summaryrefslogtreecommitdiffstats
path: root/lib/Target/Mips/MipsISelDAGToDAG.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'lib/Target/Mips/MipsISelDAGToDAG.cpp')
-rw-r--r--lib/Target/Mips/MipsISelDAGToDAG.cpp392
1 files changed, 392 insertions, 0 deletions
diff --git a/lib/Target/Mips/MipsISelDAGToDAG.cpp b/lib/Target/Mips/MipsISelDAGToDAG.cpp
new file mode 100644
index 0000000..f05ac70
--- /dev/null
+++ b/lib/Target/Mips/MipsISelDAGToDAG.cpp
@@ -0,0 +1,392 @@
+//===-- MipsISelDAGToDAG.cpp - A dag to dag inst selector for Mips --------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines an instruction selector for the MIPS target.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "mips-isel"
+#include "Mips.h"
+#include "MipsISelLowering.h"
+#include "MipsMachineFunction.h"
+#include "MipsRegisterInfo.h"
+#include "MipsSubtarget.h"
+#include "MipsTargetMachine.h"
+#include "llvm/GlobalValue.h"
+#include "llvm/Instructions.h"
+#include "llvm/Intrinsics.h"
+#include "llvm/Support/CFG.h"
+#include "llvm/Type.h"
+#include "llvm/CodeGen/MachineConstantPool.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/SelectionDAGISel.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Debug.h"
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// Instruction Selector Implementation
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+// MipsDAGToDAGISel - MIPS specific code to select MIPS machine
+// instructions for SelectionDAG operations.
+//===----------------------------------------------------------------------===//
+namespace {
+
+class VISIBILITY_HIDDEN MipsDAGToDAGISel : public SelectionDAGISel {
+
+ /// TM - Keep a reference to MipsTargetMachine.
+ MipsTargetMachine &TM;
+
+ /// Subtarget - Keep a pointer to the MipsSubtarget around so that we can
+ /// make the right decision when generating code for different targets.
+ const MipsSubtarget &Subtarget;
+
+public:
+ explicit MipsDAGToDAGISel(MipsTargetMachine &tm) :
+ SelectionDAGISel(tm),
+ TM(tm), Subtarget(tm.getSubtarget<MipsSubtarget>()) {}
+
+ virtual void InstructionSelect();
+
+ // Pass Name
+ virtual const char *getPassName() const {
+ return "MIPS DAG->DAG Pattern Instruction Selection";
+ }
+
+
+private:
+ // Include the pieces autogenerated from the target description.
+ #include "MipsGenDAGISel.inc"
+
+ SDValue getGlobalBaseReg();
+ SDNode *Select(SDValue N);
+
+ // Complex Pattern.
+ bool SelectAddr(SDValue Op, SDValue N,
+ SDValue &Base, SDValue &Offset);
+
+
+ // getI32Imm - Return a target constant with the specified
+ // value, of type i32.
+ inline SDValue getI32Imm(unsigned Imm) {
+ return CurDAG->getTargetConstant(Imm, MVT::i32);
+ }
+
+
+ #ifndef NDEBUG
+ unsigned Indent;
+ #endif
+};
+
+}
+
+/// InstructionSelect - This callback is invoked by
+/// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
+void MipsDAGToDAGISel::
+InstructionSelect()
+{
+ DEBUG(BB->dump());
+ // Codegen the basic block.
+ #ifndef NDEBUG
+ DOUT << "===== Instruction selection begins:\n";
+ Indent = 0;
+ #endif
+
+ // Select target instructions for the DAG.
+ SelectRoot(*CurDAG);
+
+ #ifndef NDEBUG
+ DOUT << "===== Instruction selection ends:\n";
+ #endif
+
+ CurDAG->RemoveDeadNodes();
+}
+
+/// getGlobalBaseReg - Output the instructions required to put the
+/// GOT address into a register.
+SDValue MipsDAGToDAGISel::getGlobalBaseReg() {
+ MachineFunction* MF = BB->getParent();
+ unsigned GP = 0;
+ for(MachineRegisterInfo::livein_iterator ii = MF->getRegInfo().livein_begin(),
+ ee = MF->getRegInfo().livein_end(); ii != ee; ++ii)
+ if (ii->first == Mips::GP) {
+ GP = ii->second;
+ break;
+ }
+ assert(GP && "GOT PTR not in liveins");
+ // FIXME is there a sensible place to get debug info for this?
+ return CurDAG->getCopyFromReg(CurDAG->getEntryNode(),
+ DebugLoc::getUnknownLoc(), GP, MVT::i32);
+}
+
+/// ComplexPattern used on MipsInstrInfo
+/// Used on Mips Load/Store instructions
+bool MipsDAGToDAGISel::
+SelectAddr(SDValue Op, SDValue Addr, SDValue &Offset, SDValue &Base)
+{
+ // if Address is FI, get the TargetFrameIndex.
+ if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(Addr)) {
+ Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i32);
+ Offset = CurDAG->getTargetConstant(0, MVT::i32);
+ return true;
+ }
+
+ // on PIC code Load GA
+ if (TM.getRelocationModel() == Reloc::PIC_) {
+ if ((Addr.getOpcode() == ISD::TargetGlobalAddress) ||
+ (Addr.getOpcode() == ISD::TargetJumpTable)){
+ Base = CurDAG->getRegister(Mips::GP, MVT::i32);
+ Offset = Addr;
+ return true;
+ }
+ } else {
+ if ((Addr.getOpcode() == ISD::TargetExternalSymbol ||
+ Addr.getOpcode() == ISD::TargetGlobalAddress))
+ return false;
+ }
+
+ // Operand is a result from an ADD.
+ if (Addr.getOpcode() == ISD::ADD) {
+ if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1))) {
+ if (Predicate_immSExt16(CN)) {
+
+ // If the first operand is a FI, get the TargetFI Node
+ if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>
+ (Addr.getOperand(0))) {
+ Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i32);
+ } else {
+ Base = Addr.getOperand(0);
+ }
+
+ Offset = CurDAG->getTargetConstant(CN->getZExtValue(), MVT::i32);
+ return true;
+ }
+ }
+ }
+
+ Base = Addr;
+ Offset = CurDAG->getTargetConstant(0, MVT::i32);
+ return true;
+}
+
+/// Select instructions not customized! Used for
+/// expanded, promoted and normal instructions
+SDNode* MipsDAGToDAGISel::
+Select(SDValue N)
+{
+ SDNode *Node = N.getNode();
+ unsigned Opcode = Node->getOpcode();
+ DebugLoc dl = Node->getDebugLoc();
+
+ // Dump information about the Node being selected
+ #ifndef NDEBUG
+ DOUT << std::string(Indent, ' ') << "Selecting: ";
+ DEBUG(Node->dump(CurDAG));
+ DOUT << "\n";
+ Indent += 2;
+ #endif
+
+ // If we have a custom node, we already have selected!
+ if (Node->isMachineOpcode()) {
+ #ifndef NDEBUG
+ DOUT << std::string(Indent-2, ' ') << "== ";
+ DEBUG(Node->dump(CurDAG));
+ DOUT << "\n";
+ Indent -= 2;
+ #endif
+ return NULL;
+ }
+
+ ///
+ // Instruction Selection not handled by the auto-generated
+ // tablegen selection should be handled here.
+ ///
+ switch(Opcode) {
+
+ default: break;
+
+ case ISD::SUBE:
+ case ISD::ADDE: {
+ SDValue InFlag = Node->getOperand(2), CmpLHS;
+ unsigned Opc = InFlag.getOpcode(); Opc=Opc;
+ assert(((Opc == ISD::ADDC || Opc == ISD::ADDE) ||
+ (Opc == ISD::SUBC || Opc == ISD::SUBE)) &&
+ "(ADD|SUB)E flag operand must come from (ADD|SUB)C/E insn");
+
+ unsigned MOp;
+ if (Opcode == ISD::ADDE) {
+ CmpLHS = InFlag.getValue(0);
+ MOp = Mips::ADDu;
+ } else {
+ CmpLHS = InFlag.getOperand(0);
+ MOp = Mips::SUBu;
+ }
+
+ SDValue Ops[] = { CmpLHS, InFlag.getOperand(1) };
+
+ SDValue LHS = Node->getOperand(0);
+ SDValue RHS = Node->getOperand(1);
+
+ MVT VT = LHS.getValueType();
+ SDNode *Carry = CurDAG->getTargetNode(Mips::SLTu, dl, VT, Ops, 2);
+ SDNode *AddCarry = CurDAG->getTargetNode(Mips::ADDu, dl, VT,
+ SDValue(Carry,0), RHS);
+
+ return CurDAG->SelectNodeTo(N.getNode(), MOp, VT, MVT::Flag,
+ LHS, SDValue(AddCarry,0));
+ }
+
+ /// Mul/Div with two results
+ case ISD::SDIVREM:
+ case ISD::UDIVREM:
+ case ISD::SMUL_LOHI:
+ case ISD::UMUL_LOHI: {
+ SDValue Op1 = Node->getOperand(0);
+ SDValue Op2 = Node->getOperand(1);
+
+ unsigned Op;
+ if (Opcode == ISD::UMUL_LOHI || Opcode == ISD::SMUL_LOHI)
+ Op = (Opcode == ISD::UMUL_LOHI ? Mips::MULTu : Mips::MULT);
+ else
+ Op = (Opcode == ISD::UDIVREM ? Mips::DIVu : Mips::DIV);
+
+ SDNode *Node = CurDAG->getTargetNode(Op, dl, MVT::Flag, Op1, Op2);
+
+ SDValue InFlag = SDValue(Node, 0);
+ SDNode *Lo = CurDAG->getTargetNode(Mips::MFLO, dl, MVT::i32,
+ MVT::Flag, InFlag);
+ InFlag = SDValue(Lo,1);
+ SDNode *Hi = CurDAG->getTargetNode(Mips::MFHI, dl, MVT::i32, InFlag);
+
+ if (!N.getValue(0).use_empty())
+ ReplaceUses(N.getValue(0), SDValue(Lo,0));
+
+ if (!N.getValue(1).use_empty())
+ ReplaceUses(N.getValue(1), SDValue(Hi,0));
+
+ return NULL;
+ }
+
+ /// Special Muls
+ case ISD::MUL:
+ case ISD::MULHS:
+ case ISD::MULHU: {
+ SDValue MulOp1 = Node->getOperand(0);
+ SDValue MulOp2 = Node->getOperand(1);
+
+ unsigned MulOp = (Opcode == ISD::MULHU ? Mips::MULTu : Mips::MULT);
+ SDNode *MulNode = CurDAG->getTargetNode(MulOp, dl,
+ MVT::Flag, MulOp1, MulOp2);
+
+ SDValue InFlag = SDValue(MulNode, 0);
+
+ if (MulOp == ISD::MUL)
+ return CurDAG->getTargetNode(Mips::MFLO, dl, MVT::i32, InFlag);
+ else
+ return CurDAG->getTargetNode(Mips::MFHI, dl, MVT::i32, InFlag);
+ }
+
+ /// Div/Rem operations
+ case ISD::SREM:
+ case ISD::UREM:
+ case ISD::SDIV:
+ case ISD::UDIV: {
+ SDValue Op1 = Node->getOperand(0);
+ SDValue Op2 = Node->getOperand(1);
+
+ unsigned Op, MOp;
+ if (Opcode == ISD::SDIV || Opcode == ISD::UDIV) {
+ Op = (Opcode == ISD::SDIV ? Mips::DIV : Mips::DIVu);
+ MOp = Mips::MFLO;
+ } else {
+ Op = (Opcode == ISD::SREM ? Mips::DIV : Mips::DIVu);
+ MOp = Mips::MFHI;
+ }
+ SDNode *Node = CurDAG->getTargetNode(Op, dl, MVT::Flag, Op1, Op2);
+
+ SDValue InFlag = SDValue(Node, 0);
+ return CurDAG->getTargetNode(MOp, dl, MVT::i32, InFlag);
+ }
+
+ // Get target GOT address.
+ case ISD::GLOBAL_OFFSET_TABLE: {
+ SDValue Result = getGlobalBaseReg();
+ ReplaceUses(N, Result);
+ return NULL;
+ }
+
+ /// Handle direct and indirect calls when using PIC. On PIC, when
+ /// GOT is smaller than about 64k (small code) the GA target is
+ /// loaded with only one instruction. Otherwise GA's target must
+ /// be loaded with 3 instructions.
+ case MipsISD::JmpLink: {
+ if (TM.getRelocationModel() == Reloc::PIC_) {
+ //bool isCodeLarge = (TM.getCodeModel() == CodeModel::Large);
+ SDValue Chain = Node->getOperand(0);
+ SDValue Callee = Node->getOperand(1);
+ SDValue T9Reg = CurDAG->getRegister(Mips::T9, MVT::i32);
+ SDValue InFlag(0, 0);
+
+ if ( (isa<GlobalAddressSDNode>(Callee)) ||
+ (isa<ExternalSymbolSDNode>(Callee)) )
+ {
+ /// Direct call for global addresses and external symbols
+ SDValue GPReg = CurDAG->getRegister(Mips::GP, MVT::i32);
+
+ // Use load to get GOT target
+ SDValue Ops[] = { Callee, GPReg, Chain };
+ SDValue Load = SDValue(CurDAG->getTargetNode(Mips::LW, dl, MVT::i32,
+ MVT::Other, Ops, 3), 0);
+ Chain = Load.getValue(1);
+
+ // Call target must be on T9
+ Chain = CurDAG->getCopyToReg(Chain, dl, T9Reg, Load, InFlag);
+ } else
+ /// Indirect call
+ Chain = CurDAG->getCopyToReg(Chain, dl, T9Reg, Callee, InFlag);
+
+ // Emit Jump and Link Register
+ SDNode *ResNode = CurDAG->getTargetNode(Mips::JALR, dl, MVT::Other,
+ MVT::Flag, T9Reg, Chain);
+ Chain = SDValue(ResNode, 0);
+ InFlag = SDValue(ResNode, 1);
+ ReplaceUses(SDValue(Node, 0), Chain);
+ ReplaceUses(SDValue(Node, 1), InFlag);
+ return ResNode;
+ }
+ }
+ }
+
+ // Select the default instruction
+ SDNode *ResNode = SelectCode(N);
+
+ #ifndef NDEBUG
+ DOUT << std::string(Indent-2, ' ') << "=> ";
+ if (ResNode == NULL || ResNode == N.getNode())
+ DEBUG(N.getNode()->dump(CurDAG));
+ else
+ DEBUG(ResNode->dump(CurDAG));
+ DOUT << "\n";
+ Indent -= 2;
+ #endif
+
+ return ResNode;
+}
+
+/// createMipsISelDag - This pass converts a legalized DAG into a
+/// MIPS-specific DAG, ready for instruction scheduling.
+FunctionPass *llvm::createMipsISelDag(MipsTargetMachine &TM) {
+ return new MipsDAGToDAGISel(TM);
+}
OpenPOWER on IntegriCloud