Hi Jeroen, AFAIK, if you don't specify strict-align, the back-end assumes unaligned access is ok, so the behaviour is already covered.
If you want GCC compatibility, you could just add the alias to strict align, and a dummy option to no-strict-align? cheers, --renato On 17 August 2013 09:46, Jeroen Hofstee <[email protected]> wrote: > Hello, > > In commit [1] mstrict-align is added as a cc1 option for ARM. > "Force all memory accesses to be aligned. (ARM only)" > > GCC has this flag, but only for powerpc, which states: > "On System V.4 and embedded PowerPC systems do not (do) > assume that unaligned memory references are handled by > the system. " > > On ARM gcc supports the -munaligned-access / -mno-unaligned-access, > flags, which I am looking for: > > "Enables (or disables) reading and writing of 16- and 32- bit > values from addresses that are not 16- or 32- bit aligned. > By default unaligned access is disabled for all pre-ARMv6 > and all ARMv6-M architectures, and enabled for all other > architectures. If unaligned access is not enabled then > words in packed data structures will be accessed a byte > at a time." > > I am not sure if there are subtle differences between these. > Attached patch assumes they are exactly the same and adds > the gcc flags while preserving the cc1 as well. > > This patch depends on the -ffixed-r9 patch for creating the > ARM specific group. > > Regards, > Jeroen > > [1] > http://llvm.org/viewvc/llvm-**project?view=revision&**revision=167619<http://llvm.org/viewvc/llvm-project?view=revision&revision=167619> > [2] http://gcc.gnu.org/onlinedocs/**gcc-4.8.1/gcc/RS_002f6000-and-** > PowerPC-Options.html#RS_**002f6000-and-PowerPC-Options<http://gcc.gnu.org/onlinedocs/gcc-4.8.1/gcc/RS_002f6000-and-PowerPC-Options.html#RS_002f6000-and-PowerPC-Options> > [3] http://gcc.gnu.org/onlinedocs/**gcc-4.8.1/gcc/ARM-Options.** > html#ARM-Options<http://gcc.gnu.org/onlinedocs/gcc-4.8.1/gcc/ARM-Options.html#ARM-Options> > > _______________________________________________ > cfe-commits mailing list > [email protected] > http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits > >
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