diff --git a/sbc/asm_gen.ts b/sbc/asm_gen.ts
index dba7b90..464d203 100644
--- a/sbc/asm_gen.ts
+++ b/sbc/asm_gen.ts
@@ -132,13 +132,15 @@ export class AsmGen {
}
private generateFnBody(fn: lir.Fn) {
+ let bodyIdx = 0;
const allocator = new StackAllocator();
- for (const { ins } of fn.lines) {
+ for (const [i, { ins }] of fn.lines.entries()) {
if (ins.tag === "alloc_param") {
allocator.allocParam(ins.reg, ins.size);
} else if (ins.tag === "alloc_local") {
allocator.allocLocal(ins.reg, ins.size);
} else {
+ bodyIdx = i;
break;
}
}
@@ -154,7 +156,7 @@ export class AsmGen {
this.writeIns(`sub rsp, ${this.layout.frameSize}`);
this.writeIns(`jmp .L${fn.mir.entry.id}`);
- for (const line of fn.lines) {
+ for (const line of fn.lines.slice(bodyIdx)) {
for (const label of line.labels) {
this.writeln(`.L${label}:`);
}
diff --git a/sbc/lir_gen.ts b/sbc/lir_gen.ts
index aa9231b..49952b3 100644
--- a/sbc/lir_gen.ts
+++ b/sbc/lir_gen.ts
@@ -10,6 +10,7 @@ import {
import { MirGen } from "./mir_gen.ts";
import * as ast from "./ast.ts";
import * as mir from "./mir.ts";
+import { optimizeMirFn } from "./mir_optimize.ts";
export class LirGen {
private strings = new StringIntern();
@@ -29,6 +30,7 @@ export class LirGen {
throw new Error("only functions can compile top level");
}
const mir = this.mirGen.fnMir(stmt, stmt.kind);
+ optimizeMirFn(mir);
const id = this.fnIds++;
const label = `sbc__${stmt.kind.ident}`;
const fn: Fn = {
diff --git a/sbc/lir_optimize.ts b/sbc/lir_optimize.ts
index d4d47fa..3b227bc 100644
--- a/sbc/lir_optimize.ts
+++ b/sbc/lir_optimize.ts
@@ -8,18 +8,17 @@ import {
Reg,
} from "./lir.ts";
-export function lirOptimize(program: Program) {
- console.log("=== BEFORE OPTIMIZATION ===");
- console.log(new ProgramStringifyer(program).stringify());
+export function optimizeLir(program: Program) {
+ //console.log("=== BEFORE OPTIMIZATION ===");
+ //console.log(new ProgramStringifyer(program).stringify());
- let changed = true;
let sizeBefore = program.fns
.reduce((acc, fn) => acc + fn.lines.length, 0);
const sizeHistory = new Set([sizeBefore]);
let repeats = 0;
- while (changed && repeats < 3) {
+ while (repeats < 1) {
for (const fn of program.fns) {
eliminatePushPop(fn);
eliminateMovFnCall(fn);
@@ -28,9 +27,6 @@ export function lirOptimize(program: Program) {
}
const sizeAfter = program.fns
.reduce((acc, fn) => acc + fn.lines.length, 0);
- if (sizeAfter !== sizeBefore) {
- changed = true;
- }
sizeBefore = sizeAfter;
if (sizeHistory.has(sizeBefore)) {
repeats += 1;
@@ -38,8 +34,8 @@ export function lirOptimize(program: Program) {
sizeHistory.add(sizeBefore);
}
- console.log("=== AFTER OPTIMIZATION ===");
- console.log(new ProgramStringifyer(program).stringify());
+ //console.log("=== AFTER OPTIMIZATION ===");
+ //console.log(new ProgramStringifyer(program).stringify());
}
function eliminatePushPop(fn: Fn) {
diff --git a/sbc/main.ts b/sbc/main.ts
index 61d4dd4..568279b 100644
--- a/sbc/main.ts
+++ b/sbc/main.ts
@@ -5,7 +5,7 @@ import { FnStringifyer } from "./mir.ts";
import { LirGen } from "./lir_gen.ts";
import { ProgramStringifyer } from "./lir.ts";
import { AsmGen } from "./asm_gen.ts";
-import { lirOptimize } from "./lir_optimize.ts";
+import { optimizeLir } from "./lir_optimize.ts";
async function main() {
const text = await Deno.readTextFile(Deno.args[0]);
@@ -32,7 +32,7 @@ async function main() {
// console.log("=== LIR ===");
// console.log(new ProgramStringifyer(lir).stringify());
- lirOptimize(lir);
+ optimizeLir(lir);
const asm = new AsmGen(lir).generate();
// console.log("=== ASM ===");
diff --git a/sbc/mir.ts b/sbc/mir.ts
index a0b9609..1fd221f 100644
--- a/sbc/mir.ts
+++ b/sbc/mir.ts
@@ -73,7 +73,11 @@ export class FnStringifyer {
}
return `${kind.ident}:\n${
this.fn.locals
- .map((local) => ` %${local.id}: ${tyToString(local.ty)}\n`)
+ .map((local) =>
+ ` %${local.id} :: ${tyToString(local.ty)}${
+ local.ident ? ` '${local.ident}'` : ""
+ }\n`
+ )
.join("")
}${
this.fn.blocks
diff --git a/sbc/mir_optimize.ts b/sbc/mir_optimize.ts
new file mode 100644
index 0000000..4a6def5
--- /dev/null
+++ b/sbc/mir_optimize.ts
@@ -0,0 +1,97 @@
+import * as ast from "./ast.ts";
+import { Block, Fn, FnStringifyer } from "./mir.ts";
+
+export function optimizeMirFn(fn: Fn) {
+ //console.log(`=== OPTIMIZING ${(fn.stmt.kind as ast.FnStmt).ident} ===`);
+ //console.log("=== BEFORE OPTIMIZATION ===");
+ //console.log(new FnStringifyer(fn).stringify());
+
+ const blockSize = fn.blocks
+ .map((block) => block.stmts.length)
+ .toSorted()
+ .at(-1)! + 1;
+ let sizeBefore = fnSize(fn, blockSize);
+
+ const sizeHistory = new Set([sizeBefore]);
+ let repeats = 0;
+
+ while (repeats < 1) {
+ eliminateUnreachable(fn);
+ joinSequentialBlocks(fn);
+
+ const sizeAfter = fnSize(fn, blockSize);
+ sizeBefore = sizeAfter;
+ if (sizeHistory.has(sizeBefore)) {
+ repeats += 1;
+ }
+ sizeHistory.add(sizeBefore);
+ }
+
+ //console.log("=== AFTER OPTIMIZATION ===");
+ //console.log(new FnStringifyer(fn).stringify());
+}
+
+function fnSize(fn: Fn, blockSize: number): number {
+ return fn.blocks
+ .reduce((acc, block) => acc + blockSize + block.stmts.length, 0);
+}
+
+function eliminateUnreachable(fn: Fn) {
+ const toRemove = new Set<number>();
+
+ for (const block of fn.blocks) {
+ const preds = cfgPredecessors(fn, block);
+
+ if (block.id === fn.entry.id || preds.length !== 0) {
+ continue;
+ }
+ toRemove.add(block.id);
+ }
+
+ fn.blocks = fn.blocks
+ .filter((block) => !toRemove.has(block.id));
+}
+
+function joinSequentialBlocks(fn: Fn) {
+ const toRemove = new Set<number>();
+
+ for (const first of fn.blocks) {
+ const firstSuccs = cfgSuccessors(first);
+ if (firstSuccs.length !== 1) {
+ continue;
+ }
+ const [second] = firstSuccs;
+ const secondPreds = cfgPredecessors(fn, second);
+ if (secondPreds.length !== 1) {
+ continue;
+ }
+ first.stmts.push(...second.stmts);
+ first.ter = second.ter;
+ toRemove.add(second.id);
+ if (second.id === fn.exit.id) {
+ fn.exit = first;
+ }
+ }
+
+ fn.blocks = fn.blocks
+ .filter((block) => !toRemove.has(block.id));
+}
+
+function cfgPredecessors(fn: Fn, block: Block): Block[] {
+ return fn.blocks
+ .filter((b) => cfgSuccessors(b).some((s) => s.id === block.id));
+}
+
+function cfgSuccessors(block: Block): Block[] {
+ const tk = block.ter.kind;
+ switch (tk.tag) {
+ case "error":
+ case "unset":
+ case "return":
+ return [];
+ case "goto":
+ return [tk.target];
+ case "if":
+ return [tk.truthy, tk.falsy];
+ }
+}
diff --git a/sbc/ty.ts b/sbc/ty.ts
index 08b8886..8d9054b 100644
--- a/sbc/ty.ts
+++ b/sbc/ty.ts
@@ -23,7 +23,7 @@ export function tyToString(ty: Ty): string {
case "fn": {
const k = ty.stmt.kind as ast.StmtKind & { tag: "fn" };
const params = ty.params
- .map((param, i) => `${k.params[i]}: ${tyToString(param)}`)
+ .map((param, i) => `${k.params[i].ident}: ${tyToString(param)}`)
.join(", ");
const returnTy = tyToString(ty.returnTy);
return `fn ${k.ident}(${params}) -> ${returnTy}`;