This code is there not for performance
Posted Feb 17, 2008 19:50 UTC (Sun) by giraffedata
In reply to: This code is there not for performance
Parent article: vmsplice(): the making of a local root exploit
It is unfortunate that the CPU cannot enforce signedness and size types.
The unfortunateness is at a lower level than that. It's unfortunate that a CPU can't do ordinary integer math, where 2 + 2 = 4. I understand why the very first CPUs wrapped around integers -- it happens naturally with the simplest implementations. But I don't get why no CPU today provides even the option of trapping on an arithmetic overflow instead of wrapping around silently. They do it for floating point, but not for integers.
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