6502/millfork
1
0
Fork 0
mirror of https://github.com/KarolS/millfork.git synced 2025-01-10 20:29:35 +00:00
Code Issues Projects Releases Wiki Activity

6502: Optimizations for certain byte additions (#50)

Browse Source
This commit is contained in:
Karol Stasiak 2020-07-19 00:54:23 +02:00
parent 5fe4a4e3ac
commit 09ff184172
2 changed files with 9 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
src/main/scala/millfork/assembly/mos/opt/LaterOptimizations.scala
View File

@ -501,6 +501,14 @@ object LaterOptimizations {
(Elidable & HasOpcode(LDA) & MatchParameter(0) & MatchAddrMode(1)) ~~>{ code =>
code.init :+ AssemblyLine.implied(TYA).pos(code.last.source)
},
((HasOpcode(STA) & HasAddrModeIn(Absolute, LongAbsolute, ZeroPage) & MatchAddrMode(0) & MatchParameter(1)) ~
(Linear & DoesntChangeMemoryAt(0, 1) & Not(ChangesA)).*).capture(4) ~
(Elidable & HasOpcode(LDA) & DoesntMatterWhatItDoesWith(State.N, State.Z) & MatchAddrMode(2) & MatchParameter(3)).capture(66) ~
((Linear & DoesntChangeMemoryAt(0, 1) & DoesntChangeMemoryAt(2, 3) & DoesntChangeIndexingInAddrMode(2) & Not(ConcernsA)).*).capture(5) ~
(Elidable & HasOpcodeIn(ADC, ORA, EOR, AND) & HasAddrModeIn(Absolute, LongAbsolute, ZeroPage) & MatchParameter(1)) ~~> { (code, ctx) =>
ctx.get[List[AssemblyLine]](4) ++ ctx.get[List[AssemblyLine]](5) ++ ctx.get[List[AssemblyLine]](66).map(_.copy(opcode = code.last.opcode))
},
)
val DontUseIndexRegisters = new RuleBasedAssemblyOptimization("Don't use index registers unnecessarily",

2
src/main/scala/millfork/compiler/mos/BuiltIns.scala
View File

@ -1505,7 +1505,7 @@ object BuiltIns {
AssemblyLine.implied(CLC),
AssemblyLine.absolute(JSR, ctx.env.get[ThingInMemory]("__adc_decimal"))
)) ++ storeLhs
} else if (!subtract && simplicity(env, v) > simplicity(env, addend)) {
} else if (!subtract && simplicity(env, v) >= simplicity(env, addend)) {
val loadRhs = MosExpressionCompiler.compile(ctx, addend, Some(b -> RegisterVariable(MosRegister.A, b)), NoBranching)
val modifyAcc = insertBeforeLast(AssemblyLine.implied(CLC), simpleOperation(ADC, ctx, v, IndexChoice.PreferY, preserveA = true, commutative = true, decimal = decimal))
val storeLhs = MosExpressionCompiler.compileByteStorage(ctx, MosRegister.A, v)