[llvm-dev] Difference in EHType between ARM and AArch64

Grang, Mandeep Singh via llvm-dev llvm-dev at lists.llvm.org
Thu Apr 6 14:39:59 PDT 2017

Thanks for your explanation Renato.
So I guess with Joerg's patch which changes emitting .cfi_sections, my 
AArch64 test is now "supposed" to fail.


On 4/6/2017 2:22 AM, Renato Golin wrote:
> On 5 April 2017 at 21:35, Grang, Mandeep Singh via llvm-dev
> <llvm-dev at lists.llvm.org> wrote:
>> Could you please clarify, why the behavior for handling .cfi_sections needs
>> to be different between ARM and AArch64?
> Hi Mandeep,
> Many years ago, ARM devised a specially crafted exception handling
> system tuned for code size and embedded targets, which was the whole
> point of their hardware designs. This was called the EHABI.
> AArch64 was never meant to be an embedded architecture (ARMv8M is
> still AArch32), and the complexity added by having a completely
> different exception handling just wasn't worth the trouble.
> For that reason, AArch64 follows the Dwarf EH while AArch32 follows the EHABI.
> cheers,
> --renato

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