On Thu, Sep 20, 2018 at 11:37:36AM +0800, Bin Meng wrote: > Hi Tom, > > On Mon, Sep 17, 2018 at 1:30 PM Bin Meng <bmeng...@gmail.com> wrote: > > > > The -fstrict-aliasing option is implicitly enabled at levels -O2, > > -O3, -Os by GCC. This option allows the compiler to assume the > > strictest aliasing rules applicable to the language being compiled. > > For example, the practice of reading from a different union member > > than the one most recently written to (called "type-punning") is > > common. In this case, "type-punning" only works if the memory is > > accessed through the union type, but might not work by taking the > > address, casting the resulting pointer and dereferencing the result, > > which is an undefined behavior per the "strict aliasing rules". > > > > GCC's -Wstrict-aliasing (included in -Wall) option does not catch > > all cases, but does attempt to catch the more common pitfalls. So > > there are cases that GCC does not report but the codes are violating > > the "strict aliasing rules". > > > > Given lots of codes that may be written to rely on "type-punning", > > and Linux kernel disables it by -fno-strict-aliasing globally, since > > U-Boot currently does this on nds32/riscv/x86 builds only, extend > > this for all architecture builds. > > > > Signed-off-by: Bin Meng <bmeng...@gmail.com> > > Reviewed-by: Tom Rini <tr...@konsulko.com> > > Reviewed-by: Simon Glass <s...@chromium.org> > > --- > > > > Makefile | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > When will this series be applied? Another risc-v series has conflicts > in [PATCH 2/2] and if this is applied in mainline, I can respin my > risc-v series on top of this to save some time for Rick's handle it > himself.
I will try and get to this soon, thanks for your patience. -- Tom
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