Commit Graph

5 Commits

Author SHA1 Message Date
Joseph Tremoulet 8220bcc570 [WinEH] Require token linkage in EH pad/ret signatures
Summary:
WinEHPrepare is going to require that cleanuppad and catchpad produce values
of token type which are consumed by any cleanupret or catchret exiting the
pad.  This change updates the signatures of those operators to require/enforce
that the type produced by the pads is token type and that the rets have an
appropriate argument.

The catchpad argument of a `CatchReturnInst` must be a `CatchPadInst` (and
similarly for `CleanupReturnInst`/`CleanupPadInst`).  To accommodate that
restriction, this change adds a notion of an operator constraint to both
LLParser and BitcodeReader, allowing appropriate sentinels to be constructed
for forward references and appropriate error messages to be emitted for
illegal inputs.

Also add a verifier rule (noted in LangRef) that a catchpad with a catchpad
predecessor must have no other predecessors; this ensures that WinEHPrepare
will see the expected linear relationship between sibling catches on the
same try.

Lastly, remove some superfluous/vestigial casts from instruction operand
setters operating on BasicBlocks.

Reviewers: rnk, majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D12108

llvm-svn: 245797
2015-08-23 00:26:33 +00:00
David Majnemer 83f4bb23c4 [WinEHPrepare] Replace unreasonable funclet terminators with unreachable
It is possible to be in a situation where more than one funclet token is
a valid SSA value.  If we see a terminator which exits a funclet which
doesn't use the funclet's token, replace it with unreachable.

Differential Revision: http://reviews.llvm.org/D12074

llvm-svn: 245238
2015-08-17 20:56:39 +00:00
Joseph Tremoulet 7031c9fc2e [WinEHPrepare] Fix catchret successor phi demotion
Summary:
When demoting an SSA value that has a use on a phi and one of the phi's
predecessors terminates with catchret, the edge needs to be split and the
load inserted in the new block, else we'll still have a cross-funclet SSA
value.

Add a test for this, and for the similar case where a def to be spilled is
on and invoke and a critical edge, which was already implemented but
missing a test.

Reviewers: majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D12065

llvm-svn: 245218
2015-08-17 13:51:37 +00:00
David Majnemer 0bc0eef71c [IR] Give catchret an optional 'return value' operand
Some personality routines require funclet exit points to be clearly
marked, this is done by producing a token at the funclet pad and
consuming it at the corresponding ret instruction.  CleanupReturnInst
already had a spot for this operand but CatchReturnInst did not.
Other personality routines don't need to use this which is why it has
been made optional.

llvm-svn: 245149
2015-08-15 02:46:08 +00:00
Joseph Tremoulet c9ff914ced [WinEHPrepare] Update demotion logic
Summary:
Update the demotion logic in WinEHPrepare to avoid creating new cleanups by
walking predecessors as necessary to insert stores for EH-pad PHIs.

Also avoid creating stores for EH-pad PHIs that have no uses.

The store/load placement is still pretty naive.  Likely future improvements
(at least for optimized compiles) include:
 - Share loads for related uses as possible
 - Coalesce non-interfering use/def-related PHIs
 - Store at definition point rather than each PHI pred for non-interfering
   lifetimes.


Reviewers: rnk, majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D11955

llvm-svn: 244894
2015-08-13 14:30:10 +00:00