bridge(loop): exit PHI を SSOT へ統一（break/continue スナップショットの stack 化）+ ループ比較スモーク（bridge）追加\n\n- lowering.rs: ループ用 break/continue スナップショットを thread-local stack で管理（push/pop/record）\n- loop_.rs: continue/break スナップを取り込み、seal_incomplete_phis_with・build_exit_phis_with に委譲\n- smokes: bridge_loop_sum/break/continue を opt-in 追加（SMOKES_ENABLE_LOOP_BRIDGE=1）

src/runner/json_v0_bridge/lowering.rs

@@ -4,6 +4,7 @@ use crate::mir::{
     MirPrinter, MirType, ValueId,
 };
 use std::collections::HashMap;
+use std::cell::RefCell;
 
 // Split out merge/new_block helpers for readability (no behavior change)
 mod merge;
@@ -23,6 +24,41 @@ pub(super) struct LoopContext {
     pub(super) exit_bb: BasicBlockId,
 }
 
+// Snapshot stacks for loop break/continue (per-nested-loop frame)
+thread_local! {
+    static EXIT_SNAPSHOT_STACK: RefCell<Vec<Vec<(BasicBlockId, HashMap<String, ValueId>)>>> = RefCell::new(Vec::new());
+    static CONT_SNAPSHOT_STACK: RefCell<Vec<Vec<(BasicBlockId, HashMap<String, ValueId>)>>> = RefCell::new(Vec::new());
+}
+
+pub(super) fn push_loop_snapshot_frames() {
+    EXIT_SNAPSHOT_STACK.with(|s| s.borrow_mut().push(Vec::new()));
+    CONT_SNAPSHOT_STACK.with(|s| s.borrow_mut().push(Vec::new()));
+}
+
+pub(super) fn pop_exit_snapshots() -> Vec<(BasicBlockId, HashMap<String, ValueId>)> {
+    EXIT_SNAPSHOT_STACK.with(|s| s.borrow_mut().pop().unwrap_or_default())
+}
+
+pub(super) fn pop_continue_snapshots() -> Vec<(BasicBlockId, HashMap<String, ValueId>)> {
+    CONT_SNAPSHOT_STACK.with(|s| s.borrow_mut().pop().unwrap_or_default())
+}
+
+fn record_exit_snapshot(cur_bb: BasicBlockId, vars: &HashMap<String, ValueId>) {
+    EXIT_SNAPSHOT_STACK.with(|s| {
+        if let Some(top) = s.borrow_mut().last_mut() {
+            top.push((cur_bb, vars.clone()));
+        }
+    });
+}
+
+fn record_continue_snapshot(cur_bb: BasicBlockId, vars: &HashMap<String, ValueId>) {
+    CONT_SNAPSHOT_STACK.with(|s| {
+        if let Some(top) = s.borrow_mut().last_mut() {
+            top.push((cur_bb, vars.clone()));
+        }
+    });
+}
+
 #[derive(Clone)]
 pub(super) struct BridgeEnv {
     pub(super) throw_enabled: bool,
@@ -128,12 +164,16 @@ pub(super) fn lower_stmt_with_vars(
         }
         StmtV0::Break => {
             if let Some(ctx) = loop_stack.last().copied() {
+                // snapshot variables at break
+                record_exit_snapshot(cur_bb, vars);
                 lower_break_stmt(f, cur_bb, ctx.exit_bb);
             }
             Ok(cur_bb)
         }
         StmtV0::Continue => {
             if let Some(ctx) = loop_stack.last().copied() {
+                // snapshot variables at continue
+                record_continue_snapshot(cur_bb, vars);
                 lower_continue_stmt(f, cur_bb, ctx.cond_bb);
             }
             Ok(cur_bb)

src/runner/json_v0_bridge/lowering/loop_.rs

@@ -30,7 +30,7 @@ pub(super) fn lower_loop_stmt(
         }
     }
 
-    // 3) LoopPhiOps アダプタ
+    // 3) LoopPhiOps アダプタ（準備用: preheader seed 専用）
     struct Ops<'a> {
         f: &'a mut MirFunction,
         vars: &'a mut HashMap<String, ValueId>,
@@ -81,6 +81,8 @@ pub(super) fn lower_loop_stmt(
     let mut incomplete = crate::mir::phi_core::loop_phi::prepare_loop_variables_with(
         &mut ops, cond_bb, cur_bb, &base_vars,
     )?;
+    // Header snapshot for exit PHIs
+    let header_vars_snapshot = ops.vars.clone();
 
     let (cval, _cend) = super::expr::lower_expr_with_vars(env, ops.f, cond_bb, cond, ops.vars)?;
     if let Some(bb) = ops.f.get_block_mut(cond_bb) {
@@ -91,12 +93,19 @@ pub(super) fn lower_loop_stmt(
         });
     }
     let mut body_vars = ops.vars.clone();
+    // open snapshot frames for nested break/continue
+    super::push_loop_snapshot_frames();
     loop_stack.push(LoopContext { cond_bb, exit_bb });
     let bend_res = lower_stmt_list_with_vars(ops.f, body_bb, body, &mut body_vars, loop_stack, env);
     loop_stack.pop();
     let bend = bend_res?;
-    // latch（body末尾）スナップショット
-    block_var_maps.insert(bend, body_vars.clone());
+    // collect snapshots for this loop level
+    let continue_snaps = super::pop_continue_snapshots();
+    let exit_snaps = super::pop_exit_snapshots();
+    // latch（body末尾）スナップショットを別マップに構築
+    let mut block_var_maps2: HashMap<BasicBlockId, HashMap<String, ValueId>> = HashMap::new();
+    block_var_maps2.insert(cur_bb, base_vars.clone());
+    block_var_maps2.insert(bend, body_vars.clone());
     if let Some(bb) = ops.f.get_block_mut(bend) {
         if !bb.is_terminated() {
             bb.set_terminator(MirInstruction::Jump { target: cond_bb });
@@ -110,14 +119,23 @@ pub(super) fn lower_loop_stmt(
     );
     if backedge_to_cond {
         // 5) header の不完全PHIを完成（latch + continue スナップショット集約）
-        let continue_snaps: Vec<(BasicBlockId, HashMap<String, ValueId>)> = Vec::new();
+        let mut ops_seal = Ops { f: ops.f, vars: ops.vars, block_var_maps: &block_var_maps2 };
         crate::mir::phi_core::loop_phi::seal_incomplete_phis_with(
-            &mut ops,
+            &mut ops_seal,
             cond_bb,
             bend,
             std::mem::take(&mut incomplete),
             &continue_snaps,
         )?;
     }
+    // 6) exit PHIs（breakの合流 + headerからのフォールスルー）
+    let mut ops_exit = Ops { f: ops.f, vars: ops.vars, block_var_maps: &block_var_maps2 };
+    crate::mir::phi_core::loop_phi::build_exit_phis_with(
+        &mut ops_exit,
+        cond_bb,
+        exit_bb,
+        &header_vars_snapshot,
+        &exit_snaps,
+    )?;
     Ok(exit_bb)
 }