[BITS 64] vmovntdqa ymm1, yword [rsi] ; fails: "error: invalid combination of opcode and operands" vmovntdqa ymm1, [rsi] ; works vmovntdqa xmm1, oword [rsi] ; works movntdqa xmm1, oword [rsi] ; fails, see bug 978756: "error: mismatch in operand sizes" movntdqa xmm1, [rsi] ; works