handling infinite loops properly

Cargo.toml

@@ -23,7 +23,7 @@ hbjit = { path = "jit" }
 
 [profile.release]
 lto = true
-#debug = true
+debug = true
 #strip = true
 codegen-units = 1
 panic = "abort"
@@ -42,3 +42,9 @@ inherits = "dev"
 opt-level = "z"
 strip = "debuginfo"
 panic = "abort"
+
+[profile.fuzz]
+inherits = "dev"
+debug = true
+opt-level = 3
+panic = "abort"

lang/Cargo.toml

@@ -7,6 +7,10 @@ edition = "2021"
 name = "hbc"
 path = "src/main.rs"
 
+[[bin]]
+name = "fuzz"
+path = "src/fuzz_main.rs"
+
 [dependencies]
 hashbrown = { version = "0.15.0", default-features = false, features = ["raw-entry", "allocator-api2"] }
 hbbytecode = { workspace = true, features = ["disasm"] }

lang/README.md

@@ -1011,6 +1011,11 @@ main := fn(): uint {
 		return 6
 	}
 
+	infinite_loop()
+	return 0
+}
+
+infinite_loop := fn(): void {
 	f := 0
 	loop {
 		if f == 1 {
@@ -1124,3 +1129,15 @@ main := fn(): uint {
 	return 1
 }
 ```
+
+#### infinite_loop_after_peephole
+```hb
+main := fn(): uint {
+	n := 0
+	f := 0
+	loop if n != 0 break else {
+		f += 1
+	}
+	return f
+}
+```

lang/src/fuzz.rs

@@ -0,0 +1,139 @@
+use {
+    crate::{
+        lexer::TokenKind,
+        parser,
+        son::{Codegen, CodegenCtx},
+    },
+    core::{fmt::Write, hash::BuildHasher, ops::Range},
+    std::string::String,
+};
+
+#[derive(Default)]
+struct Rand(pub u64);
+
+impl Rand {
+    pub fn next(&mut self) -> u64 {
+        self.0 = crate::FnvBuildHasher::default().hash_one(self.0);
+        self.0
+    }
+
+    pub fn range(&mut self, min: u64, max: u64) -> u64 {
+        self.next() % (max - min) + min
+    }
+
+    fn bool(&mut self) -> bool {
+        self.next() % 2 == 0
+    }
+}
+
+#[derive(Default)]
+struct FuncGen {
+    rand: Rand,
+    buf: String,
+    vars: u64,
+}
+
+impl FuncGen {
+    fn gen(&mut self, seed: u64) -> &str {
+        self.rand = Rand(seed);
+        self.buf.clear();
+        self.buf.push_str("main := fn(): void ");
+        self.block().unwrap();
+        &self.buf
+    }
+
+    fn block(&mut self) -> core::fmt::Result {
+        let prev_vars = self.vars;
+        self.buf.push('{');
+        for _ in 0..self.rand.range(1, 10) {
+            self.stmt()?;
+        }
+        self.buf.push('}');
+        self.vars = prev_vars;
+
+        Ok(())
+    }
+
+    fn stmt(&mut self) -> core::fmt::Result {
+        match self.rand.range(0, 100) {
+            0..4 => _ = self.block(),
+            4..10 => {
+                write!(self.buf, "var{} := ", self.vars)?;
+                self.expr()?;
+                self.vars += 1;
+            }
+
+            10..20 if self.vars != 0 => {
+                write!(self.buf, "var{} = ", self.rand.range(0, self.vars))?;
+                self.expr()?;
+            }
+            20..23 => {
+                self.buf.push_str("if ");
+                self.expr()?;
+                self.block()?;
+                if self.rand.bool() {
+                    self.buf.push_str(" else ");
+                    self.block()?;
+                }
+            }
+            _ => {
+                self.buf.push_str("return ");
+                self.expr()?;
+            }
+        }
+
+        self.buf.push(';');
+        Ok(())
+    }
+
+    fn expr(&mut self) -> core::fmt::Result {
+        match self.rand.range(0, 100) {
+            0..80 => {
+                write!(self.buf, "{}", self.rand.next())
+            }
+            80..90 if self.vars != 0 => {
+                write!(self.buf, "var{}", self.rand.range(0, self.vars))
+            }
+            80..100 => {
+                self.expr()?;
+                let ops = [
+                    TokenKind::Add,
+                    TokenKind::Sub,
+                    TokenKind::Mul,
+                    TokenKind::Div,
+                    TokenKind::Shl,
+                    TokenKind::Eq,
+                    TokenKind::Ne,
+                    TokenKind::Lt,
+                    TokenKind::Gt,
+                    TokenKind::Le,
+                    TokenKind::Ge,
+                    TokenKind::Band,
+                    TokenKind::Bor,
+                    TokenKind::Xor,
+                    TokenKind::Mod,
+                    TokenKind::Shr,
+                ];
+                let op = ops[self.rand.range(0, ops.len() as u64) as usize];
+                write!(self.buf, " {op} ")?;
+                self.expr()
+            }
+            _ => unreachable!(),
+        }
+    }
+}
+
+pub fn fuzz(seed_range: Range<u64>) {
+    let mut gen = FuncGen::default();
+    let mut ctx = CodegenCtx::default();
+    for i in seed_range {
+        ctx.clear();
+        let src = gen.gen(i);
+        let parsed = parser::Ast::new("fuzz", src, &mut ctx.parser, &mut parser::no_loader);
+
+        assert!(ctx.parser.errors.get_mut().is_empty());
+
+        let mut cdg = Codegen::new(core::slice::from_ref(&parsed), &mut ctx);
+        cdg.generate(0);
+    }
+}

lang/src/fuzz_main.rs

@@ -0,0 +1,3 @@
+fn main() {
+    hblang::fuzz::fuzz(0..1000000);
+}

lang/src/lexer.rs

@@ -277,6 +277,7 @@ impl TokenKind {
             Self::Add => a.wrapping_add(b),
             Self::Sub => a.wrapping_sub(b),
             Self::Mul => a.wrapping_mul(b),
+            Self::Div if b == 0 => 0,
             Self::Div => a.wrapping_div(b),
             Self::Shl => a.wrapping_shl(b as _),
             Self::Eq => (a == b) as i64,

lang/src/lib.rs

@@ -75,6 +75,8 @@ pub mod lexer;
 #[cfg(feature = "opts")]
 mod vc;
 
+pub mod fuzz;
+
 mod debug {
 
     pub fn panicking() -> bool {

lang/src/parser.rs

@@ -1147,8 +1147,18 @@ fn report_to(file: &str, path: &str, pos: Pos, msg: &dyn fmt::Display, out: &mut
         ..file[pos as usize..].find('\n').map_or(file.len(), |i| i + pos as usize)];
     col += line.matches('\t').count() * 3;
 
-    _ = writeln!(out, "{}", line.replace("\t", "    "));
-    _ = writeln!(out, "{}^", " ".repeat(col - 1));
+    for char in line.chars() {
+        if char == '\t' {
+            _ = out.write_str("    ");
+        } else {
+            _ = out.write_char(char);
+        }
+    }
+    _ = out.write_char('\n');
+    for _ in 0..col - 1 {
+        _ = out.write_str(" ");
+    }
+    _ = out.write_str("^\n");
 }
 
 #[derive(PartialEq, Eq, Hash)]

lang/src/son.rs

@@ -35,6 +35,8 @@ const VOID: Nid = 0;
 const NEVER: Nid = 1;
 const ENTRY: Nid = 2;
 const MEM: Nid = 3;
+const LOOPS: Nid = 4;
+const ARG_START: usize = 3;
 
 type Nid = u16;
 
@@ -154,23 +156,23 @@ impl Nodes {
     fn graphviz_in_browser(&self, tys: &Types, files: &[parser::Ast]) {
         #[cfg(all(debug_assertions, feature = "std"))]
         {
-            let out = &mut String::new();
-            _ = self.graphviz_low(tys, files, out);
-            if !std::process::Command::new("brave")
-                .arg(format!("https://dreampuf.github.io/GraphvizOnline/#{out}"))
-                .status()
-                .unwrap()
-                .success()
-            {
-                log::error!("{out}");
-            }
+            //     let out = &mut String::new();
+            //     _ = self.graphviz_low(tys, files, out);
+            //     if !std::process::Command::new("brave")
+            //         .arg(format!("https://dreampuf.github.io/GraphvizOnline/#{out}"))
+            //         .status()
+            //         .unwrap()
+            //         .success()
+            //     {
+            //         log::error!("{out}");
+            //     }
         }
     }
 
     fn gcm(&mut self) {
+        fix_loops(self);
         self.visited.clear(self.values.len());
         push_up(self);
-        // TODO: handle infinte loops
         self.visited.clear(self.values.len());
         push_down(self, VOID);
     }
@@ -313,13 +315,12 @@ impl Nodes {
         None
     }
 
-    fn iter_peeps(&mut self, mut fuel: usize) {
-        self.lock(NEVER);
+    fn iter_peeps(&mut self, mut fuel: usize, stack: &mut Vec<Nid>) {
+        stack.clear();
 
-        let mut stack = self
-            .iter()
+        self.iter()
             .filter_map(|(id, node)| node.kind.is_peeped().then_some(id))
-            .collect::<Vec<_>>();
+            .collect_into(stack);
         stack.iter().for_each(|&s| self.lock(s));
 
         while fuel != 0
@@ -340,8 +341,6 @@ impl Nodes {
                 stack.iter().skip(prev_len).for_each(|&n| self.lock(n));
             }
         }
-
-        self.unlock(NEVER);
     }
 
     fn peephole(&mut self, target: Nid) -> Option<Nid> {
@@ -524,6 +523,11 @@ impl Nodes {
 
                 return Some(ctrl);
             }
+            K::Call { .. } | K::Return => {
+                if self[target].inputs[0] == NEVER {
+                    return Some(NEVER);
+                }
+            }
             K::Phi => {
                 let &[ctrl, lhs, rhs] = self[target].inputs.as_slice() else { unreachable!() };
 
@@ -667,7 +671,7 @@ impl Nodes {
         }
         match self[node].kind {
             Kind::Start => unreachable!(),
-            Kind::End => unreachable!(),
+            Kind::End => return Ok(()),
             Kind::If => write!(out, "  if:      "),
             Kind::Region | Kind::Loop => writeln!(out, "      goto: {node}"),
             Kind::Return => write!(out, " ret:      "),
@@ -692,6 +696,7 @@ impl Nodes {
             Kind::Load => write!(out, "load:      "),
             Kind::Stre => write!(out, "stre:      "),
             Kind::Mem => write!(out, " mem:      "),
+            Kind::Loops => write!(out, " loops:      "),
             Kind::Extend => write!(out, " ext:      "),
         }?;
 
@@ -819,10 +824,16 @@ impl Nodes {
                 log::error!("{} {} {:?}", node.lock_rc, 0, node.kind);
                 failed = true;
             }
-            if !matches!(node.kind, Kind::End | Kind::Mem | Kind::Arg) && node.outputs.is_empty() {
+            if !matches!(node.kind, Kind::End | Kind::Mem | Kind::Arg | Kind::Loops)
+                && node.outputs.is_empty()
+            {
                 log::error!("outputs are empry {id} {:?}", node.kind);
                 failed = true;
             }
+            if node.inputs.first() == Some(&NEVER) && id != NEVER {
+                log::error!("is unreachable but still present {id} {:?}", node.kind);
+                failed = true;
+            }
         }
 
         if failed {
@@ -1021,7 +1032,10 @@ pub enum Kind {
     Start,
     // [ctrl]
     Entry,
+    // [VOID]
     Mem,
+    // [VOID]
+    Loops,
     // [terms...]
     End,
     // [ctrl, cond]
@@ -1070,7 +1084,7 @@ pub enum Kind {
 
 impl Kind {
     fn is_pinned(&self) -> bool {
-        self.is_cfg() || matches!(self, Self::Phi | Self::Arg | Self::Mem)
+        self.is_cfg() || matches!(self, Self::Phi | Self::Arg | Self::Mem | Self::Loops)
     }
 
     fn is_cfg(&self) -> bool {
@@ -1140,7 +1154,7 @@ impl Node {
 
     fn is_not_gvnd(&self) -> bool {
         (self.kind == Kind::Phi && self.inputs[2] == 0)
-            || matches!(self.kind, Kind::Arg | Kind::Stck)
+            || matches!(self.kind, Kind::Arg | Kind::Stck | Kind::End)
     }
 
     fn is_mem(&self) -> bool {
@@ -1368,16 +1382,20 @@ impl ItemCtx {
         let mem = self.nodes.new_node(ty::Id::VOID, Kind::Mem, [VOID]);
         debug_assert_eq!(mem, MEM);
         self.nodes.lock(mem);
+        let loops = self.nodes.new_node(ty::Id::VOID, Kind::Loops, [VOID]);
+        debug_assert_eq!(loops, LOOPS);
+        self.nodes.lock(loops);
         self.scope.store = Variable::new(0, ty::Id::VOID, false, MEM, &mut self.nodes);
     }
 
-    fn finalize(&mut self) {
+    fn finalize(&mut self, stack: &mut Vec<Nid>) {
         self.scope.clear(&mut self.nodes);
-        self.nodes.unlock(NEVER);
         mem::take(&mut self.ctrl).soft_remove(&mut self.nodes);
-        self.nodes.unlock(MEM);
         self.nodes.eliminate_stack_temporaries();
-        self.nodes.iter_peeps(1000);
+        self.nodes.iter_peeps(1000, stack);
+        self.nodes.unlock(MEM);
+        self.nodes.unlock(NEVER);
+        self.nodes.unlock(LOOPS);
     }
 
     fn emit(&mut self, instr: (usize, [u8; instrs::MAX_SIZE])) {
@@ -1438,7 +1456,7 @@ impl ItemCtx {
 
         let (retl, mut parama) = tys.parama(sig.ret);
         let mut typs = sig.args.args();
-        let mut args = fuc.nodes[VOID].outputs[2..].iter();
+        let mut args = fuc.nodes[VOID].outputs[ARG_START..].iter();
         while let Some(aty) = typs.next(tys) {
             let Arg::Value(ty) = aty else { continue };
             let Some(loc) = parama.next(ty, tys) else { continue };
@@ -1710,6 +1728,7 @@ impl ItemCtx {
                     | Kind::Entry
                     | Kind::Mem
                     | Kind::End
+                    | Kind::Loops
                     | Kind::Then
                     | Kind::Else
                     | Kind::Phi
@@ -1852,6 +1871,7 @@ struct Pool {
     cis: Vec<ItemCtx>,
     used_cis: usize,
     ralloc: Regalloc,
+    nid_stack: Vec<Nid>,
 }
 
 impl Pool {
@@ -2840,7 +2860,7 @@ impl<'a> Codegen<'a> {
                 let prev_file = mem::replace(&mut self.ci.file, file);
                 self.ci.inline_depth += 1;
 
-                if self.expr(body).is_some() && sig.ret == ty::Id::VOID {
+                if self.expr(body).is_some() && sig.ret != ty::Id::VOID {
                     self.report(
                         body.pos(),
                         "expected all paths in the fucntion to return \
@@ -3052,7 +3072,11 @@ impl<'a> Codegen<'a> {
             }
             Expr::Loop { body, .. } => {
                 self.ci.ctrl.set(
-                    self.ci.nodes.new_node(ty::Id::VOID, Kind::Loop, [self.ci.ctrl.get(); 2]),
+                    self.ci.nodes.new_node(ty::Id::VOID, Kind::Loop, [
+                        self.ci.ctrl.get(),
+                        self.ci.ctrl.get(),
+                        LOOPS,
+                    ]),
                     &mut self.ci.nodes,
                 );
                 self.ci.loops.push(Loop {
@@ -3121,6 +3145,7 @@ impl<'a> Codegen<'a> {
                     }
                     scope.clear(&mut self.ci.nodes);
                     self.ci.ctrl.set(NEVER, &mut self.ci.nodes);
+
                     return None;
                 };
 
@@ -3182,9 +3207,9 @@ impl<'a> Codegen<'a> {
                     self.ci.nodes.new_node(ty::Id::VOID, Kind::If, [self.ci.ctrl.get(), cnd.id]);
 
                 'b: {
-                    let branch = match self.tof(if_node).expand().inner() {
-                        ty::LEFT_UNREACHABLE => else_,
-                        ty::RIGHT_UNREACHABLE => Some(then),
+                    let branch = match self.ci.nodes[if_node].ty {
+                        ty::Id::LEFT_UNREACHABLE => else_,
+                        ty::Id::RIGHT_UNREACHABLE => Some(then),
                         _ => break 'b,
                     };
 
@@ -3471,11 +3496,6 @@ impl<'a> Codegen<'a> {
         None
     }
 
-    #[inline(always)]
-    fn tof(&self, id: Nid) -> ty::Id {
-        self.ci.nodes[id].ty
-    }
-
     fn complete_call_graph(&mut self) -> bool {
         let prev_err_len = self.errors.borrow().len();
         while self.ci.task_base < self.tys.tasks.len()
@@ -3535,17 +3555,24 @@ impl<'a> Codegen<'a> {
             }
         }
 
-        if self.expr(body).is_some() && sig.ret == ty::Id::VOID {
+        if self.expr(body).is_some() {
+            if sig.ret == ty::Id::VOID {
+                self.expr(&Expr::Return { pos: body.pos(), val: None });
+            } else {
                 self.report(
                     body.pos(),
+                    fa!(
                         "expected all paths in the fucntion to return \
-                or the return type to be 'void'",
+                        or the return type to be 'void' (return type is '{}')",
+                        self.ty_display(sig.ret),
+                    ),
                 );
             }
+        }
 
         self.ci.scope.vars.drain(..).for_each(|v| v.remove_ignore_arg(&mut self.ci.nodes));
 
-        self.ci.finalize();
+        self.ci.finalize(&mut self.pool.nid_stack);
 
         if self.errors.borrow().len() == prev_err_len {
             self.ci.emit_body(self.tys, self.files, sig, &mut self.pool.ralloc);
@@ -3675,7 +3702,7 @@ impl TypeParser for Codegen<'_> {
         self.expr(&Expr::Return { pos: expr.pos(), val: Some(expr) });
 
         scope = mem::take(&mut self.ci.scope.vars);
-        self.ci.finalize();
+        self.ci.finalize(&mut self.pool.nid_stack);
 
         let res = if self.errors.borrow().len() == prev_err_len {
             self.emit_and_eval(file, ret, &mut [])
@@ -3719,7 +3746,7 @@ impl TypeParser for Codegen<'_> {
 
         self.expr(&(Expr::Return { pos: expr.pos(), val: Some(expr) }));
 
-        self.ci.finalize();
+        self.ci.finalize(&mut self.pool.nid_stack);
 
         let ret = self.ci.ret.expect("for return type to be infered");
         if self.errors.borrow().len() == prev_err_len {
@@ -3881,7 +3908,6 @@ impl<'a> Function<'a> {
                 debug_assert_matches!(self.nodes[node.outputs[0]].kind, Kind::Entry);
                 self.emit_node(node.outputs[0], VOID)
             }
-            Kind::End => {}
             Kind::If => {
                 self.nodes[nid].ralloc_backref = self.nodes[prev].ralloc_backref;
 
@@ -3974,7 +4000,7 @@ impl<'a> Function<'a> {
                 let (ret, mut parama) = self.tys.parama(self.sig.ret);
                 let mut typs = self.sig.args.args();
                 #[allow(clippy::unnecessary_to_owned)]
-                let mut args = self.nodes[VOID].outputs[2..].to_owned().into_iter();
+                let mut args = self.nodes[VOID].outputs[ARG_START..].to_owned().into_iter();
                 while let Some(ty) = typs.next_value(self.tys) {
                     let arg = args.next().unwrap();
                     match parama.next(ty, self.tys) {
@@ -4136,7 +4162,8 @@ impl<'a> Function<'a> {
                 let ops = vec![self.drg(nid)];
                 self.add_instr(nid, ops);
             }
-            Kind::Phi | Kind::Arg | Kind::Mem => {}
+            Kind::End |
+            Kind::Phi | Kind::Arg | Kind::Mem | Kind::Loops  => {}
             Kind::Load { .. } if node.ty.loc(self.tys) == Loc::Stack => {
                 self.nodes.lock(nid)
             }
@@ -4414,6 +4441,27 @@ fn idepth(nodes: &mut Nodes, target: Nid) -> IDomDepth {
     nodes[target].depth
 }
 
+fn fix_loops(nodes: &mut Nodes) {
+    'o: for l in nodes[LOOPS].outputs.clone() {
+        let mut cursor = nodes[l].inputs[1];
+        while cursor != l {
+            if nodes[cursor].kind == Kind::If
+                && nodes[cursor]
+                    .outputs
+                    .clone()
+                    .into_iter()
+                    .any(|b| loop_depth(b, nodes) < loop_depth(cursor, nodes))
+            {
+                continue 'o;
+            }
+            cursor = idom(nodes, cursor);
+        }
+
+        nodes[l].outputs.push(NEVER);
+        nodes[NEVER].inputs.push(l);
+    }
+}
+
 fn push_up(nodes: &mut Nodes) {
     fn collect_rpo(node: Nid, nodes: &mut Nodes, rpo: &mut Vec<Nid>) {
         if !nodes.is_cfg(node) || !nodes.visited.set(node) {
@@ -4491,13 +4539,15 @@ fn push_up(nodes: &mut Nodes) {
         nodes
             .iter()
             .map(|(n, _)| n)
-            .filter(|&n| !nodes.visited.get(n) && !matches!(nodes[n].kind, Kind::Arg | Kind::Mem))
+            .filter(|&n| !nodes.visited.get(n)
+                && !matches!(nodes[n].kind, Kind::Arg | Kind::Mem | Kind::Loops))
             .collect::<Vec<_>>(),
         vec![],
         "{:?}",
         nodes
             .iter()
-            .filter(|&(n, nod)| !nodes.visited.get(n) && !matches!(nod.kind, Kind::Arg | Kind::Mem))
+            .filter(|&(n, nod)| !nodes.visited.get(n)
+                && !matches!(nod.kind, Kind::Arg | Kind::Mem | Kind::Loops))
             .collect::<Vec<_>>()
     );
 }
@@ -4609,100 +4659,11 @@ fn common_dom(mut a: Nid, mut b: Nid, nodes: &mut Nodes) -> Nid {
 #[cfg(test)]
 mod tests {
     use {
-        super::{Codegen, CodegenCtx},
-        crate::{
-            lexer::TokenKind,
-            parser::{self},
-        },
+        super::CodegenCtx,
         alloc::{string::String, vec::Vec},
-        core::{fmt::Write, hash::BuildHasher, ops::Range},
+        core::fmt::Write,
     };
 
-    #[derive(Default)]
-    struct Rand(pub u64);
-
-    impl Rand {
-        pub fn next(&mut self) -> u64 {
-            self.0 = crate::FnvBuildHasher::default().hash_one(self.0);
-            self.0
-        }
-
-        pub fn range(&mut self, min: u64, max: u64) -> u64 {
-            self.next() % (max - min) + min
-        }
-    }
-
-    #[derive(Default)]
-    struct FuncGen {
-        rand: Rand,
-        buf: String,
-    }
-
-    impl FuncGen {
-        fn gen(&mut self, seed: u64) -> &str {
-            self.rand = Rand(seed);
-            self.buf.clear();
-            self.buf.push_str("main := fn(): void { return ");
-            self.expr().unwrap();
-            self.buf.push('}');
-            &self.buf
-        }
-
-        fn expr(&mut self) -> core::fmt::Result {
-            match self.rand.range(0, 100) {
-                0..80 => {
-                    write!(self.buf, "{}", self.rand.next())
-                }
-                80..100 => {
-                    self.expr()?;
-                    let ops = [
-                        TokenKind::Add,
-                        TokenKind::Sub,
-                        TokenKind::Mul,
-                        TokenKind::Div,
-                        TokenKind::Shl,
-                        TokenKind::Eq,
-                        TokenKind::Ne,
-                        TokenKind::Lt,
-                        TokenKind::Gt,
-                        TokenKind::Le,
-                        TokenKind::Ge,
-                        TokenKind::Band,
-                        TokenKind::Bor,
-                        TokenKind::Xor,
-                        TokenKind::Mod,
-                        TokenKind::Shr,
-                    ];
-                    let op = ops[self.rand.range(0, ops.len() as u64) as usize];
-                    write!(self.buf, " {op} ")?;
-                    self.expr()
-                }
-                _ => unreachable!(),
-            }
-        }
-    }
-
-    fn fuzz(seed_range: Range<u64>) {
-        let mut gen = FuncGen::default();
-        let mut ctx = CodegenCtx::default();
-        for i in seed_range {
-            ctx.clear();
-            let src = gen.gen(i);
-            let parsed = parser::Ast::new("fuzz", src, &mut ctx.parser, &mut parser::no_loader);
-
-            let mut cdg = Codegen::new(core::slice::from_ref(&parsed), &mut ctx);
-            cdg.generate(0);
-        }
-    }
-
-    #[test]
-    #[ignore]
-    fn fuzz_test() {
-        _ = log::set_logger(&crate::fs::Logger);
-        log::set_max_level(log::LevelFilter::Info);
-        fuzz(0..10000);
-    }
-
     fn generate(ident: &'static str, input: &'static str, output: &mut String) {
         _ = log::set_logger(&crate::fs::Logger);
         log::set_max_level(log::LevelFilter::Info);
@@ -4795,5 +4756,6 @@ mod tests {
         conditional_stores;
         loop_stores;
         dead_code_in_loop;
+        infinite_loop_after_peephole;
     }
 }

lang/tests/son_tests_exhaustive_loop_testing.txt

@@ -15,56 +15,65 @@ continue_and_state_change:
  4: ADDI64 r2, r2, 1d
  3: JMP :6
  5: JALA r0, r31, 0a
+infinite_loop:
+    ADDI64 r254, r254, -24d
+    ST r31, r254, 0a, 24h
+    LI64 r32, 1d
+    LI64 r33, 0d
+    CP r1, r33
+ 1: JNE r1, r32, :0
+    JMP :0
+ 0: CP r2, r33
+    JAL r31, r0, :continue_and_state_change
+    JMP :1
+    LD r31, r254, 0a, 24h
+    ADDI64 r254, r254, 24d
+    JALA r0, r31, 0a
 main:
-    ADDI64 r254, r254, -64d
-    ST r31, r254, 0a, 64h
+    ADDI64 r254, r254, -56d
+    ST r31, r254, 0a, 56h
     LI64 r32, 0d
     CP r2, r32
     JAL r31, r0, :multiple_breaks
-    LI64 r6, 1d
-    LI64 r7, 3d
-    JEQ r1, r7, :0
-    CP r1, r6
+    CP r2, r1
+    LI64 r1, 3d
+    JEQ r2, r1, :0
+    LI64 r1, 1d
     JMP :1
- 0: CP r33, r6
-    CP r34, r7
-    LI64 r35, 4d
-    CP r2, r35
+ 0: CP r33, r1
+    LI64 r34, 4d
+    CP r2, r34
     JAL r31, r0, :multiple_breaks
-    CP r36, r35
-    LI64 r37, 10d
-    JEQ r1, r37, :2
+    CP r35, r34
+    LI64 r36, 10d
+    JEQ r1, r36, :2
     LI64 r1, 2d
     JMP :1
  2: CP r2, r32
     JAL r31, r0, :state_change_in_break
     JEQ r1, r32, :3
-    CP r1, r34
+    CP r1, r33
     JMP :1
- 3: CP r2, r36
+ 3: CP r2, r35
     JAL r31, r0, :state_change_in_break
-    JEQ r1, r37, :4
-    CP r1, r36
+    JEQ r1, r36, :4
+    CP r1, r35
     JMP :1
- 4: CP r2, r37
+ 4: CP r2, r36
     JAL r31, r0, :continue_and_state_change
-    JEQ r1, r37, :5
+    JEQ r1, r36, :5
     LI64 r1, 5d
     JMP :1
- 5: CP r2, r34
+ 5: CP r2, r33
     JAL r31, r0, :continue_and_state_change
     JEQ r1, r32, :6
     LI64 r1, 6d
     JMP :1
- 6: CP r1, r32
-    CP r38, r33
- 8: JNE r1, r38, :7
-    JMP :7
- 7: CP r2, r32
-    JAL r31, r0, :continue_and_state_change
-    JMP :8
- 1: LD r31, r254, 0a, 64h
-    ADDI64 r254, r254, 64d
+ 6: CP r37, r32
+    JAL r31, r0, :infinite_loop
+    CP r1, r37
+ 1: LD r31, r254, 0a, 56h
+    ADDI64 r254, r254, 56d
     JALA r0, r31, 0a
 multiple_breaks:
     LI64 r6, 3d
@@ -91,6 +100,6 @@ state_change_in_break:
     JMP :4
  3: JALA r0, r31, 0a
 timed out
-code size: 582
+code size: 668
 ret: 10
 status: Ok(())

lang/tests/son_tests_infinite_loop_after_peephole.txt

@@ -0,0 +1,9 @@
+main:
+    LI64 r2, 0d
+ 0: ADDI64 r2, r2, 1d
+    JMP :0
+    JALA r0, r31, 0a
+timed out
+code size: 45
+ret: 0
+status: Ok(())

lang/tests/son_tests_string_flip.txt

@@ -7,30 +7,29 @@ main:
     CP r9, r4
  6: JNE r9, r6, :0
     LI64 r6, 2d
-    CP r7, r4
- 4: JNE r7, r8, :1
+    ADDI64 r7, r254, 32d
+    CP r9, r4
+ 4: JNE r9, r8, :1
     LD r1, r254, 0a, 8h
     JMP :2
- 1: CP r10, r4
- 5: ADD64 r9, r7, r8
-    JNE r10, r6, :3
-    CP r7, r9
+ 1: MUL64 r12, r9, r6
+    ADD64 r9, r9, r8
+    SUB64 r10, r6, r9
+    MUL64 r10, r10, r6
+    CP r3, r4
+ 5: JNE r3, r6, :3
     JMP :4
- 3: ADD64 r3, r10, r8
-    MUL64 r12, r7, r6
-    SUB64 r11, r6, r9
-    ADD64 r9, r12, r10
-    MUL64 r11, r11, r6
-    MULI64 r9, r9, 8d
-    ADD64 r11, r11, r10
-    ADD64 r9, r5, r9
-    MULI64 r11, r11, 8d
-    ADDI64 r10, r254, 32d
-    ADD64 r11, r5, r11
-    BMC r9, r10, 8h
-    BMC r11, r9, 8h
-    BMC r10, r11, 8h
-    CP r10, r3
+ 3: ADD64 r11, r3, r8
+    ADD64 r1, r12, r3
+    MULI64 r1, r1, 8d
+    ADD64 r2, r10, r3
+    ADD64 r1, r5, r1
+    MULI64 r2, r2, 8d
+    ADD64 r2, r5, r2
+    BMC r1, r7, 8h
+    BMC r2, r1, 8h
+    BMC r7, r2, 8h
+    CP r3, r11
     JMP :5
  0: ADD64 r2, r9, r8
     MULI64 r12, r9, 8d
@@ -40,6 +39,6 @@ main:
     JMP :6
  2: ADDI64 r254, r254, 40d
     JALA r0, r31, 0a
-code size: 274
+code size: 271
 ret: 2
 status: Ok(())