[llvm-dev] llc -O3 generates basic blocks that end without jump

Tim Northover via llvm-dev llvm-dev at lists.llvm.org
Tue Feb 7 19:27:07 PST 2017


On 7 February 2017 at 16:16, Alex Susu via llvm-dev
<llvm-dev at lists.llvm.org> wrote:
>     These are not really 2 basic blocks, so the first block without jump
> should be merged with the successor block (if just one successor, which is
> always the case as far as I can see on the tests I ran).

Like Matt, I don't see much benefit in merging these or think they're
malformed (they're just a trivial configuration for part of the CFG).

In many cases this structure will actually be necessary since LLVM
blocks can only have one entry point. So if some other block jumps to
LBB0_1 (in your case), they have to remain separate.

Cheers.

Tim.


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