[cfe-dev] [libunwind] relation between llvm libunwind and nongnu libunwind

Joerg Sonnenberger via cfe-dev cfe-dev at lists.llvm.org
Sun Sep 4 11:15:24 PDT 2016


On Sun, Sep 04, 2016 at 06:44:46PM +0100, David Chisnall via cfe-dev wrote:
> This libunwind was created for Itanium, where it was effectively
> impossible to implement setjmp / longjmp in the conventional way and
> so some other mechanism was required to unwind the stack.

The classic setjmp/longjmp would be used on Itanium just as well. It was
expensive due to the huge register set, but that's the only problem it
ever had. Even that is more a question of how many registers actually
have to be preserved...

Joerg


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