[fpc-devel] Enable LLVM?
jonas.maebe at elis.ugent.be
Tue Jul 14 10:58:44 CEST 2015
Adriaan van Os wrote:
> Jonas Maebe wrote:
>> d) trampolines for interface methods
> Ehw, trampolines. They requires executable stacks.
No, they don't.
> Is there a
> possibility to pass activation frames instead or apply lambda/lifting ?
Trampolines for interface methods are generated at compile time are are
of the form:
branch(interfacemethod); // can either be a direct or indirect branch
This cannot be expressed in LLVM IR. The above can in principle be
replaced by a tail call that passes on all arguments (although LLVM
won't generate an actual tail call, because it only supports tail calls
for functions using the C fastcall calling convention) because FPC does
not support C-style varargs functions (in which case "calling through
passing the caller arguments" again could not be expressed), but since
inline assembly needs to be supported anyway, it's probably easier to
just generate assembler for them and call that.
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