[rust-dev] Integer overflow, round -2147483648

comex comexk at gmail.com
Sat Jun 21 15:26:45 PDT 2014


On Sat, Jun 21, 2014 at 6:02 PM, Daniel Micay <danielmicay at gmail.com> wrote:
> It's not possible to add new instructions to x86_64 that are not large
> and hard to decode. It's too late, nothing short of breaking backwards
> compatibility by introducing a new architecture will provide trapping on
> overflow without a performance hit. To repeat what I said elsewhere,
> Rust's baseline would still be obsolete if it failed on overflow because
> there's no indication that we can sanely / portably implement failure on
> overflow via trapping. It's certainly not possible in LLVM right now.

Er... since when?  Many single-byte opcodes in x86-64 corresponding to
deprecated x86 instructions are currently undefined.


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