On 10/1/20 8:32 AM, John Paul Adrian Glaubitz wrote:
Hi Nathan!
Thanks for the explanations!
On 10/1/20 2:27 PM, Nathan Sidwell wrote:
do you know what those 2 functions you mention provide on say x86? Then it
might be easier to map onto 68k.
From [1]:
Register X86TargetLowering::getExceptionPointerRegister(
const Constant *PersonalityFn) const {
if (classifyEHPersonality(PersonalityFn) == EHPersonality::CoreCLR)
return Subtarget.isTarget64BitLP64() ? X86::RDX : X86::EDX;
return Subtarget.isTarget64BitLP64() ? X86::RAX : X86::EAX;
}
Register X86TargetLowering::getExceptionSelectorRegister(
const Constant *PersonalityFn) const {
// Funclet personalities don't use selectors (the runtime does the
selection).
assert(!isFuncletEHPersonality(classifyEHPersonality(PersonalityFn)));
return Subtarget.isTarget64BitLP64() ? X86::RDX : X86::EDX;
}
Aha! it is EH_RETURN :) and it appears stack adjustment is something
different.
for x86, gcc has:
#define EH_RETURN_DATA_REGNO(N) ((N) <= DX_REG ? (N) : INVALID_REGNUM)
thus N can either be AX_REG or DX_REG. (which is eax/rax and edx/rdx
depending on compilation mode)
for m68k gcc has:
#define EH_RETURN_DATA_REGNO(N) \
((N) < 2 ? (N) : INVALID_REGNUM)
so that's registers d0 and d1
I'm guessing EHPersonality:CoreCLR is a different ABI that you're not
concerned with. Thus I think you want:
getExceptionPointerRegister to return d0 and
getExceptionSelectorRegister to return d1.
give that a go, and see if you can throw/catch exceptions between code
compiled by your llvm port and a gcc
hope that helps.
Adrian
[1]
https://raw.githubusercontent.com/llvm/llvm-project/master/llvm/lib/Target/X86/X86ISelLowering.cpp
--
Nathan Sidwell
