[llvm-dev] Is the correct behavior of getelementptr i192* for opt + llc -march=aarch64?

[Mehdi Amini via llvm-dev]

Can you provide the full repro?

Also what is the IR output of opt -O3?

— 
Mehdi

> On Nov 8, 2016, at 7:31 PM, MITSUNARI Shigeo via llvm-dev <llvm-dev at lists.llvm.org> wrote:
> 
> Hi all,
> opt and opt + llc generate the difference aarch64 asm code for the following LLVM code.
> 
> Is it intended behavior?
> I expected (A) because I cast %p from i192* to i64*.
> The information is dropped by opt and 8-byte padding is inserted or I write a bad code?
> 
> % cat a.ll
> define void @store0_to_p4(i192* %p)
> {
>  %p1 = bitcast i192* %p to i64*
>  %p2 = getelementptr i64, i64* %p1, i64 3
>  %p3 = getelementptr i64, i64* %p2, i64 1
>  store i64 0, i64* %p3
>  ret void
> }
> 
> % llc-3.8 a.ll -O3 -o - -march=aarch64
> store0_to_p4:
>  str     xzr, [x0, #32] ; (A)
>  ret
> 
> % opt-3.8 -O3 a.ll -o - | llc-3.8 -O3 -o - -march=aarch64
> store0_to_p4:
>  str     xzr, [x0, #40] ; (B)
>  ret
> 
> Yours,
> Shigeo
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