1 //== APSIntType.h - Simple record of the type of APSInts --------*- 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 #ifndef LLVM_CLANG_SA_CORE_APSINTTYPE_H
11 #define LLVM_CLANG_SA_CORE_APSINTTYPE_H
13 #include "llvm/ADT/APSInt.h"
19 /// \brief A record of the "type" of an APSInt, used for conversions.
25 APSIntType(uint32_t Width, bool Unsigned)
26 : BitWidth(Width), IsUnsigned(Unsigned) {}
28 /* implicit */ APSIntType(const llvm::APSInt &Value)
29 : BitWidth(Value.getBitWidth()), IsUnsigned(Value.isUnsigned()) {}
31 uint32_t getBitWidth() const { return BitWidth; }
32 bool isUnsigned() const { return IsUnsigned; }
34 /// \brief Convert a given APSInt, in place, to match this type.
36 /// This behaves like a C cast: converting 255u8 (0xFF) to s16 gives
37 /// 255 (0x00FF), and converting -1s8 (0xFF) to u16 gives 65535 (0xFFFF).
38 void apply(llvm::APSInt &Value) const {
39 // Note the order here. We extend first to preserve the sign, if this value
40 // is signed, /then/ match the signedness of the result type.
41 Value = Value.extOrTrunc(BitWidth);
42 Value.setIsUnsigned(IsUnsigned);
45 /// Convert and return a new APSInt with the given value, but this
46 /// type's bit width and signedness.
49 llvm::APSInt convert(const llvm::APSInt &Value) const LLVM_READONLY {
50 llvm::APSInt Result(Value, Value.isUnsigned());
55 /// Returns an all-zero value for this type.
56 llvm::APSInt getZeroValue() const LLVM_READONLY {
57 return llvm::APSInt(BitWidth, IsUnsigned);
60 /// Returns the minimum value for this type.
61 llvm::APSInt getMinValue() const LLVM_READONLY {
62 return llvm::APSInt::getMinValue(BitWidth, IsUnsigned);
65 /// Returns the maximum value for this type.
66 llvm::APSInt getMaxValue() const LLVM_READONLY {
67 return llvm::APSInt::getMaxValue(BitWidth, IsUnsigned);
70 llvm::APSInt getValue(uint64_t RawValue) const LLVM_READONLY {
71 return (llvm::APSInt(BitWidth, IsUnsigned) = RawValue);
74 /// Used to classify whether a value is representable using this type.
77 enum RangeTestResultKind {
78 RTR_Below = -1, ///< Value is less than the minimum representable value.
79 RTR_Within = 0, ///< Value is representable using this type.
80 RTR_Above = 1 ///< Value is greater than the maximum representable value.
83 /// Tests whether a given value is losslessly representable using this type.
85 /// \param Val The value to test.
86 /// \param AllowMixedSign Whether or not to allow signedness conversions.
87 /// This determines whether -1s8 is considered in range
88 /// for 'unsigned char' (u8).
89 RangeTestResultKind testInRange(const llvm::APSInt &Val,
90 bool AllowMixedSign) const LLVM_READONLY;
92 bool operator==(const APSIntType &Other) const {
93 return BitWidth == Other.BitWidth && IsUnsigned == Other.IsUnsigned;
96 /// \brief Provide an ordering for finding a common conversion type.
98 /// Unsigned integers are considered to be better conversion types than
99 /// signed integers of the same width.
100 bool operator<(const APSIntType &Other) const {
101 return std::tie(BitWidth, IsUnsigned) <
102 std::tie(Other.BitWidth, Other.IsUnsigned);
106 } // end ento namespace
107 } // end clang namespace