llvm-project/llvm/lib/CodeGen/CodeGen.cpp

81 lines
3.2 KiB
C++
Raw Normal View History

//===-- CodeGen.cpp -------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the common initialization routines for the
// CodeGen library.
//
//===----------------------------------------------------------------------===//
#include "llvm/InitializePasses.h"
#include "llvm-c/Initialization.h"
#include "llvm/PassRegistry.h"
using namespace llvm;
/// initializeCodeGen - Initialize all passes linked into the CodeGen library.
void llvm::initializeCodeGen(PassRegistry &Registry) {
initializeAtomicExpandLoadLinkedPass(Registry);
Switch TargetTransformInfo from an immutable analysis pass that requires a TargetMachine to construct (and thus isn't always available), to an analysis group that supports layered implementations much like AliasAnalysis does. This is a pretty massive change, with a few parts that I was unable to easily separate (sorry), so I'll walk through it. The first step of this conversion was to make TargetTransformInfo an analysis group, and to sink the nonce implementations in ScalarTargetTransformInfo and VectorTargetTranformInfo into a NoTargetTransformInfo pass. This allows other passes to add a hard requirement on TTI, and assume they will always get at least on implementation. The TargetTransformInfo analysis group leverages the delegation chaining trick that AliasAnalysis uses, where the base class for the analysis group delegates to the previous analysis *pass*, allowing all but tho NoFoo analysis passes to only implement the parts of the interfaces they support. It also introduces a new trick where each pass in the group retains a pointer to the top-most pass that has been initialized. This allows passes to implement one API in terms of another API and benefit when some other pass above them in the stack has more precise results for the second API. The second step of this conversion is to create a pass that implements the TargetTransformInfo analysis using the target-independent abstractions in the code generator. This replaces the ScalarTargetTransformImpl and VectorTargetTransformImpl classes in lib/Target with a single pass in lib/CodeGen called BasicTargetTransformInfo. This class actually provides most of the TTI functionality, basing it upon the TargetLowering abstraction and other information in the target independent code generator. The third step of the conversion adds support to all TargetMachines to register custom analysis passes. This allows building those passes with access to TargetLowering or other target-specific classes, and it also allows each target to customize the set of analysis passes desired in the pass manager. The baseline LLVMTargetMachine implements this interface to add the BasicTTI pass to the pass manager, and all of the tools that want to support target-aware TTI passes call this routine on whatever target machine they end up with to add the appropriate passes. The fourth step of the conversion created target-specific TTI analysis passes for the X86 and ARM backends. These passes contain the custom logic that was previously in their extensions of the ScalarTargetTransformInfo and VectorTargetTransformInfo interfaces. I separated them into their own file, as now all of the interface bits are private and they just expose a function to create the pass itself. Then I extended these target machines to set up a custom set of analysis passes, first adding BasicTTI as a fallback, and then adding their customized TTI implementations. The fourth step required logic that was shared between the target independent layer and the specific targets to move to a different interface, as they no longer derive from each other. As a consequence, a helper functions were added to TargetLowering representing the common logic needed both in the target implementation and the codegen implementation of the TTI pass. While technically this is the only change that could have been committed separately, it would have been a nightmare to extract. The final step of the conversion was just to delete all the old boilerplate. This got rid of the ScalarTargetTransformInfo and VectorTargetTransformInfo classes, all of the support in all of the targets for producing instances of them, and all of the support in the tools for manually constructing a pass based around them. Now that TTI is a relatively normal analysis group, two things become straightforward. First, we can sink it into lib/Analysis which is a more natural layer for it to live. Second, clients of this interface can depend on it *always* being available which will simplify their code and behavior. These (and other) simplifications will follow in subsequent commits, this one is clearly big enough. Finally, I'm very aware that much of the comments and documentation needs to be updated. As soon as I had this working, and plausibly well commented, I wanted to get it committed and in front of the build bots. I'll be doing a few passes over documentation later if it sticks. Commits to update DragonEgg and Clang will be made presently. llvm-svn: 171681
2013-01-07 09:37:14 +08:00
initializeBasicTTIPass(Registry);
initializeBranchFolderPassPass(Registry);
initializeCodeGenPreparePass(Registry);
initializeDeadMachineInstructionElimPass(Registry);
initializeEarlyIfConverterPass(Registry);
initializeExpandPostRAPass(Registry);
initializeExpandISelPseudosPass(Registry);
initializeFinalizeMachineBundlesPass(Registry);
initializeGCMachineCodeAnalysisPass(Registry);
initializeGCModuleInfoPass(Registry);
initializeIfConverterPass(Registry);
initializeLiveDebugVariablesPass(Registry);
initializeLiveIntervalsPass(Registry);
initializeLiveStacksPass(Registry);
initializeLiveVariablesPass(Registry);
initializeLocalStackSlotPassPass(Registry);
initializeMachineBlockFrequencyInfoPass(Registry);
Implement a block placement pass based on the branch probability and block frequency analyses. This differs substantially from the existing block-placement pass in LLVM: 1) It operates on the Machine-IR in the CodeGen layer. This exposes much more (and more precise) information and opportunities. Also, the results are more stable due to fewer transforms ocurring after the pass runs. 2) It uses the generalized probability and frequency analyses. These can model static heuristics, code annotation derived heuristics as well as eventual profile loading. By basing the optimization on the analysis interface it can work from any (or a combination) of these inputs. 3) It uses a more aggressive algorithm, both building chains from tho bottom up to maximize benefit, and using an SCC-based walk to layout chains of blocks in a profitable ordering without O(N^2) iterations which the old pass involves. The pass is currently gated behind a flag, and not enabled by default because it still needs to grow some important features. Most notably, it needs to support loop aligning and careful layout of loop structures much as done by hand currently in CodePlacementOpt. Once it supports these, and has sufficient testing and quality tuning, it should replace both of these passes. Thanks to Nick Lewycky and Richard Smith for help authoring & debugging this, and to Jakob, Andy, Eric, Jim, and probably a few others I'm forgetting for reviewing and answering all my questions. Writing a backend pass is *sooo* much better now than it used to be. =D llvm-svn: 142641
2011-10-21 14:46:38 +08:00
initializeMachineBlockPlacementPass(Registry);
initializeMachineBlockPlacementStatsPass(Registry);
initializeMachineCopyPropagationPass(Registry);
initializeMachineCSEPass(Registry);
initializeMachineDominatorTreePass(Registry);
initializeMachinePostDominatorTreePass(Registry);
initializeMachineLICMPass(Registry);
initializeMachineLoopInfoPass(Registry);
initializeMachineModuleInfoPass(Registry);
initializeMachineSchedulerPass(Registry);
initializeMachineSinkingPass(Registry);
initializeMachineVerifierPassPass(Registry);
initializeOptimizePHIsPass(Registry);
initializePHIEliminationPass(Registry);
initializePeepholeOptimizerPass(Registry);
initializePostMachineSchedulerPass(Registry);
initializePostRASchedulerPass(Registry);
initializeProcessImplicitDefsPass(Registry);
initializePEIPass(Registry);
initializeRegisterCoalescerPass(Registry);
initializeSlotIndexesPass(Registry);
initializeStackProtectorPass(Registry);
initializeStackColoringPass(Registry);
initializeStackSlotColoringPass(Registry);
initializeTailDuplicatePassPass(Registry);
initializeTargetPassConfigPass(Registry);
initializeTwoAddressInstructionPassPass(Registry);
initializeUnpackMachineBundlesPass(Registry);
initializeUnreachableBlockElimPass(Registry);
initializeUnreachableMachineBlockElimPass(Registry);
initializeVirtRegMapPass(Registry);
initializeVirtRegRewriterPass(Registry);
initializeLowerIntrinsicsPass(Registry);
initializeMachineFunctionPrinterPassPass(Registry);
initializeStackMapLivenessPass(Registry);
}
void LLVMInitializeCodeGen(LLVMPassRegistryRef R) {
initializeCodeGen(*unwrap(R));
}