Comment 15 for bug 1489560

I built edk2 with and without the arm64-no-expensive-optimizations patch, dumping the trees in both case (with -fdump-tree-bswap with the patch and -fdump-tree-sincos without). Fortunately, the diff is quite small and I could review it all. Transformations all look sound and indeed there is a few transformations that wasn't done before the patch mentionned in the initial bug report.

One thing that it does and could pose problem is transforming a serie of byte load into a single unaligned 32bit load. This is allowed for this target by default so nothing wrong here but maybe in this case unaligned load should not be done. If that is the case, -mstrict-align should be used when compiling all files. Dann, could you try compiling with this flag instead of -mno-expensive-optimizations and see if you still hit the bug? Unfortunately I don't have access to an aarch64 machine with KVM available.

Best regards.