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* [opt] Port the debugify passes to the new pass managerVedant Kumar2018-02-151-4/+1
| | | | llvm-svn: 325294
* Pass a module reference to CloneModule.Rafael Espindola2018-02-141-4/+4
| | | | | | | It can never be null and most callers were already using references or std::unique_ptr. llvm-svn: 325160
* LLParser: add an argument for overriding data layout and do not check alloca ↵Yaxun Liu2018-01-301-7/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | addr space Sometimes users do not specify data layout in LLVM assembly and let llc set the data layout by target triple after loading the LLVM assembly. Currently the parser checks alloca address space no matter whether the LLVM assembly contains data layout definition, which causes false alarm since the default data layout does not contain the correct alloca address space. The parser also calls verifier to check debug info and updating invalid debug info. Currently there is no way to let the verifier to check debug info only. If the verifier finds non-debug-info issues the parser will fail. For llc, the fix is to remove the check of alloca addr space in the parser and disable updating debug info, and defer the updating of debug info and verification to be after setting data layout of the IR by target. For other llvm tools, since they do not override data layout by target but instead can override data layout by a command line option, an argument for overriding data layout is added to the parser. In cases where data layout overriding is necessary for the parser, the data layout can be provided by command line. Differential Revision: https://reviews.llvm.org/D41832 llvm-svn: 323826
* Another try to commit 323321 (aggressive instruction combine).Amjad Aboud2018-01-251-0/+1
| | | | llvm-svn: 323416
* Reverted 323321.Amjad Aboud2018-01-241-1/+0
| | | | llvm-svn: 323326
* [InstCombine] Introducing Aggressive Instruction Combine pass ↵Amjad Aboud2018-01-241-0/+1
| | | | | | | | | | | | | | | | | | (-aggressive-instcombine). Combine expression patterns to form expressions with fewer, simple instructions. This pass does not modify the CFG. For example, this pass reduce width of expressions post-dominated by TruncInst into smaller width when applicable. It differs from instcombine pass in that it contains pattern optimization that requires higher complexity than the O(1), thus, it should run fewer times than instcombine pass. Differential Revision: https://reviews.llvm.org/D38313 llvm-svn: 323321
* [Debugify] Add a mode to opt to enable faster testingVedant Kumar2018-01-231-0/+14
| | | | | | | | | | | | | | | | | | Opt's "-enable-debugify" mode adds an instance of Debugify at the beginning of the pass pipeline, and an instance of CheckDebugify at the end. You can enable this mode with lit using: -Dopt="opt -enable-debugify". Note that running test suites in this mode will result in many failures due to strict FileCheck commands, etc. It can be more useful to look for assertion failures which arise only when Debugify is enabled, e.g to prove that we have (or do not have) test coverage for some code path with debug info present. Differential Revision: https://reviews.llvm.org/D41793 llvm-svn: 323256
* Introduce the "retpoline" x86 mitigation technique for variant #2 of the ↵Chandler Carruth2018-01-221-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | speculative execution vulnerabilities disclosed today, specifically identified by CVE-2017-5715, "Branch Target Injection", and is one of the two halves to Spectre.. Summary: First, we need to explain the core of the vulnerability. Note that this is a very incomplete description, please see the Project Zero blog post for details: https://googleprojectzero.blogspot.com/2018/01/reading-privileged-memory-with-side.html The basis for branch target injection is to direct speculative execution of the processor to some "gadget" of executable code by poisoning the prediction of indirect branches with the address of that gadget. The gadget in turn contains an operation that provides a side channel for reading data. Most commonly, this will look like a load of secret data followed by a branch on the loaded value and then a load of some predictable cache line. The attacker then uses timing of the processors cache to determine which direction the branch took *in the speculative execution*, and in turn what one bit of the loaded value was. Due to the nature of these timing side channels and the branch predictor on Intel processors, this allows an attacker to leak data only accessible to a privileged domain (like the kernel) back into an unprivileged domain. The goal is simple: avoid generating code which contains an indirect branch that could have its prediction poisoned by an attacker. In many cases, the compiler can simply use directed conditional branches and a small search tree. LLVM already has support for lowering switches in this way and the first step of this patch is to disable jump-table lowering of switches and introduce a pass to rewrite explicit indirectbr sequences into a switch over integers. However, there is no fully general alternative to indirect calls. We introduce a new construct we call a "retpoline" to implement indirect calls in a non-speculatable way. It can be thought of loosely as a trampoline for indirect calls which uses the RET instruction on x86. Further, we arrange for a specific call->ret sequence which ensures the processor predicts the return to go to a controlled, known location. The retpoline then "smashes" the return address pushed onto the stack by the call with the desired target of the original indirect call. The result is a predicted return to the next instruction after a call (which can be used to trap speculative execution within an infinite loop) and an actual indirect branch to an arbitrary address. On 64-bit x86 ABIs, this is especially easily done in the compiler by using a guaranteed scratch register to pass the target into this device. For 32-bit ABIs there isn't a guaranteed scratch register and so several different retpoline variants are introduced to use a scratch register if one is available in the calling convention and to otherwise use direct stack push/pop sequences to pass the target address. This "retpoline" mitigation is fully described in the following blog post: https://support.google.com/faqs/answer/7625886 We also support a target feature that disables emission of the retpoline thunk by the compiler to allow for custom thunks if users want them. These are particularly useful in environments like kernels that routinely do hot-patching on boot and want to hot-patch their thunk to different code sequences. They can write this custom thunk and use `-mretpoline-external-thunk` *in addition* to `-mretpoline`. In this case, on x86-64 thu thunk names must be: ``` __llvm_external_retpoline_r11 ``` or on 32-bit: ``` __llvm_external_retpoline_eax __llvm_external_retpoline_ecx __llvm_external_retpoline_edx __llvm_external_retpoline_push ``` And the target of the retpoline is passed in the named register, or in the case of the `push` suffix on the top of the stack via a `pushl` instruction. There is one other important source of indirect branches in x86 ELF binaries: the PLT. These patches also include support for LLD to generate PLT entries that perform a retpoline-style indirection. The only other indirect branches remaining that we are aware of are from precompiled runtimes (such as crt0.o and similar). The ones we have found are not really attackable, and so we have not focused on them here, but eventually these runtimes should also be replicated for retpoline-ed configurations for completeness. For kernels or other freestanding or fully static executables, the compiler switch `-mretpoline` is sufficient to fully mitigate this particular attack. For dynamic executables, you must compile *all* libraries with `-mretpoline` and additionally link the dynamic executable and all shared libraries with LLD and pass `-z retpolineplt` (or use similar functionality from some other linker). We strongly recommend also using `-z now` as non-lazy binding allows the retpoline-mitigated PLT to be substantially smaller. When manually apply similar transformations to `-mretpoline` to the Linux kernel we observed very small performance hits to applications running typical workloads, and relatively minor hits (approximately 2%) even for extremely syscall-heavy applications. This is largely due to the small number of indirect branches that occur in performance sensitive paths of the kernel. When using these patches on statically linked applications, especially C++ applications, you should expect to see a much more dramatic performance hit. For microbenchmarks that are switch, indirect-, or virtual-call heavy we have seen overheads ranging from 10% to 50%. However, real-world workloads exhibit substantially lower performance impact. Notably, techniques such as PGO and ThinLTO dramatically reduce the impact of hot indirect calls (by speculatively promoting them to direct calls) and allow optimized search trees to be used to lower switches. If you need to deploy these techniques in C++ applications, we *strongly* recommend that you ensure all hot call targets are statically linked (avoiding PLT indirection) and use both PGO and ThinLTO. Well tuned servers using all of these techniques saw 5% - 10% overhead from the use of retpoline. We will add detailed documentation covering these components in subsequent patches, but wanted to make the core functionality available as soon as possible. Happy for more code review, but we'd really like to get these patches landed and backported ASAP for obvious reasons. We're planning to backport this to both 6.0 and 5.0 release streams and get a 5.0 release with just this cherry picked ASAP for distros and vendors. This patch is the work of a number of people over the past month: Eric, Reid, Rui, and myself. I'm mailing it out as a single commit due to the time sensitive nature of landing this and the need to backport it. Huge thanks to everyone who helped out here, and everyone at Intel who helped out in discussions about how to craft this. Also, credit goes to Paul Turner (at Google, but not an LLVM contributor) for much of the underlying retpoline design. Reviewers: echristo, rnk, ruiu, craig.topper, DavidKreitzer Subscribers: sanjoy, emaste, mcrosier, mgorny, mehdi_amini, hiraditya, llvm-commits Differential Revision: https://reviews.llvm.org/D41723 llvm-svn: 323155
* Rename CommandFlags.h -> CommandFlags.defDavid Blaikie2017-11-271-1/+1
| | | | | | | | | Since this isn't a real header - it includes static functions and had external linkage variables (though this change makes them static, since that's what they should be) so can't be included more than once in a program. llvm-svn: 319082
* Rename CountingFunctionInserter and use for both mcount and cygprofile ↵Hans Wennborg2017-11-141-1/+2
| | | | | | | | | | | | | | | | | | | | | | calls, before and after inlining Clang implements the -finstrument-functions flag inherited from GCC, which inserts calls to __cyg_profile_func_{enter,exit} on function entry and exit. This is useful for getting a trace of how the functions in a program are executed. Normally, the calls remain even if a function is inlined into another function, but it is useful to be able to turn this off for users who are interested in a lower-level trace, i.e. one that reflects what functions are called post-inlining. (We use this to generate link order files for Chromium.) LLVM already has a pass for inserting similar instrumentation calls to mcount(), which it does after inlining. This patch renames and extends that pass to handle calls both to mcount and the cygprofile functions, before and/or after inlining as controlled by function attributes. Differential Revision: https://reviews.llvm.org/D39287 llvm-svn: 318195
* re-land [ExpandMemCmp] Split ExpandMemCmp from CodeGen into its own pass."Clement Courbet2017-11-031-0/+1
| | | | | | Fix undefined references: ExpandMemCmp belongs to CodeGen/, not Scalar/. llvm-svn: 317318
* [opt] Initialize WriteBitcode pass.Michael Kruse2017-10-241-0/+1
| | | | | | | | | | | | | | | Probably due to a change of how some pass initializes its dependencies, the -write-bitcode pass (Bitcode/Writer/BitcodeWriterPass.cpp) is not initialized in opt anymore and therefore not usable with opt -write-bitcode Explicitly call initializeWriteBitcodePassPass() to make it available in opt again. Differential Revision: https://reviews.llvm.org/D39223 llvm-svn: 316464
* Revert "TargetMachine: Merge TargetMachine and LLVMTargetMachine"Matthias Braun2017-10-121-3/+4
| | | | | | | | | | Reverting to investigate layering effects of MCJIT not linking libCodeGen but using TargetMachine::getNameWithPrefix() breaking the lldb bots. This reverts commit r315633. llvm-svn: 315637
* TargetMachine: Merge TargetMachine and LLVMTargetMachineMatthias Braun2017-10-121-4/+3
| | | | | | | | | | | | | | | Merge LLVMTargetMachine into TargetMachine. - There is no in-tree target anymore that just implements TargetMachine but not LLVMTargetMachine. - It should still be possible to stub out all the various functions in case a target does not want to use lib/CodeGen - This simplifies the code and avoids methods ending up in the wrong interface. Differential Revision: https://reviews.llvm.org/D38489 llvm-svn: 315633
* Move the stripping of invalid debug info from the Verifier to AutoUpgrade.Adrian Prantl2017-10-021-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | This came out of a recent discussion on llvm-dev (https://reviews.llvm.org/D38042). Currently the Verifier will strip the debug info metadata from a module if it finds the dbeug info to be malformed. This feature is very valuable since it allows us to improve the Verifier by making it stricter without breaking bcompatibility, but arguable the Verifier pass should not be modifying the IR. This patch moves the stripping of broken debug info into AutoUpgrade (UpgradeDebugInfo to be precise), which is a much better location for this since the stripping of malformed (i.e., produced by older, buggy versions of Clang) is a (harsh) form of AutoUpgrade. This change is mostly NFC in nature, the one big difference is the behavior when LLVM module passes are introducing malformed debug info. Prior to this patch, a NoAsserts build would have printed a warning and stripped the debug info, after this patch the Verifier will report a fatal error. I believe this behavior is actually more desirable anyway. Differential Revision: https://reviews.llvm.org/D38184 llvm-svn: 314699
* [Support] Rename tool_output_file to ToolOutputFile, NFCReid Kleckner2017-09-231-9/+9
| | | | | | | This class isn't similar to anything from the STL, so it shouldn't use the STL naming conventions. llvm-svn: 314050
* Keep Optimization Remark Yaml in NewPMSam Elliott2017-08-201-9/+10
| | | | | | | | | | | | | | | | | | | Summary: The New Pass Manager infrastructure was forgetting to keep around the optimization remark yaml file that the compiler might have been producing. This meant setting the option to '-' for stdout worked, but setting it to a filename didn't give file output (presumably it was deleted because compilation didn't explicitly keep it). This change just ensures that the file is kept if compilation succeeds. So far I have updated one of the optimization remark output tests to add a version with the new pass manager. It is my intention for this patch to also include changes to all tests that use `-opt-remark-output=` but I wanted to get the code patch ready for review while I was making all those changes. Fixes https://bugs.llvm.org/show_bug.cgi?id=33951 Reviewers: anemet, chandlerc Reviewed By: anemet, chandlerc Subscribers: javed.absar, chandlerc, fhahn, llvm-commits Differential Revision: https://reviews.llvm.org/D36906 llvm-svn: 311271
* Delete Default and JITDefault code modelsRafael Espindola2017-08-031-1/+1
| | | | | | | | | | | | | | | IMHO it is an antipattern to have a enum value that is Default. At any given piece of code it is not clear if we have to handle Default or if has already been mapped to a concrete value. In this case in particular, only the target can do the mapping and it is nice to make sure it is always done. This deletes the two default enum values of CodeModel and uses an explicit Optional<CodeModel> when it is possible that it is unspecified. llvm-svn: 309911
* [ORE] Add diagnostics hotness thresholdBrian Gesiak2017-06-301-0/+8
| | | | | | | | | | | | | | | | | | | | Summary: Add an option to prevent diagnostics that do not meet a minimum hotness threshold from being output. When generating optimization remarks for large codebases with a ton of cold code paths, this option can be used to limit the optimization remark output at a reasonable size. Discussion of this change can be read here: http://lists.llvm.org/pipermail/llvm-dev/2017-June/114377.html Reviewers: anemet, davidxl, hfinkel Reviewed By: anemet Subscribers: qcolombet, javed.absar, fhahn, eraman, llvm-commits Differential Revision: https://reviews.llvm.org/D34867 llvm-svn: 306912
* [ORE] Unify spelling as "diagnostics hotness"Brian Gesiak2017-06-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | Summary: To enable profile hotness information in diagnostics output, Clang takes the option `-fdiagnostics-show-hotness` -- that's "diagnostics", with an "s" at the end. Clang also defines `CodeGenOptions::DiagnosticsWithHotness`. LLVM, on the other hand, defines `LLVMContext::getDiagnosticHotnessRequested` -- that's "diagnostic", not "diagnostics". It's a small difference, but it's confusing, typo-inducing, and frustrating. Add a new method with the spelling "diagnostics", and "deprecate" the old spelling. Reviewers: anemet, davidxl Reviewed By: anemet Subscribers: llvm-commits, mehdi_amini Differential Revision: https://reviews.llvm.org/D34864 llvm-svn: 306848
* [ThinLTO] Migrate ThinLTOBitcodeWriter to the new PM.Tim Shen2017-06-011-2/+4
| | | | | | | | | | | | Summary: Also see D33429 for other ThinLTO + New PM related changes. Reviewers: davide, chandlerc, tejohnson Subscribers: mehdi_amini, Prazek, cfe-commits, inglorion, llvm-commits, eraman Differential Revision: https://reviews.llvm.org/D33525 llvm-svn: 304378
* [LegacyPassManager] Remove TargetMachine constructorsFrancis Visoiu Mistrih2017-05-181-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This provides a new way to access the TargetMachine through TargetPassConfig, as a dependency. The patterns replaced here are: * Passes handling a null TargetMachine call `getAnalysisIfAvailable<TargetPassConfig>`. * Passes not handling a null TargetMachine `addRequired<TargetPassConfig>` and call `getAnalysis<TargetPassConfig>`. * MachineFunctionPasses now use MF.getTarget(). * Remove all the TargetMachine constructors. * Remove INITIALIZE_TM_PASS. This fixes a crash when running `llc -start-before prologepilog`. PEI needs StackProtector, which gets constructed without a TargetMachine by the pass manager. The StackProtector pass doesn't handle the case where there is no TargetMachine, so it segfaults. Related to PR30324. Differential Revision: https://reviews.llvm.org/D33222 llvm-svn: 303360
* [X86] Relocate code of replacement of subtarget unsupported masked memory ↵Ayman Musa2017-05-151-0/+1
| | | | | | | | | | | | | | intrinsics to run also on -O0 option. Currently, when masked load, store, gather or scatter intrinsics are used, we check in CodeGenPrepare pass if the subtarget support these intrinsics, if not we replace them with scalar code - this is a functional transformation not an optimization (not optional). CodeGenPrepare pass does not run when the optimization level is set to CodeGenOpt::None (-O0). Functional transformation should run with all optimization levels, so here I created a new pass which runs on all optimization levels and does no more than this transformation. Differential Revision: https://reviews.llvm.org/D32487 llvm-svn: 303050
* Add a late IR expansion pass for the experimental reduction intrinsics.Amara Emerson2017-05-101-0/+1
| | | | | | | | | This pass uses a new target hook to decide whether or not to expand a particular intrinsic to the shuffevector sequence. Differential Revision: https://reviews.llvm.org/D32245 llvm-svn: 302631
* [CodeGen] Split SafeStack into a LegacyPass and a utility. NFC.Ahmed Bougacha2017-05-101-1/+1
| | | | | | | | | This lets the pass focus on gathering the required analyzes, and the utility class focus on the transformation. Differential Revision: https://reviews.llvm.org/D31303 llvm-svn: 302609
* [ThinLTO] Add support for emitting minimized bitcode for thin linkTeresa Johnson2017-03-231-1/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: The cumulative size of the bitcode files for a very large application can be huge, particularly with -g. In a distributed build environment, all of these files must be sent to the remote build node that performs the thin link step, and this can exceed size limits. The thin link actually only needs the summary along with a bitcode symbol table. Until we have a proper bitcode symbol table, simply stripping the debug metadata results in significant size reduction. Add support for an option to additionally emit minimized bitcode modules, just for use in the thin link step, which for now just strips all debug metadata. I plan to add a cc1 option so this can be invoked easily during the compile step. However, care must be taken to ensure that these minimized thin link bitcode files produce the same index as with the original bitcode files, as these original bitcode files will be used in the backends. Specifically: 1) The module hash used for caching is typically produced by hashing the written bitcode, and we want to include the hash that would correspond to the original bitcode file. This is because we want to ensure that changes in the stripped portions affect caching. Added plumbing to emit the same module hash in the minimized thin link bitcode file. 2) The module paths in the index are constructed from the module ID of each thin linked bitcode, and typically is automatically generated from the input file path. This is the path used for finding the modules to import from, and obviously we need this to point to the original bitcode files. Added gold-plugin support to take a suffix replacement during the thin link that is used to override the identifier on the MemoryBufferRef constructed from the loaded thin link bitcode file. The assumption is that the build system can specify that the minimized bitcode file has a name that is similar but uses a different suffix (e.g. out.thinlink.bc instead of out.o). Added various tests to ensure that we get identical index files out of the thin link step. Reviewers: mehdi_amini, pcc Subscribers: Prazek, llvm-commits Differential Revision: https://reviews.llvm.org/D31027 llvm-svn: 298638
* Do not inline hot callsites for samplepgo in thinlto compile phase.Dehao Chen2017-03-211-1/+1
| | | | | | | | | | | | | | Summary: Because SamplePGO passes will be invoked twice in ThinLTO build: once at compile phase, the other at backend. We want to make sure the IR at the 2nd phase matches the hot part in profile, thus we do not want to inline hot callsites in the first phase. Reviewers: tejohnson, eraman Reviewed By: tejohnson Subscribers: mehdi_amini, llvm-commits, Prazek Differential Revision: https://reviews.llvm.org/D31201 llvm-svn: 298428
* opt: Rename -default-data-layout flag to -data-layout and make it always ↵Peter Collingbourne2017-02-171-11/+7
| | | | | | | | | | override the layout. There isn't much point in a flag that only works if the data layout is empty. Differential Revision: https://reviews.llvm.org/D30014 llvm-svn: 295468
* Replace addEarlyAsPossiblePasses callback with adjustPassManagerStanislav Mekhanoshin2017-01-261-6/+1
| | | | | | | | | | | | | | This change introduces adjustPassManager target callback giving a target an opportunity to tweak PassManagerBuilder before pass managers are populated. This generalizes and replaces addEarlyAsPossiblePasses target callback. In particular that can be used to add custom passes to extension points other than EP_EarlyAsPossible. Differential Revision: https://reviews.llvm.org/D28336 llvm-svn: 293189
* IPO: Introduce ThinLTOBitcodeWriter pass.Peter Collingbourne2016-12-161-1/+7
| | | | | | | | | | | | | | This pass prepares a module containing type metadata for ThinLTO by splitting it into regular and thin LTO parts if possible, and writing both parts to a multi-module bitcode file. Modules that do not contain type metadata are written unmodified as a single module. All globals with type metadata are added to the regular LTO module, and the rest are added to the thin LTO module. Differential Revision: https://reviews.llvm.org/D27324 llvm-svn: 289899
* Change setDiagnosticsOutputFile to take a unique_ptr from a raw pointer (NFC)Mehdi Amini2016-11-191-1/+2
| | | | | | | | | | | | | | Summary: This makes it explicit that ownership is taken. Also replace all `new` with make_unique<> at call sites. Reviewers: anemet Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D26884 llvm-svn: 287449
* Restore "[ThinLTO] Prevent exporting of locals used/defined in module level asm"Teresa Johnson2016-11-141-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This restores the rest of r286297 (part was restored in r286475). Specifically, it restores the part requiring adding a dependency from the Analysis to Object library (downstream use changed to correctly model split BitReader vs BitWriter libraries). Original description of this part of patch follows: Module level asm may also contain defs of values. We need to prevent export of any refs to local values defined in module level asm (e.g. a ref in normal IR), since that also requires renaming/promotion of the local. To do that, the summary index builder looks at all values in the module level asm string that are not marked Weak or Global, which is exactly the set of locals that are defined. A summary is created for each of these local defs and flagged as NoRename. This required adding handling to the BitcodeWriter to look at GV declarations to see if they have a summary (rather than skipping them all). Finally, added an assert to IRObjectFile::CollectAsmUndefinedRefs to ensure that an MCAsmParser is available, otherwise the module asm parse would silently fail. Initialized the asm parser in the opt tool for use in testing this fix. Fixes PR30610. llvm-svn: 286844
* Revert "[ThinLTO] Prevent exporting of locals used/defined in module level asm"Mehdi Amini2016-11-091-1/+0
| | | | | | | | This reverts commit r286297. Introduces a dependency from libAnalysis to libObject, which I missed during the review. llvm-svn: 286329
* [ThinLTO] Prevent exporting of locals used/defined in module level asmTeresa Johnson2016-11-081-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This patch uses the same approach added for inline asm in r285513 to similarly prevent promotion/renaming of locals used or defined in module level asm. All static global values defined in normal IR and used in module level asm should be included on either the llvm.used or llvm.compiler.used global. The former were already being flagged as NoRename in the summary, and I've simply added llvm.compiler.used values to this handling. Module level asm may also contain defs of values. We need to prevent export of any refs to local values defined in module level asm (e.g. a ref in normal IR), since that also requires renaming/promotion of the local. To do that, the summary index builder looks at all values in the module level asm string that are not marked Weak or Global, which is exactly the set of locals that are defined. A summary is created for each of these local defs and flagged as NoRename. This required adding handling to the BitcodeWriter to look at GV declarations to see if they have a summary (rather than skipping them all). Finally, added an assert to IRObjectFile::CollectAsmUndefinedRefs to ensure that an MCAsmParser is available, otherwise the module asm parse would silently fail. Initialized the asm parser in the opt tool for use in testing this fix. Fixes PR30610. Reviewers: mehdi_amini Subscribers: johanengelen, krasin, llvm-commits Differential Revision: https://reviews.llvm.org/D26146 llvm-svn: 286297
* Output optimization remarks in YAMLAdam Nemet2016-09-271-0/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | (Re-committed after moving the template specialization under the yaml namespace. GCC was complaining about this.) This allows various presentation of this data using an external tool. This was first recommended here[1]. As an example, consider this module: 1 int foo(); 2 int bar(); 3 4 int baz() { 5 return foo() + bar(); 6 } The inliner generates these missed-optimization remarks today (the hotness information is pulled from PGO): remark: /tmp/s.c:5:10: foo will not be inlined into baz (hotness: 30) remark: /tmp/s.c:5:18: bar will not be inlined into baz (hotness: 30) Now with -pass-remarks-output=<yaml-file>, we generate this YAML file: --- !Missed Pass: inline Name: NotInlined DebugLoc: { File: /tmp/s.c, Line: 5, Column: 10 } Function: baz Hotness: 30 Args: - Callee: foo - String: will not be inlined into - Caller: baz ... --- !Missed Pass: inline Name: NotInlined DebugLoc: { File: /tmp/s.c, Line: 5, Column: 18 } Function: baz Hotness: 30 Args: - Callee: bar - String: will not be inlined into - Caller: baz ... This is a summary of the high-level decisions: * There is a new streaming interface to emit optimization remarks. E.g. for the inliner remark above: ORE.emit(DiagnosticInfoOptimizationRemarkMissed( DEBUG_TYPE, "NotInlined", &I) << NV("Callee", Callee) << " will not be inlined into " << NV("Caller", CS.getCaller()) << setIsVerbose()); NV stands for named value and allows the YAML client to process a remark using its name (NotInlined) and the named arguments (Callee and Caller) without parsing the text of the message. Subsequent patches will update ORE users to use the new streaming API. * I am using YAML I/O for writing the YAML file. YAML I/O requires you to specify reading and writing at once but reading is highly non-trivial for some of the more complex LLVM types. Since it's not clear that we (ever) want to use LLVM to parse this YAML file, the code supports and asserts that we're writing only. On the other hand, I did experiment that the class hierarchy starting at DiagnosticInfoOptimizationBase can be mapped back from YAML generated here (see D24479). * The YAML stream is stored in the LLVM context. * In the example, we can probably further specify the IR value used, i.e. print "Function" rather than "Value". * As before hotness is computed in the analysis pass instead of DiganosticInfo. This avoids the layering problem since BFI is in Analysis while DiagnosticInfo is in IR. [1] https://reviews.llvm.org/D19678#419445 Differential Revision: https://reviews.llvm.org/D24587 llvm-svn: 282539
* Revert "Output optimization remarks in YAML"Adam Nemet2016-09-271-23/+0
| | | | | | | | This reverts commit r282499. The GCC bots are failing llvm-svn: 282503
* Output optimization remarks in YAMLAdam Nemet2016-09-271-0/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This allows various presentation of this data using an external tool. This was first recommended here[1]. As an example, consider this module: 1 int foo(); 2 int bar(); 3 4 int baz() { 5 return foo() + bar(); 6 } The inliner generates these missed-optimization remarks today (the hotness information is pulled from PGO): remark: /tmp/s.c:5:10: foo will not be inlined into baz (hotness: 30) remark: /tmp/s.c:5:18: bar will not be inlined into baz (hotness: 30) Now with -pass-remarks-output=<yaml-file>, we generate this YAML file: --- !Missed Pass: inline Name: NotInlined DebugLoc: { File: /tmp/s.c, Line: 5, Column: 10 } Function: baz Hotness: 30 Args: - Callee: foo - String: will not be inlined into - Caller: baz ... --- !Missed Pass: inline Name: NotInlined DebugLoc: { File: /tmp/s.c, Line: 5, Column: 18 } Function: baz Hotness: 30 Args: - Callee: bar - String: will not be inlined into - Caller: baz ... This is a summary of the high-level decisions: * There is a new streaming interface to emit optimization remarks. E.g. for the inliner remark above: ORE.emit(DiagnosticInfoOptimizationRemarkMissed( DEBUG_TYPE, "NotInlined", &I) << NV("Callee", Callee) << " will not be inlined into " << NV("Caller", CS.getCaller()) << setIsVerbose()); NV stands for named value and allows the YAML client to process a remark using its name (NotInlined) and the named arguments (Callee and Caller) without parsing the text of the message. Subsequent patches will update ORE users to use the new streaming API. * I am using YAML I/O for writing the YAML file. YAML I/O requires you to specify reading and writing at once but reading is highly non-trivial for some of the more complex LLVM types. Since it's not clear that we (ever) want to use LLVM to parse this YAML file, the code supports and asserts that we're writing only. On the other hand, I did experiment that the class hierarchy starting at DiagnosticInfoOptimizationBase can be mapped back from YAML generated here (see D24479). * The YAML stream is stored in the LLVM context. * In the example, we can probably further specify the IR value used, i.e. print "Function" rather than "Value". * As before hotness is computed in the analysis pass instead of DiganosticInfo. This avoids the layering problem since BFI is in Analysis while DiagnosticInfo is in IR. [1] https://reviews.llvm.org/D19678#419445 Differential Revision: https://reviews.llvm.org/D24587 llvm-svn: 282499
* [opt] Remove an unused argument to runPassPipeline().Davide Italiano2016-09-071-1/+1
| | | | | | I have plans to use this API also in libLTO (and maybe lld). llvm-svn: 280770
* Add a counter-function insertion passHal Finkel2016-09-011-0/+1
| | | | | | | | | | | | | | | | | | As discussed in https://reviews.llvm.org/D22666, our current mechanism to support -pg profiling, where we insert calls to mcount(), or some similar function, is fundamentally broken. We insert these calls in the frontend, which means they get duplicated when inlining, and so the accumulated execution counts for the inlined-into functions are wrong. Because we don't want the presence of these functions to affect optimizaton, they should be inserted in the backend. Here's a pass which would do just that. The knowledge of the name of the counting function lives in the frontend, so we're passing it here as a function attribute. Clang will be updated to use this mechanism. Differential Revision: https://reviews.llvm.org/D22825 llvm-svn: 280347
* [PM] Port the always inliner to the new pass manager in a much moreChandler Carruth2016-08-171-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | minimal and boring form than the old pass manager's version. This pass does the very minimal amount of work necessary to inline functions declared as always-inline. It doesn't support a wide array of things that the legacy pass manager did support, but is alse ... about 20 lines of code. So it has that going for it. Notably things this doesn't support: - Array alloca merging - To support the above, bottom-up inlining with careful history tracking and call graph updates - DCE of the functions that become dead after this inlining. - Inlining through call instructions with the always_inline attribute. Instead, it focuses on inlining functions with that attribute. The first I've omitted because I'm hoping to just turn it off for the primary pass manager. If that doesn't pan out, I can add it here but it will be reasonably expensive to do so. The second should really be handled by running global-dce after the inliner. I don't want to re-implement the non-trivial logic necessary to do comdat-correct DCE of functions. This means the -O0 pipeline will have to be at least 'always-inline,global-dce', but that seems reasonable to me. If others are seriously worried about this I'd like to hear about it and understand why. Again, this is all solveable by factoring that logic into a utility and calling it here, but I'd like to wait to do that until there is a clear reason why the existing pass-based factoring won't work. The final point is a serious one. I can fairly easily add support for this, but it seems both costly and a confusing construct for the use case of the always inliner running at -O0. This attribute can of course still impact the normal inliner easily (although I find that a questionable re-use of the same attribute). I've started a discussion to sort out what semantics we want here and based on that can figure out if it makes sense ta have this complexity at O0 or not. One other advantage of this design is that it should be quite a bit faster due to checking for whether the function is a viable candidate for inlining exactly once per function instead of doing it for each call site. Anyways, hopefully a reasonable starting point for this pass. Differential Revision: https://reviews.llvm.org/D23299 llvm-svn: 278896
* [PM] Port ModuleSummaryIndex analysis to new pass managerTeresa Johnson2016-08-121-1/+2
| | | | | | | | | | | | | | | | | | | Summary: Port the ModuleSummaryAnalysisWrapperPass to the new pass manager. Use it in the ported BitcodeWriterPass (similar to how we use the legacy ModuleSummaryAnalysisWrapperPass in the legacy WriteBitcodePass). Also, pass the -module-summary opt flag through to the new pass manager pipeline and through to the bitcode writer pass, and add a test that uses it. Reviewers: mehdi_amini Subscribers: llvm-commits, mehdi_amini Differential Revision: https://reviews.llvm.org/D23439 llvm-svn: 278508
* opt: Adding -O0 to opt toolGor Nishanov2016-08-051-1/+14
| | | | | | | | | | | | | | Summary: Having -O0 in opt allows testing that -O0 optimization pipeline is built correctly. Reviewers: majnemer Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D23208 llvm-svn: 277829
* [coroutines] Part 3 of N: Adding Boilerplate for Coroutine PassesDavid Majnemer2016-07-281-0/+10
| | | | | | | | | | | | | This adds boilerplate code for all coroutine passes, the passes are no-ops for now. Also, a small test has been added to verify that passes execute in the expected order or not at all if coroutine support is disabled. Patch by Gor Nishanov! Differential Revision: https://reviews.llvm.org/D22847 llvm-svn: 277033
* [PM] Port SymbolRewriter to the new PMMichael Kuperstein2016-07-251-1/+1
| | | | | | Differential Revision: https://reviews.llvm.org/D22703 llvm-svn: 276687
* [OptRemark,LDist] RFC: Add hotness attributeAdam Nemet2016-07-151-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This is the first set of changes implementing the RFC from http://thread.gmane.org/gmane.comp.compilers.llvm.devel/98334 This is a cross-sectional patch; rather than implementing the hotness attribute for all optimization remarks and all passes in a patch set, it implements it for the 'missed-optimization' remark for Loop Distribution. My goal is to shake out the design issues before scaling it up to other types and passes. Hotness is computed as an integer as the multiplication of the block frequency with the function entry count. It's only printed in opt currently since clang prints the diagnostic fields directly. E.g.: remark: /tmp/t.c:3:3: loop not distributed: use -Rpass-analysis=loop-distribute for more info (hotness: 300) A new API added is similar to emitOptimizationRemarkMissed. The difference is that it additionally takes a code region that the diagnostic corresponds to. From this, hotness is computed using BFI. The new API is exposed via an analysis pass so that it can be made dependent on LazyBFI. (Thanks to Hal for the analysis pass idea.) This feature can all be enabled by setDiagnosticHotnessRequested in the LLVM context. If this is off, LazyBFI is not calculated (D22141) so there should be no overhead. A new command-line option is added to turn this on in opt. My plan is to switch all user of emitOptimizationRemark* to use this module instead. Reviewers: hfinkel Subscribers: rcox2, mzolotukhin, llvm-commits Differential Revision: http://reviews.llvm.org/D21771 llvm-svn: 275583
* [PM] Port UnreachableBlockElim to the new Pass ManagerWei Mi2016-07-081-0/+1
| | | | | | Differential Revision: http://reviews.llvm.org/D22124 llvm-svn: 274824
* [PM] Port PreISelIntrinsicLowering to the new PMMichael Kuperstein2016-06-241-1/+1
| | | | llvm-svn: 273713
* Use FPasses in opt exactly when it is initialized.Patrik Hagglund2016-06-151-1/+1
| | | | | | | | | | | | | Previously, there was a discrepancy between the population of function passes in FPasses, and their invocation. Function passes specified on the command line, after an optimizaton level was simply discared. This fix PR27509. Patch by Jesper Antonsson. Differential Review: http://reviews.llvm.org/D20725 llvm-svn: 272770
* Search for llvm-symbolizer binary in the same directory as argv[0], beforeRichard Smith2016-06-091-1/+1
| | | | | | | looking for it along $PATH. This allows installs of LLVM tools outside of $PATH to find the symbolizer and produce pretty backtraces if they crash. llvm-svn: 272232
* [ARM, AArch64] Properly initialize InterleavedAccessPassMatthew Simpson2016-05-191-0/+1
| | | | | | | InterleavedAccessPass is an IR-level pass, so this change will enable testing it with opt. This is part of D20250. llvm-svn: 270101
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