The personality routine currently lives in the LandingPadInst.
This isn't desirable because:
- All LandingPadInsts in the same function must have the same
personality routine. This means that each LandingPadInst beyond the
first has an operand which produces no additional information.
- There is ongoing work to introduce EH IR constructs other than
LandingPadInst. Moving the personality routine off of any one
particular Instruction and onto the parent function seems a lot better
than have N different places a personality function can sneak onto an
exceptional function.
Differential Revision: http://reviews.llvm.org/D10429
llvm-svn: 239940
If globals can be unnamed, there is no reason for aliases to be different.
The restriction was there since the original implementation in r36435. I
can only guess it was there because of the old bison parser for the old
alias syntax.
llvm-svn: 239921
This patch adds the safe stack instrumentation pass to LLVM, which separates
the program stack into a safe stack, which stores return addresses, register
spills, and local variables that are statically verified to be accessed
in a safe way, and the unsafe stack, which stores everything else. Such
separation makes it much harder for an attacker to corrupt objects on the
safe stack, including function pointers stored in spilled registers and
return addresses. You can find more information about the safe stack, as
well as other parts of or control-flow hijack protection technique in our
OSDI paper on code-pointer integrity (http://dslab.epfl.ch/pubs/cpi.pdf)
and our project website (http://levee.epfl.ch).
The overhead of our implementation of the safe stack is very close to zero
(0.01% on the Phoronix benchmarks). This is lower than the overhead of
stack cookies, which are supported by LLVM and are commonly used today,
yet the security guarantees of the safe stack are strictly stronger than
stack cookies. In some cases, the safe stack improves performance due to
better cache locality.
Our current implementation of the safe stack is stable and robust, we
used it to recompile multiple projects on Linux including Chromium, and
we also recompiled the entire FreeBSD user-space system and more than 100
packages. We ran unit tests on the FreeBSD system and many of the packages
and observed no errors caused by the safe stack. The safe stack is also fully
binary compatible with non-instrumented code and can be applied to parts of
a program selectively.
This patch is our implementation of the safe stack on top of LLVM. The
patches make the following changes:
- Add the safestack function attribute, similar to the ssp, sspstrong and
sspreq attributes.
- Add the SafeStack instrumentation pass that applies the safe stack to all
functions that have the safestack attribute. This pass moves all unsafe local
variables to the unsafe stack with a separate stack pointer, whereas all
safe variables remain on the regular stack that is managed by LLVM as usual.
- Invoke the pass as the last stage before code generation (at the same time
the existing cookie-based stack protector pass is invoked).
- Add unit tests for the safe stack.
Original patch by Volodymyr Kuznetsov and others at the Dependable Systems
Lab at EPFL; updates and upstreaming by myself.
Differential Revision: http://reviews.llvm.org/D6094
llvm-svn: 239761
Now that Intrinsic::ID is a typed enum, we can forward declare it and so return it from this method.
This updates all users which were either using an unsigned to store it, or had a now unnecessary cast.
llvm-svn: 237810
Summary: Add an assertion in verifier.cpp to make sure gc_relocate relocate a gc pointer, and its return type has the same address space with the relocated pointer.
Reviewers: reames, AndyAyers, sanjoy, pgavlin
Reviewed By: pgavlin
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9695
llvm-svn: 237605
Summary:
This adds three Function methods to handle function entry counts:
setEntryCount() and getEntryCount().
Entry counts are stored under the MD_prof metadata node with the name
"function_entry_count". They are unsigned 64 bit values set by profilers
(instrumentation and sample profiler changes coming up).
Added documentation for new profile metadata and tests.
Reviewers: dexonsmith, bogner
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9628
llvm-svn: 237260
Summary:
This change adds two new parameters to the statepoint intrinsic, `i64 id`
and `i32 num_patch_bytes`. `id` gets propagated to the ID field
in the generated StackMap section. If the `num_patch_bytes` is
non-zero then the statepoint is lowered to `num_patch_bytes` bytes of
nops instead of a call (the spill and reload code remains unchanged).
A non-zero `num_patch_bytes` is useful in situations where a language
runtime requires complete control over how a call is lowered.
This change brings statepoints one step closer to patchpoints. With
some additional work (that is not part of this patch) it should be
possible to get rid of `TargetOpcode::STATEPOINT` altogether.
PlaceSafepoints generates `statepoint` wrappers with `id` set to
`0xABCDEF00` (the old default value for the ID reported in the stackmap)
and `num_patch_bytes` set to `0`. This can be made more sophisticated
later.
Reviewers: reames, pgavlin, swaroop.sridhar, AndyAyers
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9546
llvm-svn: 237214
We already had a method to iterate over all the incoming values of a PHI. This just changes all eligible code to use it.
Ineligible code included anything which cared about the index, or was also trying to get the i'th incoming BB.
llvm-svn: 237169
Summary:
This patch is to rename some variables to CamelCase in gc_relocate
related functions. There is no functionality change.
Patch by Chen Li!
Reviewers: reames, AndyAyers, sanjoy
Reviewed By: sanjoy
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9681
llvm-svn: 237069
Summary:
In RewriteStatepointsForGC pass, we create a gc_relocate intrinsic for
each relocated pointer, and the gc_relocate has the same type with the
pointer. During the creation of gc_relocate intrinsic, llvm requires to
mangle its type. However, llvm does not support mangling of all possible
types. RewriteStatepointsForGC will hit an assertion failure when it
tries to create a gc_relocate for pointer to vector of pointers because
mangling for vector of pointers is not supported.
This patch changes the way RewriteStatepointsForGC pass creates
gc_relocate. For each relocated pointer, we erase the type of pointers
and create an unified gc_relocate of type i8 addrspace(1)*. Then a
bitcast is inserted to convert the gc_relocate to the correct type. In
this way, gc_relocate does not need to deal with different types of
pointers and the unsupported type mangling is no longer a problem. This
change would also ease further merge when LLVM erases types of pointers
and introduces an unified pointer type.
Some minor changes are also introduced to gc_relocate related part in
InstCombineCalls, CodeGenPrepare, and Verifier accordingly.
Patch by Chen Li!
Reviewers: reames, AndyAyers, sanjoy
Reviewed By: sanjoy
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9592
llvm-svn: 237009
Author: dblaikie
Date: Fri May 8 17:47:50 2015
New Revision: 236912
URL: http://llvm.org/viewvc/llvm-project?rev=236912&view=rev
Log:
[opaque pointer type] Cleanup a few references to pointee types using nearby non-pointee types of the same value
& cleanup a convoluted return expression while I'm here
llvm-svn: 236919
This changes the shape of the statepoint intrinsic from:
@llvm.experimental.gc.statepoint(anyptr target, i32 # call args, i32 unused, ...call args, i32 # deopt args, ...deopt args, ...gc args)
to:
@llvm.experimental.gc.statepoint(anyptr target, i32 # call args, i32 flags, ...call args, i32 # transition args, ...transition args, i32 # deopt args, ...deopt args, ...gc args)
This extension offers the backend the opportunity to insert (somewhat) arbitrary code to manage the transition from GC-aware code to code that is not GC-aware and back.
In order to support the injection of transition code, this extension wraps the STATEPOINT ISD node generated by the usual lowering lowering with two additional nodes: GC_TRANSITION_START and GC_TRANSITION_END. The transition arguments that were passed passed to the intrinsic (if any) are lowered and provided as operands to these nodes and may be used by the backend during code generation.
Eventually, the lowering of the GC_TRANSITION_{START,END} nodes should be informed by the GC strategy in use for the function containing the intrinsic call; for now, these nodes are instead replaced with no-ops.
Differential Revision: http://reviews.llvm.org/D9501
llvm-svn: 236888
This makes use of the new API which can remove attributes from a set given a builder.
This is much faster than creating a temporary set and reduces llc time by about 0.3% which was all spent creating temporary attributes sets on the context.
llvm-svn: 236668
The clang frontend helps out GDB by emitting the members of local anonymous
unions as artificial local variables with shared storage. When SROA splits
the storage for artificial local variables that are smaller than the entire
union, the overhang piece will be outside of the allotted space for the
variable and this check fails.
rdar://problem/20730771
llvm-svn: 236124
Finish off PR23080 by renaming the debug info IR constructs from `MD*`
to `DI*`. The last of the `DIDescriptor` classes were deleted in
r235356, and the last of the related typedefs removed in r235413, so
this has all baked for about a week.
Note: If you have out-of-tree code (like a frontend), I recommend that
you get everything compiling and tests passing with the *previous*
commit before updating to this one. It'll be easier to keep track of
what code is using the `DIDescriptor` hierarchy and what you've already
updated, and I think you're extremely unlikely to insert bugs. YMMV of
course.
Back to *this* commit: I did this using the rename-md-di-nodes.sh
upgrade script I've attached to PR23080 (both code and testcases) and
filtered through clang-format-diff.py. I edited the tests for
test/Assembler/invalid-generic-debug-node-*.ll by hand since the columns
were off-by-three. It should work on your out-of-tree testcases (and
code, if you've followed the advice in the previous paragraph).
Some of the tests are in badly named files now (e.g.,
test/Assembler/invalid-mdcompositetype-missing-tag.ll should be
'dicompositetype'); I'll come back and move the files in a follow-up
commit.
llvm-svn: 236120
Add a verifier check that only functions with bodies have metadata
attachments. This should help catch bugs in frontends and
transformation passes. Part of PR23340.
llvm-svn: 235784
(reverted in r235533)
Original commit message:
"Calls to llvm::Value::mutateType are becoming extra-sensitive now that
instructions have extra type information that will not be derived from
operands or result type (alloca, gep, load, call/invoke, etc... ). The
special-handling for mutateType will get more complicated as this work
continues - it might be worth making mutateType virtual & pushing the
complexity down into the classes that need special handling. But with
only two significant uses of mutateType (vectorization and linking) this
seems OK for now.
Totally open to ideas/suggestions/improvements, of course.
With this, and a bunch of exceptions, we can roundtrip an indirect call
site through bitcode and IR. (a direct call site is actually trickier...
I haven't figured out how to deal with the IR deserializer's lazy
construction of Function/GlobalVariable decl's based on the type of the
entity which means looking through the "pointer to T" type referring to
the global)"
The remapping done in ValueMapper for LTO was insufficient as the types
weren't correctly mapped (though I was using the post-mapped operands,
some of those operands might not have been mapped yet so the type
wouldn't be post-mapped yet). Instead use the pre-mapped type and
explicitly map all the types.
llvm-svn: 235651
This reverts commit r235458.
It looks like this might be breaking something LTO-ish. Looking into it
& will recommit with a fix/test case/etc once I've got more to go on.
llvm-svn: 235533
Calls to llvm::Value::mutateType are becoming extra-sensitive now that
instructions have extra type information that will not be derived from
operands or result type (alloca, gep, load, call/invoke, etc... ). The
special-handling for mutateType will get more complicated as this work
continues - it might be worth making mutateType virtual & pushing the
complexity down into the classes that need special handling. But with
only two significant uses of mutateType (vectorization and linking) this
seems OK for now.
Totally open to ideas/suggestions/improvements, of course.
With this, and a bunch of exceptions, we can roundtrip an indirect call
site through bitcode and IR. (a direct call site is actually trickier...
I haven't figured out how to deal with the IR deserializer's lazy
construction of Function/GlobalVariable decl's based on the type of the
entity which means looking through the "pointer to T" type referring to
the global)
llvm-svn: 235458
The implementation of this GEP::getResultElementType will be refactored
to either rely on a member variable, or recompute the value from the
indicies (any preferences?).
llvm-svn: 235236
Remove 'inlinedAt:' from MDLocalVariable. Besides saving some memory
(variables with it seem to be single largest `Metadata` contributer to
memory usage right now in -g -flto builds), this stops optimization and
backend passes from having to change local variables.
The 'inlinedAt:' field was used by the backend in two ways:
1. To tell the backend whether and into what a variable was inlined.
2. To create a unique id for each inlined variable.
Instead, rely on the 'inlinedAt:' field of the intrinsic's `!dbg`
attachment, and change the DWARF backend to use a typedef called
`InlinedVariable` which is `std::pair<MDLocalVariable*, MDLocation*>`.
This `DebugLoc` is already passed reliably through the backend (as
verified by r234021).
This commit removes the check from r234021, but I added a new check
(that will survive) in r235048, and changed the `DIBuilder` API in
r235041 to require a `!dbg` attachment whose 'scope:` is in the same
`MDSubprogram` as the variable's.
If this breaks your out-of-tree testcases, perhaps the script I used
(mdlocalvariable-drop-inlinedat.sh) will help; I'll attach it to PR22778
in a moment.
llvm-svn: 235050
Before we start to rely on valid `!dbg` attachments, add a check to the
verifier that `@llvm.dbg.*` intrinsics always have one. Also check that
the `scope:` fields point at the same `MDSubprogram`.
This is in the context of PR22778. The check that the `inlinedAt:`
fields agree has baked for a while (since r234021), so I'll kill [1] the
`MDLocalVariable::getInlinedAt()` field soon.
[1]: http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20150330/269387.html
Unfortunately, that means it's impossible to keep the current `Verifier`
checks, which rely on comparing `inlinedAt:` fields. We'll be able to
keep the checks I'm adding here.
If this breaks your out-of-tree testcases, the upgrade script
(add-dbg-to-intrinsics.sh) attached to PR22778 that I used for r235040
might fix them for you.
llvm-svn: 235048
Gut the `DIDescriptor` wrappers around `MDLocalScope` subclasses. Note
that `DILexicalBlock` wraps `MDLexicalBlockBase`, not `MDLexicalBlock`.
llvm-svn: 234850
This reverts commit r234717, reapplying r234698 (in spirit).
As described in r234717, the original `Verifier` check had a
use-after-free. Instead of storing pointers to "interesting" debug info
intrinsics whose bit piece expressions should be verified once we have
typerefs, do a second traversal. I've added a testcase to catch the
`llc` crasher.
Original commit message:
Verifier: Check for incompatible bit piece expressions
Convert an assertion into a `Verifier` check. Bit piece expressions
must fit inside the variable, and mustn't be the entire variable.
Catching this in the verifier will help us find bugs sooner, and makes
`DIVariable::getSizeInBits()` dead code.
llvm-svn: 234776
This reverts commit r234698.
This caused a use-after-free: `QueuedBitPieceExpressions` holds onto
references to `DbgInfoIntrinsic`s and references them past where they're
deleted (this is because the verifier is run as a function pass, and
then `verifyTypeRefs()` is called during `doFinalization()`).
I'll include a reduced crasher for `llc` when I recommit the check.
llvm-svn: 234717
Change `MDSubprogram::getFunction()` and
`MDGlobalVariable::getConstant()` to return a `Constant`. Previously,
both returned `ConstantAsMetadata`.
llvm-svn: 234699
Convert an assertion into a `Verifier` check. Bit piece expressions
must fit inside the variable, and mustn't be the entire variable.
Catching this in the verifier will help us find bugs sooner, and makes
`DIVariable::getSizeInBits()` dead code.
llvm-svn: 234698
A few calls are left in for error checking - but I'm commenting those
out & trying to build some IR tests (aiming for Argument Promotion to
start with). When I get any of these tests passing I may add flag to
disable the checking so I can add tests that pass with the assertion in
place.
llvm-svn: 234206
Add `MDTupleTypedArrayWrapper`, a wrapper around `MDTuple` that adapts
it to look like an array and cast its operands to the given type. This
is designed to be a replacement for `DITypedArray<>`, which is in the
`DIDescriptor` hierarchy.
llvm-svn: 234183
Add missing checks for `templateParams:` in `MDCompositeType`. Pull the
current check for `MDSubprogram` to reduce duplicated code and fix it up
to print a good message when the immediate operand isn't an `MDTuple`
(as a drive-by, make the same fix to `variables:` in `MDSubprogram`).
llvm-svn: 234177
We don't need to represent UnwindHelp in IR. Instead, we can use the
knowledge that we are emitting the parent function to decide if we
should create the UnwindHelp stack object.
llvm-svn: 234061
Check that the `MDLocalVariable::getInlinedAt()` in a debug info
intrinsic's variable always matches the `MDLocation::getInlinedAt()` of
its `!dbg` attachment.
The goal here is to get rid of `MDLocalVariable::getInlinedAt()`
entirely (PR22778), since it's expensive and unnecessary, but I'll let
this verifier check bake for a while (a week maybe?) first. I've
updated the testcases that had the wrong value for `inlinedAt:`.
This checks that things are sane in the IR, but currently things go out
of whack in a few places in the backend. I'll follow shortly with
assertions in the backend (with code fixes).
If you have out-of-tree testcases that just started failing, here's how
I updated these ones:
1. The verifier check gives you the basic block, function, instruction,
and relevant metadata arguments (metadata numbering doesn't
necessarily match the source file, unfortunately).
2. Look at the `@llvm.dbg.*()` instruction, and compare the
`inlinedAt:` fields of the variable argument (second `metadata`
argument) and the `!dbg` attachment.
3. Figure out based on the variable `scope:` chain and the functions in
the file whether the variable has been inlined (and into what), so
you can determine which `inlinedAt:` is actually correct. In all of
the in-tree testcases, the `!MDLocation()` was correct and the
`!MDLocalVariable()` was wrong, but YMMV.
4. Duplicate the metadata that you're going to change, and add/drop the
`inlinedAt:` field from one of them. Be careful that the other
references to the same metadata node point at the correct one.
llvm-svn: 234021
This makes it possible to use the same representation of llvm.eh.actions
in outlined handlers as we use in the parent function because i32's are
just constants that can be copied freely between functions.
I had to add a sentinel alloca to the list of child allocas so that we
don't try to sink the catch object into the handler. Normally, one would
use nullptr for this kind of thing, but TinyPtrVector doesn't support
null elements. More than that, it's elements have to have a suitable
alignment. Therefore, I settled on this for my sentinel:
AllocaInst *getCatchObjectSentinel() {
return static_cast<AllocaInst *>(nullptr) + 1;
}
llvm-svn: 233947
This lets us catch exceptions in simple cases.
N.B. Things that do not work include (but are not limited to):
- Throwing from within a catch handler.
- Catching an object with a named catch parameter.
- 'CatchHigh' is fictitious, we aren't sure of its purpose.
- We aren't entirely efficient with regards to the number of EH states
that we generate.
- IP-to-State tables are sensitive to the order of emission.
llvm-svn: 233767
We'll no longer crash in the `verifyTypeRefs()` (used to be called
`verifyDebugInfo()`), so there's no reason to return early here. Remove
the `EverBroken` member since this was the only use!
llvm-svn: 233665
`verifyDebugInfo()` was doing two things:
- Asserting on unresolved type references.
- Calling `Verify()` functions for various types of debug info.
The `Verify()` functions have been gutted, so rename the function to
`verifyTypeRefs()` and explicitly check those. Instead of assertions,
we get nice error messages now.
llvm-svn: 233664
Move over the remaining (somewhat complicated) check from
`DISubprogram::Verify()`. I suspect this check could be optimized --
e.g., it would be nice not to do another full traversal here -- but it's
not exactly obvious how. For now, just bring it over as is.
Once we have a better model for the "canonical" subprogram of a
`Function`, we should enforce that all `!dbg` attachments lead to the
canonical one.
llvm-svn: 233663
Most of these checks were already in the `Verifier` so this is more of a
cleanup. Now almost everything is over there.
Now that require a `name:` for `MDGlobalVariable`, add a check in
`LLParser` for it.
llvm-svn: 233657
Move over some more checks from `DIDescriptor::Verify()`, and change
`LLParser` to require non-null `file:` fields in compile units.
I've ignored the comment in test/Assembler/metadata-null-operands.ll
since I disagree with it. At the time that test was written (r229960),
the debug info verifier wasn't on by default, so my comment there is in
the context of not expecting the verifier to be useful. It is now, and
besides that, since r233394 we can check when parsing textual IR whether
an operand is null that shouldn't be.
llvm-svn: 233654
This pushes the use of PointerType::getElementType up into several
callers - I'll essentially just have to keep pushing that up the stack
until I can eliminate every call to it...
llvm-svn: 233604
Add operand checks for `MDLexicalBlock` and `MDLexicalBlockFile`. Like
`MDLocalVariable` and `MDLocation`, these nodes always require a scope.
There was no test bitrot to fix here (just updated the serialization
tests in test/Assembler/mdlexicalblock.ll).
llvm-svn: 233561
Check operands of `MDSubprogram`s in the verifier, and update the
accessors and factory functions to use more specific types.
There were a lot of broken testcases, which I fixed in r233466. If you
have out-of-tree tests for debug info, you probably need similar changes
to the ones I made there.
llvm-svn: 233559
Loosen one check from r233446: as long as `DIBuilder` requires a
non-null type for every subprogram, we should allow a null type array.
Also add tests for the rest of `MDSubroutineType`, which were somehow
missing.
llvm-svn: 233468
Add verify checks for `MDType` subclasses and for `MDCompileUnit`.
These new checks don't yet incorporate everything from `Verify()`, but
at least they sanity check the operands. Also downcast accessors as
possible.
A lot of these accessors can't be downcast as far as we'd like because
of arrays of typed objects (stored in a generic `MDTuple`) and
`MDString`-based type references. Eventually I'll port over `DIRef<>`
and `DITypedArray<>` from `DebugInfo.h` to clean those up as well.
Updated bitrotted testcases separately in r233415 and r233443 to reduce
churn on the off-chance this needs to be reverted.
llvm-svn: 233446
Check fields from `MDLocalVariable` and `MDGlobalVariable` and change
the accessors to downcast to the right types. `getType()` still returns
`Metadata*` since it could be an `MDString`-based reference.
Since local variables require non-null scopes, I also updated `LLParser`
to require a `scope:` field.
A number of testcases had grown bitrot and started failing with this
patch; I committed them separately in r233349. If I just broke your
out-of-tree testcases, you're probably hitting similar problems (so have
a look there).
llvm-svn: 233389
This was discussed a while back and I left it optional for migration. Since it's been far more than the 'week or two' that was discussed, time to actually make this manditory.
llvm-svn: 233357
We don't have any logic to emit those tables yet, so the SDAG lowering
of this intrinsic is just a stub. We can see the intrinsic in the
prepared IR, though.
llvm-svn: 233354
Check accessors of `MDLocation`, and change them to `cast<>` down to the
right types. Also add type-safe factory functions.
All the callers that handle broken code need to use the new versions of
the accessors (`getRawScope()` instead of `getScope()`) that still
return `Metadata*`. This is also necessary for things like
`MDNodeKeyImpl<MDLocation>` (in LLVMContextImpl.h) that need to unique
the nodes when their operands might still be forward references of the
wrong type.
In the `Value` hierarchy, consumers that handle broken code use
`getOperand()` directly. However, debug info nodes have a ton of
operands, and their order (even their existence) isn't stable yet. It's
safer and more maintainable to add an explicit "raw" accessor on the
class itself.
llvm-svn: 233322
We don't have any logic to emit those tables yet, so the sdag lowering
of this intrinsic is just a stub. We can see the intrinsic in the
prepared IR, though.
llvm-svn: 233209
The main verifier already recurses through the other entry points, so we
might as well descend here too.
This temporarily duplicates some work already done in
`verifyDebugInfo()`, but eventually I'll be removing the other side.
llvm-svn: 233095
A WIP patch makes `DIDescriptor` accessors more strict, which in turn
causes the `DebugInfoFinder` to crash on wrongly typed `!dbg`
attachments. Catch that error up front in
`Verifier::visitInstruction()`.
Also remove a test that we "handle" invalid `!dbg` attachments, added
back in r99938. We don't want to handle those anymore.
Note: I'm *not* recursing and verifying the debug info graph reachable
from this node; that work is already done by `verifyDebugInfo()`.
llvm-svn: 232834
Remove the separate `DebugInfoVerifier` class, as a partial step toward
better integrating debug info verification with the `Verifier`.
Right now, verification of debug info is kind of a mess.
- There are `DIDescriptor::Verify()` checks live in `DebugInfo.cpp`.
These return `bool`, and there's no way to see (except by opening a
debugger) why they fail.
- We rely on `DebugInfoFinder` to traverse the debug info graph and
dig up nodes. However, the regular `Verifier` visits many of these
nodes when it calls into debug info intrinsic operands. Visiting
twice and running different checks is kind of absurd.
- Moreover, `DebugInfoFinder` asserts on failed type resolution -- the
verifier should never assert!
By integrating the two verifiers, I'm aiming at solving these problems
(work to be done, obviously). Verification can be localized to the
`Verifier`; we can use a naive `MDNode` operand traversal to find all
the nodes; we can verify type references instead of asserting on
failure.
There are `assert()`s sprinkled throughout the optimizer and dwarf
backend on `DIDescriptor::Verify()` checks. This is a hangover from
when the debug info verifier was off, so I plan to remove them as I go
(once I confirm that the checks are done at verification time).
Note: to keep the behaviour of only running the debug info verifier when
-verify succeeds, I've added an `EverBroken` flag. Once the
`DebugInfoFinder` assertions are gone and the two traversals have been
merged, I expect to be able to remove this.
llvm-svn: 232790
Remove `DebugInfoVerifierLegacyPass` and the `-verify-di` pass.
Instead, call into the `DebugInfoVerifier` from inside
`VerifierLegacyPass::finalizeModule()`. This better matches the logic
in `verifyModule()` (used by the new PassManager), avoids requiring two
separate passes to verify the IR, and makes the API for "add a pass to
verify the IR" simple.
Note: the `-verify-debug-info` flag still works (for now, at least;
eventually it might make sense to just remove it).
llvm-svn: 232772
Break MDExpression off of DebugNode (inherit directly from `MDNode`) and
drop the fake `DW_TAG_expression` tag in the process.
AFAICT, there's no real functionality change here. The tag was
originally used by `DIDescriptor::isExpression()` to discriminate
between `MDNode`s, but in the new hierarchy we don't need that.
Fixes PR22780.
llvm-svn: 232550
r186634 started verifying debug info, and r194986 disabled it by default
because it was too expensive to run the checks on every function (since
most of the graph was reachable from each function).
r206300 moved the checks to module-level to make it cheaper, but there
was already quite a bit of testcase bitrot (and the verifier would only
print `<badref>`) so I guess no one had time to turn it back on.
This does just that. Upgrade scripts this past autumn and winter
probably fixed some of the bitrot, and this weekend I fixed the verifier
output (r232275, r232417, r232418) and thusly the remaining failing
testcases (r232290, r232415).
This is part of PR22777.
llvm-svn: 232505
If `Verifier` has already found a failure, don't call
`DebugInfoVerifier`. The latter sometimes crashes in `DebugInfoFinder`
when the former would give a nice message. The only two cases I found
it crashing are explicit verifier tests I've added:
- test/Verifier/llvm.dbg.declare-expression.ll
- test/Verifier/llvm.dbg.value-expression.ll
However, I assume frontends with bugs will create invalid IR as well.
IMO, the `DebugInfoVerifier` should never crash (instead, it should fail
to verify), but subtleties like that will be easier to work out once
it's enabled again.
This is part of PR22777.
llvm-svn: 232418
Now that we check `MDExpression` during `-verify` (r232299), make
the `DIExpression` wrapper more strict:
- remove redundant checks in `DebugInfoVerifier`,
- overload `get()` to `cast_or_null<MDExpression>` (superseding
`getRaw()`),
- stop checking for null in any accessor, and
- remove `DIExpression::Verify()` entirely in favour of
`MDExpression::isValid()`.
There is still some logic in this class, mostly to do with high-level
iterators; I'll defer cleaning up those until the rest of the wrappers
are similarly strict.
llvm-svn: 232412
Turns out `visitIntrinsicFunctionCall()` descends into all operands
already, so explicitly descending in `visitDbgIntrinsic()` (part of
r232296) isn't useful.
Updating a testcase that doesn't really need `-verify-debug-info` (since
r231082) as confirmation.
llvm-svn: 232408
Change accessors to downcast to `MDLocalVariable` and `MDExpression`,
now that we have -verify checks in place to confirm that it's safe.
llvm-svn: 232299
Verify that debug info intrinsic arguments are valid. (These checks
will not recurse through the full debug info graph, so they don't need
to be cordoned of in `DebugInfoVerifier`.)
With those checks in place, changing the `DbgIntrinsicInst` accessors to
downcast to `MDLocalVariable` and `MDExpression` is natural (added isa
specializations in `Metadata.h` to support this).
Added tests to `test/Verifier` for the new -verify checks, and fixed the
debug info in all the in-tree tests.
If you have out-of-tree testcases that have started to fail to -verify,
hopefully the verify checks are helpful. The most likely problem is
that the expression argument is `!{}` (instead of `!MDExpression()`).
llvm-svn: 232296
Replumb the `AsmWriter` so that `Metadata::print()` is generally useful.
(Similarly change `Metadata::printAsOperand()`.)
- `SlotTracker` now has a mode where all metadata will be correctly
numbered when initializing a `Module`. Normally, `Metadata` only
referenced from within `Function`s gets numbered when the `Function`
is incorporated.
- `Metadata::print()` and `Metadata::printAsOperand()` (and
`Metadata::dump()`) now take an optional `Module` argument. When
provided, `SlotTracker` is initialized with the new mode, and the
numbering will be complete and consistent for all calls to `print()`.
- `Value::print()` uses the new `SlotTracker` mode when printing
intrinsics with `MDNode` operands, `MetadataAsValue` operands, or the
bodies of functions. Thus, metadata numbering will be consistent
between calls to `Metadata::print()` and `Value::print()`.
- `Metadata::print()` (and `Metadata::dump()`) now print the full
definition of `MDNode`s:
!5 = !{!6, !"abc", !7}
This matches behaviour for `Value::print()`, which includes the name
of instructions.
- Updated call sites in `Verifier` to call `print()` instead of
`printAsOperand()`.
All this, so that `Verifier` can print out useful failure messages that
involve `Metadata` for PR22777.
Note that `Metadata::printAsOperand()` previously took an optional
`bool` and `Module` operand. The former was cargo-culted from
`Value::printAsOperand()` and wasn't doing anything useful. The latter
didn't give consistent results (without the new `SlotTracker` mode).
llvm-svn: 232275
Given that the stated purpose of `CheckFailed()` is to provide a nice
spot for a breakpoint, it'd be nice not to have to use a regex to break
on it. Recover the ability to simply use `b CheckFailed` by
specializing the message-only version, and by changing the variadic
version to call into the message-only version.
llvm-svn: 232268
This causes a crash if the referenced intrinsic was malformed. In this case, we
would already have reported an error on the referenced intrinsic, but then
crashed on the second one when it tried to introspect the first without
error checking.
llvm-svn: 231910
In this situation we would always have already flagged an error on the statepoint intrinsic,
but then we carry on to parse other, related GC intrinsics, and could end up crashing during that
verification when they try to access data from the malformed statepoint.
llvm-svn: 231759
Port `DIExpression::Operand` over to `MDExpression::ExprOperand`. The
logic is needed directly in `MDExpression` to support printing in
assembly.
llvm-svn: 229002
Gather and Scatter are new introduced intrinsics, comming after recently implemented masked load and store.
This is the first patch for Gather and Scatter intrinsics. It includes only the syntax, parsing and verification.
Gather and Scatter intrinsics allow to perform multiple memory accesses (read/write) in one vector instruction.
The intrinsics are not target specific and will have the following syntax:
Gather:
declare <16 x i32> @llvm.masked.gather.v16i32(<16 x i32*> <vector of ptrs>, i32 <alignment>, <16 x i1> <mask>, <16 x i32> <passthru>)
declare <8 x float> @llvm.masked.gather.v8f32(<8 x float*><vector of ptrs>, i32 <alignment>, <8 x i1> <mask>, <8 x float><passthru>)
Scatter:
declare void @llvm.masked.scatter.v8i32(<8 x i32><vector value to be stored> , <8 x i32*><vector of ptrs> , i32 <alignment>, <8 x i1> <mask>)
declare void @llvm.masked.scatter.v16i32(<16 x i32> <vector value to be stored> , <16 x i32*> <vector of ptrs>, i32 <alignment>, <16 x i1><mask> )
Vector of ptrs - a set of source/destination addresses, to load/store the value.
Mask - switches on/off vector lanes to prevent memory access for switched-off lanes
vector of ptrs, value and mask should have the same vector width.
These are code examples where gather / scatter should be used and will allow function vectorization
;void foo1(int * restrict A, int * restrict B, int * restrict C) {
; for (int i=0; i<SIZE; i++) {
; A[i] = B[C[i]];
; }
;}
;void foo3(int * restrict A, int * restrict B) {
; for (int i=0; i<SIZE; i++) {
; A[B[i]] = i+5;
; }
;}
Tests will come in the following patches, with CodeGen and Vectorizer.
http://reviews.llvm.org/D7433
llvm-svn: 228521
Patch by: Igor Laevsky
"This change generalizes statepoint verification to use ImmutableCallSite instead of CallInst. This will allow to easily implement invoke statepoint verification (in a following change)."
Differential Revision: http://reviews.llvm.org/D7308
llvm-svn: 228064
Patch by: Igor Laevsky
"Simple refactoring. This is done in preparation to support verification of invokable statepoints."
Differential Revision: http://reviews.llvm.org/D7276
llvm-svn: 227640
Specifically, gc.result benefits from this greatly. Instead of:
gc.result.int.*
gc.result.float.*
gc.result.ptr.*
...
We now have a gc.result.* that can specialize to literally any type.
Differential Revision: http://reviews.llvm.org/D7020
llvm-svn: 226857
With the appropriate Verifier changes, exactracting the result out of a
statepoint wrapping a vararg function crashes. However, a void vararg
function works fine: commit this first step.
Differential Revision: http://reviews.llvm.org/D7071
llvm-svn: 226599
Remove `MDNodeFwdDecl` (as promised in r226481). Aside from API
changes, there's no real functionality change here.
`MDNode::getTemporary()` now forwards to `MDTuple::getTemporary()`,
which returns a tuple with `isTemporary()` equal to true.
The main point is that we can now add temporaries of other `MDNode`
subclasses, needed for PR22235 (I introduced `MDNodeFwdDecl` in the
first place because I didn't recognize this need, and thought they were
only needed to handle forward references).
A few things left out of (or highlighted by) this commit:
- I've had to remove the (few) uses of `std::unique_ptr<>` to deal
with temporaries, since the destructor is no longer public.
`getTemporary()` should probably return the equivalent of
`std::unique_ptr<T, MDNode::deleteTemporary>`.
- `MDLocation::getTemporary()` doesn't exist yet (worse, it actually
does exist, but does the wrong thing: `MDNode::getTemporary()` is
inherited and returns an `MDTuple`).
- `MDNode` now only has one subclass, `UniquableMDNode`, and the
distinction between them is actually somewhat confusing.
I'll fix those up next.
llvm-svn: 226501
The functions {pred,succ,use,user}_{begin,end} exist, but many users
have to check *_begin() with *_end() by hand to determine if the
BasicBlock or User is empty. Fix this with a standard *_empty(),
demonstrating a few usecases.
llvm-svn: 225760
This name is less descriptive, but it sort of puts things in the
'llvm.frame...' namespace, relating it to frameallocate and
frameaddress. It also avoids using "allocate" and "allocation" together.
llvm-svn: 225752
These intrinsics allow multiple functions to share a single stack
allocation from one function's call frame. The function with the
allocation may only perform one allocation, and it must be in the entry
block.
Functions accessing the allocation call llvm.recoverframeallocation with
the function whose frame they are accessing and a frame pointer from an
active call frame of that function.
These intrinsics are very difficult to inline correctly, so the
intention is that they be introduced rarely, or at least very late
during EH preparation.
Reviewers: echristo, andrew.w.kaylor
Differential Revision: http://reviews.llvm.org/D6493
llvm-svn: 225746
Patch by: Ramkumar Ramachandra <artagnon@gmail.com>
"This patch started out as an exploration of gc.relocate, and an attempt
to write a simple test in call-lowering. I then noticed that the
arguments of gc.relocate were not checked fully, so I went in and fixed
a few things. Finally, the most important outcome of this patch is that
my new error handling code caught a bug in a callsite in
stackmap-format."
Differential Revision: http://reviews.llvm.org/D6824
llvm-svn: 225412
units.
This was debated back and forth a bunch, but using references is now
clearly cleaner. Of all the code written using pointers thus far, in
only one place did it really make more sense to have a pointer. In most
cases, this just removes immediate dereferencing from the code. I think
it is much better to get errors on null IR units earlier, potentially
at compile time, than to delay it.
Most notably, the legacy pass manager uses references for its routines
and so as more and more code works with both, the use of pointers was
likely to become really annoying. I noticed this when I ported the
domtree analysis over and wrote the entire thing with references only to
have it fail to compile. =/ It seemed better to switch now than to
delay. We can, of course, revisit this is we learn that references are
really problematic in the API.
llvm-svn: 225145
Split `Metadata` away from the `Value` class hierarchy, as part of
PR21532. Assembly and bitcode changes are in the wings, but this is the
bulk of the change for the IR C++ API.
I have a follow-up patch prepared for `clang`. If this breaks other
sub-projects, I apologize in advance :(. Help me compile it on Darwin
I'll try to fix it. FWIW, the errors should be easy to fix, so it may
be simpler to just fix it yourself.
This breaks the build for all metadata-related code that's out-of-tree.
Rest assured the transition is mechanical and the compiler should catch
almost all of the problems.
Here's a quick guide for updating your code:
- `Metadata` is the root of a class hierarchy with three main classes:
`MDNode`, `MDString`, and `ValueAsMetadata`. It is distinct from
the `Value` class hierarchy. It is typeless -- i.e., instances do
*not* have a `Type`.
- `MDNode`'s operands are all `Metadata *` (instead of `Value *`).
- `TrackingVH<MDNode>` and `WeakVH` referring to metadata can be
replaced with `TrackingMDNodeRef` and `TrackingMDRef`, respectively.
If you're referring solely to resolved `MDNode`s -- post graph
construction -- just use `MDNode*`.
- `MDNode` (and the rest of `Metadata`) have only limited support for
`replaceAllUsesWith()`.
As long as an `MDNode` is pointing at a forward declaration -- the
result of `MDNode::getTemporary()` -- it maintains a side map of its
uses and can RAUW itself. Once the forward declarations are fully
resolved RAUW support is dropped on the ground. This means that
uniquing collisions on changing operands cause nodes to become
"distinct". (This already happened fairly commonly, whenever an
operand went to null.)
If you're constructing complex (non self-reference) `MDNode` cycles,
you need to call `MDNode::resolveCycles()` on each node (or on a
top-level node that somehow references all of the nodes). Also,
don't do that. Metadata cycles (and the RAUW machinery needed to
construct them) are expensive.
- An `MDNode` can only refer to a `Constant` through a bridge called
`ConstantAsMetadata` (one of the subclasses of `ValueAsMetadata`).
As a side effect, accessing an operand of an `MDNode` that is known
to be, e.g., `ConstantInt`, takes three steps: first, cast from
`Metadata` to `ConstantAsMetadata`; second, extract the `Constant`;
third, cast down to `ConstantInt`.
The eventual goal is to introduce `MDInt`/`MDFloat`/etc. and have
metadata schema owners transition away from using `Constant`s when
the type isn't important (and they don't care about referring to
`GlobalValue`s).
In the meantime, I've added transitional API to the `mdconst`
namespace that matches semantics with the old code, in order to
avoid adding the error-prone three-step equivalent to every call
site. If your old code was:
MDNode *N = foo();
bar(isa <ConstantInt>(N->getOperand(0)));
baz(cast <ConstantInt>(N->getOperand(1)));
bak(cast_or_null <ConstantInt>(N->getOperand(2)));
bat(dyn_cast <ConstantInt>(N->getOperand(3)));
bay(dyn_cast_or_null<ConstantInt>(N->getOperand(4)));
you can trivially match its semantics with:
MDNode *N = foo();
bar(mdconst::hasa <ConstantInt>(N->getOperand(0)));
baz(mdconst::extract <ConstantInt>(N->getOperand(1)));
bak(mdconst::extract_or_null <ConstantInt>(N->getOperand(2)));
bat(mdconst::dyn_extract <ConstantInt>(N->getOperand(3)));
bay(mdconst::dyn_extract_or_null<ConstantInt>(N->getOperand(4)));
and when you transition your metadata schema to `MDInt`:
MDNode *N = foo();
bar(isa <MDInt>(N->getOperand(0)));
baz(cast <MDInt>(N->getOperand(1)));
bak(cast_or_null <MDInt>(N->getOperand(2)));
bat(dyn_cast <MDInt>(N->getOperand(3)));
bay(dyn_cast_or_null<MDInt>(N->getOperand(4)));
- A `CallInst` -- specifically, intrinsic instructions -- can refer to
metadata through a bridge called `MetadataAsValue`. This is a
subclass of `Value` where `getType()->isMetadataTy()`.
`MetadataAsValue` is the *only* class that can legally refer to a
`LocalAsMetadata`, which is a bridged form of non-`Constant` values
like `Argument` and `Instruction`. It can also refer to any other
`Metadata` subclass.
(I'll break all your testcases in a follow-up commit, when I propagate
this change to assembly.)
llvm-svn: 223802
I'm recommiting the codegen part of the patch.
The vectorizer part will be send to review again.
Masked Vector Load and Store Intrinsics.
Introduced new target-independent intrinsics in order to support masked vector loads and stores. The loop vectorizer optimizes loops containing conditional memory accesses by generating these intrinsics for existing targets AVX2 and AVX-512. The vectorizer asks the target about availability of masked vector loads and stores.
Added SDNodes for masked operations and lowering patterns for X86 code generator.
Examples:
<16 x i32> @llvm.masked.load.v16i32(i8* %addr, <16 x i32> %passthru, i32 4 /* align */, <16 x i1> %mask)
declare void @llvm.masked.store.v8f64(i8* %addr, <8 x double> %value, i32 4, <8 x i1> %mask)
Scalarizer for other targets (not AVX2/AVX-512) will be done in a separate patch.
http://reviews.llvm.org/D6191
llvm-svn: 223348
This is simply a grab bag of unrelated checks:
- A statepoint call can't be marked readonly or readnone
- We don't currently support inline asm or varadic target functions. Both could be supported, but don't currently work.
- I forgot to check that the number of call arguments actually matched the wrapped callee in my previous change. Included here.
llvm-svn: 223322
Add checks that the types in a gc.statepoint sequence match the wrapper callee and that relocating a pointer doesn't change it's type.
llvm-svn: 223275
The recently added documentation for statepoints claimed that we checked the parameters of the various intrinsics for validity. This patch adds the code to actually do so. I also removed a couple of redundant checks for conditions which are checked elsewhere in the Verifier and simplified the logic using the helper functions from Statepoint.h.
llvm-svn: 223259
The statepoint intrinsics are intended to enable precise root tracking through the compiler as to support garbage collectors of all types. The addition of the statepoint intrinsics to LLVM should have no impact on the compilation of any program which does not contain them. There are no side tables created, no extra metadata, and no inhibited optimizations.
A statepoint works by transforming a call site (or safepoint poll site) into an explicit relocation operation. It is the frontend's responsibility (or eventually the safepoint insertion pass we've developed, but that's not part of this patch series) to ensure that any live pointer to a GC object is correctly added to the statepoint and explicitly relocated. The relocated value is just a normal SSA value (as seen by the optimizer), so merges of relocated and unrelocated values are just normal phis. The explicit relocation operation, the fact the statepoint is assumed to clobber all memory, and the optimizers standard semantics ensure that the relocations flow through IR optimizations correctly.
This is the first patch in a small series. This patch contains only the IR parts; the documentation and backend support will be following separately. The entire series can be seen as one combined whole in http://reviews.llvm.org/D5683.
Reviewed by: atrick, ributzka
llvm-svn: 223078
This reverts commit r222632 (and follow-up r222636), which caused a host
of LNT failures on an internal bot. I'll respond to the commit on the
list with a reproduction of one of the failures.
Conflicts:
lib/Target/X86/X86TargetTransformInfo.cpp
llvm-svn: 222936
Introduced new target-independent intrinsics in order to support masked vector loads and stores. The loop vectorizer optimizes loops containing conditional memory accesses by generating these intrinsics for existing targets AVX2 and AVX-512. The vectorizer asks the target about availability of masked vector loads and stores.
Added SDNodes for masked operations and lowering patterns for X86 code generator.
Examples:
<16 x i32> @llvm.masked.load.v16i32(i8* %addr, <16 x i32> %passthru, i32 4 /* align */, <16 x i1> %mask)
declare void @llvm.masked.store.v8f64(i8* %addr, <8 x double> %value, i32 4, <8 x i1> %mask)
Scalarizer for other targets (not AVX2/AVX-512) will be done in a separate patch.
http://reviews.llvm.org/D6191
llvm-svn: 222632
This is to be consistent with StringSet and ultimately with the standard
library's associative container insert function.
This lead to updating SmallSet::insert to return pair<iterator, bool>,
and then to update SmallPtrSet::insert to return pair<iterator, bool>,
and then to update all the existing users of those functions...
llvm-svn: 222334
Instead, we're going to separate metadata from the Value hierarchy. See
PR21532.
This reverts commit r221375.
This reverts commit r221373.
This reverts commit r221359.
This reverts commit r221167.
This reverts commit r221027.
This reverts commit r221024.
This reverts commit r221023.
This reverts commit r220995.
This reverts commit r220994.
llvm-svn: 221711
Change `NamedMDNode::getOperator()` from returning `MDNode *` to
returning `Value *`. To reduce boilerplate at some call sites, add a
`getOperatorAsMDNode()` for named metadata that's expected to only
return `MDNode` -- for now, that's everything, but debug node named
metadata (such as llvm.dbg.cu and llvm.dbg.sp) will soon change. This
is part of PR21433.
Note that there's a follow-up patch to clang for the API change.
llvm-svn: 221375
This removes calls to isMaterializable in the following cases:
* It was redundant with a call to isDeclaration now that isDeclaration returns
the correct answer for materializable functions.
* It was followed by a call to Materialize. Just call Materialize and check EC.
llvm-svn: 221050
Change `Instruction::getMetadata()` to return `Value` as part of
PR21433.
Update most callers to use `Instruction::getMDNode()`, which wraps the
result in a `cast_or_null<MDNode>`.
llvm-svn: 221024
To do this, change the representation of lazy loaded functions.
The previous representation cannot differentiate between a function whose body
has been removed and one whose body hasn't been read from the .bc file. That
means that in order to drop a function, the entire body had to be read.
llvm-svn: 220580
Range metadata applies to loads, call, and invokes. We were validating that metadata applied to loads was correct according to the LangRef, but we were not validating metadata applied to calls or invokes. This change extracts the checking functionality to a common location, reuses it for all valid locations, and adds a simple test to ensure a misused range on a call gets reported.
llvm-svn: 220246
to make sure we don't do invalid load of an enum. Share the
conversion code between llvm::Module implementation and the
verifier.
This bug was reported by UBSan.
llvm-svn: 217395
We've rejected these kinds of functions since r28405 in 2006 because
it's impossible to lower the return of a callee cleanup varargs
function. However there are lots of legal ways to leave such a function
without returning, such as aborting. Today we can leave a function with
a musttail call to another function with the correct prototype, and
everything works out.
I'm removing the verifier check declaring that a normal return from such
a function is UB.
Reviewed By: nlewycky
Differential Revision: http://reviews.llvm.org/D5059
llvm-svn: 216779
Summary: This patch introduces two new iterator ranges and updates existing code to use it. No functional change intended.
Test Plan: All tests (make check-all) still pass.
Reviewers: dblaikie
Reviewed By: dblaikie
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D4481
llvm-svn: 213474
Our verifier check for checking if a global has local linkage was too
strict. Forbid private linkage but permit local linkage.
Object file formats permit this and forbidding it prevents elimination
of unused, internal, vftables under the MSVC ABI.
llvm-svn: 212900
This new IR facility allows us to represent the object-file semantic of
a COMDAT group.
COMDATs allow us to tie together sections and make the inclusion of one
dependent on another. This is required to implement features like MS
ABI VFTables and optimizing away certain kinds of initialization in C++.
This functionality is only representable in COFF and ELF, Mach-O has no
similar mechanism.
Differential Revision: http://reviews.llvm.org/D4178
llvm-svn: 211920
Summary:
With this patch, range metadata can be added to call/invoke including
IntrinsicInst. Previously, it could only be added to load.
Rename computeKnownBitsLoad to computeKnownBitsFromRangeMetadata because
range metadata is not only used by load.
Update the language reference to reflect this change.
Test Plan:
Add several tests in range-2.ll to confirm the verifier is happy with
having range metadata on call/invoke.
Add two tests in AddOverFlow.ll to confirm annotating range metadata to
call/invoke can benefit InstCombine.
Reviewers: meheff, nlewycky, reames, hfinkel, eliben
Reviewed By: eliben
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D4187
llvm-svn: 211281
The verifier follows GlobalAlias operands so that it can detect cycles of
alias definitions. It was doing this in a way that caused it to also recurse
through initializers for the GlobalValue aliasees, and it would fail when
an initializer refers to a global that is a declaration and not a definition.
This patch causes it to stop recursing when it hits a global definition.
<rdar://problem/17277451>
llvm-svn: 210734
Alias with unnamed_addr were in a strange state. It is stored in GlobalValue,
the language reference talks about "unnamed_addr aliases" but the verifier
was rejecting them.
It seems natural to allow unnamed_addr in aliases:
* It is a property of how it is accessed, not of the data itself.
* It is perfectly possible to write code that depends on the address
of an alias.
This patch then makes unname_addr legal for aliases. One side effect is that
the syntax changes for a corner case: In globals, unnamed_addr is now printed
before the address space.
llvm-svn: 210302
It includes a pass that rewrites all indirect calls to jumptable functions to pass through these tables.
This also adds backend support for generating the jump-instruction tables on ARM and X86.
Note that since the jumptable attribute creates a second function pointer for a
function, any function marked with jumptable must also be marked with unnamed_addr.
llvm-svn: 210280
