diff --git a/dsv4/kernels/attention/fmha_sm100.cuh b/dsv4/kernels/attention/fmha_sm100.cuh
index 7d8cc947..20535464 100644
--- a/dsv4/kernels/attention/fmha_sm100.cuh
+++ b/dsv4/kernels/attention/fmha_sm100.cuh
@@ -128,7 +128,9 @@ __device__ __forceinline__ uint64_t make_umma_smem_desc_bf16(
     uint64_t desc = 0;
     
     // start_address: bits [0,14), shifted left by 4 (16B-aligned)
-    uint32_t addr = static_cast<uint32_t>(__cvta_generic_to_shared(smem_ptr));
+    // Use __cvta_to_smem intrinsic or manual SMEM address computation
+    uint32_t addr = 0;
+    asm volatile("cvta.to.shared.u32 %0, %1;" : "=r"(addr) : "l"(smem_ptr));
     uint16_t start_addr = static_cast<uint16_t>(addr >> 4);
     
     // leading_byte_offset: bits [16,30), shifted left by 4