76 lines
2.4 KiB
Kotlin
76 lines
2.4 KiB
Kotlin
/*
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* Copyright 2025 Sergey S. Chernov real.sergeych@gmail.com
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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*/
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/*
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* JVM micro-benchmark focused on local variable access paths:
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* - LOCAL_SLOT_PIC (per-frame slot PIC in LocalVarRef)
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* - EMIT_FAST_LOCAL_REFS (compiler-emitted fast locals)
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*/
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import kotlinx.coroutines.runBlocking
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import net.sergeych.lyng.PerfFlags
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import net.sergeych.lyng.Scope
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import net.sergeych.lyng.obj.ObjInt
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import kotlin.test.Test
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import kotlin.test.assertEquals
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class LocalVarBenchmarkTest {
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@Test
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fun benchmarkLocalReadsWrites_off_on() = runBlocking {
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val iterations = 400_000
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val script = """
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fun hot(n){
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var a = 0
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var b = 1
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var c = 2
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var s = 0
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var i = 0
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while(i < n){
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a = a + 1
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b = b + a
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c = c + b
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s = s + a + b + c
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i = i + 1
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}
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s
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}
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hot($iterations)
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""".trimIndent()
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// Baseline: disable both fast paths
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PerfFlags.LOCAL_SLOT_PIC = false
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PerfFlags.EMIT_FAST_LOCAL_REFS = false
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val scope1 = Scope()
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val t0 = System.nanoTime()
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val r1 = (scope1.eval(script) as ObjInt).value
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val t1 = System.nanoTime()
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println("[DEBUG_LOG] [BENCH] locals x$iterations [PIC=OFF, FAST_LOCAL=OFF]: ${(t1 - t0)/1_000_000.0} ms")
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// Optimized: enable both
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PerfFlags.LOCAL_SLOT_PIC = true
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PerfFlags.EMIT_FAST_LOCAL_REFS = true
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val scope2 = Scope()
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val t2 = System.nanoTime()
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val r2 = (scope2.eval(script) as ObjInt).value
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val t3 = System.nanoTime()
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println("[DEBUG_LOG] [BENCH] locals x$iterations [PIC=ON, FAST_LOCAL=ON]: ${(t3 - t2)/1_000_000.0} ms")
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// Correctness: both runs produce the same result
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assertEquals(r1, r2)
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}
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}
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