From 3ee2af7d1c0decb43729d239b5c6c0052b5308b7 Mon Sep 17 00:00:00 2001 From: Hal Finkel Date: Fri, 18 Jul 2014 23:29:49 +0000 Subject: [PowerPC] 32-bit ELF PIC support This adds initial support for PPC32 ELF PIC (Position Independent Code; the -fPIC variety), thus rectifying a long-standing deficiency in the PowerPC backend. Patch by Justin Hibbits! llvm-svn: 213427 --- llvm/lib/Target/PowerPC/PPCISelLowering.cpp | 57 +++++++++++++++++++++++------ 1 file changed, 45 insertions(+), 12 deletions(-) (limited to 'llvm/lib/Target/PowerPC/PPCISelLowering.cpp') diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp index bc057bfd3b6..e2826f726dd 100644 --- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp +++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp @@ -1491,10 +1491,9 @@ static bool GetLabelAccessInfo(const TargetMachine &TM, unsigned &HiOpFlags, HiOpFlags = PPCII::MO_HA; LoOpFlags = PPCII::MO_LO; - // Don't use the pic base if not in PIC relocation model. Or if we are on a - // non-darwin platform. We don't support PIC on other platforms yet. - bool isPIC = TM.getRelocationModel() == Reloc::PIC_ && - TM.getSubtarget().isDarwin(); + // Don't use the pic base if not in PIC relocation model. + bool isPIC = TM.getRelocationModel() == Reloc::PIC_; + if (isPIC) { HiOpFlags |= PPCII::MO_PIC_FLAG; LoOpFlags |= PPCII::MO_PIC_FLAG; @@ -1550,6 +1549,15 @@ SDValue PPCTargetLowering::LowerConstantPool(SDValue Op, unsigned MOHiFlag, MOLoFlag; bool isPIC = GetLabelAccessInfo(DAG.getTarget(), MOHiFlag, MOLoFlag); + + 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)); + } + SDValue CPIHi = DAG.getTargetConstantPool(C, PtrVT, CP->getAlignment(), 0, MOHiFlag); SDValue CPILo = @@ -1571,6 +1579,15 @@ SDValue PPCTargetLowering::LowerJumpTable(SDValue Op, SelectionDAG &DAG) const { unsigned MOHiFlag, MOLoFlag; bool isPIC = GetLabelAccessInfo(DAG.getTarget(), MOHiFlag, MOLoFlag); + + 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)); + } + SDValue JTIHi = DAG.getTargetJumpTable(JT->getIndex(), PtrVT, MOHiFlag); SDValue JTILo = DAG.getTargetJumpTable(JT->getIndex(), PtrVT, MOLoFlag); return LowerLabelRef(JTIHi, JTILo, isPIC, DAG); @@ -1700,6 +1717,14 @@ SDValue PPCTargetLowering::LowerGlobalAddress(SDValue Op, unsigned MOHiFlag, MOLoFlag; bool isPIC = GetLabelAccessInfo(DAG.getTarget(), MOHiFlag, MOLoFlag, GV); + if (isPIC && Subtarget.isSVR4ABI()) { + 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)); + } + SDValue GAHi = DAG.getTargetGlobalAddress(GV, DL, PtrVT, GSDN->getOffset(), MOHiFlag); SDValue GALo = @@ -3357,15 +3382,18 @@ unsigned PrepareCall(SelectionDAG &DAG, SDValue &Callee, SDValue &InFlag, // far-call stubs may be outside relocation limits for a BL instruction. if (!DAG.getTarget().getSubtarget().isJITCodeModel()) { unsigned OpFlags = 0; - if (DAG.getTarget().getRelocationModel() != Reloc::Static && + if ((DAG.getTarget().getRelocationModel() != Reloc::Static && (Subtarget.getTargetTriple().isMacOSX() && Subtarget.getTargetTriple().isMacOSXVersionLT(10, 5)) && (G->getGlobal()->isDeclaration() || - G->getGlobal()->isWeakForLinker())) { + G->getGlobal()->isWeakForLinker())) || + (Subtarget.isTargetELF() && !isPPC64 && + !G->getGlobal()->hasLocalLinkage() && + DAG.getTarget().getRelocationModel() == Reloc::PIC_)) { // PC-relative references to external symbols should go through $stub, // unless we're building with the leopard linker or later, which // automatically synthesizes these stubs. - OpFlags = PPCII::MO_DARWIN_STUB; + OpFlags = PPCII::MO_PLT_OR_STUB; } // If the callee is a GlobalAddress/ExternalSymbol node (quite common, @@ -3381,13 +3409,15 @@ unsigned PrepareCall(SelectionDAG &DAG, SDValue &Callee, SDValue &InFlag, if (ExternalSymbolSDNode *S = dyn_cast(Callee)) { unsigned char OpFlags = 0; - if (DAG.getTarget().getRelocationModel() != Reloc::Static && - (Subtarget.getTargetTriple().isMacOSX() && - Subtarget.getTargetTriple().isMacOSXVersionLT(10, 5))) { + if ((DAG.getTarget().getRelocationModel() != Reloc::Static && + (Subtarget.getTargetTriple().isMacOSX() && + Subtarget.getTargetTriple().isMacOSXVersionLT(10, 5))) || + (Subtarget.isTargetELF() && !isPPC64 && + DAG.getTarget().getRelocationModel() == Reloc::PIC_) ) { // PC-relative references to external symbols should go through $stub, // unless we're building with the leopard linker or later, which // automatically synthesizes these stubs. - OpFlags = PPCII::MO_DARWIN_STUB; + OpFlags = PPCII::MO_PLT_OR_STUB; } Callee = DAG.getTargetExternalSymbol(S->getSymbol(), Callee.getValueType(), @@ -6613,7 +6643,10 @@ PPCTargetLowering::emitEHSjLjLongJmp(MachineInstr *MI, // Since FP is only updated here but NOT referenced, it's treated as GPR. unsigned FP = (PVT == MVT::i64) ? PPC::X31 : PPC::R31; unsigned SP = (PVT == MVT::i64) ? PPC::X1 : PPC::R1; - unsigned BP = (PVT == MVT::i64) ? PPC::X30 : PPC::R30; + unsigned BP = (PVT == MVT::i64) ? PPC::X30 : + (Subtarget.isSVR4ABI() && + MF->getTarget().getRelocationModel() == Reloc::PIC_ ? + PPC::R29 : PPC::R30); MachineInstrBuilder MIB; -- cgit v1.2.3