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Fixed invalid BNE optimization

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This commit is contained in:
Karol Stasiak 2017-12-19 18:57:13 +01:00
parent 1dd8c3d855
commit 115f040fe2
1 changed files with 3 additions and 1 deletions
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4
src/main/scala/millfork/assembly/opt/AlwaysGoodOptimizations.scala
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@ -265,6 +265,8 @@ object AlwaysGoodOptimizations {
(OverwritesV & Elidable) ~ (LinearOrLabel & Not(ReadsV) & Not(DiscardsV)).* ~ DiscardsV ~~> (_.tail)
)
// Optimizing Bxx to JMP is generally bad, but it may allow for better optimizations later
// It's okay to undo it at a later stage, but it's not done yet
val FlagFlowAnalysis = new RuleBasedAssemblyOptimization("Flag flow analysis",
needsFlowInfo = FlowInfoRequirement.ForwardFlow,
(HasSet(State.C) & HasOpcode(SEC) & Elidable) ~~> (_ => Nil),
@ -279,7 +281,7 @@ object AlwaysGoodOptimizations {
(HasClear(State.V) & HasOpcode(BVC) & Elidable) ~~> (c => c.map(_.copy(opcode = JMP, addrMode = Absolute))),
(HasSet(State.V) & HasOpcode(BVS) & Elidable) ~~> (c => c.map(_.copy(opcode = JMP, addrMode = Absolute))),
(HasSet(State.Z) & HasOpcode(BEQ) & Elidable) ~~> (c => c.map(_.copy(opcode = JMP, addrMode = Absolute))),
(HasClear(State.Z) & HasOpcode(BNE) & Elidable) ~~> (_ => Nil),
(HasClear(State.Z) & HasOpcode(BNE) & Elidable) ~~> (c => c.map(_.copy(opcode = JMP, addrMode = Absolute))),
)
val ReverseFlowAnalysis = new RuleBasedAssemblyOptimization("Reverse flow analysis",