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Simplify some basic instructions using peephole optimization

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DUP_X1; POP = SWAP

p1_a; p1_b; SWAP = p1_b; p1_a
where p1_a, p1_b are instructions without side effects pushing value of
size 1 on stack.
E.g.: ACONST_NULL; ALOAD 0; SWAP = ALOAD 0; ACONST_NULL

NOP; NOP = NOP
This commit is contained in:
Dmitry Petrov
2017-07-06 12:23:58 +03:00
parent 224848163d
commit ea95f31f99
4 changed files with 126 additions and 96 deletions
Download Patch File Download Diff File Expand all files Collapse all files
compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/OptimizationMethodVisitor.kt
+2 -2
View File
@@ -17,7 +17,7 @@
package org.jetbrains.kotlin.codegen.optimization
import org.jetbrains.kotlin.codegen.TransformationMethodVisitor
import org.jetbrains.kotlin.codegen.optimization.boxing.FastPopBackwardPropagationTransformer
import org.jetbrains.kotlin.codegen.optimization.boxing.StackPeepholeOptimizationsTransformer
import org.jetbrains.kotlin.codegen.optimization.boxing.RedundantBoxingMethodTransformer
import org.jetbrains.kotlin.codegen.optimization.boxing.PopBackwardPropagationTransformer
import org.jetbrains.kotlin.codegen.optimization.common.prepareForEmitting
@@ -55,7 +55,7 @@ class OptimizationMethodVisitor(
RedundantCheckCastEliminationMethodTransformer(),
ConstantConditionEliminationMethodTransformer(),
RedundantBoxingMethodTransformer(),
FastPopBackwardPropagationTransformer(),
StackPeepholeOptimizationsTransformer(),
PopBackwardPropagationTransformer(),
DeadCodeEliminationMethodTransformer(),
RedundantGotoMethodTransformer(),
compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/FastPopBackwardPropagationTransformer.kt
-89
View File
@@ -1,89 +0,0 @@
/*
* Copyright 2010-2017 JetBrains s.r.o.
*
* 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.
*/
package org.jetbrains.kotlin.codegen.optimization.boxing
import org.jetbrains.kotlin.codegen.optimization.common.findPreviousOrNull
import org.jetbrains.kotlin.codegen.optimization.transformer.MethodTransformer
import org.jetbrains.org.objectweb.asm.Opcodes
import org.jetbrains.org.objectweb.asm.tree.AbstractInsnNode
import org.jetbrains.org.objectweb.asm.tree.InsnNode
import org.jetbrains.org.objectweb.asm.tree.MethodNode
class FastPopBackwardPropagationTransformer : MethodTransformer() {
override fun transform(internalClassName: String, methodNode: MethodNode) {
while (transformOnce(methodNode)) {
}
}
private fun transformOnce(methodNode: MethodNode): Boolean {
val toRemove = ArrayList<AbstractInsnNode>()
val toReplaceWithNop = ArrayList<AbstractInsnNode>()
val insns = methodNode.instructions.toArray()
forInsn@ for (i in 1 until insns.size) {
val insn = insns[i]
val prev = insn.findPreviousOrNull { it.opcode != Opcodes.NOP } ?: continue@forInsn
when (insn.opcode) {
Opcodes.POP -> {
if (prev.isEliminatedByPop()) {
toReplaceWithNop.add(insn)
toRemove.add(prev)
}
}
Opcodes.POP2 -> {
if (prev.isEliminatedByPop2()) {
toReplaceWithNop.add(insn)
toRemove.add(prev)
}
else if (i > 1) {
val prev2 = prev.findPreviousOrNull { it.opcode != Opcodes.NOP } ?: continue@forInsn
if (prev.isEliminatedByPop() && prev2.isEliminatedByPop()) {
toReplaceWithNop.add(insn)
toRemove.add(prev)
toRemove.add(prev2)
}
}
}
}
}
toReplaceWithNop.forEach { methodNode.instructions.set(it, InsnNode(Opcodes.NOP)) }
toRemove.forEach { methodNode.instructions.remove(it) }
return toReplaceWithNop.isNotEmpty() &&
toRemove.isNotEmpty()
}
private fun AbstractInsnNode.isEliminatedByPop() =
opcode in Opcodes.ACONST_NULL..Opcodes.FCONST_2 ||
opcode in Opcodes.BIPUSH..Opcodes.ILOAD ||
opcode == Opcodes.FLOAD ||
opcode == Opcodes.ALOAD ||
isUnitInstance() ||
opcode == Opcodes.DUP
private fun AbstractInsnNode.isEliminatedByPop2() =
opcode == Opcodes.LCONST_0 || opcode == Opcodes.LCONST_1 ||
opcode == Opcodes.DCONST_0 || opcode == Opcodes.DCONST_1 ||
opcode == Opcodes.LLOAD ||
opcode == Opcodes.DLOAD ||
opcode == Opcodes.DUP2
}
compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/StackPeepholeOptimizationsTransformer.kt
+122
View File
@@ -0,0 +1,122 @@
/*
* Copyright 2010-2017 JetBrains s.r.o.
*
* 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.
*/
package org.jetbrains.kotlin.codegen.optimization.boxing
import org.jetbrains.kotlin.codegen.optimization.common.findPreviousOrNull
import org.jetbrains.kotlin.codegen.optimization.transformer.MethodTransformer
import org.jetbrains.org.objectweb.asm.Opcodes
import org.jetbrains.org.objectweb.asm.tree.AbstractInsnNode
import org.jetbrains.org.objectweb.asm.tree.InsnList
import org.jetbrains.org.objectweb.asm.tree.InsnNode
import org.jetbrains.org.objectweb.asm.tree.MethodNode
class StackPeepholeOptimizationsTransformer : MethodTransformer() {
override fun transform(internalClassName: String, methodNode: MethodNode) {
while (transformOnce(methodNode)) {
}
}
private fun transformOnce(methodNode: MethodNode): Boolean {
val actions = ArrayList<(InsnList) -> Unit>()
val insns = methodNode.instructions.toArray()
forInsn@ for (i in 1 until insns.size) {
val insn = insns[i]
val prev = insn.previous
val prevNonNop = insn.findPreviousOrNull { it.opcode != Opcodes.NOP } ?: continue@forInsn
when (insn.opcode) {
Opcodes.POP -> {
when {
prevNonNop.isEliminatedByPop() -> actions.add {
it.set(insn, InsnNode(Opcodes.NOP))
it.remove(prevNonNop)
}
prevNonNop.opcode == Opcodes.DUP_X1 -> actions.add {
it.remove(insn)
it.set(prevNonNop, InsnNode(Opcodes.SWAP))
}
}
}
Opcodes.SWAP -> {
val prevNonNop2 = prevNonNop.findPreviousOrNull { it.opcode != Opcodes.NOP } ?: continue@forInsn
if (prevNonNop.isPurePushOfSize1() && prevNonNop2.isPurePushOfSize1()) {
actions.add {
it.remove(insn)
it.set(prevNonNop, prevNonNop2.clone(emptyMap()))
it.set(prevNonNop2, prevNonNop.clone(emptyMap()))
}
}
}
Opcodes.POP2 -> {
if (prevNonNop.isEliminatedByPop2()) {
actions.add {
it.set(insn, InsnNode(Opcodes.NOP))
it.remove(prevNonNop)
}
}
else if (i > 1) {
val prevNonNop2 = prevNonNop.findPreviousOrNull { it.opcode != Opcodes.NOP } ?: continue@forInsn
if (prevNonNop.isEliminatedByPop() && prevNonNop2.isEliminatedByPop()) {
actions.add {
it.set(insn, InsnNode(Opcodes.NOP))
it.remove(prevNonNop)
it.remove(prevNonNop2)
}
}
}
}
Opcodes.NOP ->
if (prev.opcode == Opcodes.NOP) {
actions.add {
it.remove(prev)
}
}
}
}
actions.forEach { it(methodNode.instructions) }
return actions.isNotEmpty()
}
private fun AbstractInsnNode.isEliminatedByPop() =
isPurePushOfSize1() ||
opcode == Opcodes.DUP
private fun AbstractInsnNode.isPurePushOfSize1(): Boolean =
opcode in Opcodes.ACONST_NULL..Opcodes.FCONST_2 ||
opcode in Opcodes.BIPUSH..Opcodes.ILOAD ||
opcode == Opcodes.FLOAD ||
opcode == Opcodes.ALOAD ||
isUnitInstance()
private fun AbstractInsnNode.isEliminatedByPop2() =
isPurePushOfSize2() ||
opcode == Opcodes.DUP2
private fun AbstractInsnNode.isPurePushOfSize2(): Boolean =
opcode == Opcodes.LCONST_0 || opcode == Opcodes.LCONST_1 ||
opcode == Opcodes.DCONST_0 || opcode == Opcodes.DCONST_1 ||
opcode == Opcodes.LLOAD ||
opcode == Opcodes.DLOAD
}
compiler/testData/codegen/bytecodeText/coercionToUnitOptimization/inRangeCheckWithConst.kt
Vendored
+2 -5
View File
@@ -3,8 +3,5 @@
fun testPrimitiveArray(ints: IntArray) =
10 in ints.indices
// We currently fail to optimize this method because of DUP_X1 instruction generated for range check.
// TODO either don't generate DUP_X1/DUP2_X2 instructions for range checks (extra local variable + extra instructions),
// or support DUPn_Xm instructions in PopBackwardPropagationTransformer
// - 0 DUP
// - 0 POP
// 0 DUP
// 0 POP