[llvm-bugs] [Bug 45656] New: Wrong alignment of load instruction when load vector cast from other pointer

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=45656

            Bug ID: 45656
           Summary: Wrong alignment of load instruction when load vector
                    cast from other pointer
           Product: clang
           Version: unspecified
          Hardware: PC
                OS: All
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: Frontend
          Assignee: unassignedclangbugs at nondot.org
          Reporter: JunMa at linux.alibaba.com
                CC: llvm-bugs at lists.llvm.org, neeilans at live.com,
                    richard-llvm at metafoo.co.uk

see testcase in https://godbolt.org/z/Fz3vG4 we cast void* ptr to v8si*, and
then read it. 

It seems clang generates the load instruction with alignment of vector type,
not the element type which is wrong.

when we build with march=core-avx2, llvm emits vmovdqa which may cause seg
fault when ptr is not 32byte align.

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