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* Clean up the processing of dbg.value in various placesKeno Fischer2015-12-191-4/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: First up is instcombine, where in the dbg.declare -> dbg.value conversion, the llvm.dbg.value needs to be called on the actual loaded value, rather than the address (since the whole point of this transformation is to be able to get rid of the alloca). Further, now that that's cleaned up, we can remove a hack in the backend, that would add an implicit OP_deref if the argument to dbg.value was an alloca. This stems from before the existence of DIExpression and is no longer necessary since the deref can be expressed explicitly. Now, in order to make sure that the tests pass with this change, we need to correct the printing of DEBUG_VALUE comments to take into account the expression, which wasn't taken into account before. Unfortunately, for both these changes, there were a number of incorrect test cases (mostly the wrong number of DW_OP_derefs, but also a couple where the test itself was broken more badly). aprantl and I have gone through and adjusted these test case in order to make them pass with these fixes and in some cases to make sure they're actually testing what they are meant to test. Reviewers: aprantl Subscribers: dsanders Differential Revision: http://reviews.llvm.org/D14186 llvm-svn: 256077
* [WinEH] Use operand bundles to describe call sitesDavid Majnemer2015-12-151-3/+1
| | | | | | | | | | | | | | | | | SimplifyCFG allows tail merging with code which terminates in unreachable which, in turn, makes it possible for an invoke to end up in a funclet which it was not originally part of. Using operand bundles on invokes allows us to determine whether or not an invoke was part of a funclet in the source program. Furthermore, it allows us to unambiguously answer questions about the legality of inlining into call sites which the personality may have trouble with. Differential Revision: http://reviews.llvm.org/D15517 llvm-svn: 255674
* [IR] Remove terminatepadDavid Majnemer2015-12-141-7/+0
| | | | | | | | | | | | | It turns out that terminatepad gives little benefit over a cleanuppad which calls the termination function. This is not sufficient to implement fully generic filters but MSVC doesn't support them which makes terminatepad a little over-designed. Depends on D15478. Differential Revision: http://reviews.llvm.org/D15479 llvm-svn: 255522
* [IR] Reformulate LLVM's EH funclet IRDavid Majnemer2015-12-121-7/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While we have successfully implemented a funclet-oriented EH scheme on top of LLVM IR, our scheme has some notable deficiencies: - catchendpad and cleanupendpad are necessary in the current design but they are difficult to explain to others, even to seasoned LLVM experts. - catchendpad and cleanupendpad are optimization barriers. They cannot be split and force all potentially throwing call-sites to be invokes. This has a noticable effect on the quality of our code generation. - catchpad, while similar in some aspects to invoke, is fairly awkward. It is unsplittable, starts a funclet, and has control flow to other funclets. - The nesting relationship between funclets is currently a property of control flow edges. Because of this, we are forced to carefully analyze the flow graph to see if there might potentially exist illegal nesting among funclets. While we have logic to clone funclets when they are illegally nested, it would be nicer if we had a representation which forbade them upfront. Let's clean this up a bit by doing the following: - Instead, make catchpad more like cleanuppad and landingpad: no control flow, just a bunch of simple operands; catchpad would be splittable. - Introduce catchswitch, a control flow instruction designed to model the constraints of funclet oriented EH. - Make funclet scoping explicit by having funclet instructions consume the token produced by the funclet which contains them. - Remove catchendpad and cleanupendpad. Their presence can be inferred implicitly using coloring information. N.B. The state numbering code for the CLR has been updated but the veracity of it's output cannot be spoken for. An expert should take a look to make sure the results are reasonable. Reviewers: rnk, JosephTremoulet, andrew.w.kaylor Differential Revision: http://reviews.llvm.org/D15139 llvm-svn: 255422
* Add arg_begin() and arg_end() to CallInst and InvokeInst; NFCISanjoy Das2015-12-101-2/+1
| | | | | | | | | | - This simplifies the CallSite class, arg_begin / arg_end are now simple wrapper getters. - In several places, we were creating CallSite instances solely to call arg_begin and arg_end. With this change, that's no longer required. llvm-svn: 255226
* [OperandBundles] Fix a transform in simplifycfgSanjoy Das2015-12-081-2/+6
| | | | | | | | | | Reviewers: pcc, majnemer, reames Subscribers: reames, llvm-commits Differential Revision: http://reviews.llvm.org/D15345 llvm-svn: 255062
* Move EH-specific helper functions to a more appropriate placeDavid Majnemer2015-12-021-1/+1
| | | | | | No functionality change is intended. llvm-svn: 254562
* [safestack] Protect byval function arguments.Evgeniy Stepanov2015-12-011-5/+11
| | | | | | | Detect unsafe byval function arguments and move them to the unsafe stack. llvm-svn: 254353
* Preserve load alignment and dereferenceable metadata during some transformationsArtur Pilipenko2015-11-021-0/+9
| | | | | | | | Reviewed By: hfinkel Differential Revision: http://reviews.llvm.org/D13953 llvm-svn: 251809
* TransformUtils: Remove implicit ilist iterator conversions, NFCDuncan P. N. Exon Smith2015-10-131-12/+14
| | | | | | | | | | | Continuing the work from last week to remove implicit ilist iterator conversions. First related commit was probably r249767, with some more motivation in r249925. This edition gets LLVMTransformUtils compiling without the implicit conversions. No functional change intended. llvm-svn: 250142
* [PlaceSafeopints] Extract out `callsGCLeafFunction`, NFCSanjoy Das2015-10-081-0/+17
| | | | | | | | | | | | | Summary: This will be used in a later change to RewriteStatepointsForGC. Reviewers: reames, swaroop.sridhar Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D13490 llvm-svn: 249777
* inariant.group handling in GVNPiotr Padlewski2015-10-021-1/+14
| | | | | | | | | | | | The most important part required to make clang devirtualization works ( ͡°͜ʖ ͡°). The code is able to find non local dependencies, but unfortunatelly because the caller can only handle local dependencies, I had to add some restrictions to look for dependencies only in the same BB. http://reviews.llvm.org/D12992 llvm-svn: 249196
* Fix debug info with SafeStack.Evgeniy Stepanov2015-09-301-3/+11
| | | | llvm-svn: 248933
* Move dbg.declare intrinsics when merging and replacing allocas.Evgeniy Stepanov2015-09-291-4/+4
| | | | | | | | | | | | | | Place new and update dbg.declare calls immediately after the corresponding alloca. Current code in replaceDbgDeclareForAlloca puts the new dbg.declare at the end of the basic block. LLVM codegen has problems emitting debug info in a situation when dbg.declare appears after all uses of the variable. This usually kinda works for inlining and ASan (two users of this function) but not for SafeStack (see the pending change in http://reviews.llvm.org/D13178). llvm-svn: 248769
* Improve performance of SimplifyInstructionsInBlockFiona Glaser2015-09-281-12/+60
| | | | | | | | | | | | | | | | | | | | 1. Use a worklist, not a recursive approach, to avoid needless revisitation and being repeatedly forced to jump back to the start of the BB if a handle is invalidated. 2. Only insert operands to the worklist if they become unused after a dead instruction is removed, so we don’t have to visit them again in most cases. 3. Use a SmallSetVector to track the worklist. 4. Instead of pre-initting the SmallSetVector like in DeadCodeEliminationPass, only put things into the worklist if they have to be revisited after the first run-through. This minimizes how much the actual SmallSetVector gets used, which saves a lot of time. llvm-svn: 248727
* [EH] Create removeUnwindEdge utilityJoseph Tremoulet2015-09-271-0/+37
| | | | | | | | | | | | | | | | | 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 llvm-svn: 248677
* Constant propagation after hitting assume(cmp) bugfixPiotr Padlewski2015-09-021-0/+20
| | | | | | | | | Last time code run into assertion `BBE.isSingleEdge()` in lib/IR/Dominators.cpp:200. http://reviews.llvm.org/D12170 llvm-svn: 246696
* [RemoveDuplicatePHINodes] Start over after removing a PHI.Benjamin Kramer2015-09-021-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This makes RemoveDuplicatePHINodes more effective and fixes an assertion failure. Triggering the assertions requires a DenseSet reallocation so this change only contains a constructive test. I'll explain the issue with a small example. In the following function there's a duplicate PHI, %4 and %5 are identical. When this is found the DenseSet in RemoveDuplicatePHINodes contains %2, %3 and %4. define void @F() { br label %1 ; <label>:1 ; preds = %1, %0 %2 = phi i32 [ 42, %0 ], [ %4, %1 ] %3 = phi i32 [ 42, %0 ], [ %5, %1 ] %4 = phi i32 [ 42, %0 ], [ 23, %1 ] %5 = phi i32 [ 42, %0 ], [ 23, %1 ] br label %1 } after RemoveDuplicatePHINodes runs the function looks like this. %3 has changed and is now identical to %2, but RemoveDuplicatePHINodes never saw this. define void @F() { br label %1 ; <label>:1 ; preds = %1, %0 %2 = phi i32 [ 42, %0 ], [ %4, %1 ] %3 = phi i32 [ 42, %0 ], [ %4, %1 ] %4 = phi i32 [ 42, %0 ], [ 23, %1 ] br label %1 } If the DenseSet does a reallocation now it will reinsert all keys and stumble over %3 now having a different hash value than it had when inserted into the map for the first time. This change clears the set whenever a PHI is deleted and starts the progress from the beginning, allowing %3 to be deleted and avoiding inconsistent DenseSet state. This potentially has a negative performance impact because it rescans all PHIs, but I don't think that this ever makes a difference in practice. llvm-svn: 246694
* Revert r246244 and r246243Steven Wu2015-08-281-20/+0
| | | | | | These two commits cause clang/llvm bootstrap to hang. llvm-svn: 246279
* Constant propagation after hitting assume(cmp) bugfixPiotr Padlewski2015-08-281-0/+20
| | | | | | | | | Last time code run into assertion `BBE.isSingleEdge()` in lib/IR/Dominators.cpp:200. http://reviews.llvm.org/D12170 llvm-svn: 246244
* Rename Instruction::dropUnknownMetadata() to dropUnknownNonDebugMetadata()Adrian Prantl2015-08-201-1/+1
| | | | | | | | | | | and make it always preserve debug locations, since all callers wanted this behavior anyway. This is addressing a post-commit review feedback for r245589. NFC (inside the LLVM tree). llvm-svn: 245622
* [ConstantFoldTerminator] Preserve make.implicit metadata when converting ↵Chen Li2015-08-071-0/+5
| | | | | | | | | | | | | | SwitchInst to BranchInst Summary: llvm::ConstantFoldTerminator function can convert SwitchInst with single case (and default) to a conditional BranchInst. This patch adds support to preserve make.implicit metadata on this conversion. Reviewers: sanjoy, weimingz, chenli Subscribers: mcrosier, llvm-commits Differential Revision: http://reviews.llvm.org/D11841 llvm-svn: 244348
* Convert a bunch of loops to foreach. NFC.Pete Cooper2015-08-061-2/+1
| | | | | | | | After r244074, we now have a successors() method to iterate over all the successors of a TerminatorInst. This commit changes a bunch of eligible loops to use it. llvm-svn: 244260
* New EH representation for MSVC compatibilityDavid Majnemer2015-07-311-2/+3
| | | | | | | | | | This introduces new instructions neccessary to implement MSVC-compatible exception handling support. Most of the middle-end and none of the back-end haven't been audited or updated to take them into account. Differential Revision: http://reviews.llvm.org/D11097 llvm-svn: 243766
* Update enforceKnownAlignment after the isWeakForLinker semantic changeReid Kleckner2015-07-141-7/+4
| | | | | | | | | | | | | Previously we would refrain from attempting to increase the linkage of available_externally globals because they were considered weak for the linker. Now they are treated more like a declaration instead of a weak definition. This was causing SSE alignment faults in Chromuim, when some code assumed it could increase the alignment of a dllimported global that it didn't control. http://crbug.com/509256 llvm-svn: 242091
* Revert the new EH instructionsDavid Majnemer2015-07-101-3/+2
| | | | | | This reverts commits r241888-r241891, I didn't mean to commit them. llvm-svn: 241893
* New EH representation for MSVC compatibilityDavid Majnemer2015-07-101-2/+3
| | | | | | | | | | | | | | | Summary: This introduces new instructions neccessary to implement MSVC-compatible exception handling support. Most of the middle-end and none of the back-end haven't been audited or updated to take them into account. Reviewers: rnk, JosephTremoulet, reames, nlewycky, rjmccall Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D11041 llvm-svn: 241888
* [EliminateDuplicatePHINodes] Replace custom hash map with DenseSet.Benjamin Kramer2015-06-181-51/+34
| | | | | | | While there use hash_combine instead of hand-rolled hashing. No functionality change intended. llvm-svn: 240023
* Move the personality function from LandingPadInst to FunctionDavid Majnemer2015-06-171-3/+4
| | | | | | | | | | | | | | | | | | | 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
* Extend EarlyCSE to handle basic cases from JumpThreading and CVPPhilip Reames2015-05-221-0/+20
| | | | | | | | | | | | | | This patch extends EarlyCSE to take advantage of the information that a controlling branch gives us about the value of a Value within this and dominated basic blocks. If the current block has a single predecessor with a controlling branch, we can infer what the branch condition must have been to execute this block. The actual change to support this is downright simple because EarlyCSE's existing scoped hash table logic deals with most of the complexity around merging. The patch actually implements two optimizations. 1) The first is analogous to JumpThreading in that it enables EarlyCSE's CSE handling to fold branches which are exactly redundant due to a previous branch to branches on constants. (It doesn't actually replace the branch or change the CFG.) This is pretty clearly a win since it enables substantial CFG simplification before we start trying to inline. 2) The second is analogous to CVP in that it exploits the knowledge gained to replace dominated *uses* of the original value. EarlyCSE does not otherwise reason about specific uses, so this is the more arguable one. It does enable further simplication and constant folding within the rest of the visit by EarlyCSE. In both cases, the added code only handles the easy dominance based case of each optimization. The general case is deferred to the existing passes. Differential Revision: http://reviews.llvm.org/D9763 llvm-svn: 238071
* IR: Give 'DI' prefix to debug info metadataDuncan P. N. Exon Smith2015-04-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* DebugInfo: Drop rest of DIDescriptor subclassesDuncan P. N. Exon Smith2015-04-211-10/+10
| | | | | | | Delete the remaining subclasses of (the already deleted) `DIDescriptor`. Part of PR23080. llvm-svn: 235404
* DebugInfo: Assert dbg.declare/value insts are validDuncan P. N. Exon Smith2015-04-211-6/+3
| | | | | | | | | | Remove early returns for when `getVariable()` is null, and just assert that it never happens. The Verifier already confirms that there's a valid variable on these intrinsics, so we should assume the debug info isn't broken. I also updated a check for a `!dbg` attachment, which the Verifier similarly guarantees. llvm-svn: 235400
* Silencing a -Wunused-but-set-variable warning; NFC.Aaron Ballman2015-04-161-5/+4
| | | | llvm-svn: 235094
* DebugInfo: Require a DebugLoc in DIBuilder::insertDeclare()Duncan P. N. Exon Smith2015-04-151-12/+9
| | | | | | | | | | | | | | | | | | | | | Change `DIBuilder::insertDeclare()` and `insertDbgValueIntrinsic()` to take an `MDLocation*`/`DebugLoc` parameter which it attaches to the created intrinsic. Assert at creation time that the `scope:` field's subprogram matches the variable's. There's a matching `clang` commit to use the API. The context for this is PR22778, which is removing the `inlinedAt:` field from `MDLocalVariable`, instead deferring to the `!dbg` location attached to the debug info intrinsic. The best way to ensure we always have a `!dbg` attachment is to require one at creation time. I'll be adding verifier checks next, but this API change is the best way to shake out frontend bugs. Note: I added an `llvm_unreachable()` in `bindings/go` and passed in `nullptr` for the `DebugLoc`. The `llgo` folks will eventually need to pass a valid `DebugLoc` here. llvm-svn: 235041
* DebugInfo: Gut DIExpressionDuncan P. N. Exon Smith2015-04-141-2/+1
| | | | | | | | | | | | | | | | Completely gut `DIExpression`, turning it into a simple wrapper around `MDExpression *`. There are two bits of magic left: - It's constructed from `const MDExpression*` but convertible to `MDExpression*`. - It's default-constructed to `nullptr`. Otherwise, it should behave quite like a raw pointer. Once I've done the same to the rest of the `DIDescriptor` subclasses, I'll come back to delete them entirely (and update call sites as necessary to deal with the missing magic). llvm-svn: 234832
* Transforms: Stop using DIDescriptor::is*() and auto-castingDuncan P. N. Exon Smith2015-04-061-12/+6
| | | | | | Same as r234255, but for lib/Analysis and lib/Transforms. llvm-svn: 234257
* Re-sort includes with sort-includes.py and insert raw_ostream.h where it's used.Benjamin Kramer2015-03-231-1/+1
| | | | llvm-svn: 232998
* DataLayout is mandatory, update the API to reflect it with references.Mehdi Amini2015-03-101-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Now that the DataLayout is a mandatory part of the module, let's start cleaning the codebase. This patch is a first attempt at doing that. This patch is not exactly NFC as for instance some places were passing a nullptr instead of the DataLayout, possibly just because there was a default value on the DataLayout argument to many functions in the API. Even though it is not purely NFC, there is no change in the validation. I turned as many pointer to DataLayout to references, this helped figuring out all the places where a nullptr could come up. I had initially a local version of this patch broken into over 30 independant, commits but some later commit were cleaning the API and touching part of the code modified in the previous commits, so it seemed cleaner without the intermediate state. Test Plan: Reviewers: echristo Subscribers: llvm-commits From: Mehdi Amini <mehdi.amini@apple.com> llvm-svn: 231740
* Don't promote asynch EH invokes of nounwind functions to callsReid Kleckner2015-02-111-1/+2
| | | | | | | | | | | If the landingpad of the invoke is using a personality function that catches asynch exceptions, then it can catch a trap. Also add some landingpads to invalid LLVM IR test cases that lack them. Over-the-shoulder reviewed by David Majnemer. llvm-svn: 228782
* IR: Take uint64_t in DIBuilder::createExpression()Duncan P. N. Exon Smith2015-02-091-1/+1
| | | | | | | | | | | `DIExpression` deals with `uint64_t`, so it doesn't make sense that `createExpression()` is created from `int64_t`. Switch to `uint64_t` to unify them. I've temporarily left in the `int64_t` version, which forwards to the `uint64_t` version. I'll delete it once I've updated the callers. llvm-svn: 228619
* Correctly combine alias.scope metadata by a union instead of intersectingBjorn Steinbrink2015-02-081-0/+2
| | | | | | | | | | | | | | | | | Summary: The alias.scope metadata represents sets of things an instruction might alias with. When generically combining the metadata from two instructions the result must be the union of the original sets, because the new instruction might alias with anything any of the original instructions aliased with. Reviewers: hfinkel Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D7490 llvm-svn: 228525
* Inliner: Use replaceDbgDeclareForAlloca() instead of splicing theAdrian Prantl2015-01-301-12/+16
| | | | | | | instruction and generalize it to optionally dereference the variable. Follow-up to r227544. llvm-svn: 227604
* Make ConstantFoldTerminator() handle switches with unreachable default.Hans Wennborg2015-01-261-4/+10
| | | | | | | | Tested by Transforms/SimplifyCFG/switch-to-br.ll's @unreachable function. Differential Revision: http://reviews.llvm.org/D6471 llvm-svn: 227124
* [PM] Replace the Pass argument in MergeBasicBlockIntoOnlyPred withChandler Carruth2015-01-201-9/+5
| | | | | | | | | | a DominatorTree argument as that is the analysis that it wants to update. This removes the last non-loop utility function in Utils/ which accepts a raw Pass argument. llvm-svn: 226537
* [PM] Split the AssumptionTracker immutable pass into two separate APIs:Chandler Carruth2015-01-041-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | a cache of assumptions for a single function, and an immutable pass that manages those caches. The motivation for this change is two fold. Immutable analyses are really hacks around the current pass manager design and don't exist in the new design. This is usually OK, but it requires that the core logic of an immutable pass be reasonably partitioned off from the pass logic. This change does precisely that. As a consequence it also paves the way for the *many* utility functions that deal in the assumptions to live in both pass manager worlds by creating an separate non-pass object with its own independent API that they all rely on. Now, the only bits of the system that deal with the actual pass mechanics are those that actually need to deal with the pass mechanics. Once this separation is made, several simplifications become pretty obvious in the assumption cache itself. Rather than using a set and callback value handles, it can just be a vector of weak value handles. The callers can easily skip the handles that are null, and eventually we can wrap all of this up behind a filter iterator. For now, this adds boiler plate to the various passes, but this kind of boiler plate will end up making it possible to port these passes to the new pass manager, and so it will end up factored away pretty reasonably. llvm-svn: 225131
* Remove unneeded curly braces.Frederic Riss2014-12-091-4/+2
| | | | llvm-svn: 223809
* Reorder the code to avoid inserting at the beginning of a vector.Frederic Riss2014-12-091-1/+1
| | | | | | As per dblaikie suggestion, thanks\! llvm-svn: 223808
* IR: Split Metadata from ValueDuncan P. N. Exon Smith2014-12-091-8/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Correctly handle complex locations expressions in replaceDbgDeclareForAlloca()Frederic Riss2014-12-091-2/+2
| | | | | | | | | | | | | | | | replaceDbgDeclareForAlloca() replaces an alloca by a value storing the address of what was the alloca. If there is a dbg.declare corresponding to that alloca, we need to lower it to a dbg.value describing the additional dereference operation to be performed to get to the underlying variable. This is done by adding a DW_OP_deref to the complex location part of the location description. This deref was added to the end of the operation list, which is wrong. The expression applies to what is described by the dbg.{declare,value}, and as we are changing this, we need to apply the DW_OP_deref as the first operation in the list. Part of the fix for rdar://19162268. llvm-svn: 223799
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