1 //===-- llvm/CallingConvLower.h - Calling Conventions -----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file declares the CCState and CCValAssign classes, used for lowering
11 // and implementing calling conventions.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_CODEGEN_CALLINGCONVLOWER_H
16 #define LLVM_CODEGEN_CALLINGCONVLOWER_H
18 #include "llvm/ADT/SmallVector.h"
19 #include "llvm/CodeGen/MachineFunction.h"
20 #include "llvm/CodeGen/ValueTypes.h"
21 #include "llvm/Target/TargetCallingConv.h"
22 #include "llvm/CallingConv.h"
25 class TargetRegisterInfo;
29 /// CCValAssign - Represent assignment of one arg/retval to a location.
33 Full, // The value fills the full location.
34 SExt, // The value is sign extended in the location.
35 ZExt, // The value is zero extended in the location.
36 AExt, // The value is extended with undefined upper bits.
37 BCvt, // The value is bit-converted in the location.
38 VExt, // The value is vector-widened in the location.
39 // FIXME: Not implemented yet. Code that uses AExt to mean
40 // vector-widen should be fixed to use VExt instead.
41 Indirect // The location contains pointer to the value.
42 // TODO: a subset of the value is in the location.
45 /// ValNo - This is the value number begin assigned (e.g. an argument number).
48 /// Loc is either a stack offset or a register number.
51 /// isMem - True if this is a memory loc, false if it is a register loc.
54 /// isCustom - True if this arg/retval requires special handling.
57 /// Information about how the value is assigned.
60 /// ValVT - The type of the value being assigned.
63 /// LocVT - The type of the location being assigned to.
67 static CCValAssign getReg(unsigned ValNo, MVT ValVT,
68 unsigned RegNo, MVT LocVT,
81 static CCValAssign getCustomReg(unsigned ValNo, MVT ValVT,
82 unsigned RegNo, MVT LocVT,
85 Ret = getReg(ValNo, ValVT, RegNo, LocVT, HTP);
90 static CCValAssign getMem(unsigned ValNo, MVT ValVT,
91 unsigned Offset, MVT LocVT,
104 static CCValAssign getCustomMem(unsigned ValNo, MVT ValVT,
105 unsigned Offset, MVT LocVT,
108 Ret = getMem(ValNo, ValVT, Offset, LocVT, HTP);
113 unsigned getValNo() const { return ValNo; }
114 MVT getValVT() const { return ValVT; }
116 bool isRegLoc() const { return !isMem; }
117 bool isMemLoc() const { return isMem; }
119 bool needsCustom() const { return isCustom; }
121 unsigned getLocReg() const { assert(isRegLoc()); return Loc; }
122 unsigned getLocMemOffset() const { assert(isMemLoc()); return Loc; }
123 MVT getLocVT() const { return LocVT; }
125 LocInfo getLocInfo() const { return HTP; }
126 bool isExtInLoc() const {
127 return (HTP == AExt || HTP == SExt || HTP == ZExt);
132 /// CCAssignFn - This function assigns a location for Val, updating State to
133 /// reflect the change. It returns 'true' if it failed to handle Val.
134 typedef bool CCAssignFn(unsigned ValNo, MVT ValVT,
135 MVT LocVT, CCValAssign::LocInfo LocInfo,
136 ISD::ArgFlagsTy ArgFlags, CCState &State);
138 /// CCCustomFn - This function assigns a location for Val, possibly updating
139 /// all args to reflect changes and indicates if it handled it. It must set
140 /// isCustom if it handles the arg and returns true.
141 typedef bool CCCustomFn(unsigned &ValNo, MVT &ValVT,
142 MVT &LocVT, CCValAssign::LocInfo &LocInfo,
143 ISD::ArgFlagsTy &ArgFlags, CCState &State);
145 typedef enum { Invalid, Prologue, Call } ParmContext;
147 /// CCState - This class holds information needed while lowering arguments and
148 /// return values. It captures which registers are already assigned and which
149 /// stack slots are used. It provides accessors to allocate these values.
151 CallingConv::ID CallingConv;
154 const TargetMachine &TM;
155 const TargetRegisterInfo &TRI;
156 SmallVector<CCValAssign, 16> &Locs;
157 LLVMContext &Context;
159 unsigned StackOffset;
160 SmallVector<uint32_t, 16> UsedRegs;
161 unsigned FirstByValReg;
162 bool FirstByValRegValid;
163 ParmContext CallOrPrologue;
165 CCState(CallingConv::ID CC, bool isVarArg, MachineFunction &MF,
166 const TargetMachine &TM, SmallVector<CCValAssign, 16> &locs,
169 void addLoc(const CCValAssign &V) {
173 LLVMContext &getContext() const { return Context; }
174 const TargetMachine &getTarget() const { return TM; }
175 MachineFunction &getMachineFunction() const { return MF; }
176 CallingConv::ID getCallingConv() const { return CallingConv; }
177 bool isVarArg() const { return IsVarArg; }
179 unsigned getNextStackOffset() const { return StackOffset; }
181 /// isAllocated - Return true if the specified register (or an alias) is
183 bool isAllocated(unsigned Reg) const {
184 return UsedRegs[Reg/32] & (1 << (Reg&31));
187 /// AnalyzeFormalArguments - Analyze an array of argument values,
188 /// incorporating info about the formals into this state.
189 void AnalyzeFormalArguments(const SmallVectorImpl<ISD::InputArg> &Ins,
192 /// AnalyzeReturn - Analyze the returned values of a return,
193 /// incorporating info about the result values into this state.
194 void AnalyzeReturn(const SmallVectorImpl<ISD::OutputArg> &Outs,
197 /// CheckReturn - Analyze the return values of a function, returning
198 /// true if the return can be performed without sret-demotion, and
200 bool CheckReturn(const SmallVectorImpl<ISD::OutputArg> &ArgsFlags,
203 /// AnalyzeCallOperands - Analyze the outgoing arguments to a call,
204 /// incorporating info about the passed values into this state.
205 void AnalyzeCallOperands(const SmallVectorImpl<ISD::OutputArg> &Outs,
208 /// AnalyzeCallOperands - Same as above except it takes vectors of types
209 /// and argument flags.
210 void AnalyzeCallOperands(SmallVectorImpl<MVT> &ArgVTs,
211 SmallVectorImpl<ISD::ArgFlagsTy> &Flags,
214 /// AnalyzeCallResult - Analyze the return values of a call,
215 /// incorporating info about the passed values into this state.
216 void AnalyzeCallResult(const SmallVectorImpl<ISD::InputArg> &Ins,
219 /// AnalyzeCallResult - Same as above except it's specialized for calls which
220 /// produce a single value.
221 void AnalyzeCallResult(MVT VT, CCAssignFn Fn);
223 /// getFirstUnallocated - Return the first unallocated register in the set, or
224 /// NumRegs if they are all allocated.
225 unsigned getFirstUnallocated(const unsigned *Regs, unsigned NumRegs) const {
226 for (unsigned i = 0; i != NumRegs; ++i)
227 if (!isAllocated(Regs[i]))
232 /// AllocateReg - Attempt to allocate one register. If it is not available,
233 /// return zero. Otherwise, return the register, marking it and any aliases
235 unsigned AllocateReg(unsigned Reg) {
236 if (isAllocated(Reg)) return 0;
241 /// Version of AllocateReg with extra register to be shadowed.
242 unsigned AllocateReg(unsigned Reg, unsigned ShadowReg) {
243 if (isAllocated(Reg)) return 0;
245 MarkAllocated(ShadowReg);
249 /// AllocateReg - Attempt to allocate one of the specified registers. If none
250 /// are available, return zero. Otherwise, return the first one available,
251 /// marking it and any aliases as allocated.
252 unsigned AllocateReg(const unsigned *Regs, unsigned NumRegs) {
253 unsigned FirstUnalloc = getFirstUnallocated(Regs, NumRegs);
254 if (FirstUnalloc == NumRegs)
255 return 0; // Didn't find the reg.
257 // Mark the register and any aliases as allocated.
258 unsigned Reg = Regs[FirstUnalloc];
263 /// Version of AllocateReg with list of registers to be shadowed.
264 unsigned AllocateReg(const unsigned *Regs, const unsigned *ShadowRegs,
266 unsigned FirstUnalloc = getFirstUnallocated(Regs, NumRegs);
267 if (FirstUnalloc == NumRegs)
268 return 0; // Didn't find the reg.
270 // Mark the register and any aliases as allocated.
271 unsigned Reg = Regs[FirstUnalloc], ShadowReg = ShadowRegs[FirstUnalloc];
273 MarkAllocated(ShadowReg);
277 /// AllocateStack - Allocate a chunk of stack space with the specified size
279 unsigned AllocateStack(unsigned Size, unsigned Align) {
280 assert(Align && ((Align-1) & Align) == 0); // Align is power of 2.
281 StackOffset = ((StackOffset + Align-1) & ~(Align-1));
282 unsigned Result = StackOffset;
287 /// Version of AllocateStack with extra register to be shadowed.
288 unsigned AllocateStack(unsigned Size, unsigned Align, unsigned ShadowReg) {
289 MarkAllocated(ShadowReg);
290 return AllocateStack(Size, Align);
293 // HandleByVal - Allocate a stack slot large enough to pass an argument by
294 // value. The size and alignment information of the argument is encoded in its
295 // parameter attribute.
296 void HandleByVal(unsigned ValNo, MVT ValVT,
297 MVT LocVT, CCValAssign::LocInfo LocInfo,
298 int MinSize, int MinAlign, ISD::ArgFlagsTy ArgFlags);
300 // First GPR that carries part of a byval aggregate that's split
301 // between registers and memory.
302 unsigned getFirstByValReg() { return FirstByValRegValid ? FirstByValReg : 0; }
303 void setFirstByValReg(unsigned r) { FirstByValReg = r; FirstByValRegValid = true; }
304 void clearFirstByValReg() { FirstByValReg = 0; FirstByValRegValid = false; }
305 bool isFirstByValRegValid() { return FirstByValRegValid; }
307 ParmContext getCallOrPrologue() { return CallOrPrologue; }
308 void setCallOrPrologue(ParmContext pc) { CallOrPrologue = pc; }
311 /// MarkAllocated - Mark a register and all of its aliases as allocated.
312 void MarkAllocated(unsigned Reg);
317 } // end namespace llvm