60 lines
1.5 KiB
TypeScript
60 lines
1.5 KiB
TypeScript
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import { createCfg } from "./cfg.ts";
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import { Block, Mir } from "./mir.ts";
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export function eliminateOnlyChildsBlocks(mir: Mir) {
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for (const fn of mir.fns) {
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const cfg = createCfg(fn);
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const candidates: { parent: Block; child: Block }[] = [];
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for (const block of fn.blocks) {
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const children = cfg.children(block);
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if (children.length !== 1) {
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continue;
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}
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if (cfg.parents(children[0]).length !== 1) {
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continue;
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}
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candidates.push({ parent: block, child: children[0] });
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}
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const elimIndices: number[] = [];
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for (const { parent, child } of candidates) {
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parent.ops.push(...child.ops);
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parent.ter = child.ter;
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elimIndices.push(cfg.index(child));
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}
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for (const i of elimIndices.toReversed()) {
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fn.blocks.splice(i, 1);
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}
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}
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}
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export function eliminateUnreachableBlocks(mir: Mir) {
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for (const fn of mir.fns) {
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const cfg = createCfg(fn);
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const candidates: Block[] = [];
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for (const block of fn.blocks) {
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if (block.id === fn.entry) {
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continue;
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}
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if (cfg.parents(block).length !== 0) {
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continue;
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}
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candidates.push(block);
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}
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for (
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const i of candidates
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.map((block) => cfg.index(block))
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.toReversed()
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) {
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fn.blocks.splice(i, 1);
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}
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}
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}
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