diff options
| -rw-r--r-- | lib/Target/Mips/MipsISelLowering.cpp | 45 | ||||
| -rw-r--r-- | lib/Target/Mips/MipsISelLowering.h | 7 | ||||
| -rw-r--r-- | lib/Target/Mips/MipsSubtarget.cpp | 8 | ||||
| -rw-r--r-- | lib/Target/Mips/MipsSubtarget.h | 5 |
4 files changed, 59 insertions, 6 deletions
diff --git a/lib/Target/Mips/MipsISelLowering.cpp b/lib/Target/Mips/MipsISelLowering.cpp index b05de6d313..2b7cee8d7a 100644 --- a/lib/Target/Mips/MipsISelLowering.cpp +++ b/lib/Target/Mips/MipsISelLowering.cpp @@ -210,6 +210,37 @@ AddLiveIn(MachineFunction &MF, unsigned PReg, TargetRegisterClass *RC) return VReg; } +// A address must be loaded from a small section if its size is less than the +// small section size threshold. Data in this section must be addressed using +// gp_rel operator. +bool MipsTargetLowering::IsInSmallSection(unsigned Size) { + return (Size > 0 && (Size <= Subtarget->getSSectionThreshold())); +} + +// Discover if this global address can be placed into small data/bss section. +bool MipsTargetLowering::IsGlobalInSmallSection(GlobalValue *GV) +{ + const TargetData *TD = getTargetData(); + const GlobalVariable *GVA = dyn_cast<GlobalVariable>(GV); + + if (!GVA) + return false; + + const Type *Ty = GV->getType()->getElementType(); + unsigned Size = TD->getTypeAllocSize(Ty); + + // if this is a internal constant string, there is a special + // section for it, but not in small data/bss. + if (GVA->hasInitializer() && GV->hasLocalLinkage()) { + Constant *C = GVA->getInitializer(); + const ConstantArray *CVA = dyn_cast<ConstantArray>(C); + if (CVA && CVA->isCString()) + return false; + } + + return IsInSmallSection(Size); +} + // Get fp branch code (not opcode) from condition code. static Mips::FPBranchCode GetFPBranchCodeFromCond(Mips::CondCode CC) { if (CC >= Mips::FCOND_F && CC <= Mips::FCOND_NGT) @@ -485,17 +516,23 @@ LowerSELECT(SDValue Op, SelectionDAG &DAG) Cond, True, False, CCNode); } -SDValue MipsTargetLowering:: -LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) -{ +SDValue MipsTargetLowering::LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) { // FIXME there isn't actually debug info here DebugLoc dl = Op.getDebugLoc(); GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal(); SDValue GA = DAG.getTargetGlobalAddress(GV, MVT::i32); if (getTargetMachine().getRelocationModel() != Reloc::PIC_) { + SDVTList VTs = DAG.getVTList(MVT::i32); + + // %gp_rel relocation + if (!isa<Function>(GV) && IsGlobalInSmallSection(GV)) { + SDValue GPRelNode = DAG.getNode(MipsISD::GPRel, dl, VTs, &GA, 1); + SDValue GOT = DAG.getGLOBAL_OFFSET_TABLE(MVT::i32); + return DAG.getNode(ISD::ADD, dl, MVT::i32, GOT, GPRelNode); + } // %hi/%lo relocation - SDValue HiPart = DAG.getNode(MipsISD::Hi, dl, MVT::i32, GA); + SDValue HiPart = DAG.getNode(MipsISD::Hi, dl, VTs, &GA, 1); SDValue Lo = DAG.getNode(MipsISD::Lo, dl, MVT::i32, GA); return DAG.getNode(ISD::ADD, dl, MVT::i32, HiPart, Lo); diff --git a/lib/Target/Mips/MipsISelLowering.h b/lib/Target/Mips/MipsISelLowering.h index 656abe5840..ec2124325b 100644 --- a/lib/Target/Mips/MipsISelLowering.h +++ b/lib/Target/Mips/MipsISelLowering.h @@ -66,8 +66,8 @@ namespace llvm { //===--------------------------------------------------------------------===// // TargetLowering Implementation //===--------------------------------------------------------------------===// - class MipsTargetLowering : public TargetLowering - { + + class MipsTargetLowering : public TargetLowering { public: explicit MipsTargetLowering(MipsTargetMachine &TM); @@ -88,6 +88,9 @@ namespace llvm { // Subtarget Info const MipsSubtarget *Subtarget; + bool IsGlobalInSmallSection(GlobalValue *GV); + bool IsInSmallSection(unsigned Size); + // Lower Operand helpers SDValue LowerCallResult(SDValue Chain, SDValue InFlag, unsigned CallConv, bool isVarArg, diff --git a/lib/Target/Mips/MipsSubtarget.cpp b/lib/Target/Mips/MipsSubtarget.cpp index a85028cb96..956fe91754 100644 --- a/lib/Target/Mips/MipsSubtarget.cpp +++ b/lib/Target/Mips/MipsSubtarget.cpp @@ -17,6 +17,11 @@ #include "llvm/Support/CommandLine.h" using namespace llvm; +static cl::opt<unsigned> +SSThreshold("mips-ssection-threshold", cl::Hidden, + cl::desc("Small data and bss section threshold size (default=8)"), + cl::init(8)); + MipsSubtarget::MipsSubtarget(const std::string &TT, const std::string &FS, bool little) : MipsArchVersion(Mips1), MipsABI(O32), IsLittle(little), IsSingleFloat(false), @@ -30,6 +35,9 @@ MipsSubtarget::MipsSubtarget(const std::string &TT, const std::string &FS, // Parse features string. ParseSubtargetFeatures(FS, CPU); + // Small section size threshold + SSectionThreshold = SSThreshold; + // Is the target system Linux ? if (TT.find("linux") == std::string::npos) IsLinux = false; diff --git a/lib/Target/Mips/MipsSubtarget.h b/lib/Target/Mips/MipsSubtarget.h index 1d6f87d8c0..a254b6562c 100644 --- a/lib/Target/Mips/MipsSubtarget.h +++ b/lib/Target/Mips/MipsSubtarget.h @@ -60,6 +60,10 @@ protected: // isLinux - Target system is Linux. Is false we consider ELFOS for now. bool IsLinux; + // Put global and static items less than or equal to SSectionThreshold + // bytes into the small data or bss section. The default is 8. + unsigned SSectionThreshold; + /// Features related to the presence of specific instructions. // HasSEInReg - SEB and SEH (signext in register) instructions. @@ -109,6 +113,7 @@ public: bool isNotSingleFloat() const { return !IsSingleFloat; }; bool hasVFPU() const { return HasVFPU; }; bool isLinux() const { return IsLinux; }; + unsigned getSSectionThreshold() const { return SSectionThreshold; } /// Features related to the presence of specific instructions. bool hasSEInReg() const { return HasSEInReg; }; |