> __ARM_FEATURE_UNALIGNED (cf., > http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0774f/chr1383660321827.html) > . MIPSEL does not define such a macro. > > # MIPS ci20 creator with GCC 4.6 > $ gcc -march=native -dM -E - </dev/null | grep -i align > #define __BIGGEST_ALIGNMENT__ 8 > > If the MIPS CPU does not tolerate unaligned data access, then the > following could SIGBUS: > >> + u32 *data = buf; >> + *data = jz4780_rng_readl(jz4780_rng, REG_RNG_DATA); > > If GCC emits code that uses the MIPS unaligned load and store > instructions, then there's probably going to be a performance penalty. > > Regardless of what the CPU tolerates, I believe unaligned data access > is undefined behavior in C/C++. I believe you should memcpy the value > into the buffer. I am not sure whether this is required. 'buf' is part of a structure so I guess it is properly aligned by padding. Not sure though, will look about this.
