llvm-project/llvm/lib/Analysis/Analysis.cpp

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//===-- Analysis.cpp ------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm-c/Analysis.h"
#include "llvm-c/Initialization.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Verifier.h"
#include "llvm/InitializePasses.h"
#include "llvm/PassRegistry.h"
#include "llvm/Support/raw_ostream.h"
#include <cstring>
using namespace llvm;
/// initializeAnalysis - Initialize all passes linked into the Analysis library.
void llvm::initializeAnalysis(PassRegistry &Registry) {
initializeAliasAnalysisAnalysisGroup(Registry);
initializeAliasAnalysisCounterPass(Registry);
initializeAAEvalPass(Registry);
initializeAliasSetPrinterPass(Registry);
initializeNoAAPass(Registry);
initializeBasicAliasAnalysisPass(Registry);
initializeBlockFrequencyInfoWrapperPassPass(Registry);
initializeBranchProbabilityInfoWrapperPassPass(Registry);
initializeCostModelAnalysisPass(Registry);
initializeCFGViewerPass(Registry);
initializeCFGPrinterPass(Registry);
initializeCFGOnlyViewerPass(Registry);
initializeCFGOnlyPrinterPass(Registry);
initializeCFLAliasAnalysisPass(Registry);
initializeDependenceAnalysisPass(Registry);
initializeDelinearizationPass(Registry);
initializeDemandedBitsPass(Registry);
initializeDivergenceAnalysisPass(Registry);
initializeDominanceFrontierPass(Registry);
initializeDomViewerPass(Registry);
initializeDomPrinterPass(Registry);
initializeDomOnlyViewerPass(Registry);
initializePostDomViewerPass(Registry);
initializeDomOnlyPrinterPass(Registry);
initializePostDomPrinterPass(Registry);
initializePostDomOnlyViewerPass(Registry);
initializePostDomOnlyPrinterPass(Registry);
initializeIVUsersPass(Registry);
initializeInstCountPass(Registry);
initializeIntervalPartitionPass(Registry);
initializeLazyValueInfoPass(Registry);
initializeLintPass(Registry);
initializeLoopInfoWrapperPassPass(Registry);
initializeMemDepPrinterPass(Registry);
initializeMemDerefPrinterPass(Registry);
initializeMemoryDependenceAnalysisPass(Registry);
initializeModuleDebugInfoPrinterPass(Registry);
initializePostDominatorTreePass(Registry);
initializeRegionInfoPassPass(Registry);
initializeRegionViewerPass(Registry);
initializeRegionPrinterPass(Registry);
initializeRegionOnlyViewerPass(Registry);
initializeRegionOnlyPrinterPass(Registry);
[PM] Port ScalarEvolution to the new pass manager. This change makes ScalarEvolution a stand-alone object and just produces one from a pass as needed. Making this work well requires making the object movable, using references instead of overwritten pointers in a number of places, and other refactorings. I've also wired it up to the new pass manager and added a RUN line to a test to exercise it under the new pass manager. This includes basic printing support much like with other analyses. But there is a big and somewhat scary change here. Prior to this patch ScalarEvolution was never *actually* invalidated!!! Re-running the pass just re-wired up the various other analyses and didn't remove any of the existing entries in the SCEV caches or clear out anything at all. This might seem OK as everything in SCEV that can uses ValueHandles to track updates to the values that serve as SCEV keys. However, this still means that as we ran SCEV over each function in the module, we kept accumulating more and more SCEVs into the cache. At the end, we would have a SCEV cache with every value that we ever needed a SCEV for in the entire module!!! Yowzers. The releaseMemory routine would dump all of this, but that isn't realy called during normal runs of the pipeline as far as I can see. To make matters worse, there *is* actually a key that we don't update with value handles -- there is a map keyed off of Loop*s. Because LoopInfo *does* release its memory from run to run, it is entirely possible to run SCEV over one function, then over another function, and then lookup a Loop* from the second function but find an entry inserted for the first function! Ouch. To make matters still worse, there are plenty of updates that *don't* trip a value handle. It seems incredibly unlikely that today GVN or another pass that invalidates SCEV can update values in *just* such a way that a subsequent run of SCEV will incorrectly find lookups in a cache, but it is theoretically possible and would be a nightmare to debug. With this refactoring, I've fixed all this by actually destroying and recreating the ScalarEvolution object from run to run. Technically, this could increase the amount of malloc traffic we see, but then again it is also technically correct. ;] I don't actually think we're suffering from tons of malloc traffic from SCEV because if we were, the fact that we never clear the memory would seem more likely to have come up as an actual problem before now. So, I've made the simple fix here. If in fact there are serious issues with too much allocation and deallocation, I can work on a clever fix that preserves the allocations (while clearing the data) between each run, but I'd prefer to do that kind of optimization with a test case / benchmark that shows why we need such cleverness (and that can test that we actually make it faster). It's possible that this will make some things faster by making the SCEV caches have higher locality (due to being significantly smaller) so until there is a clear benchmark, I think the simple change is best. Differential Revision: http://reviews.llvm.org/D12063 llvm-svn: 245193
2015-08-17 10:08:17 +08:00
initializeScalarEvolutionWrapperPassPass(Registry);
initializeScalarEvolutionAliasAnalysisPass(Registry);
[PM] Change the core design of the TTI analysis to use a polymorphic type erased interface and a single analysis pass rather than an extremely complex analysis group. The end result is that the TTI analysis can contain a type erased implementation that supports the polymorphic TTI interface. We can build one from a target-specific implementation or from a dummy one in the IR. I've also factored all of the code into "mix-in"-able base classes, including CRTP base classes to facilitate calling back up to the most specialized form when delegating horizontally across the surface. These aren't as clean as I would like and I'm planning to work on cleaning some of this up, but I wanted to start by putting into the right form. There are a number of reasons for this change, and this particular design. The first and foremost reason is that an analysis group is complete overkill, and the chaining delegation strategy was so opaque, confusing, and high overhead that TTI was suffering greatly for it. Several of the TTI functions had failed to be implemented in all places because of the chaining-based delegation making there be no checking of this. A few other functions were implemented with incorrect delegation. The message to me was very clear working on this -- the delegation and analysis group structure was too confusing to be useful here. The other reason of course is that this is *much* more natural fit for the new pass manager. This will lay the ground work for a type-erased per-function info object that can look up the correct subtarget and even cache it. Yet another benefit is that this will significantly simplify the interaction of the pass managers and the TargetMachine. See the future work below. The downside of this change is that it is very, very verbose. I'm going to work to improve that, but it is somewhat an implementation necessity in C++ to do type erasure. =/ I discussed this design really extensively with Eric and Hal prior to going down this path, and afterward showed them the result. No one was really thrilled with it, but there doesn't seem to be a substantially better alternative. Using a base class and virtual method dispatch would make the code much shorter, but as discussed in the update to the programmer's manual and elsewhere, a polymorphic interface feels like the more principled approach even if this is perhaps the least compelling example of it. ;] Ultimately, there is still a lot more to be done here, but this was the huge chunk that I couldn't really split things out of because this was the interface change to TTI. I've tried to minimize all the other parts of this. The follow up work should include at least: 1) Improving the TargetMachine interface by having it directly return a TTI object. Because we have a non-pass object with value semantics and an internal type erasure mechanism, we can narrow the interface of the TargetMachine to *just* do what we need: build and return a TTI object that we can then insert into the pass pipeline. 2) Make the TTI object be fully specialized for a particular function. This will include splitting off a minimal form of it which is sufficient for the inliner and the old pass manager. 3) Add a new pass manager analysis which produces TTI objects from the target machine for each function. This may actually be done as part of #2 in order to use the new analysis to implement #2. 4) Work on narrowing the API between TTI and the targets so that it is easier to understand and less verbose to type erase. 5) Work on narrowing the API between TTI and its clients so that it is easier to understand and less verbose to forward. 6) Try to improve the CRTP-based delegation. I feel like this code is just a bit messy and exacerbating the complexity of implementing the TTI in each target. Many thanks to Eric and Hal for their help here. I ended up blocked on this somewhat more abruptly than I expected, and so I appreciate getting it sorted out very quickly. Differential Revision: http://reviews.llvm.org/D7293 llvm-svn: 227669
2015-01-31 11:43:40 +08:00
initializeTargetTransformInfoWrapperPassPass(Registry);
initializeTypeBasedAliasAnalysisPass(Registry);
Add scoped-noalias metadata This commit adds scoped noalias metadata. The primary motivations for this feature are: 1. To preserve noalias function attribute information when inlining 2. To provide the ability to model block-scope C99 restrict pointers Neither of these two abilities are added here, only the necessary infrastructure. In fact, there should be no change to existing functionality, only the addition of new features. The logic that converts noalias function parameters into this metadata during inlining will come in a follow-up commit. What is added here is the ability to generally specify noalias memory-access sets. Regarding the metadata, alias-analysis scopes are defined similar to TBAA nodes: !scope0 = metadata !{ metadata !"scope of foo()" } !scope1 = metadata !{ metadata !"scope 1", metadata !scope0 } !scope2 = metadata !{ metadata !"scope 2", metadata !scope0 } !scope3 = metadata !{ metadata !"scope 2.1", metadata !scope2 } !scope4 = metadata !{ metadata !"scope 2.2", metadata !scope2 } Loads and stores can be tagged with an alias-analysis scope, and also, with a noalias tag for a specific scope: ... = load %ptr1, !alias.scope !{ !scope1 } ... = load %ptr2, !alias.scope !{ !scope1, !scope2 }, !noalias !{ !scope1 } When evaluating an aliasing query, if one of the instructions is associated with an alias.scope id that is identical to the noalias scope associated with the other instruction, or is a descendant (in the scope hierarchy) of the noalias scope associated with the other instruction, then the two memory accesses are assumed not to alias. Note that is the first element of the scope metadata is a string, then it can be combined accross functions and translation units. The string can be replaced by a self-reference to create globally unqiue scope identifiers. [Note: This overview is slightly stylized, since the metadata nodes really need to just be numbers (!0 instead of !scope0), and the scope lists are also global unnamed metadata.] Existing noalias metadata in a callee is "cloned" for use by the inlined code. This is necessary because the aliasing scopes are unique to each call site (because of possible control dependencies on the aliasing properties). For example, consider a function: foo(noalias a, noalias b) { *a = *b; } that gets inlined into bar() { ... if (...) foo(a1, b1); ... if (...) foo(a2, b2); } -- now just because we know that a1 does not alias with b1 at the first call site, and a2 does not alias with b2 at the second call site, we cannot let inlining these functons have the metadata imply that a1 does not alias with b2. llvm-svn: 213864
2014-07-24 22:25:39 +08:00
initializeScopedNoAliasAAPass(Registry);
}
void LLVMInitializeAnalysis(LLVMPassRegistryRef R) {
initializeAnalysis(*unwrap(R));
}
LLVMBool LLVMVerifyModule(LLVMModuleRef M, LLVMVerifierFailureAction Action,
char **OutMessages) {
raw_ostream *DebugOS = Action != LLVMReturnStatusAction ? &errs() : nullptr;
std::string Messages;
raw_string_ostream MsgsOS(Messages);
LLVMBool Result = verifyModule(*unwrap(M), OutMessages ? &MsgsOS : DebugOS);
// Duplicate the output to stderr.
if (DebugOS && OutMessages)
*DebugOS << MsgsOS.str();
if (Action == LLVMAbortProcessAction && Result)
report_fatal_error("Broken module found, compilation aborted!");
if (OutMessages)
*OutMessages = strdup(MsgsOS.str().c_str());
return Result;
}
LLVMBool LLVMVerifyFunction(LLVMValueRef Fn, LLVMVerifierFailureAction Action) {
LLVMBool Result = verifyFunction(
*unwrap<Function>(Fn), Action != LLVMReturnStatusAction ? &errs()
: nullptr);
if (Action == LLVMAbortProcessAction && Result)
report_fatal_error("Broken function found, compilation aborted!");
return Result;
}
void LLVMViewFunctionCFG(LLVMValueRef Fn) {
Function *F = unwrap<Function>(Fn);
F->viewCFG();
}
void LLVMViewFunctionCFGOnly(LLVMValueRef Fn) {
Function *F = unwrap<Function>(Fn);
F->viewCFGOnly();
}