//===- llvm/InlineAsm.h - Class to represent inline asm strings -*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This class represents the inline asm strings, which are Value*'s that are
// used as the callee operand of call instructions. InlineAsm's are uniqued
// like constants, and created via InlineAsm::get(...).
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_IR_INLINEASM_H
#define LLVM_IR_INLINEASM_H
#include "llvm/ADT/StringRef.h"
#include "llvm/IR/Value.h"
#include <cassert>
#include <string>
#include <vector>
namespace llvm {
class FunctionType;
class PointerType;
template <class ConstantClass> class ConstantUniqueMap;
class InlineAsm final : public Value {
public:
enum AsmDialect {
AD_ATT,
AD_Intel
};
private:
friend struct InlineAsmKeyType;
friend class ConstantUniqueMap<InlineAsm>;
std::string AsmString, Constraints;
FunctionType *FTy;
bool HasSideEffects;
bool IsAlignStack;
AsmDialect Dialect;
InlineAsm(FunctionType *Ty, const std::string &AsmString,
const std::string &Constraints, bool hasSideEffects,
bool isAlignStack, AsmDialect asmDialect);
/// When the ConstantUniqueMap merges two types and makes two InlineAsms
/// identical, it destroys one of them with this method.
void destroyConstant();
public:
InlineAsm(const InlineAsm &) = delete;
InlineAsm &operator=(const InlineAsm &) = delete;
/// InlineAsm::get - Return the specified uniqued inline asm string.
///
static InlineAsm *get(FunctionType *Ty, StringRef AsmString,
StringRef Constraints, bool hasSideEffects,
bool isAlignStack = false,
AsmDialect asmDialect = AD_ATT);
bool hasSideEffects() const { return HasSideEffects; }
bool isAlignStack() const { return IsAlignStack; }
AsmDialect getDialect() const { return Dialect; }
/// getType - InlineAsm's are always pointers.
///
PointerType *getType() const {
return reinterpret_cast<PointerType*>(Value::getType());
}
/// getFunctionType - InlineAsm's are always pointers to functions.
///
FunctionType *getFunctionType() const;
const std::string &getAsmString() const { return AsmString; }
const std::string &getConstraintString() const { return Constraints; }
/// Verify - This static method can be used by the parser to check to see if
/// the specified constraint string is legal for the type. This returns true
/// if legal, false if not.
///
static bool Verify(FunctionType *Ty, StringRef Constraints);
// Constraint String Parsing
enum ConstraintPrefix {
isInput, // 'x'
isOutput, // '=x'
isClobber // '~x'
};
using ConstraintCodeVector = std::vector<std::string>;
struct SubConstraintInfo {
/// MatchingInput - If this is not -1, this is an output constraint where an
/// input constraint is required to match it (e.g. "0"). The value is the
/// constraint number that matches this one (for example, if this is
/// constraint #0 and constraint #4 has the value "0", this will be 4).
int MatchingInput = -1;
/// Code - The constraint code, either the register name (in braces) or the
/// constraint letter/number.
ConstraintCodeVector Codes;
/// Default constructor.
SubConstraintInfo() = default;
};
using SubConstraintInfoVector = std::vector<SubConstraintInfo>;
struct ConstraintInfo;
using ConstraintInfoVector = std::vector<ConstraintInfo>;
struct ConstraintInfo {
/// Type - The basic type of the constraint: input/output/clobber
///
ConstraintPrefix Type = isInput;
/// isEarlyClobber - "&": output operand writes result before inputs are all
/// read. This is only ever set for an output operand.
bool isEarlyClobber = false;
/// MatchingInput - If this is not -1, this is an output constraint where an
/// input constraint is required to match it (e.g. "0"). The value is the
/// constraint number that matches this one (for example, if this is
/// constraint #0 and constraint #4 has the value "0", this will be 4).
int MatchingInput = -1;
/// hasMatchingInput - Return true if this is an output constraint that has
/// a matching input constraint.
bool hasMatchingInput() const { return MatchingInput != -1; }
/// isCommutative - This is set to true for a constraint that is commutative
/// with the next operand.
bool isCommutative = false;
/// isIndirect - True if this operand is an indirect operand. This means
/// that the address of the source or destination is present in the call
/// instruction, instead of it being returned or passed in explicitly. This
/// is represented with a '*' in the asm string.
bool isIndirect = false;
/// Code - The constraint code, either the register name (in braces) or the
/// constraint letter/number.
ConstraintCodeVector Codes;
/// isMultipleAlternative - '|': has multiple-alternative constraints.
bool isMultipleAlternative = false;
/// multipleAlternatives - If there are multiple alternative constraints,
/// this array will contain them. Otherwise it will be empty.
SubConstraintInfoVector multipleAlternatives;
/// The currently selected alternative constraint index.
unsigned currentAlternativeIndex = 0;
/// Default constructor.
ConstraintInfo() = default;
/// Parse - Analyze the specified string (e.g. "=*&{eax}") and fill in the
/// fields in this structure. If the constraint string is not understood,
/// return true, otherwise return false.
bool Parse(StringRef Str, ConstraintInfoVector &ConstraintsSoFar);
/// selectAlternative - Point this constraint to the alternative constraint
/// indicated by the index.
void selectAlternative(unsigned index);
};
/// ParseConstraints - Split up the constraint string into the specific
/// constraints and their prefixes. If this returns an empty vector, and if
/// the constraint string itself isn't empty, there was an error parsing.
static ConstraintInfoVector ParseConstraints(StringRef ConstraintString);
/// ParseConstraints - Parse the constraints of this inlineasm object,
/// returning them the same way that ParseConstraints(str) does.
ConstraintInfoVector ParseConstraints() const {
return ParseConstraints(Constraints);
}
// Methods for support type inquiry through isa, cast, and dyn_cast:
static bool classof(const Value *V) {
return V->getValueID() == Value::InlineAsmVal;
}
// These are helper methods for dealing with flags in the INLINEASM SDNode
// in the backend.
//
// The encoding of the flag word is currently:
// Bits 2-0 - A Kind_* value indicating the kind of the operand.
// Bits 15-3 - The number of SDNode operands associated with this inline
// assembly operand.
// If bit 31 is set:
// Bit 30-16 - The operand number that this operand must match.
// When bits 2-0 are Kind_Mem, the Constraint_* value must be
// obtained from the flags for this operand number.
// Else if bits 2-0 are Kind_Mem:
// Bit 30-16 - A Constraint_* value indicating the original constraint
// code.
// Else:
// Bit 30-16 - The register class ID to use for the operand.
enum : uint32_t {
// Fixed operands on an INLINEASM SDNode.
Op_InputChain = 0,
Op_AsmString = 1,
Op_MDNode = 2,
Op_ExtraInfo = 3, // HasSideEffects, IsAlignStack, AsmDialect.
Op_FirstOperand = 4,
// Fixed operands on an INLINEASM MachineInstr.
MIOp_AsmString = 0,
MIOp_ExtraInfo = 1, // HasSideEffects, IsAlignStack, AsmDialect.
MIOp_FirstOperand = 2,
// Interpretation of the MIOp_ExtraInfo bit field.
Extra_HasSideEffects = 1,
Extra_IsAlignStack = 2,
Extra_AsmDialect = 4,
Extra_MayLoad = 8,
Extra_MayStore = 16,
Extra_IsConvergent = 32,
// Inline asm operands map to multiple SDNode / MachineInstr operands.
// The first operand is an immediate describing the asm operand, the low
// bits is the kind:
Kind_RegUse = 1, // Input register, "r".
Kind_RegDef = 2, // Output register, "=r".
Kind_RegDefEarlyClobber = 3, // Early-clobber output register, "=&r".
Kind_Clobber = 4, // Clobbered register, "~r".
Kind_Imm = 5, // Immediate.
Kind_Mem = 6, // Memory operand, "m".
// Memory constraint codes.
// These could be tablegenerated but there's little need to do that since
// there's plenty of space in the encoding to support the union of all
// constraint codes for all targets.
Constraint_Unknown = 0,
Constraint_es,
Constraint_i,
Constraint_m,
Constraint_o,
Constraint_v,
Constraint_Q,
Constraint_R,
Constraint_S,
Constraint_T,
Constraint_Um,
Constraint_Un,
Constraint_Uq,
Constraint_Us,
Constraint_Ut,
Constraint_Uv,
Constraint_Uy,
Constraint_X,
Constraint_Z,
Constraint_ZC,
Constraint_Zy,
Constraints_Max = Constraint_Zy,
Constraints_ShiftAmount = 16,
Flag_MatchingOperand = 0x80000000
};
static unsigned getFlagWord(unsigned Kind, unsigned NumOps) {
assert(((NumOps << 3) & ~0xffff) == 0 && "Too many inline asm operands!");
assert(Kind >= Kind_RegUse && Kind <= Kind_Mem && "Invalid Kind");
return Kind | (NumOps << 3);
}
static bool isRegDefKind(unsigned Flag){ return getKind(Flag) == Kind_RegDef;}
static bool isImmKind(unsigned Flag) { return getKind(Flag) == Kind_Imm; }
static bool isMemKind(unsigned Flag) { return getKind(Flag) == Kind_Mem; }
static bool isRegDefEarlyClobberKind(unsigned Flag) {
return getKind(Flag) == Kind_RegDefEarlyClobber;
}
static bool isClobberKind(unsigned Flag) {
return getKind(Flag) == Kind_Clobber;
}
/// getFlagWordForMatchingOp - Augment an existing flag word returned by
/// getFlagWord with information indicating that this input operand is tied
/// to a previous output operand.
static unsigned getFlagWordForMatchingOp(unsigned InputFlag,
unsigned MatchedOperandNo) {
assert(MatchedOperandNo <= 0x7fff && "Too big matched operand");
assert((InputFlag & ~0xffff) == 0 && "High bits already contain data");
return InputFlag | Flag_MatchingOperand | (MatchedOperandNo << 16);
}
/// getFlagWordForRegClass - Augment an existing flag word returned by
/// getFlagWord with the required register class for the following register
/// operands.
/// A tied use operand cannot have a register class, use the register class
/// from the def operand instead.
static unsigned getFlagWordForRegClass(unsigned InputFlag, unsigned RC) {
// Store RC + 1, reserve the value 0 to mean 'no register class'.
++RC;
assert(!isImmKind(InputFlag) && "Immediates cannot have a register class");
assert(!isMemKind(InputFlag) && "Memory operand cannot have a register class");
assert(RC <= 0x7fff && "Too large register class ID");
assert((InputFlag & ~0xffff) == 0 && "High bits already contain data");
return InputFlag | (RC << 16);
}
/// Augment an existing flag word returned by getFlagWord with the constraint
/// code for a memory constraint.
static unsigned getFlagWordForMem(unsigned InputFlag, unsigned Constraint) {
assert(isMemKind(InputFlag) && "InputFlag is not a memory constraint!");
assert(Constraint <= 0x7fff && "Too large a memory constraint ID");
assert(Constraint <= Constraints_Max && "Unknown constraint ID");
assert((InputFlag & ~0xffff) == 0 && "High bits already contain data");
return InputFlag | (Constraint << Constraints_ShiftAmount);
}
static unsigned convertMemFlagWordToMatchingFlagWord(unsigned InputFlag) {
assert(isMemKind(InputFlag));
return InputFlag & ~(0x7fff << Constraints_ShiftAmount);
}
static unsigned getKind(unsigned Flags) {
return Flags & 7;
}
static unsigned getMemoryConstraintID(unsigned Flag) {
assert(isMemKind(Flag));
return (Flag >> Constraints_ShiftAmount) & 0x7fff;
}
/// getNumOperandRegisters - Extract the number of registers field from the
/// inline asm operand flag.
static unsigned getNumOperandRegisters(unsigned Flag) {
return (Flag & 0xffff) >> 3;
}
/// isUseOperandTiedToDef - Return true if the flag of the inline asm
/// operand indicates it is an use operand that's matched to a def operand.
static bool isUseOperandTiedToDef(unsigned Flag, unsigned &Idx) {
if ((Flag & Flag_MatchingOperand) == 0)
return false;
Idx = (Flag & ~Flag_MatchingOperand) >> 16;
return true;
}
/// hasRegClassConstraint - Returns true if the flag contains a register
/// class constraint. Sets RC to the register class ID.
static bool hasRegClassConstraint(unsigned Flag, unsigned &RC) {
if (Flag & Flag_MatchingOperand)
return false;
unsigned High = Flag >> 16;
// getFlagWordForRegClass() uses 0 to mean no register class, and otherwise
// stores RC + 1.
if (!High)
return false;
RC = High - 1;
return true;
}
};
} // end namespace llvm
#endif // LLVM_IR_INLINEASM_H