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Add empty parameter store removal optimization

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This commit is contained in:
Karol Stasiak 2018-07-16 23:03:52 +02:00
parent ab57090790
commit 28e11873dc
2 changed files with 90 additions and 0 deletions
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10
src/main/scala/millfork/OptimizationPresets.scala
View File

@ -46,6 +46,7 @@ object OptimizationPresets {
AlwaysGoodOptimizations.PointlessOperationAfterLoad,
AlwaysGoodOptimizations.IdempotentDuplicateRemoval,
LoopUnrolling.LoopUnrolling,
AlwaysGoodOptimizations.ConstantPointer,
AlwaysGoodOptimizations.ConstantIndexPropagation,
AlwaysGoodOptimizations.PointlessLoadBeforeReturn,
AlwaysGoodOptimizations.PoinlessFlagChange,
@ -67,9 +68,11 @@ object OptimizationPresets {
LaterOptimizations.DoubleLoadToTheSameRegister,
LaterOptimizations.DoubleLoadToTwoRegistersWhenOneWillBeTrashed,
EmptyMemoryStoreRemoval,
EmptyParameterStoreRemoval,
AlwaysGoodOptimizations.PointlessOperationFromFlow,
AlwaysGoodOptimizations.PoinlessLoadBeforeAnotherLoad,
AlwaysGoodOptimizations.IdempotentDuplicateRemoval,
AlwaysGoodOptimizations.ConstantPointer,
AlwaysGoodOptimizations.ConstantIndexPropagation,
AlwaysGoodOptimizations.ConstantFlowAnalysis,
AlwaysGoodOptimizations.PointlessRegisterTransfers,
@ -86,6 +89,7 @@ object OptimizationPresets {
AlwaysGoodOptimizations.RearrangeMath,
AlwaysGoodOptimizations.LoadingOfJustWrittenValue,
EmptyMemoryStoreRemoval,
EmptyParameterStoreRemoval,
AlwaysGoodOptimizations.PointlessLoadBeforeReturn,
LaterOptimizations.PointessLoadingForShifting,
AlwaysGoodOptimizations.SimplifiableBitOpsSequence,
@ -95,6 +99,7 @@ object OptimizationPresets {
LaterOptimizations.LoadingAfterShifting,
EmptyMemoryStoreRemoval,
EmptyParameterStoreRemoval,
AlwaysGoodOptimizations.PoinlessStoreBeforeStore,
LaterOptimizations.PointlessLoadAfterStore,
AlwaysGoodOptimizations.PoinlessLoadBeforeAnotherLoad,
@ -105,6 +110,7 @@ object OptimizationPresets {
LaterOptimizations.LoadingAfterShifting,
EmptyMemoryStoreRemoval,
EmptyParameterStoreRemoval,
AlwaysGoodOptimizations.PoinlessStoreBeforeStore,
LaterOptimizations.PointlessLoadAfterStore,
AlwaysGoodOptimizations.PoinlessLoadBeforeAnotherLoad,
@ -112,7 +118,9 @@ object OptimizationPresets {
LaterOptimizations.LoadingAfterShifting,
AlwaysGoodOptimizations.PointlessAccumulatorShifting,
EmptyMemoryStoreRemoval,
EmptyParameterStoreRemoval,
AlwaysGoodOptimizations.PoinlessStoreBeforeStore,
AlwaysGoodOptimizations.ConstantPointer,
LaterOptimizations.PointlessLoadAfterStore,
AlwaysGoodOptimizations.PoinlessLoadBeforeAnotherLoad,
AlwaysGoodOptimizations.TailCallOptimization,
@ -135,6 +143,7 @@ object OptimizationPresets {
AlwaysGoodOptimizations.PointlessStackStore,
AlwaysGoodOptimizations.OptimizeZeroComparisons,
AlwaysGoodOptimizations.SimplifiableCondition,
AlwaysGoodOptimizations.ConstantPointer,
AlwaysGoodOptimizations.IncrementingIndexRegistersAfterTransfer,
AlwaysGoodOptimizations.MathOperationOnTwoIdenticalMemoryOperands,
LaterOptimizations.UseZeropageAddressingMode,
@ -167,6 +176,7 @@ object OptimizationPresets {
AlwaysGoodOptimizations.ConstantIndexPropagation,
AlwaysGoodOptimizations.DoubleJumpSimplification,
EmptyMemoryStoreRemoval,
EmptyParameterStoreRemoval,
AlwaysGoodOptimizations.FlagFlowAnalysis,
AlwaysGoodOptimizations.IdempotentDuplicateRemoval,
AlwaysGoodOptimizations.ImpossibleBranchRemoval,

80
src/main/scala/millfork/assembly/mos/opt/EmptyParameterStoreRemoval.scala Normal file
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@ -0,0 +1,80 @@
package millfork.assembly.mos.opt
import millfork.assembly.mos.AddrMode._
import millfork.assembly.mos.AssemblyLine
import millfork.assembly.mos.Opcode._
import millfork.assembly.{AssemblyOptimization, OptimizationContext}
import millfork.env._
import millfork.error.ErrorReporting
/**
* @author Karol Stasiak
*/
object EmptyParameterStoreRemoval extends AssemblyOptimization[AssemblyLine] {
override def name = "Removing pointless stores to foreign variables"
private val storeInstructions = Set(STA, STX, STY, SAX, STZ, STA_W, STX_W, STY_W, STZ_W)
private val storeAddrModes = Set(Absolute, ZeroPage, AbsoluteX, AbsoluteY, ZeroPageX, ZeroPageY)
override def optimize(f: NormalFunction, code: List[AssemblyLine], optimizationContext: OptimizationContext): List[AssemblyLine] = {
val usedFunctions = code.flatMap {
case AssemblyLine(JSR | BSR | JMP, _, MemoryAddressConstant(th), _) => Some(th.name)
case AssemblyLine(JSR | BSR | JMP, _, NumericConstant(addr, _), _) => Some("$" + addr.toHexString)
case _ => None
}.toSet
val foreignVariables = f.environment.root.things.values.flatMap {
case other: NormalFunction =>
val address = other.address match {
case Some(NumericConstant(addr, _)) => "$" + addr.toHexString
case _ => ""
}
if (other.name == f.name || usedFunctions(other.name) || usedFunctions(address)) {
Nil
} else {
val params = other.params match {
case NormalParamSignature(ps) => ps.map(_.name)
case _ => Nil
}
val locals = other.environment.things.values.flatMap{
case th: MemoryVariable if th.alloc == VariableAllocationMethod.Auto => Some(th.name)
case th: MemoryVariable if th.alloc == VariableAllocationMethod.Zeropage => Some(th.name) // TODO: ???
case _ => None
}
params ++ locals
}
case _ => Nil
}.toSet
val stillReadOrStoredVariables = code.flatMap {
case AssemblyLine(_, _, MemoryAddressConstant(th), _) => Some(th.name)
case AssemblyLine(_, _, CompoundConstant(_, MemoryAddressConstant(th), _), _) => Some(th.name)
case AssemblyLine(_, Immediate, SubbyteConstant(MemoryAddressConstant(th), _), _) => Some(th.name)
case _ => None
}.toSet
val stillReadVariables = code.flatMap {
case AssemblyLine(op, am, MemoryAddressConstant(th), true)
if storeInstructions(op) && storeAddrModes(am) => Nil
case AssemblyLine(op, am, CompoundConstant(MathOperator.Plus, MemoryAddressConstant(th), NumericConstant(_, _)), true)
if storeInstructions(op) && storeAddrModes(am) => Nil
case AssemblyLine(_, _, MemoryAddressConstant(th), _) => Some(th.name)
case AssemblyLine(_, _, CompoundConstant(_, MemoryAddressConstant(th), _), _) => Some(th.name)
case AssemblyLine(_, Immediate, SubbyteConstant(MemoryAddressConstant(th), _), _) => Some(th.name)
case _ => None
}.toSet
val unusedForeignVariables = (foreignVariables & stillReadOrStoredVariables) -- stillReadVariables
if (unusedForeignVariables.isEmpty) {
return code
}
ErrorReporting.debug(s"Removing pointless store(s) to foreign variables ${unusedForeignVariables.mkString(", ")}")
code.filterNot {
case AssemblyLine(op, am, MemoryAddressConstant(th), _)
if storeInstructions(op) && storeAddrModes(am) =>
unusedForeignVariables(th.name)
case AssemblyLine(op, am, CompoundConstant(MathOperator.Plus, MemoryAddressConstant(th), NumericConstant(_, _)), true)
if storeInstructions(op) && storeAddrModes(am) =>
unusedForeignVariables(th.name)
case _ => false
}
}
}