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Optimizations for shifting

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This commit is contained in:
Karol Stasiak 2018-06-24 23:18:18 +02:00
parent d39aac86ac
commit 57740cc6b4
3 changed files with 182 additions and 10 deletions
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7
src/main/scala/millfork/OptimizationPresets.scala
View File

@ -97,6 +97,8 @@ object OptimizationPresets {
AlwaysGoodOptimizations.PoinlessLoadBeforeAnotherLoad,
AlwaysGoodOptimizations.RearrangableLoadFromTheSameLocation,
AlwaysGoodOptimizations.ShiftingJustWrittenValue,
AlwaysGoodOptimizations.PointlessAccumulatorShifting,
AlwaysGoodOptimizations.ReverseFlowAnalysis,
LaterOptimizations.LoadingAfterShifting,
EmptyMemoryStoreRemoval,
@ -105,6 +107,7 @@ object OptimizationPresets {
AlwaysGoodOptimizations.PoinlessLoadBeforeAnotherLoad,
LaterOptimizations.LoadingAfterShifting,
AlwaysGoodOptimizations.PointlessAccumulatorShifting,
EmptyMemoryStoreRemoval,
AlwaysGoodOptimizations.PoinlessStoreBeforeStore,
LaterOptimizations.PointlessLoadAfterStore,
@ -113,6 +116,9 @@ object OptimizationPresets {
AlwaysGoodOptimizations.UnusedCodeRemoval,
AlwaysGoodOptimizations.ReverseFlowAnalysis,
AlwaysGoodOptimizations.ModificationOfJustWrittenValue,
AlwaysGoodOptimizations.ShiftingJustWrittenValue,
AlwaysGoodOptimizations.PointlessAccumulatorShifting,
AlwaysGoodOptimizations.ReverseFlowAnalysis,
AlwaysGoodOptimizations.PointlessMathFromFlow,
AlwaysGoodOptimizations.PointlessMathFromFlow,
AlwaysGoodOptimizations.PointlessMathFromFlow,
@ -170,6 +176,7 @@ object OptimizationPresets {
AlwaysGoodOptimizations.OperationsAroundShifting,
AlwaysGoodOptimizations.OptimizeZeroComparisons,
AlwaysGoodOptimizations.PoinlessFlagChange,
AlwaysGoodOptimizations.PointlessAccumulatorShifting,
AlwaysGoodOptimizations.PointlessLoadAfterLoadOrStore,
AlwaysGoodOptimizations.PoinlessLoadBeforeAnotherLoad,
AlwaysGoodOptimizations.PointlessLoadBeforeReturn,

124
src/main/scala/millfork/assembly/mos/opt/AlwaysGoodOptimizations.scala
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@ -7,6 +7,7 @@ import millfork.assembly.mos.OpcodeClasses._
import millfork.assembly.mos.{AddrMode, opt, _}
import millfork.assembly.mos.AddrMode._
import millfork.env._
import org.apache.commons.lang3.builder.HashCodeExclude
/**
* These optimizations should not remove opportunities for more complex optimizations to trigger.
@ -23,18 +24,58 @@ object AlwaysGoodOptimizations {
def getNextLabel(prefix: String) = f".$prefix%s__${counter.getAndIncrement()}%05d"
val PointlessMath = new RuleBasedAssemblyOptimization("Pointless math",
needsFlowInfo = FlowInfoRequirement.NoRequirement,
needsFlowInfo = FlowInfoRequirement.BackwardFlow,
(HasOpcode(CLC) & Elidable) ~
(HasOpcode(ADC) & Elidable & MatchParameter(0)) ~
(HasOpcode(SEC) & Elidable) ~
(HasOpcode(SBC) & Elidable & MatchParameter(0)) ~
(LinearOrLabel & Not(ReadsNOrZ) & Not(ReadsV) & Not(ReadsC) & Not(NoopDiscardsFlags) & Not(Set(ADC, SBC))).* ~
(NoopDiscardsFlags | Set(ADC, SBC)) ~~> (_.drop(4)),
(HasOpcode(SBC) & Elidable & MatchParameter(0) & DoesntMatterWhatItDoesWith(State.C, State.Z, State.V, State.N)) ~~> (_.drop(4)),
(HasOpcode(LDA) & HasImmediate(0) & Elidable) ~
(HasOpcode(CLC) & Elidable) ~
(HasOpcode(ADC) & Elidable) ~
(LinearOrLabel & Not(ReadsV) & Not(NoopDiscardsFlags) & Not(ChangesNAndZ)).* ~
(NoopDiscardsFlags | ChangesNAndZ) ~~> (code => code(2).copy(opcode = LDA) :: code.drop(3))
(HasOpcode(ADC) & Elidable & DoesntMatterWhatItDoesWith(State.C, State.Z, State.V, State.N)) ~~> (code => code(2).copy(opcode = LDA) :: code.drop(3)),
)
val PointlessAccumulatorShifting = new RuleBasedAssemblyOptimization("Pointless accumulator shifting",
needsFlowInfo = FlowInfoRequirement.BackwardFlow,
// before: A=ZXXX_XXXX C=Y
// after ROL: A=XXXX_XXXY C=Z
// after LSR: A=0XXX_XXXX C=Y
(HasOpcode(ROL) & HasAddrMode(Implied) & Elidable) ~
(HasOpcode(LSR) & HasAddrMode(Implied) & Elidable) ~~> (_ => List(AssemblyLine.immediate(AND, 0x7f))),
// before: A=XXXX_XXXZ C=Y
// after ROR: A=YXXX_XXXX C=Z
// after ASL: A=XXXX_XXX0 C=Y
(HasOpcode(ROR) & HasAddrMode(Implied) & Elidable) ~
(HasOpcode(ASL) & HasAddrMode(Implied) & Elidable) ~~> (_ => List(AssemblyLine.immediate(AND, 0xfe))),
// before: A=XXXX_XXXZ C=Y
// after LSR: A=0XXX_XXXX C=Z
// after ROL: A=XXXX_XXXZ C=0
(HasOpcode(LSR) & HasAddrMode(Implied) & Elidable) ~
(HasOpcode(ROL) & HasAddrMode(Implied) & Elidable & DoesntMatterWhatItDoesWith(State.Z, State.N)) ~~> (_ => List(AssemblyLine.implied(CLC))),
// before: A=ZXXX_XXXX C=Y
// after ASL: A=XXXX_XXX0 C=Z
// after ROR: A=ZXXX_XXXX C=0
(HasOpcode(ASL) & HasAddrMode(Implied) & Elidable) ~
(HasOpcode(ROR) & HasAddrMode(Implied) & Elidable & DoesntMatterWhatItDoesWith(State.Z, State.N)) ~~> (_ => List(AssemblyLine.implied(CLC))),
// before: A=XXXX_XXXZ C=Y
// after ROR: A=YXXX_XXXX C=Z
// after ROL: A=XXXX_XXXZ C=Y
(HasOpcode(ROR) & HasAddrMode(Implied) & Elidable) ~
(HasOpcode(ROL) & HasAddrMode(Implied) & Elidable & DoesntMatterWhatItDoesWith(State.Z, State.N)) ~~> (_ => Nil),
// before: A=ZXXX_XXXX C=Y
// after ROL: A=XXXX_XXXY C=Z
// after ROR: A=ZXXX_XXXX C=Y
(HasOpcode(ROL) & HasAddrMode(Implied) & Elidable) ~
(HasOpcode(ROR) & HasAddrMode(Implied) & Elidable & DoesntMatterWhatItDoesWith(State.Z, State.N)) ~~> (_ => Nil),
// before: A=ZXXX_XXXX C=Y
// after ASL: A=XXXX_XXX0 C=Z
// after LSR: A=0XXX_XXXX C=0
(HasOpcode(ASL) & HasAddrMode(Implied) & Elidable) ~
(HasOpcode(LSR) & HasAddrMode(Implied) & Elidable) ~~> (_ => List(AssemblyLine.immediate(AND, 0x7f), AssemblyLine.implied(CLC))),
// before: A=XXXX_XXXZ C=Y
// after LSR: A=0XXX_XXXX C=Z
// after ASL: A=XXXX_XXX0 C=0
(HasOpcode(LSR) & HasAddrMode(Implied) & Elidable) ~
(HasOpcode(ASL) & HasAddrMode(Implied) & Elidable) ~~> (_ => List(AssemblyLine.immediate(AND, 0xfe), AssemblyLine.implied(CLC))),
)
val PointlessMathFromFlow = new RuleBasedAssemblyOptimization("Pointless math from flow analysis",
@ -357,17 +398,17 @@ object AlwaysGoodOptimizations {
(Elidable & HasOpcodeIn(Set(LDA, STA)) & IsZeroPage & MatchAddrMode(0) & MatchParameter(1)) ~
(Elidable & HasOpcode(TAX) & DoesntMatterWhatItDoesWith(State.N, State.Z)) ~
(Linear & Not(ConcernsX) & DoesntChangeMemoryAt(0, 1)).* ~
(Elidable & HasOpcode(TXA) & DoesntMatterWhatItDoesWith(State.X)) ~~> (code => code.head :: (code.drop(2) :+ code.head.copy(opcode = LDA))),
(Elidable & HasOpcode(TXA) & DoesntMatterWhatItDoesWith(State.X)) ~~> (code => code.head :: (code.drop(2).init :+ code.head.copy(opcode = LDA))),
(Elidable & HasOpcodeIn(Set(LDA, STA)) & IsZeroPage & MatchAddrMode(0) & MatchParameter(1)) ~
(Elidable & HasOpcode(TAY) & DoesntMatterWhatItDoesWith(State.N, State.Z)) ~
(Linear & Not(ConcernsY) & DoesntChangeMemoryAt(0, 1)).* ~
(Elidable & HasOpcode(TYA) & DoesntMatterWhatItDoesWith(State.Y)) ~~> (code => code.head :: (code.drop(2) :+ code.head.copy(opcode = LDA))),
(Elidable & HasOpcode(TYA) & DoesntMatterWhatItDoesWith(State.Y)) ~~> (code => code.head :: (code.drop(2).init :+ code.head.copy(opcode = LDA))),
(Elidable & HasOpcodeIn(Set(LDA, STA)) & IsZeroPage & MatchAddrMode(0) & MatchParameter(1)) ~
(Elidable & HasOpcode(TAZ) & DoesntMatterWhatItDoesWith(State.N, State.Z)) ~
(Linear & Not(ConcernsIZ) & DoesntChangeMemoryAt(0, 1)).* ~
(Elidable & HasOpcode(TZA) & DoesntMatterWhatItDoesWith(State.IZ)) ~~> (code => code.head :: (code.drop(2) :+ code.head.copy(opcode = LDA))),
(Elidable & HasOpcode(TZA) & DoesntMatterWhatItDoesWith(State.IZ)) ~~> (code => code.head :: (code.drop(2).init :+ code.head.copy(opcode = LDA))),
)
private def operationPairBuilder(op1: Opcode.Value, op2: Opcode.Value, middle: AssemblyLinePattern, discardToRemove: Option[Opcode.Value]) = {
@ -804,6 +845,18 @@ object AlwaysGoodOptimizations {
modificationOfJustWrittenValue(STZ, ZeroPage, Anything, LSR, Anything, atLeastTwo = false, Seq(), (_, i) => Nil),
modificationOfJustWrittenValue(STZ, ZeroPage, Anything, INC, Anything, atLeastTwo = false, Seq(State.A), (_, i) => List(AssemblyLine.immediate(LDA, i)), STA),
modificationOfJustWrittenValue(STZ, ZeroPage, Anything, DEC, Anything, atLeastTwo = false, Seq(State.A), (_, i) => List(AssemblyLine.immediate(LDA, 256 - i)), STA),
(Elidable & HasOpcode(ROL) & Not(HasAddrMode(Implied)) & MatchAddrMode(3) & MatchParameter(0) & DoesntMatterWhatItDoesWith(State.N, State.Z)) ~
(Linear & DoesNotConcernMemoryAt(3, 0) & Not(ConcernsC) & DoesntChangeIndexingInAddrMode(3)).* ~
(Elidable & HasOpcode(ROR) & Not(HasAddrMode(Implied)) & MatchAddrMode(3) & MatchParameter(0) & DoesntMatterWhatItDoesWith(State.N, State.Z)) ~~> (_.init.tail),
(Elidable & HasOpcode(ROR) & Not(HasAddrMode(Implied)) & MatchAddrMode(3) & MatchParameter(0) & DoesntMatterWhatItDoesWith(State.N, State.Z)) ~
(Linear & DoesNotConcernMemoryAt(3, 0) & Not(ConcernsC) & DoesntChangeIndexingInAddrMode(3)).* ~
(Elidable & HasOpcode(ROL) & Not(HasAddrMode(Implied)) & MatchAddrMode(3) & MatchParameter(0) & DoesntMatterWhatItDoesWith(State.N, State.Z)) ~~> (_.init.tail),
(Elidable & HasOpcode(INC) & Not(HasAddrMode(Implied)) & MatchAddrMode(3) & MatchParameter(0) & DoesntMatterWhatItDoesWith(State.N, State.Z)) ~
(Linear & DoesNotConcernMemoryAt(3, 0) & DoesntChangeIndexingInAddrMode(3)).* ~
(Elidable & HasOpcode(DEC) & Not(HasAddrMode(Implied)) & MatchAddrMode(3) & MatchParameter(0) & DoesntMatterWhatItDoesWith(State.N, State.Z)) ~~> (_.init.tail),
(Elidable & HasOpcode(DEC) & Not(HasAddrMode(Implied)) & MatchAddrMode(3) & MatchParameter(0) & DoesntMatterWhatItDoesWith(State.N, State.Z)) ~
(Linear & DoesNotConcernMemoryAt(3, 0) & DoesntChangeIndexingInAddrMode(3)).* ~
(Elidable & HasOpcode(INC) & Not(HasAddrMode(Implied)) & MatchAddrMode(3) & MatchParameter(0) & DoesntMatterWhatItDoesWith(State.N, State.Z)) ~~> (_.init.tail),
)
val ConstantFlowAnalysis = new RuleBasedAssemblyOptimization("Constant flow analysis",
@ -1306,6 +1359,48 @@ object AlwaysGoodOptimizations {
}
}
private def byteToWordThenShiftLeft(shiftAmountAfterStore: Int, shiftBeforeStore: Boolean) = {
val originalStart = if (shiftBeforeStore) {
(Elidable & HasOpcode(ASL) & HasAddrMode(Implied)) ~
(Elidable & HasOpcode(STA) & HasAddrMode(Absolute) & MatchParameter(0)) ~
(Elidable & HasOpcode(LDA) & HasImmediate(0)) ~
(Elidable & HasOpcode(ROL) & HasAddrMode(Implied)) ~
(Elidable & HasOpcode(STA) & HasAddrMode(Absolute) & MatchParameter(1))
} else {
(Elidable & HasOpcode(STA) & HasAddrMode(Absolute) & MatchParameter(0)) ~
(Elidable & HasOpcode(LDA) & HasImmediate(0)) ~
(Elidable & HasOpcode(STA) & HasAddrMode(Absolute) & MatchParameter(1))
}
val shifting = (0 until shiftAmountAfterStore).map(_ =>
(Elidable & HasOpcode(ASL) & HasAddrMode(Absolute) & MatchParameter(0)) ~
(Elidable & HasOpcode(ROL) & HasAddrMode(Absolute) & MatchParameter(1) & DoesntMatterWhatItDoesWith(State.N, State.Z, State.A))
).reduce(_ ~ _)
val rightShiftCount = 8 - (if (shiftBeforeStore) shiftAmountAfterStore + 1 else shiftAmountAfterStore)
assert(rightShiftCount >= 0)
originalStart ~ shifting ~~> { (code, ctx) =>
if (rightShiftCount == 0) {
List(
AssemblyLine.absolute(STA, ctx.get[Constant](1)),
AssemblyLine.immediate(LDA, 0),
AssemblyLine.absolute(STA, ctx.get[Constant](0)),
AssemblyLine.implied(CLC))
} else {
val improvedStart = List(
AssemblyLine.implied(LSR),
AssemblyLine.absolute(STA, ctx.get[Constant](1)),
AssemblyLine.immediate(LDA, 0),
AssemblyLine.implied(ROR),
AssemblyLine.absolute(STA, ctx.get[Constant](0)))
val improvedShifting = if (rightShiftCount == 1) List(AssemblyLine.implied(CLC)) else (1 until rightShiftCount).flatMap(_ => List(
AssemblyLine.absolute(LSR, ctx.get[Constant](1)),
AssemblyLine.absolute(ROR, ctx.get[Constant](0))))
improvedStart ++ improvedShifting
}
}
}
val SmarterShiftingOfWords = new RuleBasedAssemblyOptimization("Smarter shifting of words",
needsFlowInfo = FlowInfoRequirement.BackwardFlow,
wordShifting(8, hiFirst = false, hiFromX = true),
@ -1324,6 +1419,14 @@ object AlwaysGoodOptimizations {
wordShifting(5, hiFirst = false, hiFromX = false),
wordShifting(5, hiFirst = true, hiFromX = true),
wordShifting(5, hiFirst = true, hiFromX = false),
byteToWordThenShiftLeft(8, false),
byteToWordThenShiftLeft(7, false),
byteToWordThenShiftLeft(7, true),
byteToWordThenShiftLeft(6, false),
byteToWordThenShiftLeft(6, true),
byteToWordThenShiftLeft(5, false),
byteToWordThenShiftLeft(5, true),
byteToWordThenShiftLeft(4, true),
)
val ShiftingJustWrittenValue = new RuleBasedAssemblyOptimization("Shifting just written value",
@ -1347,6 +1450,7 @@ object AlwaysGoodOptimizations {
val SmarterShiftingBytes = new RuleBasedAssemblyOptimization("Smarter shifting of bytes",
needsFlowInfo = FlowInfoRequirement.NoRequirement,
// TODO: Check flags:
(Elidable & HasOpcode(ASL) & HasAddrMode(Implied)) ~
(Elidable & HasOpcode(ASL) & HasAddrMode(Implied)) ~
(Elidable & HasOpcode(ASL) & HasAddrMode(Implied)) ~

61
src/test/scala/millfork/test/WordMathSuite.scala
View File

@ -218,4 +218,65 @@ class WordMathSuite extends FunSuite with Matchers {
m.readWord(0xc000) should equal(0x246)
}
}
test("Word shift 2") {
EmuBenchmarkRun("""
| word output @$c000
| void main () {
| output = five()
| output <<= 5
| }
| noinline byte five() {
| return 5
| }
""".stripMargin){ m =>
m.readWord(0xc000) should equal(5 * 32)
}
}
test("Word shift 3") {
EmuBenchmarkRun("""
| word output @$c000
| void main () {
| output = five()
| output <<= 8
| }
| noinline byte five() {
| return 5
| }
""".stripMargin){ m =>
m.readWord(0xc000) should equal(5 * 256)
}
}
test("Word shift 4") {
EmuBenchmarkRun("""
| word output @$c000
| void main () {
| output = five()
| output <<= 7
| }
| noinline byte five() {
| return 5
| }
""".stripMargin){ m =>
m.readWord(0xc000) should equal(5 * 128)
}
}
test("Word shift 5") {
EmuBenchmarkRun("""
| word output @$c000
| void main () {
| output = five()
| output <<= 1
| output >>= 1
| }
| noinline byte five() {
| return 5
| }
""".stripMargin){ m =>
m.readWord(0xc000) should equal(5)
}
}
}