mirror of https://github.com/KarolS/millfork.git
60 lines
2.7 KiB
Scala
60 lines
2.7 KiB
Scala
package millfork.assembly.opt
|
|
|
|
import millfork.assembly._
|
|
import millfork.assembly.Opcode._
|
|
import millfork.assembly.AddrMode._
|
|
import millfork.env._
|
|
|
|
/**
|
|
* @author Karol Stasiak
|
|
*/
|
|
object DangerousOptimizations {
|
|
|
|
val ConstantIndexOffsetPropagation = new RuleBasedAssemblyOptimization("Constant index offset propagation",
|
|
// TODO: try to guess when overflow can happen
|
|
needsFlowInfo = FlowInfoRequirement.BothFlows,
|
|
(Elidable & HasOpcode(CLC)).? ~
|
|
(Elidable & HasClear(State.C) & HasOpcode(ADC) & MatchImmediate(0) & DoesntMatterWhatItDoesWith(State.V, State.C)) ~
|
|
(
|
|
(HasOpcode(TAY) & DoesntMatterWhatItDoesWith(State.N, State.Z, State.A)) ~
|
|
(Linear & Not(ConcernsY)).*
|
|
).capture(1) ~
|
|
(Elidable & HasAddrMode(AbsoluteY) & DoesntMatterWhatItDoesWith(State.Y)) ~~> { (code, ctx) =>
|
|
val last = code.last
|
|
ctx.get[List[AssemblyLine]](1) :+ last.copy(parameter = last.parameter.+(ctx.get[Constant](0)).quickSimplify)
|
|
},
|
|
(Elidable & HasOpcode(CLC)).? ~
|
|
(Elidable & HasClear(State.C) & HasOpcode(ADC) & MatchImmediate(0) & DoesntMatterWhatItDoesWith(State.V, State.C)) ~
|
|
(
|
|
(HasOpcode(TAX) & DoesntMatterWhatItDoesWith(State.N, State.Z, State.A)) ~
|
|
(Linear & Not(ConcernsX)).*
|
|
).capture(1) ~
|
|
(Elidable & HasAddrMode(AbsoluteX) & DoesntMatterWhatItDoesWith(State.X)) ~~> { (code, ctx) =>
|
|
val last = code.last
|
|
ctx.get[List[AssemblyLine]](1) :+ last.copy(parameter = last.parameter.+(ctx.get[Constant](0)).quickSimplify)
|
|
},
|
|
(Elidable & HasOpcode(INY) & DoesntMatterWhatItDoesWith(State.N, State.Z)) ~
|
|
(Elidable & HasAddrMode(AbsoluteY) & DoesntMatterWhatItDoesWith(State.Y)) ~~> { (code, ctx) =>
|
|
val last = code.last
|
|
List(last.copy(parameter = last.parameter.+(1).quickSimplify))
|
|
},
|
|
(Elidable & HasOpcode(DEY) & DoesntMatterWhatItDoesWith(State.N, State.Z)) ~
|
|
(Elidable & HasAddrMode(AbsoluteY) & DoesntMatterWhatItDoesWith(State.Y)) ~~> { (code, ctx) =>
|
|
val last = code.last
|
|
List(last.copy(parameter = last.parameter.+(-1).quickSimplify))
|
|
},
|
|
(Elidable & HasOpcode(INX) & DoesntMatterWhatItDoesWith(State.N, State.Z)) ~
|
|
(Elidable & HasAddrMode(AbsoluteX) & DoesntMatterWhatItDoesWith(State.X)) ~~> { (code, ctx) =>
|
|
val last = code.last
|
|
List(last.copy(parameter = last.parameter.+(1).quickSimplify))
|
|
},
|
|
(Elidable & HasOpcode(DEX) & DoesntMatterWhatItDoesWith(State.N, State.Z)) ~
|
|
(Elidable & HasAddrMode(AbsoluteX) & DoesntMatterWhatItDoesWith(State.X)) ~~> { (code, ctx) =>
|
|
val last = code.last
|
|
List(last.copy(parameter = last.parameter.+(-1).quickSimplify))
|
|
},
|
|
)
|
|
|
|
val All: List[AssemblyOptimization] = List(ConstantIndexOffsetPropagation)
|
|
}
|