Messages in this thread | | | Subject | Re: problems with memory allocation and the alignment check | From | "Michael J. Baars" <> | Date | Mon, 22 Feb 2021 10:37:33 +0100 |
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On Mon, 2021-02-22 at 01:29 -0800, Andrew Pinski wrote: > On Mon, Feb 22, 2021 at 1:17 AM Michael J. Baars > <mjbaars1977.gcc@cyberfiber.eu> wrote: > > Hi, > > > > I just wrote this little program to demonstrate a possible flaw in both malloc and calloc. > > > > If I allocate a the simplest memory region from main(), one out of three optimization flags fail. > > If I allocate the same region from a function, three out of three optimization flags fail. > > > > Does someone know if this really is a flaw, and if so, is it a gcc or a kernel flaw? > > There is no flaw. GCC (kernel, glibc) all assume unaligned accesses > on x86 will not cause an exception.
Is this just an assumption or more like a fact? I agree with you that byte aligned is more or less the same as unaligned.
> > Thanks, > Andrew > > > Regards, > > Mischa.
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