG.getMachineFunction();
MachineFrameInfo *FrameInfo = MF.getFrameInfo();
- int FrameIdx = FrameInfo->CreateStackObject(8, 8, false);
EVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy();
- SDValue FIdx = DAG.getFrameIndex(FrameIdx, PtrVT);
- SDValue Ext64 = DAG.getNode(ISD::SIGN_EXTEND, dl, MVT::i64,
- Op.getOperand(0));
+ SDValue Ld;
+ if (PPCSubTarget.hasLFIWAX()) {
+ int FrameIdx = FrameInfo->CreateStackObject(4, 4, false);
+ SDValue FIdx = DAG.getFrameIndex(FrameIdx, PtrVT);
- // STD the extended value into the stack slot.
- SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, Ext64, FIdx,
- MachinePointerInfo(), false, false, 0);
+ SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, Op.getOperand(0), FIdx,
+ MachinePointerInfo::getFixedStack(FrameIdx),
+ false, false, 0);
- // Load the value as a double.
- SDValue Ld = DAG.getLoad(MVT::f64, dl, Store, FIdx, MachinePointerInfo(),
- false, false, false, 0);
+ assert(cast<StoreSDNode>(Store)->getMemoryVT() == MVT::i32 &&
+ "Expected an i32 store");
+ MachineMemOperand *MMO =
+ MF.getMachineMemOperand(MachinePointerInfo::getFixedStack(FrameIdx),
+ MachineMemOperand::MOLoad, 4, 4);
+ SDValue Ops[] = { Store, FIdx };
+ Ld = DAG.getMemIntrinsicNode(PPCISD::LFIWAX, dl,
+ DAG.getVTList(MVT::f64, MVT::Other), Ops, 2,
+ MVT::i32, MMO);
+ } else {
+ int FrameIdx = FrameInfo->CreateStackObject(8, 8, false);
+ SDValue FIdx = DAG.getFrameIndex(FrameIdx, PtrVT);
+
+ SDValue Ext64 = DAG.getNode(ISD::SIGN_EXTEND, dl, MVT::i64,
+ Op.getOperand(0));
+
+ // STD the extended value into the stack slot.
+ SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, Ext64, FIdx,
+ MachinePointerInfo::getFixedStack(FrameIdx),
+ false, false, 0);
+
+ // Load the value as a double.
+ Ld = DAG.getLoad(MVT::f64, dl, Store, FIdx,
+ MachinePointerInfo::getFixedStack(FrameIdx),
+ false, false, false, 0);
+ }
// FCFID it and return it.
SDValue FP = DAG.getNode(PPCISD::FCFID, dl, MVT::f64, Ld);