azalea/kotlin-fork
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Added implementations for takeHighestOneBit, countTrailingZeroBits, countLeadingZeroBits, countOneBits

Browse Source
This commit is contained in:
Sergey Bogolepov
2019-06-26 18:28:40 +07:00
committed by Ilya Gorbunov
parent ff4c932e67
commit be40916ff6
2 changed files with 54 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files
runtime/src/main/cpp/Operator.cpp
+11
View File
@@ -67,4 +67,15 @@ ALWAYS_INLINE KBoolean Kotlin_Double_isNaN(KDouble a) { return isnan(a)
ALWAYS_INLINE KBoolean Kotlin_Double_isInfinite(KDouble a) { return isinf(a); }
ALWAYS_INLINE KBoolean Kotlin_Double_isFinite(KDouble a) { return isfinite(a); }
//--- Bit operations ---------------------------------------------------------//
ALWAYS_INLINE KInt Kotlin_Int_countOneBits(KInt value) { return __builtin_popcount(value); }
ALWAYS_INLINE KInt Kotlin_Long_countOneBits(KLong value) { return __builtin_popcountll(value); }
ALWAYS_INLINE KInt Kotlin_Int_countTrailingZeroBits(KInt value) { return __builtin_ctz(value); }
ALWAYS_INLINE KInt Kotlin_Long_countTrailingZeroBits(KLong value) { return __builtin_ctzll(value); }
ALWAYS_INLINE KInt Kotlin_Int_countLeadingZeroBits(KInt value) { return __builtin_clz(value); }
ALWAYS_INLINE KInt Kotlin_Long_countLeadingZeroBits(KLong value) { return __builtin_clzll(value); }
} // extern "C"
runtime/src/main/kotlin/kotlin/Numbers.kt
+43 -18
View File
@@ -108,30 +108,38 @@ internal external fun fromBits(bits: Int): Float
*/
@SinceKotlin("1.3")
@ExperimentalStdlibApi
public actual fun Int.countOneBits(): Int {
var v = this
v = (v and 0x55555555) + (v.ushr(1) and 0x55555555)
v = (v and 0x33333333) + (v.ushr(2) and 0x33333333)
v = (v and 0x0F0F0F0F) + (v.ushr(4) and 0x0F0F0F0F)
v = (v and 0x00FF00FF) + (v.ushr(8) and 0x00FF00FF)
v = (v and 0x0000FFFF) + (v.ushr(16))
return v
}
@SymbolName("Kotlin_Int_countOneBits")
public actual external fun Int.countOneBits(): Int
/**
* Counts the number of consecutive most significant bits that are zero in the binary representation of [Int] [value].
* Returns undefined result for zero [value].
*/
@SymbolName("Kotlin_Int_countLeadingZeroBits")
private external fun countLeadingZeroBits(value: Int): Int
/**
* Counts the number of consecutive most significant bits that are zero in the binary representation of this [Int] number.
*/
@SinceKotlin("1.3")
@ExperimentalStdlibApi
public actual fun Int.countLeadingZeroBits(): Int = TODO()
public actual fun Int.countLeadingZeroBits(): Int =
if (this == 0) Int.SIZE_BITS else countLeadingZeroBits(this)
/**
* Counts the number of consecutive least significant bits that are zero in the binary representation of [Int] [value].
* Returns undefined result for zero [value].
*/
@SymbolName("Kotlin_Int_countTrailingZeroBits")
private external fun countTrailingZeroBits(value: Int): Int
/**
* Counts the number of consecutive least significant bits that are zero in the binary representation of this [Int] number.
*/
@SinceKotlin("1.3")
@ExperimentalStdlibApi
public actual fun Int.countTrailingZeroBits(): Int = TODO()
// Int.SIZE_BITS - (this or -this).inv().countLeadingZeroBits()
public actual fun Int.countTrailingZeroBits(): Int =
if (this == 0) Int.SIZE_BITS else countTrailingZeroBits(this)
/**
* Returns a number having a single bit set in the position of the most significant set bit of this [Int] number,
@@ -140,7 +148,7 @@ public actual fun Int.countTrailingZeroBits(): Int = TODO()
@SinceKotlin("1.3")
@ExperimentalStdlibApi
public actual fun Int.takeHighestOneBit(): Int =
if (this == 0) 0 else 1.shl(Int.SIZE_BITS - 1 - countLeadingZeroBits())
if (this == 0) 0 else 1.shl(Int.SIZE_BITS - 1 - countLeadingZeroBits(this))
/**
* Returns a number having a single bit set in the position of the least significant set bit of this [Int] number,
@@ -188,22 +196,38 @@ public actual fun Int.rotateRight(bitCount: Int): Int =
*/
@SinceKotlin("1.3")
@ExperimentalStdlibApi
public actual fun Long.countOneBits(): Int = TODO()
// high.countOneBits() + low.countOneBits()
@SymbolName("Kotlin_Long_countOneBits")
public actual external fun Long.countOneBits(): Int
/**
* Counts the number of consecutive most significant bits that are zero in the binary representation of [Long] [value].
* Returns undefined result for zero [value].
*/
@SymbolName("Kotlin_Long_countLeadingZeroBits")
private external fun countLeadingZeroBits(value: Long): Int
/**
* Counts the number of consecutive most significant bits that are zero in the binary representation of this [Long] number.
*/
@SinceKotlin("1.3")
@ExperimentalStdlibApi
public actual fun Long.countLeadingZeroBits(): Int = TODO()
public actual fun Long.countLeadingZeroBits(): Int =
if (this == 0L) Long.SIZE_BITS else countLeadingZeroBits(this)
/**
* Counts the number of consecutive least significant bits that are zero in the binary representation of [Long] [value].
* Returns undefined result for zero [value].
*/
@SymbolName("Kotlin_Long_countTrailingZeroBits")
private external fun countTrailingZeroBits(value: Long): Int
/**
* Counts the number of consecutive least significant bits that are zero in the binary representation of this [Long] number.
*/
@SinceKotlin("1.3")
@ExperimentalStdlibApi
public actual fun Long.countTrailingZeroBits(): Int = TODO()
public actual fun Long.countTrailingZeroBits(): Int =
if (this == 0L) Long.SIZE_BITS else countTrailingZeroBits(this)
/**
* Returns a number having a single bit set in the position of the most significant set bit of this [Long] number,
@@ -211,7 +235,8 @@ public actual fun Long.countTrailingZeroBits(): Int = TODO()
*/
@SinceKotlin("1.3")
@ExperimentalStdlibApi
public actual fun Long.takeHighestOneBit(): Long = TODO()
public actual fun Long.takeHighestOneBit(): Long =
if (this == 0L) 0L else 1L.shl(Long.SIZE_BITS - 1 - countLeadingZeroBits(this))
/**
* Returns a number having a single bit set in the position of the least significant set bit of this [Long] number,