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6502: Optimize some more rarer repeated index calculations (#50)

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This commit is contained in:
Karol Stasiak 2020-07-19 01:46:09 +02:00
parent 09ff184172
commit 8a0c552762
1 changed files with 25 additions and 3 deletions
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28
src/main/scala/millfork/assembly/mos/opt/RepeatedIndexCalculationOptimization.scala
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@ -98,7 +98,11 @@ case class RepeatedIndexCalculationOptimization(forX: Boolean) extends AssemblyO
List.fill(-delta)(AssemblyLine.implied(IN_).pos(newPos)) :+ AssemblyLine.implied(T_A).pos(newPos)
}
result ++= replacement
log.debug(s"Applied $name for run $ix ($from-$to) with delta $delta")
if (log.traceEnabled) {
log.debug(s"Applied $name for run $ix ($from-$to) with delta $delta")
} else {
log.debug(s"Applied $name")
}
firstFrom = firstFrom min from
lastTo = lastTo max to
if (log.traceEnabled) {
@ -152,9 +156,23 @@ case class RepeatedIndexCalculationOptimization(forX: Boolean) extends AssemblyO
Some(delta)
}
def endsWithSecRolTar(code: List[AssemblyLine]): Boolean = {
if (code.size < 4) return false
val penpenult = code(code.size - 3)
val penult = code(code.size - 2)
val last = code.last
penpenult.opcode == SEC && penult.opcode == ROL && penult.addrMode == Implied && (last.opcode == TAX || last.opcode == TAY)
}
def getExtraDelta(code1: List[AssemblyLine], code2: List[AssemblyLine]): Option[Int] = {
var delta = 0
// TODO: handle extra CLC/ADC#0
if (endsWithSecRolTar(code1)) {
return getExtraDelta(code1.dropRight(3) ++ List(AssemblyLine.implied(ASL), AssemblyLine.implied(CLC), AssemblyLine.immediate(ADC, 1), code1.last) ,
code2)
}
if (endsWithSecRolTar(code2)) {
return getExtraDelta(code1,
code2.dropRight(3) ++ List(AssemblyLine.implied(ASL), AssemblyLine.implied(CLC), AssemblyLine.immediate(ADC, 1), code2.last))
}
if (code1.size != code2.size) {
if (code1.size == code2.size + 2) {
return getExtraDelta(code1, code2.init ++ List(AssemblyLine.implied(CLC), AssemblyLine.immediate(ADC, 0), code2.last))
@ -164,6 +182,7 @@ case class RepeatedIndexCalculationOptimization(forX: Boolean) extends AssemblyO
}
return None
}
var delta = 0
for (i <- code1.indices) {
val l1 = code1(i)
val l2 = code2(i)
@ -203,6 +222,9 @@ case class RepeatedIndexCalculationOptimization(forX: Boolean) extends AssemblyO
xs match {
case AssemblyLine0(LDA, Immediate | ZeroPage | Absolute | LongAbsolute, _) :: tail =>
tailcall(findAllRuns(tail, offset + 1, Some(offset)))
case AssemblyLine0(CLC | SEC, _, _) :: (l2@AssemblyLine0(ROL | ROR, Implied, _)) :: tail
if l2.elidability == Elidability.Elidable =>
tailcall(findAllRuns(tail, offset + 2, latestStart))
case AssemblyLine0(CLC | SEC, _, _) :: (l2@AssemblyLine0(ADC | ADC, Immediate | ZeroPage | Absolute | LongAbsolute, _)) :: tail
if l2.elidability == Elidability.Elidable =>
tailcall(findAllRuns(tail, offset + 2, latestStart))