[LLVMdev] Calling Conventions, function prologs and epilogs.
aaronngray.lists at googlemail.com
Thu Apr 9 11:32:42 PDT 2009
On Thu, Apr 9, 2009 at 7:19 PM, Dale Johannesen <dalej at apple.com> wrote:
> On Apr 9, 2009, at 11:11 AMPDT, Aaron Gray wrote:
> On Thu, Apr 9, 2009 at 4:34 PM, Anton Korobeynikov <
> anton at korobeynikov.info> wrote:
>> Hello, Aaron
>> > How/where are function prologs and epilogs generated, is it bespoke C++
>> > or TableGen generated ?
>> > If someone could point me in the right direction please.
>> Calling convention is really-really far from prologue/epilogue emission :)
>> 1. Calling conventions
>> Partly tablegen / partly C++ code. Look for
>> Target/X86/X86CallingConv.td and around. Usually this code is run
>> during different phases of sdag lowering.
>> 2. Prologue / epilogue.
>> Pure C++ code. Look into CodeGen/PrologEpilogInserter.cpp (quite
>> obviously, right?) with bunch of target-specialized hooks, for
>> example, ones located in Target/X86/X86RegisterInfo.cpp. Information
>> about this is needed on different stages, some - even before regalloc,
>> some - in the late end of the codegen.
>> Hope this will help.
> Yes, great. One other question. AFAICS this does not allow specialization
> say for a new Windows platform (Not MinGW or Cygwin) /Target to produce
> different code from X86 Linux.
> You would add a new Subtarget to do this. That will affect a fair amount
> of code but it should all be in Target/X86.
Yes, I see now. Thanks,
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the llvm-dev