Use common implementation of fastLog2 based on countLeadingZeroBits

2019-06-20 20:56:56 +03:00
parent f8724654a1
commit 39bdf34b9f
3 changed files with 3 additions and 15 deletions
@@ -336,9 +336,11 @@ public fun Random.nextLong(range: LongRange): Long = when {


 internal expect fun defaultPlatformRandom(): Random
-internal expect fun fastLog2(value: Int): Int //  31 - Integer.numberOfLeadingZeros(value)
 internal expect fun doubleFromParts(hi26: Int, low27: Int): Double

+@UseExperimental(ExperimentalStdlibApi::class)
+internal fun fastLog2(value: Int): Int = 31 - value.countLeadingZeroBits()
+
 /** Takes upper [bitCount] bits (0..32) from this number. */
 internal fun Int.takeUpperBits(bitCount: Int): Int =
    this.ushr(32 - bitCount) and (-bitCount).shr(31)