Validate native Windows M against real PTX and correct patch-merge bounds

kernels/tools/swin_check.py

@@ -23,6 +23,10 @@ import swin_model as sm  # noqa: E402
 LAYERS = {'enc1': (64, 2, 96, 0), 'enc2': (96, 4, 128, 0), 'enc3_tube': (128, 4, 0, 0), 'dec2': (96, 4, 0, 128),
           'dec1': (64, 2, 0, 96)}
 
+# Preserve the existing Linux oracle by default; Windows strict replay enables
+# the audited 310.9 f16 patch-merge bound before final e4m3 quantisation.
+CLAMP_PATCH_MERGE = False
+
 
 def blocks(grid, n, seed=1):
     gx, gy = grid[0], grid[1]
@@ -47,7 +51,11 @@ def model_block(P, layer, bx, by):
             Wg = me.E4M3[P.wbuf[sm.woff_table(PM0 + g * 128 * C, 512, 64 * C, 4 * C, 32)]]
             bias = P.f16vec(PM0 + 4 * C * NPM + 64 * g, 32)
             cols.append(me.mma_chain(A, Wg, C0=np.broadcast_to(bias, (16, 32)).copy()))
-        merged = me.q8(sm.pair_to_nat(np.concatenate(cols, axis=1)))
+        merged = sm.pair_to_nat(np.concatenate(cols, axis=1))
+        if CLAMP_PATCH_MERGE:
+            limit = me.f16(2 * np.pi)
+            merged = np.clip(merged, -limit, limit)
+        merged = me.q8(merged)
     return out, merged