[PATCH] D114832: [SROA] Improve SROA to prevent generating redundant coalescing operations.

[Mingming Liu via Phabricator via llvm-commits]

luna added a comment.

In D114832#3163500 <https://reviews.llvm.org/D114832#3163500>, @lebedev.ri wrote:

> That's a lot of complexity. It sounds like we are missing some cleanup transforms in some other passes?
> Can you please post a standalone example of the "bad" codegen (via a godbolt link) that you are trying to avoid?

To compare the LLVM and GCC codegen, tail call is generated in GCC but not LLVM.

- (LLVM) https://godbolt.org/z/qTY6MfMGa
- (GCC) https://godbolt.org/z/srh5fG6nW

`test_struct_of_two_int` (from llvm/test/Transforms/SROA/alloca-struct.ll) shows the diff in IR level before and after this change, and run clang with this patch (`clang -S -O3 file.cpp`) would generate a tail call.


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  https://reviews.llvm.org/D114832/new/

https://reviews.llvm.org/D114832