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* CodeGen: Move TargetPassConfig from Passes.h to an own header; NFCMatthias Braun2016-05-101-821/+0
| | | | | | | | Many files include Passes.h but only a fraction needs to know about the TargetPassConfig class. Move it into an own header. Also rename Passes.cpp to TargetPassConfig.cpp while we are at it. llvm-svn: 269011
* CodeGen: Add DetectDeadLanes pass.Matthias Braun2016-04-281-0/+2
| | | | | | | | | | | | | | | | | | | | The DetectDeadLanes pass performs a dataflow analysis of used/defined subregister lanes across COPY instructions and instructions that will get lowered to copies. It detects dead definitions and uses reading undefined values which are obscured by COPY and subregister usage. These dead definitions cause trouble in the register coalescer which cannot deal with definitions suddenly becoming dead after coalescing COPY instructions. For now the pass only adds dead and undef flags to machine operands. It should be possible to extend it in the future to remove the dead instructions and redo the analysis for the affected virtual registers. Differential Revision: http://reviews.llvm.org/D18427 llvm-svn: 267851
* Introduce a "patchable-function" function attributeSanjoy Das2016-04-191-0/+2
| | | | | | | | | | | | | | | | | Summary: The `"patchable-function"` attribute can be used by an LLVM client to influence LLVM's code generation in ways that makes the generated code easily patchable at runtime (for instance, to redirect control). Right now only one patchability scheme is supported, `"prologue-short-redirect"`, but this can be expanded in the future. Reviewers: joker.eph, rnk, echristo, dberris Subscribers: joker.eph, echristo, mcrosier, llvm-commits Differential Revision: http://reviews.llvm.org/D19046 llvm-svn: 266715
* Remove extra whitespace. NFC.Junmo Park2016-01-181-2/+2
| | | | llvm-svn: 258035
* Recommit LiveDebugValues pass after fixing a couple of minor issues.Vikram TV2015-12-161-0/+1
| | | | llvm-svn: 255759
* [PostRA scheduling] Allow a target to do scheduling when it wants post RA.Jonas Paulsson2015-12-101-5/+8
| | | | | | | | | | | | | | SystemZ needs to do its scheduling after branch relaxation, which can only happen after block placement, and therefore the standard PostRAScheduler point in the pass sequence is too early. TargetMachine::targetSchedulesPostRAScheduling() is a new method that signals on returning true that target will insert the final scheduling pass on its own. Reviewed by Hal Finkel llvm-svn: 255234
* Revert "Implement a new pass - LiveDebugValues - to compute the set of live ↵Mehdi Amini2015-12-091-1/+0
| | | | | | | | | | | DEBUG_VALUEs at each basic block and insert them. Reviewed and accepted at: http://reviews.llvm.org/D11933" This reverts commit r255096. Break the bots: http://lab.llvm.org:8080/green/job/clang-stage1-cmake-RA-incremental_check/16378/ From: Mehdi Amini <mehdi.amini@apple.com> llvm-svn: 255101
* Implement a new pass - LiveDebugValues - to compute the set of live ↵Vikram TV2015-12-091-0/+1
| | | | | | DEBUG_VALUEs at each basic block and insert them. Reviewed and accepted at: http://reviews.llvm.org/D11933 llvm-svn: 255096
* Enable verifier after PeepholeOptimizerMatt Arsenault2015-10-121-1/+1
| | | | | | | No tests fail with this enabled so I assume it was an accident that it isn't enabled now. llvm-svn: 250070
* CodeGen: print and verify after TargetPassConfig::insertPass by defaultJustin Bogner2015-10-081-19/+31
| | | | | | | | | | | | | | In r224059, we started verifying after addPass, but missed doing so on insertPass. There isn't a good reason for the discrepancy, and skipping the verifier in these cases causes bugs. This also exposes a verifier error that was introduced in r249087, but the verifier doesn't run until after the register coalescer, when the issue happens to have been resolved. I've skipped the verifier after SIFixSGPRLiveRangesID to avoid the failures for now and will follow up with Matt for a proper fix. llvm-svn: 249643
* Android support for SafeStack.Evgeniy Stepanov2015-09-231-1/+1
| | | | | | | | | | | | | | | | | Add two new ways of accessing the unsafe stack pointer: * At a fixed offset from the thread TLS base. This is very similar to StackProtector cookies, but we plan to extend it to other backends (ARM in particular) soon. Bionic-side implementation here: https://android-review.googlesource.com/170988. * Via a function call, as a fallback for platforms that provide neither a fixed TLS slot, nor a reasonable TLS implementation (i.e. not emutls). This is a re-commit of a change in r248357 that was reverted in r248358. llvm-svn: 248405
* Revert "Android support for SafeStack."Evgeniy Stepanov2015-09-231-1/+1
| | | | | | | test/Transforms/SafeStack/abi.ll breaks when target is not supported; needs refactoring. llvm-svn: 248358
* Android support for SafeStack.Evgeniy Stepanov2015-09-231-1/+1
| | | | | | | | | | | | | | Add two new ways of accessing the unsafe stack pointer: * At a fixed offset from the thread TLS base. This is very similar to StackProtector cookies, but we plan to extend it to other backends (ARM in particular) soon. Bionic-side implementation here: https://android-review.googlesource.com/170988. * Via a function call, as a fallback for platforms that provide neither a fixed TLS slot, nor a reasonable TLS implementation (i.e. not emutls). llvm-svn: 248357
* [WinEH] Add a funclet layout passDavid Majnemer2015-09-171-0/+2
| | | | | | | | | Windows EH funclets need to be contiguous. The FuncletLayout pass will ensure that the funclets are together and begin with a funclet entry MBB. Differential Revision: http://reviews.llvm.org/D12943 llvm-svn: 247937
* [PM/AA] Rebuild LLVM's alias analysis infrastructure in a way compatibleChandler Carruth2015-09-091-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | with the new pass manager, and no longer relying on analysis groups. This builds essentially a ground-up new AA infrastructure stack for LLVM. The core ideas are the same that are used throughout the new pass manager: type erased polymorphism and direct composition. The design is as follows: - FunctionAAResults is a type-erasing alias analysis results aggregation interface to walk a single query across a range of results from different alias analyses. Currently this is function-specific as we always assume that aliasing queries are *within* a function. - AAResultBase is a CRTP utility providing stub implementations of various parts of the alias analysis result concept, notably in several cases in terms of other more general parts of the interface. This can be used to implement only a narrow part of the interface rather than the entire interface. This isn't really ideal, this logic should be hoisted into FunctionAAResults as currently it will cause a significant amount of redundant work, but it faithfully models the behavior of the prior infrastructure. - All the alias analysis passes are ported to be wrapper passes for the legacy PM and new-style analysis passes for the new PM with a shared result object. In some cases (most notably CFL), this is an extremely naive approach that we should revisit when we can specialize for the new pass manager. - BasicAA has been restructured to reflect that it is much more fundamentally a function analysis because it uses dominator trees and loop info that need to be constructed for each function. All of the references to getting alias analysis results have been updated to use the new aggregation interface. All the preservation and other pass management code has been updated accordingly. The way the FunctionAAResultsWrapperPass works is to detect the available alias analyses when run, and add them to the results object. This means that we should be able to continue to respect when various passes are added to the pipeline, for example adding CFL or adding TBAA passes should just cause their results to be available and to get folded into this. The exception to this rule is BasicAA which really needs to be a function pass due to using dominator trees and loop info. As a consequence, the FunctionAAResultsWrapperPass directly depends on BasicAA and always includes it in the aggregation. This has significant implications for preserving analyses. Generally, most passes shouldn't bother preserving FunctionAAResultsWrapperPass because rebuilding the results just updates the set of known AA passes. The exception to this rule are LoopPass instances which need to preserve all the function analyses that the loop pass manager will end up needing. This means preserving both BasicAAWrapperPass and the aggregating FunctionAAResultsWrapperPass. Now, when preserving an alias analysis, you do so by directly preserving that analysis. This is only necessary for non-immutable-pass-provided alias analyses though, and there are only three of interest: BasicAA, GlobalsAA (formerly GlobalsModRef), and SCEVAA. Usually BasicAA is preserved when needed because it (like DominatorTree and LoopInfo) is marked as a CFG-only pass. I've expanded GlobalsAA into the preserved set everywhere we previously were preserving all of AliasAnalysis, and I've added SCEVAA in the intersection of that with where we preserve SCEV itself. One significant challenge to all of this is that the CGSCC passes were actually using the alias analysis implementations by taking advantage of a pretty amazing set of loop holes in the old pass manager's analysis management code which allowed analysis groups to slide through in many cases. Moving away from analysis groups makes this problem much more obvious. To fix it, I've leveraged the flexibility the design of the new PM components provides to just directly construct the relevant alias analyses for the relevant functions in the IPO passes that need them. This is a bit hacky, but should go away with the new pass manager, and is already in many ways cleaner than the prior state. Another significant challenge is that various facilities of the old alias analysis infrastructure just don't fit any more. The most significant of these is the alias analysis 'counter' pass. That pass relied on the ability to snoop on AA queries at different points in the analysis group chain. Instead, I'm planning to build printing functionality directly into the aggregation layer. I've not included that in this patch merely to keep it smaller. Note that all of this needs a nearly complete rewrite of the AA documentation. I'm planning to do that, but I'd like to make sure the new design settles, and to flesh out a bit more of what it looks like in the new pass manager first. Differential Revision: http://reviews.llvm.org/D12080 llvm-svn: 247167
* [WebAssembly] Support running without a register allocator in the default ↵Dan Gohman2015-09-081-16/+19
| | | | | | | | | | | | | CodeGen passes This allows backends which don't use a traditional register allocator, but do need PHI lowering and other passes, to use the default TargetPassConfig::addFastRegAlloc and TargetPassConfig::addOptimizedRegAlloc implementations. Differential Revision: http://reviews.llvm.org/D12691 llvm-svn: 247065
* Rework of the new interface for shrink wrappingKit Barton2015-08-311-20/+3
| | | | | | | | | | | | | | | Based on comments from Hal (http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20150810/292978.html), I've changed the interface to add a callback mechanism to the TargetFrameLowering class to query whether the specific target supports shrink wrapping. By default, shrink wrapping is disabled by default. Each target can override the default behaviour using the TargetFrameLowering::targetSupportsShrinkWrapping() method. Shrink wrapping can still be explicitly enabled or disabled from the command line, using the existing -enable-shrink-wrap=<true|false> option. Phabricator: http://reviews.llvm.org/D12293 llvm-svn: 246463
* Reverting patch r244235.Kit Barton2015-08-141-3/+21
| | | | | | | | This patch will be redone in a different way. See http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20150810/292978.html for more details. llvm-svn: 245071
* [PM/AA] Hoist the interface to TBAA into a dedicated header along withChandler Carruth2015-08-141-0/+1
| | | | | | its creation function. Update the relevant includes accordingly. llvm-svn: 245019
* [PM/AA] Hoist ScopedNoAliasAA's interface into a header and move theChandler Carruth2015-08-141-0/+1
| | | | | | | | | creation function there. Same basic refactoring as the other alias analyses. Nothing special required this time around. llvm-svn: 245012
* [PM/AA] Extract a minimal interface for CFLAA to its own header file.Chandler Carruth2015-08-141-0/+1
| | | | | | | | | | I've used forward declarations and reorderd the source code some to make this reasonably clean and keep as much of the code as possible in the source file, including all the stratified set details. Just the basic AA interface and the create function are in the header file, and the header file is now included into the relevant locations. llvm-svn: 245009
* This patch changes the interface to enable the shrink wrapping optimization. Kit Barton2015-08-061-21/+3
| | | | | | | | | | | | | | | It adds a new constructor, which takes a std::function predicate function that is run at the beginning of shrink wrapping to determine whether the optimization should run on the given machine function. The std::function can be overridden by each target, allowing target-specific decisions to be made on each machine function. This is necessary for PowerPC, as the decision to run shrink wrapping is partially based on the ABI. Futhermore, this operates nicely with the GCC iFunc capability, which allows option overrides on a per-function basis. Phabricator: http://reviews.llvm.org/D11421 llvm-svn: 244235
* [PM/AA] Hoist the interface for BasicAA into a header file.Chandler Carruth2015-08-061-0/+1
| | | | | | | | | | | | | This is the first mechanical step in preparation for making this and all the other alias analysis passes available to the new pass manager. I'm factoring out all the totally boring changes I can so I'm moving code around here with no other changes. I've even minimized the formatting churn. I'll reformat and freshen comments on the interface now that its located in the right place so that the substantive changes don't triger this. llvm-svn: 244197
* Redirect DataLayout from TargetMachine to Module in SjLjEHPrepareMehdi Amini2015-07-081-1/+1
| | | | | | | | | | | | | | | | Summary: This change is part of a series of commits dedicated to have a single DataLayout during compilation by using always the one owned by the module. Reviewers: echristo Subscribers: yaron.keren, rafael, llvm-commits Differential Revision: http://reviews.llvm.org/D11009 From: Mehdi Amini <mehdi.amini@apple.com> llvm-svn: 241654
* llc: Add a 'run-pass' option.Alex Lorenz2015-07-061-4/+6
| | | | | | | | | | | | | | | This commit adds a 'run-pass' option to llc, which instructs the compiler to run one specific code generation pass only. Llc already has the 'start-after' and the 'stop-after' options, and this new option complements the other two by making it easier to write tests that want to invoke a single pass only. Reviewers: Duncan P. N. Exon Smith Differential Revision: http://reviews.llvm.org/D10776 llvm-svn: 241476
* Protection against stack-based memory corruption errors using SafeStackPeter Collingbourne2015-06-151-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* [CodeGen] Add a pass to fold null checks into nearby memory operations.Sanjoy Das2015-06-151-0/+7
| | | | | | | | | | | | | | | | | | | | | Summary: This change adds an "ImplicitNullChecks" target dependent pass. This pass folds null checks into memory operation using the FAULTING_LOAD pseudo-op introduced in previous patches. Depends on D10197 Depends on D10199 Depends on D10200 Reviewers: reames, rnk, pgavlin, JosephTremoulet, atrick Reviewed By: atrick Subscribers: ab, JosephTremoulet, llvm-commits Differential Revision: http://reviews.llvm.org/D10201 llvm-svn: 239743
* Move the code in TargetPassConfig::addPass that inserts machine printer pass toAkira Hatanaka2015-06-051-16/+18
| | | | | | | | | | | the overloaded version of addPass which takes Pass*. This change enables inserting the machine printer pass when the overloaded version of addPass that takes Pass* is called to add a pass, instead of the one which takes AnalysisID. I need this to prevent make-check tests from failing when I commit another patch later. llvm-svn: 239192
* [ShrinkWrap] Add (a simplified version) of shrink-wrapping.Quentin Colombet2015-05-051-5/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces a new pass that computes the safe point to insert the prologue and epilogue of the function. The interest is to find safe points that are cheaper than the entry and exits blocks. As an example and to avoid regressions to be introduce, this patch also implements the required bits to enable the shrink-wrapping pass for AArch64. ** Context ** Currently we insert the prologue and epilogue of the method/function in the entry and exits blocks. Although this is correct, we can do a better job when those are not immediately required and insert them at less frequently executed places. The job of the shrink-wrapping pass is to identify such places. ** Motivating example ** Let us consider the following function that perform a call only in one branch of a if: define i32 @f(i32 %a, i32 %b) { %tmp = alloca i32, align 4 %tmp2 = icmp slt i32 %a, %b br i1 %tmp2, label %true, label %false true: store i32 %a, i32* %tmp, align 4 %tmp4 = call i32 @doSomething(i32 0, i32* %tmp) br label %false false: %tmp.0 = phi i32 [ %tmp4, %true ], [ %a, %0 ] ret i32 %tmp.0 } On AArch64 this code generates (removing the cfi directives to ease readabilities): _f: ; @f ; BB#0: stp x29, x30, [sp, #-16]! mov x29, sp sub sp, sp, #16 ; =16 cmp w0, w1 b.ge LBB0_2 ; BB#1: ; %true stur w0, [x29, #-4] sub x1, x29, #4 ; =4 mov w0, wzr bl _doSomething LBB0_2: ; %false mov sp, x29 ldp x29, x30, [sp], #16 ret With shrink-wrapping we could generate: _f: ; @f ; BB#0: cmp w0, w1 b.ge LBB0_2 ; BB#1: ; %true stp x29, x30, [sp, #-16]! mov x29, sp sub sp, sp, #16 ; =16 stur w0, [x29, #-4] sub x1, x29, #4 ; =4 mov w0, wzr bl _doSomething add sp, x29, #16 ; =16 ldp x29, x30, [sp], #16 LBB0_2: ; %false ret Therefore, we would pay the overhead of setting up/destroying the frame only if we actually do the call. ** Proposed Solution ** This patch introduces a new machine pass that perform the shrink-wrapping analysis (See the comments at the beginning of ShrinkWrap.cpp for more details). It then stores the safe save and restore point into the MachineFrameInfo attached to the MachineFunction. This information is then used by the PrologEpilogInserter (PEI) to place the related code at the right place. This pass runs right before the PEI. Unlike the original paper of Chow from PLDI’88, this implementation of shrink-wrapping does not use expensive data-flow analysis and does not need hack to properly avoid frequently executed point. Instead, it relies on dominance and loop properties. The pass is off by default and each target can opt-in by setting the EnableShrinkWrap boolean to true in their derived class of TargetPassConfig. This setting can also be overwritten on the command line by using -enable-shrink-wrap. Before you try out the pass for your target, make sure you properly fix your emitProlog/emitEpilog/adjustForXXX method to cope with basic blocks that are not necessarily the entry block. ** Design Decisions ** 1. ShrinkWrap is its own pass right now. It could frankly be merged into PEI but for debugging and clarity I thought it was best to have its own file. 2. Right now, we only support one save point and one restore point. At some point we can expand this to several save point and restore point, the impacted component would then be: - The pass itself: New algorithm needed. - MachineFrameInfo: Hold a list or set of Save/Restore point instead of one pointer. - PEI: Should loop over the save point and restore point. Anyhow, at least for this first iteration, I do not believe this is interesting to support the complex cases. We should revisit that when we motivating examples. Differential Revision: http://reviews.llvm.org/D9210 <rdar://problem/3201744> llvm-svn: 236507
* Re-sort includes with sort-includes.py and insert raw_ostream.h where it's used.Benjamin Kramer2015-03-231-0/+1
| | | | llvm-svn: 232998
* Verifier: Remove the separate -verify-di passDuncan P. N. Exon Smith2015-03-191-9/+1
| | | | | | | | | | | | | | 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
* Remove unused headers.Eric Christopher2015-03-121-2/+0
| | | | llvm-svn: 232102
* Stop calling DwarfEHPrepare from WinEHPrepareReid Kleckner2015-03-121-0/+4
| | | | | | | | Instead, run both EH preparation passes, and have them both ignore functions with unrecognized EH personalities. Pass delegation involved some hacky code for creating an AnalysisResolver that we don't need now. llvm-svn: 231995
* Remove useMachineScheduler and replace it with subtarget optionsEric Christopher2015-03-111-33/+0
| | | | | | | | | | | | | that control, individually, all of the disparate things it was controlling. At the same time move a FIXME in the Hexagon port to a new subtarget function that will enable a user of the machine scheduler to avoid using the source scheduler for pre-RA-scheduling. The FIXME would have this removed, but involves either testcase changes or adding -pre-RA-sched=source to a few testcases. llvm-svn: 231980
* [PM] Remove the old 'PassManager.h' header file at the top level ofChandler Carruth2015-02-131-1/+1
| | | | | | | | | | | | | | | | | | | | LLVM's include tree and the use of using declarations to hide the 'legacy' namespace for the old pass manager. This undoes the primary modules-hostile change I made to keep out-of-tree targets building. I sent an email inquiring about whether this would be reasonable to do at this phase and people seemed fine with it, so making it a reality. This should allow us to start bootstrapping with modules to a certain extent along with making it easier to mix and match headers in general. The updates to any code for users of LLVM are very mechanical. Switch from including "llvm/PassManager.h" to "llvm/IR/LegacyPassManager.h". Qualify the types which now produce compile errors with "legacy::". The most common ones are "PassManager", "PassManagerBase", and "FunctionPassManager". llvm-svn: 229094
* Remove a gross usage of environment variables in MachineVerifier, replacing ↵Owen Anderson2015-02-041-1/+3
| | | | | | | | it with support for setting the -verify-machineinstrs flag via an environment variable in LIT. This preserves the handy functionality of force-enabling the MachineVerifier, without the need to embed usage of environment variables in LLVM client applications. llvm-svn: 228079
* Add a Windows EH preparation pass that zaps resumesReid Kleckner2015-01-291-1/+3
| | | | | | | | | | | | | | | | | | | If the personality is not a recognized MSVC personality function, this pass delegates to the dwarf EH preparation pass. This chaining supports people on *-windows-itanium or *-windows-gnu targets. Currently this recognizes some personalities used by MSVC and turns resume instructions into traps to avoid link errors. Even if cleanups are not used in the source program, LLVM requires the frontend to emit a code path that resumes unwinding after an exception. Clang does this, and we get unreachable resume instructions. PR20300 covers cleaning up these unreachable calls to resume. Reviewers: majnemer Differential Revision: http://reviews.llvm.org/D7216 llvm-svn: 227405
* Remove gc.root's performCustomLoweringPhilip Reames2015-01-281-0/+3
| | | | | | | | | | | | | | This is a refactoring to restructure the single user of performCustomLowering as a specific lowering pass and remove the custom lowering hook entirely. Before this change, the LowerIntrinsics pass (note to self: rename!) was essentially acting as a pass manager, but without being structured in terms of passes. Instead, it proxied calls to a set of GCStrategies internally. This adds a lot of conceptual complexity (i.e. GCStrategies are stateful!) for very little benefit. Since there's been interest in keeping the ShadowStackGC working, I extracting it's custom lowering pass into a dedicated pass and just added that to the pass order. It will only run for functions which opt-in to that gc. I wasn't able to find an easy way to preserve the runtime registration of custom lowering functionality. Given that no user of this exists that I'm aware of, I made the choice to just remove that. If someone really cares, we can look at restoring it via dynamic pass registration in the future. Note that despite the large diff, none of the lowering code actual changes. I added the framing needed to make it a pass and rename the class, but that's it. Differential Revision: http://reviews.llvm.org/D7218 llvm-svn: 227351
* Update a few calls to getSubtarget<> to either be getSubtargetImplEric Christopher2015-01-271-1/+1
| | | | | | | when we didn't need the cast to the base class or the cached version off of the subtarget. llvm-svn: 227176
* Classify functions by EH personality type rather than using the tripleReid Kleckner2015-01-231-2/+1
| | | | | | | | | | | | | | | This mostly reverts commit r222062 and replaces it with a new enum. At some point this enum will grow at least for other MSVC EH personalities. Also beefs up the way we were sniffing the personality function. Previously we would emit the Itanium LSDA despite using __C_specific_handler. Reviewers: majnemer Differential Revision: http://reviews.llvm.org/D6987 llvm-svn: 226920
* Move ownership of GCStrategy objects to LLVMContextPhilip Reames2015-01-161-1/+0
| | | | | | | | | | | | Note: This change ended up being slightly more controversial than expected. Chandler has tentatively okayed this for the moment, but I may be revisiting this in the near future after we settle some high level questions. Rather than have the GCStrategy object owned by the GCModuleInfo - which is an immutable analysis pass used mainly by gc.root - have it be owned by the LLVMContext. This simplifies the ownership logic (i.e. can you have two instances of the same strategy at once?), but more importantly, allows us to access the GCStrategy in the middle end optimizer. To this end, I add an accessor through Function which becomes the canonical way to get at a GCStrategy instance. In the near future, this will allows me to move some of the checks from http://reviews.llvm.org/D6808 into the Verifier itself, and to introduce optimization legality predicates for some of the recent additions to InstCombine. (These will follow as separate changes.) Differential Revision: http://reviews.llvm.org/D6811 llvm-svn: 226311
* Revert "Insert random noops to increase security against ROP attacks (llvm)"JF Bastien2015-01-141-3/+0
| | | | | | | This reverts commit: http://reviews.llvm.org/D3392 llvm-svn: 225948
* Insert random noops to increase security against ROP attacks (llvm)JF Bastien2015-01-141-0/+3
| | | | | | | | | | | | | | | | | | | | A pass that adds random noops to X86 binaries to introduce diversity with the goal of increasing security against most return-oriented programming attacks. Command line options: -noop-insertion // Enable noop insertion. -noop-insertion-percentage=X // X% of assembly instructions will have a noop prepended (default: 50%, requires -noop-insertion) -max-noops-per-instruction=X // Randomly generate X noops per instruction. ie. roll the dice X times with probability set above (default: 1). This doesn't guarantee X noop instructions. In addition, the following 'quick switch' in clang enables basic diversity using default settings (currently: noop insertion and schedule randomization; it is intended to be extended in the future). -fdiversify This is the llvm part of the patch. clang part: D3393 http://reviews.llvm.org/D3392 Patch by Stephen Crane (@rinon) llvm-svn: 225908
* CodeGen support for x86_64 SEH catch handlers in LLVMReid Kleckner2015-01-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds handling for ExceptionHandling::MSVC, used by the x86_64-pc-windows-msvc triple. It assumes that filter functions have already been outlined in either the frontend or the backend. Filter functions are used in place of the landingpad catch clause type info operands. In catch clause order, the first filter to return true will catch the exception. The C specific handler table expects the landing pad to be split into one block per handler, but LLVM IR uses a single landing pad for all possible unwind actions. This patch papers over the mismatch by synthesizing single instruction BBs for every catch clause to fill in the EH selector that the landing pad block expects. Missing functionality: - Accessing data in the parent frame from outlined filters - Cleanups (from __finally) are unsupported, as they will require outlining and parent frame access - Filter clauses are unsupported, as there's no clear analogue in SEH In other words, this is the minimal set of changes needed to write IR to catch arbitrary exceptions and resume normal execution. Reviewers: majnemer Differential Revision: http://reviews.llvm.org/D6300 llvm-svn: 225904
* Add the ExceptionHandling::MSVC enumerationReid Kleckner2014-12-191-0/+1
| | | | | | | | | | | | | | | It is intended to be used for a family of personality functions that have similar IR preparation requirements. Typically when interoperating with MSVC personality functions, bits of functionality need to be outlined from the main function into helper functions. There is also usually more than one landing pad per invoke, which does not match the LLVM IR landingpad representation. None of this is implemented yet. This change just adds a new enum that is active for *-windows-msvc and delegates to the EH removal preparation pass. No functionality change for other targets. llvm-svn: 224625
* Rename argument strings of codegen passes to avoid collisions with command lineAkira Hatanaka2014-12-131-1/+1
| | | | | | | | | | | | | | | | | | | | options. This commit changes the command line arguments (PassInfo::PassArgument) of two passes, MachineFunctionPrinter and MachineScheduler, to avoid collisions with command line options that have the same argument strings. This bug manifests when the PassList construct (defined in opt.cpp) is used in a tool that links with codegen passes. To reproduce the bug, paste the following lines into llc.cpp and run llc. #include "llvm/IR/LegacyPassNameParser.h" static llvm::cl::list<const llvm::PassInfo*, bool, llvm::PassNameParser> PassList(llvm::cl::desc("Optimizations available:")); rdar://problem/19212448 llvm-svn: 224186
* [CodeGen] Add print and verify pass after each MachineFunctionPass by defaultMatthias Braun2014-12-111-68/+66
| | | | | | | | | | | | | | | | | | | Previously print+verify passes were added in a very unsystematic way, which is annoying when debugging as you miss intermediate steps and allows bugs to stay unnotice when no verification is performed. To make this change practical I added the possibility to explicitely disable verification. I used this option on all places where no verification was performed previously (because alot of places actually don't pass the MachineVerifier). In the long term these problems should be fixed properly and verification enabled after each pass. I'll enable some more verification in subsequent commits. This is the 2nd attempt at this after realizing that PassManager::add() may actually delete the pass. llvm-svn: 224059
* This reverts commit r224043 and r224042.Rafael Espindola2014-12-111-63/+68
| | | | | | check-llvm was failing. llvm-svn: 224045
* [CodeGen] Add print and verify pass after each MachineFunctionPass by defaultMatthias Braun2014-12-111-68/+63
| | | | | | | | | | | | | | | | Previously print+verify passes were added in a very unsystematic way, which is annoying when debugging as you miss intermediate steps and allows bugs to stay unnotice when no verification is performed. To make this change practical I added the possibility to explicitely disable verification. I used this option on all places where no verification was performed previously (because alot of places actually don't pass the MachineVerifier). In the long term these problems should be fixed properly and verification enabled after each pass. I'll enable some more verification in subsequent commits. llvm-svn: 224042
* Add a print and verify pass after the RegisterCoalescerMatthias Braun2014-11-191-0/+1
| | | | llvm-svn: 222381
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