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Fix: don't swap BC and DE if jumping outside the function

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This commit is contained in:
Karol Stasiak 2019-07-09 22:39:57 +02:00
parent 7766ba932b
commit c5135423f8
1 changed files with 15 additions and 1 deletions
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16
src/main/scala/millfork/assembly/z80/opt/ChangeRegisterPair.scala
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@ -2,7 +2,7 @@ package millfork.assembly.z80.opt
import millfork.assembly.{AssemblyOptimization, Elidability, OptimizationContext}
import millfork.assembly.z80._
import millfork.env.{AssemblyParamSignature, NormalFunction, NormalParamSignature}
import millfork.env.{AssemblyParam, AssemblyParamSignature, FunctionInMemory, MemoryAddressConstant, NormalFunction, NormalParamSignature, NumericConstant, ParamSignature, ZRegisterVariable}
import millfork.error.Logger
import millfork.node.ZRegister
@ -99,8 +99,22 @@ class ChangeRegisterPair(preferBC2DE: Boolean) extends AssemblyOptimization[ZLin
}
}
private def readsBCorDE(params: ParamSignature): Boolean = {
import ZRegister._
params match {
case AssemblyParamSignature(ps) => ps.exists {
case AssemblyParam(_, ZRegisterVariable(B | C | D | E | BC | DE, _), _) => true
case _ => false
}
case NormalParamSignature(List(p)) => p.typ.size == 3 || p.typ.size == 4
case _ => false
}
}
private def canOptimize(code: List[ZLine], dir: PairDirection, loaded: Loaded): Boolean = code match {
case ZLine0(CALL, _, _) :: xs => false // TODO
case ZLine0(JP, _, MemoryAddressConstant(f: FunctionInMemory)) :: xs if readsBCorDE(f.params) => false
case ZLine0(JP, _, NumericConstant(_, _)) :: xs => false
case ZLine0(LD_16, TwoRegisters(r, IMM_16), _) :: xs => canOptimize(xs, dir, loaded = loaded.load(r))
case ZLine0(LD,
TwoRegisters(B, C) |