title: Alloca implementation
body: <p>How does one implement alloca() using inline x86 assembler in languages like D, C, and C++?  I want to create a slightly modified version of it, but first I need to know how the standard version is implemented.  Reading the disassembly from compilers doesn't help because they perform so many optimizations, and I just want the canonical form.</p>
  
  <p>Edit:  I guess the hard part is that I want this to have normal function call syntax, i.e. using a naked function or something, make it look like the normal alloca().</p>
  
  <p>Edit # 2:  Ah, what the heck, you can assume that we're not omitting the frame pointer.</p>