Now that the register allocator knows about the barriers on funclet
entry and exit, testing has shown that this is unnecessary.
We still demote PHIs on unsplittable blocks due to the differences
between the IR CFG and the Machine CFG.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253619 91177308-0d34-0410-b5e6-96231b3b80d8
Windows EH funclets need to always return to a single parent funclet. However, it is possible for earlier optimizations to combine funclets (probably based on one funclet having an unreachable terminator) in such a way that this condition is violated.
These changes add code to the WinEHPrepare pass to detect situations where a funclet has multiple parents and clone such funclets, fixing up the unwind and catch return edges so that each copy of the funclet returns to the correct parent funclet.
Differential Revision: http://reviews.llvm.org/D13274?id=39098
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252249 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
We now use the block for the catchpad itself, rather than its normal
successor, as the funclet entry.
Putting the normal successor in the map leads downstream funclet
membership computations to erroneous results.
Reviewers: majnemer, rnk
Subscribers: rnk, llvm-commits
Differential Revision: http://reviews.llvm.org/D13798
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250552 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
When a cleanup's cleanupendpad or cleanupret targets a catchendpad, stop
trying to propagate the cleanup's parent's color to the catchendpad, since
what's needed is the cleanup's grandparent's color and the catchendpad
will get that color from the catchpad linkage already. We already had
this exclusion for invokes, but were missing it for
cleanupendpad/cleanupret.
Also add a missing line that tags cleanupendpads' states in the
EHPadStateMap, without with lowering invokes that target cleanupendpads
which unwind to other handlers (and so don't have the -1 state) will fail.
This fixes the reduced IR repro in PR25163.
Reviewers: majnemer, andrew.w.kaylor, rnk
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D13797
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250534 91177308-0d34-0410-b5e6-96231b3b80d8
The new implementation works at least as well as the old implementation
did.
Also delete the associated preparation tests. They don't exercise
interesting corner cases of the new implementation. All the codegen
tests of the EH tables have already been ported.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249918 91177308-0d34-0410-b5e6-96231b3b80d8
Finish removing implicit ilist iterator conversions from LLVMCodeGen.
I'm sure there are lots more of these in lib/CodeGen/*/.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249915 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
- Recurse from cleanupendpads to their cleanuppads, to make sure the
cleanuppad is visited if it has a cleanupendpad but no cleanupret.
- Check for and avoid double-processing cleanuppads, to allow for them to
have multiple cleanuprets (plus cleanupendpads).
- Update Cxx state numbering to visit toplevel cleanupendpads and to
recurse from cleanupendpads to their preds, to ensure we number any
funclets in inlined cleanups. SEH state numbering already did this.
Reviewers: rnk
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D13374
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249792 91177308-0d34-0410-b5e6-96231b3b80d8
We remove unreachable blocks because it is pointless to consider them
for coloring. However, we still had stale pointers to these blocks in
some data structures after we removed them from the function.
Instead, remove the unreachable blocks before attempting to do anything
with the function.
This fixes PR25099.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249617 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This is necessary to keep the cloner from making bogus copies of debug
metadata attached to the IR it is cloning.
Also, avoid running RemapInstruction over all instructions in the common
case that no cloning was performed.
Reviewers: rnk, andrew.w.kaylor, majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D13514
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249591 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Set the pad MBB as a funclet entry for CoreCLR as well as MSVCCXX, and
update state numbering to put the catchpad block rather than its normal
successor into the unwind map.
Reviewers: majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D13492
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249569 91177308-0d34-0410-b5e6-96231b3b80d8
Our current emission strategy is to emit the funclet prologue in the
CatchPad's normal destination. This is problematic because
intra-funclet control flow to the normal destination is not erroneous
and results in us reevaluating the prologue if said control flow is
taken.
Instead, use the CatchPad's location for the funclet prologue. This
correctly models our desire to have unwind edges evaluate the prologue
but edges to the normal destination result in typical control flow.
Differential Revision: http://reviews.llvm.org/D13424
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249483 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Assign one state number per handler/funclet, tracking parent state,
handler type, and catch type token.
State numbers are arranged such that ancestors have lower state numbers
than their descendants.
Reviewers: majnemer, andrew.w.kaylor, rnk
Subscribers: pgavlin, AndyAyers, llvm-commits
Differential Revision: http://reviews.llvm.org/D13450
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249457 91177308-0d34-0410-b5e6-96231b3b80d8
We emit denormalized tables, where every range of invokes in the same
state gets a complete list of EH action entries. This is significantly
simpler than trying to infer the correct nested scoping structure from
the MI. Fortunately, for SEH, the nesting structure is really just a
size optimization.
With this, some basic __try / __except examples work.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249078 91177308-0d34-0410-b5e6-96231b3b80d8
Catchret transfers control from a catch funclet to an earlier funclet.
However, it is not completely clear which funclet the catchret target is
part of. Make this clear by stapling the catchret target's funclet
membership onto the CATCHRET SDAG node.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249052 91177308-0d34-0410-b5e6-96231b3b80d8
Previously we were hijacking the old LandingPadInfo data structures to
communicate our state numbers. Now we don't need that anymore.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@248763 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Factor the code that rewrites invokes to calls and rewrites WinEH
terminators to their "unwind to caller" equivalents into a helper in
Utils/Local, and use it in the three places I'm aware of that need to do
this.
Reviewers: andrew.w.kaylor, majnemer, rnk
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D13152
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@248677 91177308-0d34-0410-b5e6-96231b3b80d8
The MSVC doesn't really support exception specifications so let's just
turn these into cleanuppads. Later, we might use terminatepad to more
efficiently encode the "noexcept"-ness of a function body.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247848 91177308-0d34-0410-b5e6-96231b3b80d8
Clang now passes the adjectives as an argument to catchpad.
Getting the CatchObj working is simply a matter of threading another
static alloca through codegen, first as an alloca, then as a frame
index, and finally as a frame offset.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247844 91177308-0d34-0410-b5e6-96231b3b80d8
We are experimenting with a new approach to saving and restoring SSA
values used across funclets: let the register allocator do the dirty
work for us.
However, this means that we need to be able to clone commoned blocks
without relying on demotion.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247835 91177308-0d34-0410-b5e6-96231b3b80d8
Split the preparation machinery into several functions, we will want to
selectively enable/disable different parts of it for an alternative
mechanism for dealing with cross-funclet uses.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247834 91177308-0d34-0410-b5e6-96231b3b80d8
WinEHPrepare's new coloring algorithm really expects to see
cleanupendpads now, so Clang will start emitting them soon.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247341 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The coloring code in WinEHPrepare queues cleanuprets' successors with the
correct color (the parent one) when it sees their cleanuppad, and so later
when iterating successors knows to skip processing cleanuprets since
they've already been queued. This latter check was incorrectly under an
'else' condition and so inadvertently was not kicking in for single-block
cleanups. This change sinks the check out of the 'else' to fix the bug.
Reviewers: majnemer, andrew.w.kaylor, rnk
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D12751
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247299 91177308-0d34-0410-b5e6-96231b3b80d8
All of the complexity is in cleanupret, and it mostly follows the same
codepaths as catchret, except it doesn't take a return value in RAX.
This small example now compiles and executes successfully on win32:
extern "C" int printf(const char *, ...) noexcept;
struct Dtor {
~Dtor() { printf("~Dtor\n"); }
};
void has_cleanup() {
Dtor o;
throw 42;
}
int main() {
try {
has_cleanup();
} catch (int) {
printf("caught it\n");
}
}
Don't try to put the cleanup in the same function as the catch, or Bad
Things will happen.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247219 91177308-0d34-0410-b5e6-96231b3b80d8
The 32-bit tables don't actually contain PC range data, so emitting them
is incredibly simple.
The 64-bit tables, on the other hand, use the same table for state
numbering as well as label ranges. This makes things more difficult, so
it will be implemented later.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247192 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Add a `cleanupendpad` instruction, used to mark exceptional exits out of
cleanups (for languages/targets that can abort a cleanup with another
exception). The `cleanupendpad` instruction is similar to the `catchendpad`
instruction in that it is an EH pad which is the target of unwind edges in
the handler and which itself has an unwind edge to the next EH action.
The `cleanupendpad` instruction, similar to `cleanupret` has a `cleanuppad`
argument indicating which cleanup it exits. The unwind successors of a
`cleanuppad`'s `cleanupendpad`s must agree with each other and with its
`cleanupret`s.
Update WinEHPrepare (and docs/tests) to accomodate `cleanupendpad`.
Reviewers: rnk, andrew.w.kaylor, majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D12433
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246751 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Change the coloring algorithm in WinEHPrepare to visit a funclet's exits
in its parents' contexts and so properly classify the continuations of
nested funclets.
Also change the placement of cloned blocks to be deterministic and to
maintain the relative order of each funclet's blocks.
Add a lit test showing various patterns that require cloning, the last
several of which don't have CHECKs yet because they require cloning
entire funclets which is NYI.
Reviewers: rnk, andrew.w.kaylor, majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D12353
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246245 91177308-0d34-0410-b5e6-96231b3b80d8
We can now run 32-bit programs with empty catch bodies. The next step
is to change PEI so that we get funclet prologues and epilogues.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246235 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245797 91177308-0d34-0410-b5e6-96231b3b80d8
State numbers are calculated by performing a walk from the innermost
funclet to the outermost funclet. Rudimentary support for the new EH
constructs has been added to the assembly printer, just enough to test
the new machinery.
Differential Revision: http://reviews.llvm.org/D12098
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245331 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245238 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245218 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244894 91177308-0d34-0410-b5e6-96231b3b80d8
This adds somewhat basic preparation functionality including:
- Formation of funclets via coloring basic blocks.
- Cloning of polychromatic blocks to ensure that funclets have unique
program counters.
- Demotion of values used between different funclets.
- Some amount of cleanup once we have removed predecessors from basic
blocks.
- Verification that we are left with a CFG that makes some amount of
sense.
N.B. Arguments and numbering still need to be done.
Differential Revision: http://reviews.llvm.org/D11750
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244558 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This adds somewhat basic preparation functionality including:
- Formation of funclets via coloring basic blocks.
- Cloning of polychromatic blocks to ensure that funclets have unique
program counters.
- Demotion of values used between different funclets.
- Some amount of cleanup once we have removed predecessors from basic
blocks.
- Verification that we are left with a CFG that makes some amount of
sense.
N.B. Arguments and numbering still need to be done.
Reviewers: rnk, JosephTremoulet
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D11750
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244272 91177308-0d34-0410-b5e6-96231b3b80d8
