#define LLVM_CODEGEN_CALLINGCONVLOWER_H
#include "llvm/ADT/SmallVector.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/ValueTypes.h"
+#include "llvm/IR/CallingConv.h"
#include "llvm/Target/TargetCallingConv.h"
-#include "llvm/CallingConv.h"
namespace llvm {
class TargetRegisterInfo;
unsigned Loc;
/// isMem - True if this is a memory loc, false if it is a register loc.
- bool isMem : 1;
+ unsigned isMem : 1;
/// isCustom - True if this arg/retval requires special handling.
- bool isCustom : 1;
+ unsigned isCustom : 1;
/// Information about how the value is assigned.
LocInfo HTP : 6;
MVT &LocVT, CCValAssign::LocInfo &LocInfo,
ISD::ArgFlagsTy &ArgFlags, CCState &State);
-typedef enum { Invalid, Prologue, Call } ParmContext;
+/// ParmContext - This enum tracks whether calling convention lowering is in
+/// the context of prologue or call generation. Not all backends make use of
+/// this information.
+typedef enum { Unknown, Prologue, Call } ParmContext;
/// CCState - This class holds information needed while lowering arguments and
/// return values. It captures which registers are already assigned and which
/// stack slots are used. It provides accessors to allocate these values.
class CCState {
+private:
CallingConv::ID CallingConv;
bool IsVarArg;
MachineFunction &MF;
unsigned StackOffset;
SmallVector<uint32_t, 16> UsedRegs;
- unsigned FirstByValReg;
- bool FirstByValRegValid;
+
+ // ByValInfo and SmallVector<ByValInfo, 4> ByValRegs:
+ //
+ // Vector of ByValInfo instances (ByValRegs) is introduced for byval registers
+ // tracking.
+ // Or, in another words it tracks byval parameters that are stored in
+ // general purpose registers.
+ //
+ // For 4 byte stack alignment,
+ // instance index means byval parameter number in formal
+ // arguments set. Assume, we have some "struct_type" with size = 4 bytes,
+ // then, for function "foo":
+ //
+ // i32 foo(i32 %p, %struct_type* %r, i32 %s, %struct_type* %t)
+ //
+ // ByValRegs[0] describes how "%r" is stored (Begin == r1, End == r2)
+ // ByValRegs[1] describes how "%t" is stored (Begin == r3, End == r4).
+ //
+ // In case of 8 bytes stack alignment,
+ // ByValRegs may also contain information about wasted registers.
+ // In function shown above, r3 would be wasted according to AAPCS rules.
+ // And in that case ByValRegs[1].Waste would be "true".
+ // ByValRegs vector size still would be 2,
+ // while "%t" goes to the stack: it wouldn't be described in ByValRegs.
+ //
+ // Supposed use-case for this collection:
+ // 1. Initially ByValRegs is empty, InRegsParamsProceed is 0.
+ // 2. HandleByVal fillups ByValRegs.
+ // 3. Argument analysis (LowerFormatArguments, for example). After
+ // some byval argument was analyzed, InRegsParamsProceed is increased.
+ struct ByValInfo {
+ ByValInfo(unsigned B, unsigned E, bool IsWaste = false) :
+ Begin(B), End(E), Waste(IsWaste) {}
+ // First register allocated for current parameter.
+ unsigned Begin;
+
+ // First after last register allocated for current parameter.
+ unsigned End;
+
+ // Means that current range of registers doesn't belong to any
+ // parameters. It was wasted due to stack alignment rules.
+ // For more information see:
+ // AAPCS, 5.5 Parameter Passing, Stage C, C.3.
+ bool Waste;
+ };
+ SmallVector<ByValInfo, 4 > ByValRegs;
+
+ // InRegsParamsProceed - shows how many instances of ByValRegs was proceed
+ // during argument analysis.
+ unsigned InRegsParamsProceed;
+
+protected:
ParmContext CallOrPrologue;
+
public:
CCState(CallingConv::ID CC, bool isVarArg, MachineFunction &MF,
const TargetMachine &TM, SmallVector<CCValAssign, 16> &locs,
/// getFirstUnallocated - Return the first unallocated register in the set, or
/// NumRegs if they are all allocated.
- unsigned getFirstUnallocated(const unsigned *Regs, unsigned NumRegs) const {
+ unsigned getFirstUnallocated(const uint16_t *Regs, unsigned NumRegs) const {
for (unsigned i = 0; i != NumRegs; ++i)
if (!isAllocated(Regs[i]))
return i;
/// AllocateReg - Attempt to allocate one of the specified registers. If none
/// are available, return zero. Otherwise, return the first one available,
/// marking it and any aliases as allocated.
- unsigned AllocateReg(const unsigned *Regs, unsigned NumRegs) {
+ unsigned AllocateReg(const uint16_t *Regs, unsigned NumRegs) {
unsigned FirstUnalloc = getFirstUnallocated(Regs, NumRegs);
if (FirstUnalloc == NumRegs)
return 0; // Didn't find the reg.
}
/// Version of AllocateReg with list of registers to be shadowed.
- unsigned AllocateReg(const unsigned *Regs, const unsigned *ShadowRegs,
+ unsigned AllocateReg(const uint16_t *Regs, const uint16_t *ShadowRegs,
unsigned NumRegs) {
unsigned FirstUnalloc = getFirstUnallocated(Regs, NumRegs);
if (FirstUnalloc == NumRegs)
StackOffset = ((StackOffset + Align-1) & ~(Align-1));
unsigned Result = StackOffset;
StackOffset += Size;
+ MF.getFrameInfo()->ensureMaxAlignment(Align);
return Result;
}
MVT LocVT, CCValAssign::LocInfo LocInfo,
int MinSize, int MinAlign, ISD::ArgFlagsTy ArgFlags);
- // First GPR that carries part of a byval aggregate that's split
- // between registers and memory.
- unsigned getFirstByValReg() { return FirstByValRegValid ? FirstByValReg : 0; }
- void setFirstByValReg(unsigned r) { FirstByValReg = r; FirstByValRegValid = true; }
- void clearFirstByValReg() { FirstByValReg = 0; FirstByValRegValid = false; }
- bool isFirstByValRegValid() { return FirstByValRegValid; }
+ // Returns count of byval arguments that are to be stored (even partly)
+ // in registers.
+ unsigned getInRegsParamsCount() const { return ByValRegs.size(); }
+
+ // Returns count of byval in-regs arguments proceed.
+ unsigned getInRegsParamsProceed() const { return InRegsParamsProceed; }
+
+ // Get information about N-th byval parameter that is stored in registers.
+ // Here "ByValParamIndex" is N.
+ void getInRegsParamInfo(unsigned InRegsParamRecordIndex,
+ unsigned& BeginReg, unsigned& EndReg) const {
+ assert(InRegsParamRecordIndex < ByValRegs.size() &&
+ "Wrong ByVal parameter index");
+
+ const ByValInfo& info = ByValRegs[InRegsParamRecordIndex];
+ BeginReg = info.Begin;
+ EndReg = info.End;
+ }
+
+ // Add information about parameter that is kept in registers.
+ void addInRegsParamInfo(unsigned RegBegin, unsigned RegEnd) {
+ ByValRegs.push_back(ByValInfo(RegBegin, RegEnd));
+ }
+
+ // Goes either to next byval parameter (excluding "waste" record), or
+ // to the end of collection.
+ // Returns false, if end is reached.
+ bool nextInRegsParam() {
+ unsigned e = ByValRegs.size();
+ if (InRegsParamsProceed < e)
+ ++InRegsParamsProceed;
+ return InRegsParamsProceed < e;
+ }
+
+ // Clear byval registers tracking info.
+ void clearByValRegsInfo() {
+ InRegsParamsProceed = 0;
+ ByValRegs.clear();
+ }
- ParmContext getCallOrPrologue() { return CallOrPrologue; }
- void setCallOrPrologue(ParmContext pc) { CallOrPrologue = pc; }
+ ParmContext getCallOrPrologue() const { return CallOrPrologue; }
private:
/// MarkAllocated - Mark a register and all of its aliases as allocated.