CodeGenPrepare merges critical edges which are immediately split again by OptimizeBlock

[llvmbot]

Bugzilla Link	2466
Resolution	FIXED
Resolved on	Mar 05, 2011 02:36
Version	unspecified
OS	Linux
Attachments	testcase .bc
Reporter	LLVM Bugzilla Contributor

Extended Description

On the attached testcase I noticed that EliminateMostlyEmptyBlocks
was eliminating many blocks which later somehow popped up again.
It turns out that it was eliminating all the critical edges, which
were all restored right after by OptimizeBlock. This seems like a
waste of time and effort: presumably EliminateMostlyEmptyBlocks
should detect this case and leave critical edges alone.

[lattner]

Sounds like a compile time issue if not also a code quality issue.

[llvmbot]

CodeGenPrepare doesn't split critical edges anymore, so this can be closed.