1 //===-- X86ISelLowering.h - X86 DAG Lowering Interface ----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Chris Lattner and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the interfaces that X86 uses to lower LLVM code into a
13 //===----------------------------------------------------------------------===//
15 #ifndef X86ISELLOWERING_H
16 #define X86ISELLOWERING_H
18 #include "X86Subtarget.h"
19 #include "llvm/Target/TargetLowering.h"
20 #include "llvm/CodeGen/SelectionDAG.h"
24 // X86 Specific DAG Nodes
26 // Start the numbering where the builtin ops leave off.
27 FIRST_NUMBER = ISD::BUILTIN_OP_END+X86::INSTRUCTION_LIST_END,
29 /// ADD_FLAG, SUB_FLAG - Same as ISD::ADD and ISD::SUB except it also
30 /// produces a flag result.
34 /// ADC, SBB - Add with carry and subtraction with borrow. These
35 /// correspond to X86::ADCxx and X86::SBBxx instructions.
39 /// SHLD, SHRD - Double shift instructions. These correspond to
40 /// X86::SHLDxx and X86::SHRDxx instructions.
44 /// FILD - This instruction implements SINT_TO_FP with the integer source
45 /// in memory and FP reg result. This corresponds to the X86::FILD*m
46 /// instructions. It has three inputs (token chain, address, and source
47 /// type) and two outputs (FP value and token chain).
50 /// FP_TO_INT*_IN_MEM - This instruction implements FP_TO_SINT with the
51 /// integer destination in memory and a FP reg source. This corresponds
52 /// to the X86::FIST*m instructions and the rounding mode change stuff. It
53 /// has two inputs (token chain and address) and two outputs (int value and
59 /// FLD - This instruction implements an extending load to FP stack slots.
60 /// This corresponds to the X86::FLD32m / X86::FLD64m. It takes a chain
61 /// operand, ptr to load from, and a ValueType node indicating the type
65 /// FST - This instruction implements a truncating store to FP stack
66 /// slots. This corresponds to the X86::FST32m / X86::FST64m. It takes a
67 /// chain operand, value to store, address, and a ValueType to store it
71 /// FP_SET_RESULT - This corresponds to FpGETRESULT pseudo instrcuction
72 /// which copies from ST(0) to the destination. It takes a chain and writes
73 /// a RFP result and a chain.
76 /// FP_SET_RESULT - This corresponds to FpSETRESULT pseudo instrcuction
77 /// which copies the source operand to ST(0). It takes a chain and writes
78 /// a chain and a flag.
81 /// CALL/TAILCALL - These operations represent an abstract X86 call
82 /// instruction, which includes a bunch of information. In particular the
83 /// operands of these node are:
85 /// #0 - The incoming token chain
87 /// #2 - The number of arg bytes the caller pushes on the stack.
88 /// #3 - The number of arg bytes the callee pops off the stack.
89 /// #4 - The value to pass in AL/AX/EAX (optional)
90 /// #5 - The value to pass in DL/DX/EDX (optional)
92 /// The result values of these nodes are:
94 /// #0 - The outgoing token chain
95 /// #1 - The first register result value (optional)
96 /// #2 - The second register result value (optional)
98 /// The CALL vs TAILCALL distinction boils down to whether the callee is
99 /// known not to modify the caller's stack frame, as is standard with
104 /// RDTSC_DAG - This operation implements the lowering for
108 /// X86 compare and logical compare instructions.
111 /// X86 SetCC. Operand 1 is condition code, and operand 2 is the flag
112 /// operand produced by a CMP instruction.
115 /// X86 conditional moves. Operand 1 and operand 2 are the two values
116 /// to select from (operand 1 is a R/W operand). Operand 3 is the condition
117 /// code, and operand 4 is the flag operand produced by a CMP or TEST
118 /// instruction. It also writes a flag result.
121 /// X86 conditional branches. Operand 1 is the chain operand, operand 2
122 /// is the block to branch if condition is true, operand 3 is the
123 /// condition code, and operand 4 is the flag operand produced by a CMP
124 /// or TEST instruction.
127 /// Return with a flag operand. Operand 1 is the chain operand, operand
128 /// 2 is the number of bytes of stack to pop.
131 /// REP_STOS - Repeat fill, corresponds to X86::REP_STOSx.
134 /// REP_MOVS - Repeat move, corresponds to X86::REP_MOVSx.
138 // X86 specific condition code. These correspond to X86_*_COND in
139 // X86InstrInfo.td. They must be kept in synch.
161 //===----------------------------------------------------------------------===//
162 // X86TargetLowering - X86 Implementation of the TargetLowering interface
163 class X86TargetLowering : public TargetLowering {
164 int VarArgsFrameIndex; // FrameIndex for start of varargs area.
165 int ReturnAddrIndex; // FrameIndex for return slot.
166 int BytesToPopOnReturn; // Number of arg bytes ret should pop.
167 int BytesCallerReserves; // Number of arg bytes caller makes.
169 X86TargetLowering(TargetMachine &TM);
171 // Return the number of bytes that a function should pop when it returns (in
172 // addition to the space used by the return address).
174 unsigned getBytesToPopOnReturn() const { return BytesToPopOnReturn; }
176 // Return the number of bytes that the caller reserves for arguments passed
178 unsigned getBytesCallerReserves() const { return BytesCallerReserves; }
180 /// LowerOperation - Provide custom lowering hooks for some operations.
182 virtual SDOperand LowerOperation(SDOperand Op, SelectionDAG &DAG);
184 /// LowerArguments - This hook must be implemented to indicate how we should
185 /// lower the arguments for the specified function, into the specified DAG.
186 virtual std::vector<SDOperand>
187 LowerArguments(Function &F, SelectionDAG &DAG);
189 /// LowerCallTo - This hook lowers an abstract call to a function into an
191 virtual std::pair<SDOperand, SDOperand>
192 LowerCallTo(SDOperand Chain, const Type *RetTy, bool isVarArg, unsigned CC,
193 bool isTailCall, SDOperand Callee, ArgListTy &Args,
196 virtual std::pair<SDOperand, SDOperand>
197 LowerFrameReturnAddress(bool isFrameAddr, SDOperand Chain, unsigned Depth,
200 virtual MachineBasicBlock *InsertAtEndOfBasicBlock(MachineInstr *MI,
201 MachineBasicBlock *MBB);
203 /// getTargetNodeName - This method returns the name of a target specific
205 virtual const char *getTargetNodeName(unsigned Opcode) const;
207 /// isMaskedValueZeroForTargetNode - Return true if 'Op & Mask' is known to
208 /// be zero. Op is expected to be a target specific node. Used by DAG
210 virtual bool isMaskedValueZeroForTargetNode(const SDOperand &Op,
211 uint64_t Mask) const;
213 SDOperand getReturnAddressFrameIndex(SelectionDAG &DAG);
216 // C Calling Convention implementation.
217 std::vector<SDOperand> LowerCCCArguments(Function &F, SelectionDAG &DAG);
218 std::pair<SDOperand, SDOperand>
219 LowerCCCCallTo(SDOperand Chain, const Type *RetTy, bool isVarArg,
221 SDOperand Callee, ArgListTy &Args, SelectionDAG &DAG);
223 // Fast Calling Convention implementation.
224 std::vector<SDOperand> LowerFastCCArguments(Function &F, SelectionDAG &DAG);
225 std::pair<SDOperand, SDOperand>
226 LowerFastCCCallTo(SDOperand Chain, const Type *RetTy, bool isTailCall,
227 SDOperand Callee, ArgListTy &Args, SelectionDAG &DAG);
229 /// Subtarget - Keep a pointer to the X86Subtarget around so that we can
230 /// make the right decision when generating code for different targets.
231 const X86Subtarget *Subtarget;
233 /// X86ScalarSSE - Select between SSE2 or x87 floating point ops.
238 #endif // X86ISELLOWERING_H