translated to 
a set of about 30 native instructions 
that calculate the proper offset size 
and enforce alignment of the stack, 
otherwise incurring an exception 
in many architectures.
The translated instructions 
include a few computational intensive instructions 
such as <code>div</code> and <code>imul</code>,
so impose unwanted performance overheads
in a common path.
Since v4.20 [1], 
the compilation warning on the usage of VLA (i.e., <code>-Wvla</code>)
has been globally turned on; 
any use of VLA pre