[Bug target/78853] aligned reads/writes (vmovdqa) emitted when no such guarantee can be made
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78853 --- Comment #4 from Markus Trippelsdorf --- See: http://refspecs.linuxfoundation.org/elf/x86-64-abi-0.99.pdf
[Bug target/78853] aligned reads/writes (vmovdqa) emitted when no such guarantee can be made
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78853 --- Comment #3 from Pedro Gonnet --- OK, thanks for clarifying! The declaration of __m256i only specifies the attributes vector_size and may_alias (https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/config/i386/avxintrin.h;hb=HEAD#l56), so I'm guessing vector_size implies alignment? This does not seem to be documented anywhere obvious. Also interesting is that icc-17 produces unaligned load/stores for the same code, but there is no amount of __attribute__((aligned(32))) that will make them aligned. In any case I'll use the __m*_u types to make an unaligned version of my memswap function.
[Bug target/78853] aligned reads/writes (vmovdqa) emitted when no such guarantee can be made
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78853 Markus Trippelsdorf changed: What|Removed |Added Status|UNCONFIRMED |RESOLVED CC||trippels at gcc dot gnu.org Resolution|--- |INVALID --- Comment #2 from Markus Trippelsdorf --- Please run your code with -fsanitize=undefined before opening bugs in the future. See PR65709 for an explanation.
[Bug target/78853] aligned reads/writes (vmovdqa) emitted when no such guarantee can be made
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78853 --- Comment #1 from Andrew Pinski --- IIRC __m512i, __m256i, and __m128i all have alignment requirements which is why you are getting this code. I think your code does not check for alignment which is broken.
