D1.4: Add PtxasOptions -j64 + OptLevel(0) for faster hd=512 compilation

tests/unit/test_d1_hd512_only.py

@@ -45,7 +45,11 @@ def test():
 
     import time
     t0 = time.time()
-    compiled = cute.compile(kernel, mQ, mK, mV, mC, stream, mLSE)
+    from cutlass.base_dsl.compiler import CompileOptions, PtxasOptions, OptLevel
+    # PtxasOptions -j64: use 64 threads for ptxas register allocation (B200 has 256 cores)
+    # OptLevel(0): skip MLIR optimizations for faster compilation (first verify correctness, then optimize)
+    compile_opts = CompileOptions((PtxasOptions("-j64"), OptLevel(0)))
+    compiled = cute.compile(kernel, mQ, mK, mV, mC, stream, mLSE, config=compile_opts)
     t1 = time.time()
     print(f'Compilation took {t1-t0:.1f}s', flush=True)