[PowerPC] Make LDtocL and friends invariant loads
LDtocL, and other loads that roughly correspond to the TOC_ENTRY SDAG node,
represent loads from the TOC, which is invariant. As a result, these loads can
be hoisted out of loops, etc. In order to do this, we need to generate
GOT-style MMOs for TOC_ENTRY, which requires treating it as a legitimate memory
intrinsic node type. Once this is done, the MMO transfer is automatically
handled for TableGen-driven instruction selection, and for nodes generated
directly in PPCISelDAGToDAG, we need to transfer the MMOs manually.
Also, we were not transferring MMOs associated with pre-increment loads, so do
that too.
Lastly, this fixes an exposed bug where R30 was not added as a defined operand of
UpdateGBR.
This problem was highlighted by an example (used to generate the test case)
posted to llvmdev by Francois Pichet.
llvm-svn: 230553
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index f59cad5..ae80fa3 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -1821,6 +1821,19 @@
setUsesTOCBasePtr(DAG.getMachineFunction());
}
+static SDValue getTOCEntry(SelectionDAG &DAG, SDLoc dl, bool Is64Bit,
+ SDValue GA) {
+ EVT VT = Is64Bit ? MVT::i64 : MVT::i32;
+ SDValue Reg = Is64Bit ? DAG.getRegister(PPC::X2, VT) :
+ DAG.getNode(PPCISD::GlobalBaseReg, dl, VT);
+
+ SDValue Ops[] = { GA, Reg };
+ return DAG.getMemIntrinsicNode(PPCISD::TOC_ENTRY, dl,
+ DAG.getVTList(VT, MVT::Other), Ops, VT,
+ MachinePointerInfo::getGOT(), 0, false, true,
+ false, 0);
+}
+
SDValue PPCTargetLowering::LowerConstantPool(SDValue Op,
SelectionDAG &DAG) const {
EVT PtrVT = Op.getValueType();
@@ -1832,8 +1845,7 @@
if (Subtarget.isSVR4ABI() && Subtarget.isPPC64()) {
setUsesTOCBasePtr(DAG);
SDValue GA = DAG.getTargetConstantPool(C, PtrVT, CP->getAlignment(), 0);
- return DAG.getNode(PPCISD::TOC_ENTRY, SDLoc(CP), MVT::i64, GA,
- DAG.getRegister(PPC::X2, MVT::i64));
+ return getTOCEntry(DAG, SDLoc(CP), true, GA);
}
unsigned MOHiFlag, MOLoFlag;
@@ -1843,9 +1855,7 @@
if (isPIC && Subtarget.isSVR4ABI()) {
SDValue GA = DAG.getTargetConstantPool(C, PtrVT, CP->getAlignment(),
PPCII::MO_PIC_FLAG);
- SDLoc DL(CP);
- return DAG.getNode(PPCISD::TOC_ENTRY, DL, MVT::i32, GA,
- DAG.getNode(PPCISD::GlobalBaseReg, DL, PtrVT));
+ return getTOCEntry(DAG, SDLoc(CP), false, GA);
}
SDValue CPIHi =
@@ -1864,8 +1874,7 @@
if (Subtarget.isSVR4ABI() && Subtarget.isPPC64()) {
setUsesTOCBasePtr(DAG);
SDValue GA = DAG.getTargetJumpTable(JT->getIndex(), PtrVT);
- return DAG.getNode(PPCISD::TOC_ENTRY, SDLoc(JT), MVT::i64, GA,
- DAG.getRegister(PPC::X2, MVT::i64));
+ return getTOCEntry(DAG, SDLoc(JT), true, GA);
}
unsigned MOHiFlag, MOLoFlag;
@@ -1875,9 +1884,7 @@
if (isPIC && Subtarget.isSVR4ABI()) {
SDValue GA = DAG.getTargetJumpTable(JT->getIndex(), PtrVT,
PPCII::MO_PIC_FLAG);
- SDLoc DL(GA);
- return DAG.getNode(PPCISD::TOC_ENTRY, SDLoc(JT), PtrVT, GA,
- DAG.getNode(PPCISD::GlobalBaseReg, DL, PtrVT));
+ return getTOCEntry(DAG, SDLoc(GA), false, GA);
}
SDValue JTIHi = DAG.getTargetJumpTable(JT->getIndex(), PtrVT, MOHiFlag);
@@ -1896,8 +1903,7 @@
if (Subtarget.isSVR4ABI() && Subtarget.isPPC64()) {
setUsesTOCBasePtr(DAG);
SDValue GA = DAG.getTargetBlockAddress(BA, PtrVT, BASDN->getOffset());
- return DAG.getNode(PPCISD::TOC_ENTRY, SDLoc(BASDN), MVT::i64, GA,
- DAG.getRegister(PPC::X2, MVT::i64));
+ return getTOCEntry(DAG, SDLoc(BASDN), true, GA);
}
unsigned MOHiFlag, MOLoFlag;
@@ -2007,8 +2013,7 @@
if (Subtarget.isSVR4ABI() && Subtarget.isPPC64()) {
setUsesTOCBasePtr(DAG);
SDValue GA = DAG.getTargetGlobalAddress(GV, DL, PtrVT, GSDN->getOffset());
- return DAG.getNode(PPCISD::TOC_ENTRY, DL, MVT::i64, GA,
- DAG.getRegister(PPC::X2, MVT::i64));
+ return getTOCEntry(DAG, DL, true, GA);
}
unsigned MOHiFlag, MOLoFlag;
@@ -2019,8 +2024,7 @@
SDValue GA = DAG.getTargetGlobalAddress(GV, DL, PtrVT,
GSDN->getOffset(),
PPCII::MO_PIC_FLAG);
- return DAG.getNode(PPCISD::TOC_ENTRY, DL, MVT::i32, GA,
- DAG.getNode(PPCISD::GlobalBaseReg, DL, MVT::i32));
+ return getTOCEntry(DAG, DL, false, GA);
}
SDValue GAHi =