Merge pull request #94 from CommanderTvis/adv-expr

Optimization of expressions via ASM Bytecode Generation

kmath-ast/build.gradle.kts

@@ -2,7 +2,7 @@ plugins {
     id("scientifik.mpp")
 }
 
-repositories{
+repositories {
     maven("https://dl.bintray.com/hotkeytlt/maven")
 }
 
@@ -14,13 +14,18 @@ kotlin.sourceSets {
             implementation("com.github.h0tk3y.betterParse:better-parse-multiplatform-metadata:0.4.0-alpha-3")
         }
     }
-    jvmMain{
+
-        dependencies{
+    jvmMain {
+        dependencies {
             implementation("com.github.h0tk3y.betterParse:better-parse-jvm:0.4.0-alpha-3")
+            implementation("org.ow2.asm:asm:8.0.1")
+            implementation("org.ow2.asm:asm-commons:8.0.1")
+            implementation(kotlin("reflect"))
         }
     }
-    jsMain{
+
-        dependencies{
+    jsMain {
+        dependencies {
             implementation("com.github.h0tk3y.betterParse:better-parse-js:0.4.0-alpha-3")
         }
     }

kmath-ast/src/jvmMain/kotlin/scientifik/kmath/asm/AsmBuilders.kt

@@ -0,0 +1,56 @@
+package scientifik.kmath.asm
+
+import scientifik.kmath.asm.internal.AsmGenerationContext
+import scientifik.kmath.ast.MST
+import scientifik.kmath.ast.evaluate
+import scientifik.kmath.expressions.Expression
+import scientifik.kmath.operations.*
+
+@PublishedApi
+internal fun buildName(expression: AsmNode<*>, collision: Int = 0): String {
+    val name = "scientifik.kmath.expressions.generated.AsmCompiledExpression_${expression.hashCode()}_$collision"
+
+    try {
+        Class.forName(name)
+    } catch (ignored: ClassNotFoundException) {
+        return name
+    }
+
+    return buildName(expression, collision + 1)
+}
+
+@PublishedApi
+internal inline fun <reified T> AsmNode<T>.compile(algebra: Algebra<T>): Expression<T> {
+    val ctx =
+        AsmGenerationContext(T::class.java, algebra, buildName(this))
+    compile(ctx)
+    return ctx.generate()
+}
+
+inline fun <reified T, A : NumericAlgebra<T>, E : AsmExpressionAlgebra<T, A>> A.asm(
+    expressionAlgebra: E,
+    block: E.() -> AsmNode<T>
+): Expression<T> = expressionAlgebra.block().compile(expressionAlgebra.algebra)
+
+inline fun <reified T, A : NumericAlgebra<T>, E : AsmExpressionAlgebra<T, A>> A.asm(
+    expressionAlgebra: E,
+    ast: MST
+): Expression<T> = asm(expressionAlgebra) { evaluate(ast) }
+
+inline fun <reified T, A> A.asmSpace(block: AsmExpressionSpace<T, A>.() -> AsmNode<T>): Expression<T> where A : NumericAlgebra<T>, A : Space<T> =
+    AsmExpressionSpace(this).let { it.block().compile(it.algebra) }
+
+inline fun <reified T, A> A.asmSpace(ast: MST): Expression<T> where A : NumericAlgebra<T>, A : Space<T> =
+    asmSpace { evaluate(ast) }
+
+inline fun <reified T, A> A.asmRing(block: AsmExpressionRing<T, A>.() -> AsmNode<T>): Expression<T> where A : NumericAlgebra<T>, A : Ring<T> =
+    AsmExpressionRing(this).let { it.block().compile(it.algebra) }
+
+inline fun <reified T, A> A.asmRing(ast: MST): Expression<T> where A : NumericAlgebra<T>, A : Ring<T> =
+    asmRing { evaluate(ast) }
+
+inline fun <reified T, A> A.asmField(block: AsmExpressionField<T, A>.() -> AsmNode<T>): Expression<T> where A : NumericAlgebra<T>, A : Field<T> =
+    AsmExpressionField(this).let { it.block().compile(it.algebra) }
+
+inline fun <reified T, A> A.asmField(ast: MST): Expression<T> where A : NumericAlgebra<T>, A : Field<T> =
+    asmRing { evaluate(ast) }

kmath-ast/src/jvmMain/kotlin/scientifik/kmath/asm/AsmExpressions.kt

@@ -0,0 +1,265 @@
+package scientifik.kmath.asm
+
+import scientifik.kmath.asm.internal.AsmGenerationContext
+import scientifik.kmath.asm.internal.hasSpecific
+import scientifik.kmath.asm.internal.optimize
+import scientifik.kmath.asm.internal.tryInvokeSpecific
+import scientifik.kmath.expressions.Expression
+import scientifik.kmath.expressions.ExpressionAlgebra
+import scientifik.kmath.operations.*
+
+/**
+ * A function declaration that could be compiled to [AsmGenerationContext].
+ *
+ * @param T the type the stored function returns.
+ */
+abstract class AsmNode<T> internal constructor() {
+    /**
+     * Tries to evaluate this function without its variables. This method is intended for optimization.
+     *
+     * @return `null` if the function depends on its variables, the value if the function is a constant.
+     */
+    internal open fun tryEvaluate(): T? = null
+
+    /**
+     * Compiles this declaration.
+     *
+     * @param gen the target [AsmGenerationContext].
+     */
+    @PublishedApi
+    internal abstract fun compile(gen: AsmGenerationContext<T>)
+}
+
+internal class AsmUnaryOperation<T>(private val context: Algebra<T>, private val name: String, expr: AsmNode<T>) :
+    AsmNode<T>() {
+    private val expr: AsmNode<T> = expr.optimize()
+    override fun tryEvaluate(): T? = context { unaryOperation(name, expr.tryEvaluate() ?: return@context null) }
+
+    override fun compile(gen: AsmGenerationContext<T>) {
+        gen.visitLoadAlgebra()
+
+        if (!hasSpecific(context, name, 1))
+            gen.visitStringConstant(name)
+
+        expr.compile(gen)
+
+        if (gen.tryInvokeSpecific(context, name, 1))
+            return
+
+        gen.visitAlgebraOperation(
+            owner = AsmGenerationContext.ALGEBRA_CLASS,
+            method = "unaryOperation",
+            descriptor = "(L${AsmGenerationContext.STRING_CLASS};" +
+                    "L${AsmGenerationContext.OBJECT_CLASS};)" +
+                    "L${AsmGenerationContext.OBJECT_CLASS};"
+        )
+    }
+}
+
+internal class AsmBinaryOperation<T>(
+    private val context: Algebra<T>,
+    private val name: String,
+    first: AsmNode<T>,
+    second: AsmNode<T>
+) : AsmNode<T>() {
+    private val first: AsmNode<T> = first.optimize()
+    private val second: AsmNode<T> = second.optimize()
+
+    override fun tryEvaluate(): T? = context {
+        binaryOperation(
+            name,
+            first.tryEvaluate() ?: return@context null,
+            second.tryEvaluate() ?: return@context null
+        )
+    }
+
+    override fun compile(gen: AsmGenerationContext<T>) {
+        gen.visitLoadAlgebra()
+
+        if (!hasSpecific(context, name, 2))
+            gen.visitStringConstant(name)
+
+        first.compile(gen)
+        second.compile(gen)
+
+        if (gen.tryInvokeSpecific(context, name, 2))
+            return
+
+        gen.visitAlgebraOperation(
+            owner = AsmGenerationContext.ALGEBRA_CLASS,
+            method = "binaryOperation",
+            descriptor = "(L${AsmGenerationContext.STRING_CLASS};" +
+                    "L${AsmGenerationContext.OBJECT_CLASS};" +
+                    "L${AsmGenerationContext.OBJECT_CLASS};)" +
+                    "L${AsmGenerationContext.OBJECT_CLASS};"
+        )
+    }
+}
+
+internal class AsmVariableExpression<T>(private val name: String, private val default: T? = null) :
+    AsmNode<T>() {
+    override fun compile(gen: AsmGenerationContext<T>): Unit = gen.visitLoadFromVariables(name, default)
+}
+
+internal class AsmConstantExpression<T>(private val value: T) :
+    AsmNode<T>() {
+    override fun tryEvaluate(): T = value
+    override fun compile(gen: AsmGenerationContext<T>): Unit = gen.visitLoadFromConstants(value)
+}
+
+internal class AsmConstProductExpression<T>(
+    private val context: Space<T>,
+    expr: AsmNode<T>,
+    private val const: Number
+) : AsmNode<T>() {
+    private val expr: AsmNode<T> = expr.optimize()
+
+    override fun tryEvaluate(): T? = context { (expr.tryEvaluate() ?: return@context null) * const }
+
+    override fun compile(gen: AsmGenerationContext<T>) {
+        gen.visitLoadAlgebra()
+        gen.visitNumberConstant(const)
+        expr.compile(gen)
+
+        gen.visitAlgebraOperation(
+            owner = AsmGenerationContext.SPACE_OPERATIONS_CLASS,
+            method = "multiply",
+            descriptor = "(L${AsmGenerationContext.OBJECT_CLASS};" +
+                    "L${AsmGenerationContext.NUMBER_CLASS};)" +
+                    "L${AsmGenerationContext.OBJECT_CLASS};"
+        )
+    }
+}
+
+internal class AsmNumberExpression<T>(private val context: NumericAlgebra<T>, private val value: Number) :
+    AsmNode<T>() {
+    override fun tryEvaluate(): T? = context.number(value)
+
+    override fun compile(gen: AsmGenerationContext<T>): Unit = gen.visitNumberConstant(value)
+}
+
+internal abstract class FunctionalCompiledExpression<T> internal constructor(
+    @JvmField protected val algebra: Algebra<T>,
+    @JvmField protected val constants: Array<Any>
+) : Expression<T> {
+    abstract override fun invoke(arguments: Map<String, T>): T
+}
+
+/**
+ * A context class for [AsmNode] construction.
+ */
+interface AsmExpressionAlgebra<T, A : NumericAlgebra<T>> : NumericAlgebra<AsmNode<T>>,
+    ExpressionAlgebra<T, AsmNode<T>> {
+    /**
+     * The algebra to provide for AsmExpressions built.
+     */
+    val algebra: A
+
+    /**
+     * Builds an AsmExpression to wrap a number.
+     */
+    override fun number(value: Number): AsmNode<T> = AsmNumberExpression(algebra, value)
+
+    /**
+     * Builds an AsmExpression of constant expression which does not depend on arguments.
+     */
+    override fun const(value: T): AsmNode<T> = AsmConstantExpression(value)
+
+    /**
+     * Builds an AsmExpression to access a variable.
+     */
+    override fun variable(name: String, default: T?): AsmNode<T> = AsmVariableExpression(name, default)
+
+    /**
+     * Builds an AsmExpression of dynamic call of binary operation [operation] on [left] and [right].
+     */
+    override fun binaryOperation(operation: String, left: AsmNode<T>, right: AsmNode<T>): AsmNode<T> =
+        AsmBinaryOperation(algebra, operation, left, right)
+
+    /**
+     * Builds an AsmExpression of dynamic call of unary operation with name [operation] on [arg].
+     */
+    override fun unaryOperation(operation: String, arg: AsmNode<T>): AsmNode<T> =
+        AsmUnaryOperation(algebra, operation, arg)
+}
+
+/**
+ * A context class for [AsmNode] construction for [Space] algebras.
+ */
+open class AsmExpressionSpace<T, A>(override val algebra: A) : AsmExpressionAlgebra<T, A>,
+    Space<AsmNode<T>> where  A : Space<T>, A : NumericAlgebra<T> {
+    override val zero: AsmNode<T>
+        get() = const(algebra.zero)
+
+    /**
+     * Builds an AsmExpression of addition of two another expressions.
+     */
+    override fun add(a: AsmNode<T>, b: AsmNode<T>): AsmNode<T> =
+        AsmBinaryOperation(algebra, SpaceOperations.PLUS_OPERATION, a, b)
+
+    /**
+     * Builds an AsmExpression of multiplication of expression by number.
+     */
+    override fun multiply(a: AsmNode<T>, k: Number): AsmNode<T> = AsmConstProductExpression(algebra, a, k)
+
+    operator fun AsmNode<T>.plus(arg: T): AsmNode<T> = this + const(arg)
+    operator fun AsmNode<T>.minus(arg: T): AsmNode<T> = this - const(arg)
+    operator fun T.plus(arg: AsmNode<T>): AsmNode<T> = arg + this
+    operator fun T.minus(arg: AsmNode<T>): AsmNode<T> = arg - this
+
+    override fun unaryOperation(operation: String, arg: AsmNode<T>): AsmNode<T> =
+        super<AsmExpressionAlgebra>.unaryOperation(operation, arg)
+
+    override fun binaryOperation(operation: String, left: AsmNode<T>, right: AsmNode<T>): AsmNode<T> =
+        super<AsmExpressionAlgebra>.binaryOperation(operation, left, right)
+}
+
+/**
+ * A context class for [AsmNode] construction for [Ring] algebras.
+ */
+open class AsmExpressionRing<T, A>(override val algebra: A) : AsmExpressionSpace<T, A>(algebra),
+    Ring<AsmNode<T>> where  A : Ring<T>, A : NumericAlgebra<T> {
+    override val one: AsmNode<T>
+        get() = const(algebra.one)
+
+    /**
+     * Builds an AsmExpression of multiplication of two expressions.
+     */
+    override fun multiply(a: AsmNode<T>, b: AsmNode<T>): AsmNode<T> =
+        AsmBinaryOperation(algebra, RingOperations.TIMES_OPERATION, a, b)
+
+    operator fun AsmNode<T>.times(arg: T): AsmNode<T> = this * const(arg)
+    operator fun T.times(arg: AsmNode<T>): AsmNode<T> = arg * this
+
+    override fun unaryOperation(operation: String, arg: AsmNode<T>): AsmNode<T> =
+        super<AsmExpressionSpace>.unaryOperation(operation, arg)
+
+    override fun binaryOperation(operation: String, left: AsmNode<T>, right: AsmNode<T>): AsmNode<T> =
+        super<AsmExpressionSpace>.binaryOperation(operation, left, right)
+
+    override fun number(value: Number): AsmNode<T> = super<AsmExpressionSpace>.number(value)
+}
+
+/**
+ * A context class for [AsmNode] construction for [Field] algebras.
+ */
+open class AsmExpressionField<T, A>(override val algebra: A) :
+    AsmExpressionRing<T, A>(algebra),
+    Field<AsmNode<T>> where A : Field<T>, A : NumericAlgebra<T> {
+    /**
+     * Builds an AsmExpression of division an expression by another one.
+     */
+    override fun divide(a: AsmNode<T>, b: AsmNode<T>): AsmNode<T> =
+        AsmBinaryOperation(algebra, FieldOperations.DIV_OPERATION, a, b)
+
+    operator fun AsmNode<T>.div(arg: T): AsmNode<T> = this / const(arg)
+    operator fun T.div(arg: AsmNode<T>): AsmNode<T> = arg / this
+
+    override fun unaryOperation(operation: String, arg: AsmNode<T>): AsmNode<T> =
+        super<AsmExpressionRing>.unaryOperation(operation, arg)
+
+    override fun binaryOperation(operation: String, left: AsmNode<T>, right: AsmNode<T>): AsmNode<T> =
+        super<AsmExpressionRing>.binaryOperation(operation, left, right)
+
+    override fun number(value: Number): AsmNode<T> = super<AsmExpressionRing>.number(value)
+}

kmath-ast/src/jvmMain/kotlin/scientifik/kmath/asm/internal/AsmGenerationContext.kt

@@ -0,0 +1,319 @@
+package scientifik.kmath.asm.internal
+
+import org.objectweb.asm.ClassWriter
+import org.objectweb.asm.Label
+import org.objectweb.asm.MethodVisitor
+import org.objectweb.asm.Opcodes
+import scientifik.kmath.asm.FunctionalCompiledExpression
+import scientifik.kmath.asm.internal.AsmGenerationContext.ClassLoader
+import scientifik.kmath.operations.Algebra
+
+/**
+ * AsmGenerationContext is a structure that abstracts building a class that unwraps [AsmNode] to plain Java
+ * expression. This class uses [ClassLoader] for loading the generated class, then it is able to instantiate the new
+ * class.
+ *
+ * @param T the type of AsmExpression to unwrap.
+ * @param algebra the algebra the applied AsmExpressions use.
+ * @param className the unique class name of new loaded class.
+ */
+@PublishedApi
+internal class AsmGenerationContext<T> @PublishedApi internal constructor(
+    private val classOfT: Class<*>,
+    private val algebra: Algebra<T>,
+    private val className: String
+) {
+    private class ClassLoader(parent: java.lang.ClassLoader) : java.lang.ClassLoader(parent) {
+        internal fun defineClass(name: String?, b: ByteArray): Class<*> = defineClass(name, b, 0, b.size)
+    }
+
+    private val classLoader: ClassLoader =
+        ClassLoader(javaClass.classLoader)
+
+    @Suppress("PrivatePropertyName")
+    private val T_ALGEBRA_CLASS: String = algebra.javaClass.name.replace(oldChar = '.', newChar = '/')
+
+    @Suppress("PrivatePropertyName")
+    private val T_CLASS: String = classOfT.name.replace('.', '/')
+
+    private val slashesClassName: String = className.replace(oldChar = '.', newChar = '/')
+    private val invokeThisVar: Int = 0
+    private val invokeArgumentsVar: Int = 1
+    private var maxStack: Int = 0
+    private val constants: MutableList<Any> = mutableListOf()
+    private val asmCompiledClassWriter: ClassWriter = ClassWriter(0)
+    private val invokeMethodVisitor: MethodVisitor
+    private val invokeL0: Label
+    private lateinit var invokeL1: Label
+    private var generatedInstance: FunctionalCompiledExpression<T>? = null
+
+    init {
+        asmCompiledClassWriter.visit(
+            Opcodes.V1_8,
+            Opcodes.ACC_PUBLIC or Opcodes.ACC_FINAL or Opcodes.ACC_SUPER,
+            slashesClassName,
+            "L$FUNCTIONAL_COMPILED_EXPRESSION_CLASS<L$T_CLASS;>;",
+            FUNCTIONAL_COMPILED_EXPRESSION_CLASS,
+            arrayOf()
+        )
+
+        asmCompiledClassWriter.run {
+            visitMethod(Opcodes.ACC_PUBLIC, "<init>", "(L$ALGEBRA_CLASS;[L$OBJECT_CLASS;)V", null, null).run {
+                val thisVar = 0
+                val algebraVar = 1
+                val constantsVar = 2
+                val l0 = Label()
+                visitLabel(l0)
+                visitVarInsn(Opcodes.ALOAD, thisVar)
+                visitVarInsn(Opcodes.ALOAD, algebraVar)
+                visitVarInsn(Opcodes.ALOAD, constantsVar)
+
+                visitMethodInsn(
+                    Opcodes.INVOKESPECIAL,
+                    FUNCTIONAL_COMPILED_EXPRESSION_CLASS,
+                    "<init>",
+                    "(L$ALGEBRA_CLASS;[L$OBJECT_CLASS;)V",
+                    false
+                )
+
+                val l1 = Label()
+                visitLabel(l1)
+                visitInsn(Opcodes.RETURN)
+                val l2 = Label()
+                visitLabel(l2)
+                visitLocalVariable("this", "L$slashesClassName;", null, l0, l2, thisVar)
+
+                visitLocalVariable(
+                    "algebra",
+                    "L$ALGEBRA_CLASS;",
+                    "L$ALGEBRA_CLASS<L$T_CLASS;>;",
+                    l0,
+                    l2,
+                    algebraVar
+                )
+
+                visitLocalVariable("constants", "[L$OBJECT_CLASS;", null, l0, l2, constantsVar)
+                visitMaxs(3, 3)
+                visitEnd()
+            }
+
+            invokeMethodVisitor = visitMethod(
+                Opcodes.ACC_PUBLIC or Opcodes.ACC_FINAL,
+                "invoke",
+                "(L$MAP_CLASS;)L$T_CLASS;",
+                "(L$MAP_CLASS<L$STRING_CLASS;+L$T_CLASS;>;)L$T_CLASS;",
+                null
+            )
+
+            invokeMethodVisitor.run {
+                visitCode()
+                invokeL0 = Label()
+                visitLabel(invokeL0)
+            }
+        }
+    }
+
+    @PublishedApi
+    @Suppress("UNCHECKED_CAST")
+    internal fun generate(): FunctionalCompiledExpression<T> {
+        generatedInstance?.let { return it }
+
+        invokeMethodVisitor.run {
+            visitInsn(Opcodes.ARETURN)
+            invokeL1 = Label()
+            visitLabel(invokeL1)
+
+            visitLocalVariable(
+                "this",
+                "L$slashesClassName;",
+                T_CLASS,
+                invokeL0,
+                invokeL1,
+                invokeThisVar
+            )
+
+            visitLocalVariable(
+                "arguments",
+                "L$MAP_CLASS;",
+                "L$MAP_CLASS<L$STRING_CLASS;+L$T_CLASS;>;",
+                invokeL0,
+                invokeL1,
+                invokeArgumentsVar
+            )
+
+            visitMaxs(maxStack + 1, 2)
+            visitEnd()
+        }
+
+        asmCompiledClassWriter.visitMethod(
+            Opcodes.ACC_PUBLIC or Opcodes.ACC_FINAL or Opcodes.ACC_BRIDGE or Opcodes.ACC_SYNTHETIC,
+            "invoke",
+            "(L$MAP_CLASS;)L$OBJECT_CLASS;",
+            null,
+            null
+        ).run {
+            val thisVar = 0
+            visitCode()
+            val l0 = Label()
+            visitLabel(l0)
+            visitVarInsn(Opcodes.ALOAD, 0)
+            visitVarInsn(Opcodes.ALOAD, 1)
+            visitMethodInsn(Opcodes.INVOKEVIRTUAL, slashesClassName, "invoke", "(L$MAP_CLASS;)L$T_CLASS;", false)
+            visitInsn(Opcodes.ARETURN)
+            val l1 = Label()
+            visitLabel(l1)
+
+            visitLocalVariable(
+                "this",
+                "L$slashesClassName;",
+                T_CLASS,
+                l0,
+                l1,
+                thisVar
+            )
+
+            visitMaxs(2, 2)
+            visitEnd()
+        }
+
+        asmCompiledClassWriter.visitEnd()
+
+        val new = classLoader
+            .defineClass(className, asmCompiledClassWriter.toByteArray())
+            .constructors
+            .first()
+            .newInstance(algebra, constants.toTypedArray()) as FunctionalCompiledExpression<T>
+
+        generatedInstance = new
+        return new
+    }
+
+    internal fun visitLoadFromConstants(value: T) {
+        if (classOfT in INLINABLE_NUMBERS) {
+            visitNumberConstant(value as Number)
+            visitCastToT()
+            return
+        }
+
+        visitLoadAnyFromConstants(value as Any, T_CLASS)
+    }
+
+    private fun visitLoadAnyFromConstants(value: Any, type: String) {
+        val idx = if (value in constants) constants.indexOf(value) else constants.apply { add(value) }.lastIndex
+        maxStack++
+
+        invokeMethodVisitor.run {
+            visitLoadThis()
+            visitFieldInsn(Opcodes.GETFIELD, slashesClassName, "constants", "[L$OBJECT_CLASS;")
+            visitLdcOrIConstInsn(idx)
+            visitInsn(Opcodes.AALOAD)
+            invokeMethodVisitor.visitTypeInsn(Opcodes.CHECKCAST, type)
+        }
+    }
+
+    private fun visitLoadThis(): Unit = invokeMethodVisitor.visitVarInsn(Opcodes.ALOAD, invokeThisVar)
+
+    internal fun visitNumberConstant(value: Number) {
+        maxStack++
+        val clazz = value.javaClass
+        val c = clazz.name.replace('.', '/')
+        val sigLetter = SIGNATURE_LETTERS[clazz]
+
+        if (sigLetter != null) {
+            when (value) {
+                is Int -> invokeMethodVisitor.visitLdcOrIConstInsn(value)
+                is Double -> invokeMethodVisitor.visitLdcOrDConstInsn(value)
+                is Float -> invokeMethodVisitor.visitLdcOrFConstInsn(value)
+                else -> invokeMethodVisitor.visitLdcInsn(value)
+            }
+
+            invokeMethodVisitor.visitMethodInsn(Opcodes.INVOKESTATIC, c, "valueOf", "($sigLetter)L${c};", false)
+            return
+        }
+
+        visitLoadAnyFromConstants(value, c)
+    }
+
+    internal fun visitLoadFromVariables(name: String, defaultValue: T? = null): Unit = invokeMethodVisitor.run {
+        maxStack += 2
+        visitVarInsn(Opcodes.ALOAD, invokeArgumentsVar)
+
+        if (defaultValue != null) {
+            visitLdcInsn(name)
+            visitLoadFromConstants(defaultValue)
+
+            visitMethodInsn(
+                Opcodes.INVOKEINTERFACE,
+                MAP_CLASS,
+                "getOrDefault",
+                "(L$OBJECT_CLASS;L$OBJECT_CLASS;)L$OBJECT_CLASS;",
+                true
+            )
+
+            visitCastToT()
+            return
+        }
+
+        visitLdcInsn(name)
+        visitMethodInsn(
+            Opcodes.INVOKEINTERFACE,
+            MAP_CLASS, "get", "(L$OBJECT_CLASS;)L$OBJECT_CLASS;", true
+        )
+        visitCastToT()
+    }
+
+    internal fun visitLoadAlgebra() {
+        maxStack++
+        invokeMethodVisitor.visitVarInsn(Opcodes.ALOAD, invokeThisVar)
+
+        invokeMethodVisitor.visitFieldInsn(
+            Opcodes.GETFIELD,
+            FUNCTIONAL_COMPILED_EXPRESSION_CLASS, "algebra", "L$ALGEBRA_CLASS;"
+        )
+
+        invokeMethodVisitor.visitTypeInsn(Opcodes.CHECKCAST, T_ALGEBRA_CLASS)
+    }
+
+    internal fun visitAlgebraOperation(
+        owner: String,
+        method: String,
+        descriptor: String,
+        opcode: Int = Opcodes.INVOKEINTERFACE,
+        isInterface: Boolean = true
+    ) {
+        maxStack++
+        invokeMethodVisitor.visitMethodInsn(opcode, owner, method, descriptor, isInterface)
+        visitCastToT()
+    }
+
+    private fun visitCastToT(): Unit = invokeMethodVisitor.visitTypeInsn(Opcodes.CHECKCAST, T_CLASS)
+
+    internal fun visitStringConstant(string: String) {
+        invokeMethodVisitor.visitLdcInsn(string)
+    }
+
+    internal companion object {
+        private val SIGNATURE_LETTERS by lazy {
+            mapOf(
+                java.lang.Byte::class.java to "B",
+                java.lang.Short::class.java to "S",
+                java.lang.Integer::class.java to "I",
+                java.lang.Long::class.java to "J",
+                java.lang.Float::class.java to "F",
+                java.lang.Double::class.java to "D"
+            )
+        }
+
+        private val INLINABLE_NUMBERS by lazy { SIGNATURE_LETTERS.keys }
+
+        internal const val FUNCTIONAL_COMPILED_EXPRESSION_CLASS =
+            "scientifik/kmath/asm/FunctionalCompiledExpression"
+
+        internal const val MAP_CLASS = "java/util/Map"
+        internal const val OBJECT_CLASS = "java/lang/Object"
+        internal const val ALGEBRA_CLASS = "scientifik/kmath/operations/Algebra"
+        internal const val SPACE_OPERATIONS_CLASS = "scientifik/kmath/operations/SpaceOperations"
+        internal const val STRING_CLASS = "java/lang/String"
+        internal const val NUMBER_CLASS = "java/lang/Number"
+    }
+}

kmath-ast/src/jvmMain/kotlin/scientifik/kmath/asm/internal/MethodVisitors.kt

@@ -0,0 +1,28 @@
+package scientifik.kmath.asm.internal
+
+import org.objectweb.asm.MethodVisitor
+import org.objectweb.asm.Opcodes.*
+
+internal fun MethodVisitor.visitLdcOrIConstInsn(value: Int) = when (value) {
+    -1 -> visitInsn(ICONST_M1)
+    0 -> visitInsn(ICONST_0)
+    1 -> visitInsn(ICONST_1)
+    2 -> visitInsn(ICONST_2)
+    3 -> visitInsn(ICONST_3)
+    4 -> visitInsn(ICONST_4)
+    5 -> visitInsn(ICONST_5)
+    else -> visitLdcInsn(value)
+}
+
+internal fun MethodVisitor.visitLdcOrDConstInsn(value: Double) = when (value) {
+    0.0 -> visitInsn(DCONST_0)
+    1.0 -> visitInsn(DCONST_1)
+    else -> visitLdcInsn(value)
+}
+
+internal fun MethodVisitor.visitLdcOrFConstInsn(value: Float) = when (value) {
+    0f -> visitInsn(FCONST_0)
+    1f -> visitInsn(FCONST_1)
+    2f -> visitInsn(FCONST_2)
+    else -> visitLdcInsn(value)
+}

kmath-ast/src/jvmMain/kotlin/scientifik/kmath/asm/internal/Optimization.kt

@@ -0,0 +1,49 @@
+package scientifik.kmath.asm.internal
+
+import org.objectweb.asm.Opcodes
+import scientifik.kmath.asm.AsmConstantExpression
+import scientifik.kmath.asm.AsmNode
+import scientifik.kmath.operations.Algebra
+
+private val methodNameAdapters: Map<String, String> = mapOf("+" to "add", "*" to "multiply", "/" to "divide")
+
+internal fun <T> hasSpecific(context: Algebra<T>, name: String, arity: Int): Boolean {
+    val aName = methodNameAdapters[name] ?: name
+
+    context::class.java.methods.find { it.name == aName && it.parameters.size == arity }
+        ?: return false
+
+    return true
+}
+
+internal fun <T> AsmGenerationContext<T>.tryInvokeSpecific(context: Algebra<T>, name: String, arity: Int): Boolean {
+    val aName = methodNameAdapters[name] ?: name
+
+    context::class.java.methods.find { it.name == aName && it.parameters.size == arity }
+        ?: return false
+
+    val owner = context::class.java.name.replace('.', '/')
+
+    val sig = buildString {
+        append('(')
+        repeat(arity) { append("L${AsmGenerationContext.OBJECT_CLASS};") }
+        append(')')
+        append("L${AsmGenerationContext.OBJECT_CLASS};")
+    }
+
+    visitAlgebraOperation(
+        owner = owner,
+        method = aName,
+        descriptor = sig,
+        opcode = Opcodes.INVOKEVIRTUAL,
+        isInterface = false
+    )
+
+    return true
+}
+
+@PublishedApi
+internal fun <T> AsmNode<T>.optimize(): AsmNode<T> {
+    val a = tryEvaluate()
+    return if (a == null) this else AsmConstantExpression(a)
+}

kmath-ast/src/jvmMain/kotlin/scientifik/kmath/ast/asm.kt

@@ -1,23 +0,0 @@
-package scientifik.kmath.ast
-
-import scientifik.kmath.expressions.Expression
-import scientifik.kmath.operations.Algebra
-import scientifik.kmath.operations.NumericAlgebra
-
-//TODO stubs for asm generation
-
-interface AsmExpression<T>
-
-interface AsmExpressionAlgebra<T, A : Algebra<T>> : NumericAlgebra<AsmExpression<T>> {
-    val algebra: A
-}
-
-fun <T> AsmExpression<T>.compile(): Expression<T> = TODO()
-
-//TODO add converter for functional expressions
-
-inline fun <reified T : Any, A : Algebra<T>> A.asm(
-    block: AsmExpressionAlgebra<T, A>.() -> AsmExpression<T>
-): Expression<T> = TODO()
-
-inline fun <reified T : Any, A : Algebra<T>> A.asm(ast: MST): Expression<T> = asm { evaluate(ast) }

kmath-ast/src/jvmTest/kotlin/scietifik/kmath/ast/AsmTest.kt

@@ -0,0 +1,18 @@
+package scietifik.kmath.ast
+
+import scientifik.kmath.asm.asmField
+import scientifik.kmath.ast.parseMath
+import scientifik.kmath.expressions.invoke
+import scientifik.kmath.operations.Complex
+import scientifik.kmath.operations.ComplexField
+import kotlin.test.assertEquals
+import kotlin.test.Test
+
+class AsmTest {
+    @Test
+    fun parsedExpression() {
+        val mst = "2+2*(2+2)".parseMath()
+        val res = ComplexField.asmField(mst)()
+        assertEquals(Complex(10.0, 0.0), res)
+    }
+}

kmath-ast/src/jvmTest/kotlin/scietifik/kmath/ast/ParserTest.kt

@@ -1,17 +1,17 @@
 package scietifik.kmath.ast
 
-import org.junit.jupiter.api.Assertions.assertEquals
-import org.junit.jupiter.api.Test
 import scientifik.kmath.ast.evaluate
 import scientifik.kmath.ast.parseMath
 import scientifik.kmath.operations.Complex
 import scientifik.kmath.operations.ComplexField
+import kotlin.test.assertEquals
+import kotlin.test.Test
 
-internal class ParserTest{
+internal class ParserTest {
     @Test
-    fun parsedExpression(){
+    fun parsedExpression() {
         val mst = "2+2*(2+2)".parseMath()
         val res = ComplexField.evaluate(mst)
-        assertEquals(Complex(10.0,0.0), res)
+        assertEquals(Complex(10.0, 0.0), res)
     }
 }

kmath-ast/src/jvmTest/kotlin/scietifik/kmath/ast/asm/TestAsmAlgebras.kt

@@ -0,0 +1,75 @@
+package scietifik.kmath.ast.asm
+
+import scientifik.kmath.asm.asmField
+import scientifik.kmath.asm.asmRing
+import scientifik.kmath.asm.asmSpace
+import scientifik.kmath.expressions.invoke
+import scientifik.kmath.operations.ByteRing
+import scientifik.kmath.operations.RealField
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class TestAsmAlgebras {
+    @Test
+    fun space() {
+        val res = ByteRing.asmSpace {
+            binaryOperation(
+                "+",
+
+                unaryOperation(
+                    "+",
+                    3.toByte() - (2.toByte() + (multiply(
+                        add(const(1), const(1)),
+                        2
+                    ) + 1.toByte()) * 3.toByte() - 1.toByte())
+                ),
+
+                number(1)
+            ) + variable("x") + zero
+        }("x" to 2.toByte())
+
+        assertEquals(16, res)
+    }
+
+    @Test
+    fun ring() {
+        val res = ByteRing.asmRing {
+            binaryOperation(
+                "+",
+
+                unaryOperation(
+                    "+",
+                    (3.toByte() - (2.toByte() + (multiply(
+                        add(const(1), const(1)),
+                        2
+                    ) + 1.toByte()))) * 3.0 - 1.toByte()
+                ),
+
+                number(1)
+            ) * const(2)
+        }()
+
+        assertEquals(24, res)
+    }
+
+    @Test
+    fun field() {
+        val res = RealField.asmField {
+            divide(binaryOperation(
+                "+",
+
+                unaryOperation(
+                    "+",
+                    (3.0 - (2.0 + (multiply(
+                        add(const(1.0), const(1.0)),
+                        2
+                    ) + 1.0))) * 3 - 1.0
+                ),
+
+                number(1)
+            ) / 2, const(2.0)) * one
+        }()
+
+        assertEquals(3.0, res)
+    }
+}

kmath-ast/src/jvmTest/kotlin/scietifik/kmath/ast/asm/TestAsmExpressions.kt

@@ -0,0 +1,21 @@
+package scietifik.kmath.ast.asm
+
+import scientifik.kmath.asm.asmField
+import scientifik.kmath.expressions.invoke
+import scientifik.kmath.operations.RealField
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class TestAsmExpressions {
+    @Test
+    fun testUnaryOperationInvocation() {
+        val res = RealField.asmField { unaryOperation("+", variable("x")) }("x" to 2.0)
+        assertEquals(2.0, res)
+    }
+
+    @Test
+    fun testConstProductInvocation() {
+        val res = RealField.asmField { variable("x") * 2 }("x" to 2.0)
+        assertEquals(4.0, res)
+    }
+}

kmath-core/src/commonMain/kotlin/scientifik/kmath/expressions/Builders.kt

@@ -0,0 +1,23 @@
+package scientifik.kmath.expressions
+
+import scientifik.kmath.operations.Field
+import scientifik.kmath.operations.Ring
+import scientifik.kmath.operations.Space
+
+/**
+ * Create a functional expression on this [Space]
+ */
+fun <T> Space<T>.buildExpression(block: FunctionalExpressionSpace<T, Space<T>>.() -> Expression<T>): Expression<T> =
+    FunctionalExpressionSpace(this).run(block)
+
+/**
+ * Create a functional expression on this [Ring]
+ */
+fun <T> Ring<T>.buildExpression(block: FunctionalExpressionRing<T, Ring<T>>.() -> Expression<T>): Expression<T> =
+    FunctionalExpressionRing(this).run(block)
+
+/**
+ * Create a functional expression on this [Field]
+ */
+fun <T> Field<T>.buildExpression(block: FunctionalExpressionField<T, Field<T>>.() -> Expression<T>): Expression<T> =
+    FunctionalExpressionField(this).run(block)

kmath-core/src/commonMain/kotlin/scientifik/kmath/expressions/FunctionalExpressions.kt

@@ -0,0 +1,139 @@
+package scientifik.kmath.expressions
+
+import scientifik.kmath.operations.*
+
+internal class FunctionalUnaryOperation<T>(val context: Algebra<T>, val name: String, private val expr: Expression<T>) :
+    Expression<T> {
+    override fun invoke(arguments: Map<String, T>): T = context.unaryOperation(name, expr.invoke(arguments))
+}
+
+internal class FunctionalBinaryOperation<T>(
+    val context: Algebra<T>,
+    val name: String,
+    val first: Expression<T>,
+    val second: Expression<T>
+) : Expression<T> {
+    override fun invoke(arguments: Map<String, T>): T =
+        context.binaryOperation(name, first.invoke(arguments), second.invoke(arguments))
+}
+
+internal class FunctionalVariableExpression<T>(val name: String, val default: T? = null) : Expression<T> {
+    override fun invoke(arguments: Map<String, T>): T =
+        arguments[name] ?: default ?: error("Parameter not found: $name")
+}
+
+internal class FunctionalConstantExpression<T>(val value: T) : Expression<T> {
+    override fun invoke(arguments: Map<String, T>): T = value
+}
+
+internal class FunctionalConstProductExpression<T>(
+    val context: Space<T>,
+    private val expr: Expression<T>,
+    val const: Number
+) : Expression<T> {
+    override fun invoke(arguments: Map<String, T>): T = context.multiply(expr.invoke(arguments), const)
+}
+
+/**
+ * A context class for [Expression] construction.
+ */
+interface FunctionalExpressionAlgebra<T, A : Algebra<T>> : ExpressionAlgebra<T, Expression<T>> {
+    /**
+     * The algebra to provide for Expressions built.
+     */
+    val algebra: A
+
+    /**
+     * Builds an Expression of constant expression which does not depend on arguments.
+     */
+    override fun const(value: T): Expression<T> = FunctionalConstantExpression(value)
+
+    /**
+     * Builds an Expression to access a variable.
+     */
+    override fun variable(name: String, default: T?): Expression<T> = FunctionalVariableExpression(name, default)
+
+    /**
+     * Builds an Expression of dynamic call of binary operation [operation] on [left] and [right].
+     */
+    override fun binaryOperation(operation: String, left: Expression<T>, right: Expression<T>): Expression<T> =
+        FunctionalBinaryOperation(algebra, operation, left, right)
+
+    /**
+     * Builds an Expression of dynamic call of unary operation with name [operation] on [arg].
+     */
+    override fun unaryOperation(operation: String, arg: Expression<T>): Expression<T> =
+        FunctionalUnaryOperation(algebra, operation, arg)
+}
+
+/**
+ * A context class for [Expression] construction for [Space] algebras.
+ */
+open class FunctionalExpressionSpace<T, A>(override val algebra: A) : FunctionalExpressionAlgebra<T, A>,
+    Space<Expression<T>> where  A : Space<T> {
+    override val zero: Expression<T>
+        get() = const(algebra.zero)
+
+    /**
+     * Builds an Expression of addition of two another expressions.
+     */
+    override fun add(a: Expression<T>, b: Expression<T>): Expression<T> =
+        FunctionalBinaryOperation(algebra, SpaceOperations.PLUS_OPERATION, a, b)
+
+    /**
+     * Builds an Expression of multiplication of expression by number.
+     */
+    override fun multiply(a: Expression<T>, k: Number): Expression<T> =
+        FunctionalConstProductExpression(algebra, a, k)
+
+    operator fun Expression<T>.plus(arg: T): Expression<T> = this + const(arg)
+    operator fun Expression<T>.minus(arg: T): Expression<T> = this - const(arg)
+    operator fun T.plus(arg: Expression<T>): Expression<T> = arg + this
+    operator fun T.minus(arg: Expression<T>): Expression<T> = arg - this
+
+    override fun unaryOperation(operation: String, arg: Expression<T>): Expression<T> =
+        super<FunctionalExpressionAlgebra>.unaryOperation(operation, arg)
+
+    override fun binaryOperation(operation: String, left: Expression<T>, right: Expression<T>): Expression<T> =
+        super<FunctionalExpressionAlgebra>.binaryOperation(operation, left, right)
+}
+
+open class FunctionalExpressionRing<T, A>(override val algebra: A) : FunctionalExpressionSpace<T, A>(algebra),
+    Ring<Expression<T>> where  A : Ring<T>, A : NumericAlgebra<T> {
+    override val one: Expression<T>
+        get() = const(algebra.one)
+
+    /**
+     * Builds an Expression of multiplication of two expressions.
+     */
+    override fun multiply(a: Expression<T>, b: Expression<T>): Expression<T> =
+        FunctionalBinaryOperation(algebra, RingOperations.TIMES_OPERATION, a, b)
+
+    operator fun Expression<T>.times(arg: T): Expression<T> = this * const(arg)
+    operator fun T.times(arg: Expression<T>): Expression<T> = arg * this
+
+    override fun unaryOperation(operation: String, arg: Expression<T>): Expression<T> =
+        super<FunctionalExpressionSpace>.unaryOperation(operation, arg)
+
+    override fun binaryOperation(operation: String, left: Expression<T>, right: Expression<T>): Expression<T> =
+        super<FunctionalExpressionSpace>.binaryOperation(operation, left, right)
+}
+
+open class FunctionalExpressionField<T, A>(override val algebra: A) :
+    FunctionalExpressionRing<T, A>(algebra),
+    Field<Expression<T>> where A : Field<T>, A : NumericAlgebra<T> {
+    /**
+     * Builds an Expression of division an expression by another one.
+     */
+    override fun divide(a: Expression<T>, b: Expression<T>): Expression<T> =
+        FunctionalBinaryOperation(algebra, FieldOperations.DIV_OPERATION, a, b)
+
+    operator fun Expression<T>.div(arg: T): Expression<T> = this / const(arg)
+    operator fun T.div(arg: Expression<T>): Expression<T> = arg / this
+
+    override fun unaryOperation(operation: String, arg: Expression<T>): Expression<T> =
+        super<FunctionalExpressionRing>.unaryOperation(operation, arg)
+
+    override fun binaryOperation(operation: String, left: Expression<T>, right: Expression<T>): Expression<T> =
+        super<FunctionalExpressionRing>.binaryOperation(operation, left, right)
+}

kmath-core/src/commonMain/kotlin/scientifik/kmath/expressions/functionalExpressions.kt

@@ -1,94 +0,0 @@
-package scientifik.kmath.expressions
-
-import scientifik.kmath.operations.Field
-import scientifik.kmath.operations.Ring
-import scientifik.kmath.operations.Space
-
-internal class VariableExpression<T>(val name: String, val default: T? = null) : Expression<T> {
-    override fun invoke(arguments: Map<String, T>): T =
-        arguments[name] ?: default ?: error("Parameter not found: $name")
-}
-
-internal class ConstantExpression<T>(val value: T) : Expression<T> {
-    override fun invoke(arguments: Map<String, T>): T = value
-}
-
-internal class SumExpression<T>(
-    val context: Space<T>,
-    val first: Expression<T>,
-    val second: Expression<T>
-) : Expression<T> {
-    override fun invoke(arguments: Map<String, T>): T = context.add(first.invoke(arguments), second.invoke(arguments))
-}
-
-internal class ProductExpression<T>(
-    val context: Ring<T>,
-    val first: Expression<T>,
-    val second: Expression<T>
-) : Expression<T> {
-    override fun invoke(arguments: Map<String, T>): T =
-        context.multiply(first.invoke(arguments), second.invoke(arguments))
-}
-
-internal class ConstProductExpession<T>(val context: Space<T>, val expr: Expression<T>, val const: Number) :
-    Expression<T> {
-    override fun invoke(arguments: Map<String, T>): T = context.multiply(expr.invoke(arguments), const)
-}
-
-internal class DivExpession<T>(val context: Field<T>, val expr: Expression<T>, val second: Expression<T>) :
-    Expression<T> {
-    override fun invoke(arguments: Map<String, T>): T = context.divide(expr.invoke(arguments), second.invoke(arguments))
-}
-
-open class FunctionalExpressionSpace<T>(
-    val space: Space<T>
-) : Space<Expression<T>>, ExpressionAlgebra<T, Expression<T>> {
-
-    override val zero: Expression<T> = ConstantExpression(space.zero)
-
-    override fun const(value: T): Expression<T> = ConstantExpression(value)
-
-    override fun variable(name: String, default: T?): Expression<T> = VariableExpression(name, default)
-
-    override fun add(a: Expression<T>, b: Expression<T>): Expression<T> = SumExpression(space, a, b)
-
-    override fun multiply(a: Expression<T>, k: Number): Expression<T> = ConstProductExpession(space, a, k)
-
-
-    operator fun Expression<T>.plus(arg: T) = this + const(arg)
-    operator fun Expression<T>.minus(arg: T) = this - const(arg)
-
-    operator fun T.plus(arg: Expression<T>) = arg + this
-    operator fun T.minus(arg: Expression<T>) = arg - this
-}
-
-open class FunctionalExpressionField<T>(
-    val field: Field<T>
-) : Field<Expression<T>>, ExpressionAlgebra<T, Expression<T>>, FunctionalExpressionSpace<T>(field) {
-
-    override val one: Expression<T> = ConstantExpression(this.field.one)
-
-    fun const(value: Double): Expression<T> = const(field.run { one * value })
-
-    override fun multiply(a: Expression<T>, b: Expression<T>): Expression<T> = ProductExpression(field, a, b)
-
-    override fun divide(a: Expression<T>, b: Expression<T>): Expression<T> = DivExpession(field, a, b)
-
-    operator fun Expression<T>.times(arg: T) = this * const(arg)
-    operator fun Expression<T>.div(arg: T) = this / const(arg)
-
-    operator fun T.times(arg: Expression<T>) = arg * this
-    operator fun T.div(arg: Expression<T>) = arg / this
-}
-
-/**
- * Create a functional expression on this [Space]
- */
-fun <T> Space<T>.buildExpression(block: FunctionalExpressionSpace<T>.() -> Expression<T>): Expression<T> =
-    FunctionalExpressionSpace(this).run(block)
-
-/**
- * Create a functional expression on this [Field]
- */
-fun <T> Field<T>.buildExpression(block: FunctionalExpressionField<T>.() -> Expression<T>): Expression<T> =
-    FunctionalExpressionField(this).run(block)