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Re: gcc-4.9.1 generating different code between two successive builds


On 30/12/15 15:33, Georg-Johann Lay wrote:

> Some parts of the compiler use the address of objects to compute
> hashes, but I don't remember which part(s) actually do this.  That
> technique can lead to different code for different runs of the
> compiler even on the same system.  This is hard to reproduce as it
> depends on how the OS is supplying memory, and it might depend on
> the "history" of the machine and the actual OS.

... and many Linux kernels deliberately randomize memory layout to
provide some protection from buffer overflow attacks.

Andrew.


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