don't clobber A when trying to save X at functioncall

This commit is contained in:
Irmen de Jong 2020-09-12 18:53:44 +02:00
parent 35aebbc209
commit 97b9c8f320
4 changed files with 31 additions and 28 deletions

View File

@ -552,55 +552,60 @@ internal class AsmGen(private val program: Program,
internal fun fixNameSymbols(name: String) = name.replace("<", "prog8_").replace(">", "") // take care of the autogenerated invalid (anon) label names
internal fun saveRegister(register: CpuRegister, forFuncCall: Boolean = false, dontClobberA: Boolean = false) {
private val saveRegisterLabels = Stack<String>();
internal fun saveRegister(register: CpuRegister, forFuncCall: Boolean = false) {
when(register) {
CpuRegister.A -> out(" pha")
CpuRegister.X -> {
// TODO get rid of REG_X altogheter! replace with sta _save | txa | pha | lda _save
// TODO get rid of REG_X altogether!
when {
CompilationTarget.instance.machine.cpu == CpuType.CPU65c02 -> out(" phx")
forFuncCall -> {
if(dontClobberA)
out(" sta P8ZP_SCRATCH_REG | txa | pha | lda P8ZP_SCRATCH_REG")
else
out(" txa | pha")
val save = makeLabel("saveX")
saveRegisterLabels.push(save)
out("""
stx $save
jmp +
$save .byte 0
+""")
}
else -> out(" stx P8ZP_SCRATCH_REG_X")
}
}
CpuRegister.Y -> {
when {
CompilationTarget.instance.machine.cpu == CpuType.CPU65c02 -> out(" phy")
dontClobberA -> out(" sta P8ZP_SCRATCH_REG | tya | pha | lda P8ZP_SCRATCH_REG")
else -> out(" tya | pha")
if (CompilationTarget.instance.machine.cpu == CpuType.CPU65c02) out(" phy")
else {
val save = makeLabel("saveY")
out("""
sty $save
jmp +
$save .byte 0
+""")
}
}
}
}
internal fun restoreRegister(register: CpuRegister, forFuncCall: Boolean = false, dontClobberA: Boolean=false) {
internal fun restoreRegister(register: CpuRegister, forFuncCall: Boolean = false) {
when(register) {
CpuRegister.A -> {
require(!dontClobberA)
out(" pla")
}
CpuRegister.A -> out(" pla")
CpuRegister.X -> {
when {
CompilationTarget.instance.machine.cpu == CpuType.CPU65c02 -> out(" plx")
forFuncCall -> {
if(dontClobberA)
out(" sta P8ZP_SCRATCH_REG | pla | tax | lda P8ZP_SCRATCH_REG")
else
out(" pla | tax")
val save = saveRegisterLabels.pop()
out(" ldx $save")
}
else -> out(" ldx P8ZP_SCRATCH_REG_X")
}
}
CpuRegister.Y -> {
when {
CompilationTarget.instance.machine.cpu == CpuType.CPU65c02 -> out(" ply")
dontClobberA -> out(" sta P8ZP_SCRATCH_REG | pla | tay | lda P8ZP_SCRATCH_REG")
else -> out(" pla | tay")
if (CompilationTarget.instance.machine.cpu == CpuType.CPU65c02) out(" ply")
else {
val save = saveRegisterLabels.pop()
out(" ldy $save")
}
}
}

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@ -19,7 +19,7 @@ internal class FunctionCallAsmGen(private val program: Program, private val asmg
val sub = stmt.target.targetSubroutine(program.namespace) ?: throw AssemblyError("undefined subroutine ${stmt.target}")
val saveX = CpuRegister.X in sub.asmClobbers || sub.regXasResult() || sub.regXasParam()
if(saveX)
asmgen.saveRegister(CpuRegister.X, forFuncCall = true, dontClobberA = false) // we only save X for now (required! is the eval stack pointer), screw A and Y...
asmgen.saveRegister(CpuRegister.X, forFuncCall = true)
val subName = asmgen.asmSymbolName(stmt.target)
if(stmt.args.isNotEmpty()) {
@ -58,7 +58,7 @@ internal class FunctionCallAsmGen(private val program: Program, private val asmg
asmgen.out(" jsr $subName")
if(saveX)
asmgen.restoreRegister(CpuRegister.X, forFuncCall = true, dontClobberA = false)
asmgen.restoreRegister(CpuRegister.X, forFuncCall = true)
}
private fun registerArgsViaStackEvaluation(stmt: IFunctionCall, sub: Subroutine) {

View File

@ -248,7 +248,6 @@ waitkey:
c64.CHROUT('K')
while c64.GETIN()!=133 {
; TODO FIX THIS, DOESN'T TRIGGER ANYMORE ON F1
; endless loop until user presses F1 to restart the game
}
}

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@ -1,5 +1,4 @@
%target cx16
%import cx16textio
%import c64textio
;%import c64flt
;%option enable_floats
; %zeropage kernalsafe