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restored optimization of printing short strings into just CHROUT

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but added comment about known-constness still to be resolved
This commit is contained in:
Irmen de Jong 2021-05-13 01:46:43 +02:00
parent 83639c2535
commit b9bd541532
1 changed files with 45 additions and 0 deletions
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45
compiler/src/prog8/optimizer/StatementOptimizer.kt
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@ -47,6 +47,51 @@ internal class StatementOptimizer(private val program: Program,
}
}
// printing a literal string of just 2 or 1 characters is replaced by directly outputting those characters
if(functionCallStatement.target.nameInSource==listOf("txt", "print")) {
val arg = functionCallStatement.args.single()
val stringVar: IdentifierReference? = if(arg is AddressOf) {
arg.identifier
} else {
arg as? IdentifierReference
}
if(stringVar!=null) {
// TODO: only do this optimization if the arg is a known-constant string literal instead of a user defined variable. We can't see the difference here yet.
val vardecl = stringVar.targetVarDecl(program)!!
val string = vardecl.value as? StringLiteralValue
if(string!=null) {
val pos = functionCallStatement.position
if (string.value.length == 1) {
val firstCharEncoded = compTarget.encodeString(string.value, string.altEncoding)[0]
val chrout = FunctionCallStatement(
IdentifierReference(listOf("txt", "chrout"), pos),
mutableListOf(NumericLiteralValue(DataType.UBYTE, firstCharEncoded.toInt(), pos)),
functionCallStatement.void, pos
)
return listOf(IAstModification.ReplaceNode(functionCallStatement, chrout, parent))
} else if (string.value.length == 2) {
val firstTwoCharsEncoded = compTarget.encodeString(string.value.take(2), string.altEncoding)
val chrout1 = FunctionCallStatement(
IdentifierReference(listOf("txt", "chrout"), pos),
mutableListOf(NumericLiteralValue(DataType.UBYTE, firstTwoCharsEncoded[0].toInt(), pos)),
functionCallStatement.void, pos
)
val chrout2 = FunctionCallStatement(
IdentifierReference(listOf("txt", "chrout"), pos),
mutableListOf(NumericLiteralValue(DataType.UBYTE, firstTwoCharsEncoded[1].toInt(), pos)),
functionCallStatement.void, pos
)
return listOf(
IAstModification.InsertBefore(functionCallStatement, chrout1, parent as INameScope),
IAstModification.ReplaceNode(functionCallStatement, chrout2, parent)
)
}
}
}
}
// if the first instruction in the called subroutine is a return statement, remove the jump altogeter
val subroutine = functionCallStatement.target.targetSubroutine(program)
if(subroutine!=null) {