lyng/lynglib/src/jvmTest/kotlin/ArithmeticBenchmarkTest.kt

94 lines
3.1 KiB
Kotlin

/*
* Copyright 2025 Sergey S. Chernov real.sergeych@gmail.com
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
/*
* JVM micro-benchmarks for primitive arithmetic and comparison fast paths.
*/
import kotlinx.coroutines.runBlocking
import net.sergeych.lyng.PerfFlags
import net.sergeych.lyng.Scope
import net.sergeych.lyng.obj.ObjInt
import kotlin.test.Test
import kotlin.test.assertEquals
class ArithmeticBenchmarkTest {
@Test
fun benchmarkIntArithmeticAndComparisons() = runBlocking {
val n = 400_000
val sumScript = """
var s = 0
var i = 0
while (i < $n) {
s = s + i
i = i + 1
}
s
""".trimIndent()
// Baseline: disable primitive fast ops
PerfFlags.PRIMITIVE_FASTOPS = false
val scope1 = Scope()
val t0 = System.nanoTime()
val r1 = (scope1.eval(sumScript) as ObjInt).value
val t1 = System.nanoTime()
println("[DEBUG_LOG] [BENCH] int-sum x$n [PRIMITIVE_FASTOPS=OFF]: ${(t1 - t0)/1_000_000.0} ms")
// Optimized
PerfFlags.PRIMITIVE_FASTOPS = true
val scope2 = Scope()
val t2 = System.nanoTime()
val r2 = (scope2.eval(sumScript) as ObjInt).value
val t3 = System.nanoTime()
println("[DEBUG_LOG] [BENCH] int-sum x$n [PRIMITIVE_FASTOPS=ON]: ${(t3 - t2)/1_000_000.0} ms")
val expected = (n.toLong() - 1L) * n / 2L
assertEquals(expected, r1)
assertEquals(expected, r2)
// Comparison heavy (branchy) loop
val cmpScript = """
var s = 0
var i = 0
while (i < $n) {
if (i % 2 == 0) s = s + 1 else s = s + 2
i = i + 1
}
s
""".trimIndent()
PerfFlags.PRIMITIVE_FASTOPS = false
val scope3 = Scope()
val t4 = System.nanoTime()
val c1 = (scope3.eval(cmpScript) as ObjInt).value
val t5 = System.nanoTime()
println("[DEBUG_LOG] [BENCH] int-cmp x$n [PRIMITIVE_FASTOPS=OFF]: ${(t5 - t4)/1_000_000.0} ms")
PerfFlags.PRIMITIVE_FASTOPS = true
val scope4 = Scope()
val t6 = System.nanoTime()
val c2 = (scope4.eval(cmpScript) as ObjInt).value
val t7 = System.nanoTime()
println("[DEBUG_LOG] [BENCH] int-cmp x$n [PRIMITIVE_FASTOPS=ON]: ${(t7 - t6)/1_000_000.0} ms")
// Expected: half of n even add 1, half odd add 2 (n even assumed)
val expectedCmp = (n / 2) * 1L + (n - n / 2) * 2L
assertEquals(expectedCmp, c1)
assertEquals(expectedCmp, c2)
}
}