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/*
* Copyright 2006 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef Sk64_DEFINED
#define Sk64_DEFINED
#include "SkFixed.h"
/** \class Sk64
Sk64 is a 64-bit math package that does not require long long support from the compiler.
*/
struct SK_API Sk64 {
int32_t fHi; //!< the high 32 bits of the number (including sign)
uint32_t fLo; //!< the low 32 bits of the number
/** Returns non-zero if the Sk64 can be represented as a signed 32 bit integer
*/
SkBool is32() const { return fHi == ((int32_t)fLo >> 31); }
/** Returns non-zero if the Sk64 cannot be represented as a signed 32 bit integer
*/
SkBool is64() const { return fHi != ((int32_t)fLo >> 31); }
/** Returns non-zero if the Sk64 can be represented as a signed 48 bit integer. Used to know
if we can shift the value down by 16 to treat it as a SkFixed.
*/
SkBool isFixed() const;
/** Return the signed 32 bit integer equivalent. Asserts that is32() returns non-zero.
*/
int32_t get32() const { SkASSERT(this->is32()); return (int32_t)fLo; }
/** Return the number >> 16. Asserts that this does not loose any significant high bits.
*/
SkFixed getFixed() const {
SkASSERT(this->isFixed());
uint32_t sum = fLo + (1 << 15);
int32_t hi = fHi;
if (sum < fLo) {
hi += 1;
}
return (hi << 16) | (sum >> 16);
}
/** Return the number >> 30. Asserts that this does not loose any
significant high bits.
*/
SkFract getFract() const;
/** Returns the square-root of the number as a signed 32 bit value. */
int32_t getSqrt() const;
/** Returns the number of leading zeros of the absolute value of this.
Will return in the range [0..64]
*/
int getClzAbs() const;
/** Returns non-zero if the number is zero */
SkBool isZero() const { return (fHi | fLo) == 0; }
/** Returns non-zero if the number is non-zero */
SkBool nonZero() const { return fHi | fLo; }
/** Returns non-zero if the number is negative (number < 0) */
SkBool isNeg() const { return (uint32_t)fHi >> 31; }
/** Returns non-zero if the number is positive (number > 0) */
SkBool isPos() const { return ~(fHi >> 31) & (fHi | fLo); }
/** Returns -1,0,+1 based on the sign of the number */
int getSign() const { return (fHi >> 31) | Sk32ToBool(fHi | fLo); }
/** Negate the number */
void negate();
/** If the number < 0, negate the number
*/
void abs();
/** Returns the number of bits needed to shift the Sk64 to the right
in order to make it fit in a signed 32 bit integer.
*/
int shiftToMake32() const;
/** Set the number to zero */
void setZero() { fHi = fLo = 0; }
/** Set the high and low 32 bit values of the number */
void set(int32_t hi, uint32_t lo) { fHi = hi; fLo = lo; }
/** Set the number to the specified 32 bit integer */
void set(int32_t a) { fHi = a >> 31; fLo = a; }
/** Set the number to the product of the two 32 bit integers */
void setMul(int32_t a, int32_t b);
/** extract 32bits after shifting right by bitCount.
Note: itCount must be [0..63].
Asserts that no significant high bits were lost.
*/
int32_t getShiftRight(unsigned bitCount) const;
/** Shift the number left by the specified number of bits.
@param bits How far to shift left, must be [0..63]
*/
void shiftLeft(unsigned bits);
/** Shift the number right by the specified number of bits.
@param bits How far to shift right, must be [0..63]. This
performs an arithmetic right-shift (sign extending).
*/
void shiftRight(unsigned bits);
/** Shift the number right by the specified number of bits, but
round the result.
@param bits How far to shift right, must be [0..63]. This
performs an arithmetic right-shift (sign extending).
*/
void roundRight(unsigned bits);
/** Add the specified 32 bit integer to the number */
void add(int32_t lo) {
int32_t hi = lo >> 31; // 0 or -1
uint32_t sum = fLo + (uint32_t)lo;
fHi = fHi + hi + (sum < fLo);
fLo = sum;
}
/** Add the specified Sk64 to the number */
void add(int32_t hi, uint32_t lo) {
uint32_t sum = fLo + lo;
fHi = fHi + hi + (sum < fLo);
fLo = sum;
}
/** Add the specified Sk64 to the number */
void add(const Sk64& other) { this->add(other.fHi, other.fLo); }
/** Subtract the specified Sk64 from the number. (*this) = (*this) - num
*/
void sub(const Sk64& num);
/** Subtract the number from the specified Sk64. (*this) = num - (*this)
*/
void rsub(const Sk64& num);
/** Multiply the number by the specified 32 bit integer
*/
void mul(int32_t);
enum DivOptions {
kTrunc_DivOption, //!< truncate the result when calling div()
kRound_DivOption //!< round the result when calling div()
};
/** Divide the number by the specified 32 bit integer, using the specified
divide option (either truncate or round).
*/
void div(int32_t, DivOptions);
/** return (this + other >> 16) as a 32bit result */
SkFixed addGetFixed(const Sk64& other) const {
return this->addGetFixed(other.fHi, other.fLo);
}
/** return (this + Sk64(hi, lo) >> 16) as a 32bit result */
SkFixed addGetFixed(int32_t hi, uint32_t lo) const {
#ifdef SK_DEBUG
Sk64 tmp(*this);
tmp.add(hi, lo);
#endif
uint32_t sum = fLo + lo;
hi += fHi + (sum < fLo);
lo = sum;
sum = lo + (1 << 15);
if (sum < lo)
hi += 1;
hi = (hi << 16) | (sum >> 16);
SkASSERT(hi == tmp.getFixed());
return hi;
}
/** Return the result of dividing the number by denom, treating the answer
as a SkFixed. (*this) << 16 / denom. It is an error for denom to be 0.
*/
SkFixed getFixedDiv(const Sk64& denom) const;
friend bool operator==(const Sk64& a, const Sk64& b) {
return a.fHi == b.fHi && a.fLo == b.fLo;
}
friend bool operator!=(const Sk64& a, const Sk64& b) {
return a.fHi != b.fHi || a.fLo != b.fLo;
}
friend bool operator<(const Sk64& a, const Sk64& b) {
return a.fHi < b.fHi || (a.fHi == b.fHi && a.fLo < b.fLo);
}
friend bool operator<=(const Sk64& a, const Sk64& b) {
return a.fHi < b.fHi || (a.fHi == b.fHi && a.fLo <= b.fLo);
}
friend bool operator>(const Sk64& a, const Sk64& b) {
return a.fHi > b.fHi || (a.fHi == b.fHi && a.fLo > b.fLo);
}
friend bool operator>=(const Sk64& a, const Sk64& b) {
return a.fHi > b.fHi || (a.fHi == b.fHi && a.fLo >= b.fLo);
}
#ifdef SkLONGLONG
SkLONGLONG getLongLong() const;
#endif
};
#endif
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