mirror of
https://github.com/KarolS/millfork.git
synced 2024-06-12 22:29:33 +00:00
98 lines
4.4 KiB
Scala
98 lines
4.4 KiB
Scala
package millfork.assembly.mos.opt
|
|
|
|
import millfork.CompilationFlag
|
|
import millfork.assembly.{AssemblyOptimization, OptimizationContext}
|
|
import millfork.assembly.mos.{AssemblyLine, AssemblyLine0, OpcodeClasses}
|
|
import millfork.env.NormalFunction
|
|
|
|
import scala.collection.mutable
|
|
|
|
/**
|
|
* @author Karol Stasiak
|
|
*/
|
|
object UseAccumulatorInsteadOfYRegister extends UseAccumulatorInsteadOfIndexRegister(true)
|
|
object UseAccumulatorInsteadOfXRegister extends UseAccumulatorInsteadOfIndexRegister(false)
|
|
|
|
class UseAccumulatorInsteadOfIndexRegister(doY: Boolean) extends AssemblyOptimization[AssemblyLine] {
|
|
override def name: String = if (doY) "Use accumulator instead of the Y register" else "Use accumulator instead of the X register"
|
|
|
|
override def minimumRequiredLines: Int = 2
|
|
|
|
override def optimize(f: NormalFunction, code: List[AssemblyLine], context: OptimizationContext): List[AssemblyLine] = {
|
|
val log = context.log
|
|
if (f.params.length == 1) return code
|
|
if (!doY && f.returnType.size == 2) return code
|
|
val requiresResult = f.returnType.size == 1 || f.returnType.size == 2
|
|
if (doY) {
|
|
if (!code.exists(line => line.concernsY)) return code
|
|
} else {
|
|
if (!code.exists(line => line.concernsX)) return code
|
|
}
|
|
var resultDumped = true
|
|
val result = mutable.ListBuffer[AssemblyLine]()
|
|
val supportsInc = context.options.flag(CompilationFlag.EmitCmosOpcodes)
|
|
for(line <- code) {
|
|
import millfork.assembly.mos.Opcode._
|
|
import millfork.assembly.mos.AddrMode._
|
|
if (doY) {
|
|
if (OpcodeClasses.ChangesY(line.opcode)) resultDumped = false
|
|
} else {
|
|
if (OpcodeClasses.ChangesX(line.opcode)) resultDumped = false
|
|
}
|
|
line match {
|
|
case AssemblyLine0(_, ZeroPageY, _) => return code
|
|
case AssemblyLine0(_, AbsoluteY | ZeroPageY | IndexedSY | IndexedY | LongIndexedY, _) if doY => return code
|
|
case AssemblyLine0(_, AbsoluteX | ZeroPageX | IndexedX | LongAbsoluteX, _) if !doY => return code
|
|
case AssemblyLine0(SAY | SHY | XAA | LAS | AHX | SAX | HuSAX | SBX | SHX, _, _) => return code
|
|
case AssemblyLine0(TSX | TXS, _, _) if !doY => return code
|
|
case AssemblyLine0(INY, _, _) if doY =>
|
|
if (supportsInc) result += AssemblyLine.implied(INC)
|
|
else return code
|
|
case AssemblyLine0(INX, _, _) if !doY =>
|
|
if (supportsInc) result += AssemblyLine.implied(INC)
|
|
else return code
|
|
case AssemblyLine0(DEY, _, _) if doY =>
|
|
if (supportsInc) result += AssemblyLine.implied(DEC)
|
|
else return code
|
|
case AssemblyLine0(DEX, _, _) if !doY =>
|
|
if (supportsInc) result += AssemblyLine.implied(DEX)
|
|
else return code
|
|
case AssemblyLine0(LDY, _, _) if doY => result += line.copy(opcode = LDA)
|
|
case AssemblyLine0(LDX, _, _) if !doY => result += line.copy(opcode = LDA)
|
|
case AssemblyLine0(LAX, _, _) if !doY =>
|
|
result += line.copy(opcode = LDA)
|
|
resultDumped = true
|
|
case AssemblyLine0(STY, _, _) if doY => result += line.copy(opcode = STA)
|
|
case AssemblyLine0(STX, _, _) if !doY => result += line.copy(opcode = STA)
|
|
case AssemblyLine0(TYA, _, _) if doY =>
|
|
result += line.copy(opcode = TAY)
|
|
resultDumped = true
|
|
case AssemblyLine0(TXA, _, _) if !doY =>
|
|
result += line.copy(opcode = TAX)
|
|
resultDumped = true
|
|
case AssemblyLine0(CPY, _, _) if doY => result += line.copy(opcode = CMP)
|
|
case AssemblyLine0(CPX, _, _) if !doY => result += line.copy(opcode = CMP)
|
|
case AssemblyLine0(op, _, _) if OpcodeClasses.NoopDiscardsFlags(op) => result += line
|
|
case AssemblyLine0(op, _, _) if OpcodeClasses.ConcernsAAlways(op) => return code
|
|
case AssemblyLine0(op, Implied, _) if OpcodeClasses.ConcernsAIfImplied(op) => return code
|
|
case AssemblyLine0(RTS | RTI | JMP, _, _) =>
|
|
if (requiresResult && !resultDumped) return code
|
|
else result += line
|
|
case AssemblyLine0(LABEL, _, _) =>
|
|
resultDumped = false
|
|
result += line
|
|
case AssemblyLine0(op, _, _) if OpcodeClasses.ShortBranching(op) => result += line
|
|
case AssemblyLine0(op, _, _) if !OpcodeClasses.AllLinear(op) => return code
|
|
case _ => result += line
|
|
}
|
|
}
|
|
log.debug(name)
|
|
if (log.traceEnabled) {
|
|
code.foreach(l => log.trace(l.toString))
|
|
log.trace(" ↓")
|
|
result.foreach(l => log.trace(l.toString))
|
|
}
|
|
result.toList
|
|
}
|
|
}
|