A "high-level" language for the Gameboy
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import { R8 } from "./cpu"
import { Loc, LocType } from "../ir/loc"
import { Operand, AbsInsn2, insnReduce2 } from "../ir/insn"
import { BinaryOp, UnaryOp } from "../ast"
import type { SM83Insn } from "./insn"
export const realizeBlock = (block: Array<AbsInsn2>): Array<SM83Insn> => block.flatMap(realizeInsn)
export const realizeInsn = (insn: AbsInsn2): Array<SM83Insn> => insnReduce2(realizeCopy, realizeUnary, insn)
const getSourceName = (source: Operand): string => typeof source === "number"
? source.toString()
: source.asmName()
export const realizeCopy = (dest: Loc, source: Operand): Array<SM83Insn> => [
`LD ${dest.asmName()}, ${getSourceName(source)}`
]
export const realizeUnary = (dest: Loc, op: UnaryOp | BinaryOp, source: Operand): Array<SM83Insn> => {
if (!isA(dest)) {
throw new Error("unexpected form for unary operation")
}
switch (op) {
case "add":
return [`ADD ${getSourceName(source)}`]
case "arith_negate":
return ["CPL", "INC A"]
case "bit_negate":
return ["CPL"]
default:
throw new Error(`unsupported unary op \`${op}'`)
}
}
const isA = (loc: Operand): boolean =>
typeof loc === "object" && loc.type === LocType.REGISTER && loc.name === R8.A