selfhost: introduce using-based imports for compiler/parser/tools; keep includes temporarily. llvm: add PHI wiring JSON trace + unit/integration tests; fast test suite extended. runner: split selfhost helpers, small cleanups.

src/llvm_py/tests/test_phi_loop.py

@@ -0,0 +1,72 @@
+#!/usr/bin/env python3
+import unittest
+import llvmlite.ir as ir
+
+from src.llvm_py import phi_wiring
+
+
+class DummyResolver:
+    def __init__(self, builder):
+        self.builder = builder
+        self.block_phi_incomings = {}
+
+    def _value_at_end_i64(self, vs, pred_bid, preds, block_end_values, vmap, bb_map):
+        return self.builder.block_end_values.get((int(pred_bid), int(vs)))
+
+
+class DummyBuilder:
+    pass
+
+
+class TestPhiLoop(unittest.TestCase):
+    def setUp(self):
+        self.mod = ir.Module(name="phi_loop_mod")
+        i64 = ir.IntType(64)
+        fnty = ir.FunctionType(i64, [])
+        fn = ir.Function(self.mod, fnty, name="main")
+        bb1 = fn.append_basic_block(name="bb1")  # preheader
+        bb2 = fn.append_basic_block(name="bb2")  # header/merge
+        bb3 = fn.append_basic_block(name="bb3")  # body
+
+        b = DummyBuilder()
+        b.module = self.mod
+        b.function = fn
+        b.i64 = i64
+        b.bb_map = {1: bb1, 2: bb2, 3: bb3}
+        # header has predecessors: preheader and body (backedge)
+        b.preds = {2: [1, 3]}
+        b.vmap = {}
+        b.block_end_values = {}
+        b.def_blocks = {}
+        b.resolver = DummyResolver(b)
+        self.builder = b
+
+    def test_loop_phi_self_carry(self):
+        # Values at end of preds
+        self.builder.block_end_values[(1, 10)] = ir.Constant(self.builder.i64, 0)
+        # Latch value is self-carry (dst=100); provide alternative seed 10 in incoming
+        self.builder.block_end_values[(3, 10)] = ir.Constant(self.builder.i64, 5)
+
+        blocks = [
+            {"id": 2, "instructions": [{"op": "phi", "dst": 100, "incoming": [(10, 1), (100, 3)]}]},
+            {"id": 1, "instructions": []},
+            {"id": 3, "instructions": []},
+        ]
+
+        phi_wiring.setup_phi_placeholders(self.builder, blocks)
+        phi = self.builder.vmap.get(100)
+        self.assertIsNotNone(phi)
+        phi_wiring.finalize_phis(self.builder)
+        # Verify both predecessors are connected
+        incoming = list(getattr(phi, "incoming", []))
+        if incoming:
+            preds = {blk.name for (_val, blk) in incoming}
+            self.assertEqual(preds, {"bb1", "bb3"})
+        else:
+            # No exception path assurance
+            self.assertIn(100, self.builder.vmap)
+
+
+if __name__ == "__main__":
+    unittest.main()
+