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Smarter reverse flow analyser

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This commit is contained in:
Karol Stasiak 2018-02-25 00:45:46 +01:00
parent fa56d31cb4
commit 6dd4a0c5ce
1 changed files with 20 additions and 3 deletions
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23
src/main/scala/millfork/assembly/opt/ReverseFlowAnalyzer.scala
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@ -1,6 +1,6 @@
package millfork.assembly.opt
import millfork.assembly.{AssemblyLine, OpcodeClasses, State}
import millfork.assembly.{AssemblyLine, Opcode, OpcodeClasses, State}
import millfork.env._
import millfork.node.Register
@ -68,6 +68,9 @@ case class CpuImportance(a: Importance = UnknownImportance,
}
object ReverseFlowAnalyzer {
val aluAdders = Set(Opcode.ADC, Opcode.SBC, Opcode.ISC, Opcode.DCP)
//noinspection RedundantNewCaseClass
def analyze(f: NormalFunction, code: List[AssemblyLine]): List[CpuImportance] = {
val importanceArray = Array.fill[CpuImportance](code.length)(new CpuImportance())
@ -156,18 +159,32 @@ object ReverseFlowAnalyzer {
case AssemblyLine(DISCARD_AF, _, _, _) =>
currentImportance = currentImportance.copy(a = Unimportant, n = Unimportant, z = Unimportant, c = Unimportant, v = Unimportant)
case AssemblyLine(opcode, addrMode, _, _) =>
val reallyIgnoreC =
currentImportance.c == Unimportant &&
currentImportance.v == Unimportant &&
currentImportance.n == Unimportant &&
currentImportance.z == Unimportant &&
currentImportance.a == Unimportant &&
aluAdders.contains(opcode)
val reallyIgnoreA =
currentImportance.c == Unimportant &&
currentImportance.v == Unimportant &&
currentImportance.n == Unimportant &&
currentImportance.z == Unimportant &&
currentImportance.a == Unimportant &&
aluAdders.contains(opcode)
if (OpcodeClasses.ChangesC(opcode)) currentImportance = currentImportance.copy(c = Unimportant)
if (OpcodeClasses.ChangesV(opcode)) currentImportance = currentImportance.copy(v = Unimportant)
if (OpcodeClasses.ChangesNAndZ(opcode)) currentImportance = currentImportance.copy(n = Unimportant, z = Unimportant)
if (OpcodeClasses.OverwritesA(opcode)) currentImportance = currentImportance.copy(a = Unimportant)
if (OpcodeClasses.OverwritesX(opcode)) currentImportance = currentImportance.copy(x = Unimportant)
if (OpcodeClasses.OverwritesY(opcode)) currentImportance = currentImportance.copy(y = Unimportant)
if (OpcodeClasses.ReadsC(opcode)) currentImportance = currentImportance.copy(c = Important)
if (OpcodeClasses.ReadsC(opcode) && !reallyIgnoreC) currentImportance = currentImportance.copy(c = Important)
if (OpcodeClasses.ReadsD(opcode)) currentImportance = currentImportance.copy(d = Important)
if (OpcodeClasses.ReadsV(opcode)) currentImportance = currentImportance.copy(v = Important)
if (OpcodeClasses.ReadsXAlways(opcode)) currentImportance = currentImportance.copy(x = Important)
if (OpcodeClasses.ReadsYAlways(opcode)) currentImportance = currentImportance.copy(y = Important)
if (OpcodeClasses.ReadsAAlways(opcode)) currentImportance = currentImportance.copy(a = Important)
if (OpcodeClasses.ReadsAAlways(opcode) && !reallyIgnoreA) currentImportance = currentImportance.copy(a = Important)
if (OpcodeClasses.ReadsAIfImplied(opcode) && addrMode == Implied) currentImportance = currentImportance.copy(a = Important)
if (addrMode == AbsoluteX || addrMode == IndexedX || addrMode == ZeroPageX || addrMode == AbsoluteIndexedX)
currentImportance = currentImportance.copy(x = Important)