kernels/rr: staged-image Swin layer engine prototypes

Per-layer staged-image engine for the eleven translated denoiser Swin
layers: descriptors (verified offsets per phase), cut recipes that splice an
isolated native phase into NVIDIA's PTX, wave templates, epilogue notes and
GPU probes. The isolated phase-8 splice produces a byte-identical final
4K frame but is slower than the translated body (14.90 vs 6.59 ms) - a
correctness experiment, not a shipping improvement; docs/rr-engine.md
records the design and the next direct-converter win (B operands built
from transposed accumulators).

kernels/rr/swin_enc0_recipe.py

@@ -0,0 +1,43 @@
+"""Enc0 cut recipes; isolated phase 8 preserves NVIDIA's other phases."""
+import os
+import sys
+from pathlib import Path
+
+
+def recipe():
+    sys.path.insert(0, str(Path(__file__).resolve().parent.parent / "tex"))
+    import make_ptx
+
+    if not os.environ.get("D4R_RRSWIN_PHASE8"):
+        if os.environ.get("D4R_RRSWIN_CUT"):
+            return dict(file="0013-PREPASS_ENTRYPOINT_NAME.ptx", cut_call=(3964, 44528),
+                        extern=make_ptx.swin_cut_extern())
+        return make_ptx.KERNELS["cuda_dldn_engine_swin_enc0_kernel"]
+
+    calls = []
+    for mi, base in enumerate((6784, 6824, 6864, 6904, 6944, 6984)):
+        operands = [f"%r{base + i}" for i in range(4)]
+        operands += [f"%r{6495 + i}" for i in range(8)]
+        outputs = [f"%r{6503 + 40 * mi + 10 * nt + rh}" for nt in range(4) for rh in range(2)]
+        declarations = "\n".join(f"\t.param .b32 p8a{i};" for i in range(12))
+        stores = "\n".join(f"\tst.param.b32 [p8a{i}], {reg};" for i, reg in enumerate(operands))
+        loads = "\n".join(f"\tld.shared.b32 {reg}, [%p8out+{4 * i}];" for i, reg in enumerate(outputs))
+        args = ", ".join([f"p8a{i}" for i in range(12)] + ["p8s"])
+        calls.append(f"""{{
+\t.reg .b32 %p8out;
+{declarations}
+\t.param .b32 p8s;
+{stores}
+\tst.param.b32 [p8s], %p8base;
+\tcall.uni d4r_swin_enc0_p8, ({args});
+\tmad.lo.u32 %p8out, %laneid, 32, %p8base;
+{loads}
+}}""")
+    # input_tensor's last read is in the prologue (line 3938); only the
+    # disjoint input_noise array is read by the final surface epilogue.
+    call = "{\n\t.reg .b32 %p8base;\n"
+    call += f"\tmov.u32 %p8base, {make_ptx.SWIN_RET_SCRATCH};\n" + "\n".join(calls) + "\n}"
+    params = ",\n\t".join([f".param .b32 a{i}" for i in range(12)]
+                            + [".param .b32 scratch"])
+    return dict(file="0013-PREPASS_ENTRYPOINT_NAME.ptx", cut_call=(19770, 19935),
+                call=call, extern=f".extern .func d4r_swin_enc0_p8\n(\n\t{params}\n)\n;\n")