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TII: Add documentation about conditional exits. NFC
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Authored by iteratee on May 31 2016, 4:07 PM.



Currently the documented API for AnalyzeBranch leaves no place for
conditional returns. This leaves a blindspot after shrinkwrapping on
platforms with conditional return instructions.

The existing API can be used to handle conditional returns by using a null TBB
and a non-empty condition list. A null TBB should never mean fallthrough with a
non-empty condition list, as that wouldn't make any sense. This leaves a
natural way to represent conditional return branches.

Next up is to add support to PPC for AnalyzeBranch and conditional

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iteratee updated this revision to Diff 59146.May 31 2016, 4:07 PM
iteratee retitled this revision from to TII: Add documentation about conditional exits. NFC.
iteratee updated this object.
iteratee set the repository for this revision to rL LLVM.
iteratee added a subscriber: llvm-commits.
echristo added a subscriber: echristo.

So, I'll propose a different suggestion:

TII::BranchInfo {

enum { } // Types of branches.
// Arguments to the function with accessors


which encapsulates the existing arguments to make the code a bit more extensible and much easier to read. Then we can extend it for conditional return as a fairly straightforward change.

Sound good?