Eugene Zelenko | f27d161 | 2017-10-19 21:21:30 +0000 | [diff] [blame] | 1 | //===- ArgumentPromotion.cpp - Promote by-reference arguments -------------===// |
Misha Brukman | b1c9317 | 2005-04-21 23:48:37 +0000 | [diff] [blame] | 2 | // |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
Chris Lattner | f3ebc3f | 2007-12-29 20:36:04 +0000 | [diff] [blame] | 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
Misha Brukman | b1c9317 | 2005-04-21 23:48:37 +0000 | [diff] [blame] | 7 | // |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 8 | //===----------------------------------------------------------------------===// |
| 9 | // |
| 10 | // This pass promotes "by reference" arguments to be "by value" arguments. In |
| 11 | // practice, this means looking for internal functions that have pointer |
Gordon Henriksen | 78c63ac | 2007-10-26 03:03:51 +0000 | [diff] [blame] | 12 | // arguments. If it can prove, through the use of alias analysis, that an |
| 13 | // argument is *only* loaded, then it can pass the value into the function |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 14 | // instead of the address of the value. This can cause recursive simplification |
Chris Lattner | 254f8f8 | 2004-05-23 21:21:17 +0000 | [diff] [blame] | 15 | // of code and lead to the elimination of allocas (especially in C++ template |
| 16 | // code like the STL). |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 17 | // |
Chris Lattner | fe6f2e3 | 2004-03-08 01:04:36 +0000 | [diff] [blame] | 18 | // This pass also handles aggregate arguments that are passed into a function, |
| 19 | // scalarizing them if the elements of the aggregate are only loaded. Note that |
Matthijs Kooijman | fd30704 | 2008-07-29 10:00:13 +0000 | [diff] [blame] | 20 | // by default it refuses to scalarize aggregates which would require passing in |
| 21 | // more than three operands to the function, because passing thousands of |
Duncan Sands | 1ea0d2e | 2008-09-07 09:54:09 +0000 | [diff] [blame] | 22 | // operands for a large array or structure is unprofitable! This limit can be |
Matthijs Kooijman | fd30704 | 2008-07-29 10:00:13 +0000 | [diff] [blame] | 23 | // configured or disabled, however. |
Chris Lattner | fe6f2e3 | 2004-03-08 01:04:36 +0000 | [diff] [blame] | 24 | // |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 25 | // Note that this transformation could also be done for arguments that are only |
Gordon Henriksen | 78c63ac | 2007-10-26 03:03:51 +0000 | [diff] [blame] | 26 | // stored to (returning the value instead), but does not currently. This case |
| 27 | // would be best handled when and if LLVM begins supporting multiple return |
| 28 | // values from functions. |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 29 | // |
| 30 | //===----------------------------------------------------------------------===// |
| 31 | |
Chandler Carruth | addcda4 | 2017-02-09 23:46:27 +0000 | [diff] [blame] | 32 | #include "llvm/Transforms/IPO/ArgumentPromotion.h" |
Reid Spencer | 7c16caa | 2004-09-01 22:55:40 +0000 | [diff] [blame] | 33 | #include "llvm/ADT/DepthFirstIterator.h" |
Eugene Zelenko | f27d161 | 2017-10-19 21:21:30 +0000 | [diff] [blame] | 34 | #include "llvm/ADT/None.h" |
Chandler Carruth | addcda4 | 2017-02-09 23:46:27 +0000 | [diff] [blame] | 35 | #include "llvm/ADT/Optional.h" |
Eugene Zelenko | f27d161 | 2017-10-19 21:21:30 +0000 | [diff] [blame] | 36 | #include "llvm/ADT/STLExtras.h" |
| 37 | #include "llvm/ADT/SmallPtrSet.h" |
| 38 | #include "llvm/ADT/SmallVector.h" |
Reid Spencer | 7c16caa | 2004-09-01 22:55:40 +0000 | [diff] [blame] | 39 | #include "llvm/ADT/Statistic.h" |
Chris Lattner | 06fa176 | 2009-08-24 03:52:50 +0000 | [diff] [blame] | 40 | #include "llvm/ADT/StringExtras.h" |
Eugene Zelenko | f27d161 | 2017-10-19 21:21:30 +0000 | [diff] [blame] | 41 | #include "llvm/ADT/Twine.h" |
Chandler Carruth | ed0881b | 2012-12-03 16:50:05 +0000 | [diff] [blame] | 42 | #include "llvm/Analysis/AliasAnalysis.h" |
Daniel Jasper | aec2fa3 | 2016-12-19 08:22:17 +0000 | [diff] [blame] | 43 | #include "llvm/Analysis/AssumptionCache.h" |
Chandler Carruth | 7b560d4 | 2015-09-09 17:55:00 +0000 | [diff] [blame] | 44 | #include "llvm/Analysis/BasicAliasAnalysis.h" |
Eugene Zelenko | f27d161 | 2017-10-19 21:21:30 +0000 | [diff] [blame] | 45 | #include "llvm/Analysis/CGSCCPassManager.h" |
Chandler Carruth | ed0881b | 2012-12-03 16:50:05 +0000 | [diff] [blame] | 46 | #include "llvm/Analysis/CallGraph.h" |
Chandler Carruth | 839a98e | 2013-01-07 15:26:48 +0000 | [diff] [blame] | 47 | #include "llvm/Analysis/CallGraphSCCPass.h" |
Chandler Carruth | addcda4 | 2017-02-09 23:46:27 +0000 | [diff] [blame] | 48 | #include "llvm/Analysis/LazyCallGraph.h" |
Artur Pilipenko | 31bcca4 | 2016-02-24 12:49:04 +0000 | [diff] [blame] | 49 | #include "llvm/Analysis/Loads.h" |
Eugene Zelenko | f27d161 | 2017-10-19 21:21:30 +0000 | [diff] [blame] | 50 | #include "llvm/Analysis/MemoryLocation.h" |
Chandler Carruth | 7b560d4 | 2015-09-09 17:55:00 +0000 | [diff] [blame] | 51 | #include "llvm/Analysis/TargetLibraryInfo.h" |
Tom Stellard | 3d36e5c | 2019-01-16 05:15:31 +0000 | [diff] [blame] | 52 | #include "llvm/Analysis/TargetTransformInfo.h" |
Eugene Zelenko | f27d161 | 2017-10-19 21:21:30 +0000 | [diff] [blame] | 53 | #include "llvm/IR/Argument.h" |
| 54 | #include "llvm/IR/Attributes.h" |
| 55 | #include "llvm/IR/BasicBlock.h" |
Chandler Carruth | 1305dc3 | 2014-03-04 11:45:46 +0000 | [diff] [blame] | 56 | #include "llvm/IR/CFG.h" |
Chandler Carruth | 219b89b | 2014-03-04 11:01:28 +0000 | [diff] [blame] | 57 | #include "llvm/IR/CallSite.h" |
Chandler Carruth | 9fb823b | 2013-01-02 11:36:10 +0000 | [diff] [blame] | 58 | #include "llvm/IR/Constants.h" |
Hal Finkel | 2e42c34 | 2014-07-10 05:27:53 +0000 | [diff] [blame] | 59 | #include "llvm/IR/DataLayout.h" |
Chandler Carruth | 9fb823b | 2013-01-02 11:36:10 +0000 | [diff] [blame] | 60 | #include "llvm/IR/DerivedTypes.h" |
Eugene Zelenko | f27d161 | 2017-10-19 21:21:30 +0000 | [diff] [blame] | 61 | #include "llvm/IR/Function.h" |
| 62 | #include "llvm/IR/InstrTypes.h" |
| 63 | #include "llvm/IR/Instruction.h" |
Chandler Carruth | 9fb823b | 2013-01-02 11:36:10 +0000 | [diff] [blame] | 64 | #include "llvm/IR/Instructions.h" |
Eugene Zelenko | f27d161 | 2017-10-19 21:21:30 +0000 | [diff] [blame] | 65 | #include "llvm/IR/Metadata.h" |
Chandler Carruth | 9fb823b | 2013-01-02 11:36:10 +0000 | [diff] [blame] | 66 | #include "llvm/IR/Module.h" |
Eugene Zelenko | f27d161 | 2017-10-19 21:21:30 +0000 | [diff] [blame] | 67 | #include "llvm/IR/PassManager.h" |
| 68 | #include "llvm/IR/Type.h" |
| 69 | #include "llvm/IR/Use.h" |
| 70 | #include "llvm/IR/User.h" |
| 71 | #include "llvm/IR/Value.h" |
| 72 | #include "llvm/Pass.h" |
| 73 | #include "llvm/Support/Casting.h" |
Chandler Carruth | ed0881b | 2012-12-03 16:50:05 +0000 | [diff] [blame] | 74 | #include "llvm/Support/Debug.h" |
| 75 | #include "llvm/Support/raw_ostream.h" |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 76 | #include "llvm/Transforms/IPO.h" |
Eugene Zelenko | f27d161 | 2017-10-19 21:21:30 +0000 | [diff] [blame] | 77 | #include <algorithm> |
| 78 | #include <cassert> |
| 79 | #include <cstdint> |
| 80 | #include <functional> |
| 81 | #include <iterator> |
| 82 | #include <map> |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 83 | #include <set> |
Eugene Zelenko | f27d161 | 2017-10-19 21:21:30 +0000 | [diff] [blame] | 84 | #include <string> |
| 85 | #include <utility> |
| 86 | #include <vector> |
| 87 | |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 88 | using namespace llvm; |
| 89 | |
Chandler Carruth | 964daaa | 2014-04-22 02:55:47 +0000 | [diff] [blame] | 90 | #define DEBUG_TYPE "argpromotion" |
| 91 | |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 92 | STATISTIC(NumArgumentsPromoted, "Number of pointer arguments promoted"); |
Chris Lattner | 1631bcb | 2006-12-19 22:09:18 +0000 | [diff] [blame] | 93 | STATISTIC(NumAggregatesPromoted, "Number of aggregate arguments promoted"); |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 94 | STATISTIC(NumByValArgsPromoted, "Number of byval arguments promoted"); |
| 95 | STATISTIC(NumArgumentsDead, "Number of dead pointer args eliminated"); |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 96 | |
Sean Silva | e2133e7 | 2016-07-02 18:59:51 +0000 | [diff] [blame] | 97 | /// A vector used to hold the indices of a single GEP instruction |
Eugene Zelenko | f27d161 | 2017-10-19 21:21:30 +0000 | [diff] [blame] | 98 | using IndicesVector = std::vector<uint64_t>; |
Sean Silva | e2133e7 | 2016-07-02 18:59:51 +0000 | [diff] [blame] | 99 | |
Chris Lattner | 254f8f8 | 2004-05-23 21:21:17 +0000 | [diff] [blame] | 100 | /// DoPromotion - This method actually performs the promotion of the specified |
Chris Lattner | 37b6c4f | 2004-09-18 00:34:13 +0000 | [diff] [blame] | 101 | /// arguments, and returns the new function. At this point, we know that it's |
| 102 | /// safe to do so. |
Chandler Carruth | addcda4 | 2017-02-09 23:46:27 +0000 | [diff] [blame] | 103 | static Function * |
Chandler Carruth | 8e9c0a8 | 2017-01-29 08:03:21 +0000 | [diff] [blame] | 104 | doPromotion(Function *F, SmallPtrSetImpl<Argument *> &ArgsToPromote, |
Chandler Carruth | addcda4 | 2017-02-09 23:46:27 +0000 | [diff] [blame] | 105 | SmallPtrSetImpl<Argument *> &ByValArgsToTransform, |
| 106 | Optional<function_ref<void(CallSite OldCS, CallSite NewCS)>> |
| 107 | ReplaceCallSite) { |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 108 | // Start by computing a new prototype for the function, which is the same as |
| 109 | // the old function, but has modified arguments. |
Chris Lattner | 229907c | 2011-07-18 04:54:35 +0000 | [diff] [blame] | 110 | FunctionType *FTy = F->getFunctionType(); |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 111 | std::vector<Type *> Params; |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 112 | |
Eugene Zelenko | f27d161 | 2017-10-19 21:21:30 +0000 | [diff] [blame] | 113 | using ScalarizeTable = std::set<std::pair<Type *, IndicesVector>>; |
Chris Lattner | 1c676f7 | 2004-06-21 00:07:58 +0000 | [diff] [blame] | 114 | |
Chris Lattner | fe6f2e3 | 2004-03-08 01:04:36 +0000 | [diff] [blame] | 115 | // ScalarizedElements - If we are promoting a pointer that has elements |
| 116 | // accessed out of it, keep track of which elements are accessed so that we |
| 117 | // can add one argument for each. |
| 118 | // |
| 119 | // Arguments that are directly loaded will have a zero element value here, to |
| 120 | // handle cases where there are both a direct load and GEP accesses. |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 121 | std::map<Argument *, ScalarizeTable> ScalarizedElements; |
Chris Lattner | fe6f2e3 | 2004-03-08 01:04:36 +0000 | [diff] [blame] | 122 | |
Chris Lattner | 254f8f8 | 2004-05-23 21:21:17 +0000 | [diff] [blame] | 123 | // OriginalLoads - Keep track of a representative load instruction from the |
| 124 | // original function so that we can tell the alias analysis implementation |
| 125 | // what the new GEP/Load instructions we are inserting look like. |
Manman Ren | bc37658 | 2013-11-15 20:41:15 +0000 | [diff] [blame] | 126 | // We need to keep the original loads for each argument and the elements |
| 127 | // of the argument that are accessed. |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 128 | std::map<std::pair<Argument *, IndicesVector>, LoadInst *> OriginalLoads; |
Chris Lattner | 254f8f8 | 2004-05-23 21:21:17 +0000 | [diff] [blame] | 129 | |
Bill Wendling | 3d7b0b8 | 2012-12-19 07:18:57 +0000 | [diff] [blame] | 130 | // Attribute - Keep track of the parameter attributes for the arguments |
Duncan Sands | ad0ea2d | 2007-11-27 13:23:08 +0000 | [diff] [blame] | 131 | // that we are *not* promoting. For the ones that we do promote, the parameter |
| 132 | // attributes are lost |
Reid Kleckner | 7f72033 | 2017-04-13 00:58:09 +0000 | [diff] [blame] | 133 | SmallVector<AttributeSet, 8> ArgAttrVec; |
| 134 | AttributeList PAL = F->getAttributes(); |
Duncan Sands | 1ea0d2e | 2008-09-07 09:54:09 +0000 | [diff] [blame] | 135 | |
Matthijs Kooijman | fd30704 | 2008-07-29 10:00:13 +0000 | [diff] [blame] | 136 | // First, determine the new argument list |
Reid Kleckner | 6652a52 | 2017-04-28 18:37:16 +0000 | [diff] [blame] | 137 | unsigned ArgNo = 0; |
Duncan Sands | ad0ea2d | 2007-11-27 13:23:08 +0000 | [diff] [blame] | 138 | for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; |
Reid Kleckner | 6652a52 | 2017-04-28 18:37:16 +0000 | [diff] [blame] | 139 | ++I, ++ArgNo) { |
Duncan P. N. Exon Smith | 1732340 | 2015-10-13 17:51:03 +0000 | [diff] [blame] | 140 | if (ByValArgsToTransform.count(&*I)) { |
Matthijs Kooijman | fd30704 | 2008-07-29 10:00:13 +0000 | [diff] [blame] | 141 | // Simple byval argument? Just add all the struct element types. |
Chris Lattner | 229907c | 2011-07-18 04:54:35 +0000 | [diff] [blame] | 142 | Type *AgTy = cast<PointerType>(I->getType())->getElementType(); |
| 143 | StructType *STy = cast<StructType>(AgTy); |
Benjamin Kramer | 5fbfe2f | 2015-02-28 13:20:15 +0000 | [diff] [blame] | 144 | Params.insert(Params.end(), STy->element_begin(), STy->element_end()); |
Reid Kleckner | 7f72033 | 2017-04-13 00:58:09 +0000 | [diff] [blame] | 145 | ArgAttrVec.insert(ArgAttrVec.end(), STy->getNumElements(), |
| 146 | AttributeSet()); |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 147 | ++NumByValArgsPromoted; |
Duncan P. N. Exon Smith | 1732340 | 2015-10-13 17:51:03 +0000 | [diff] [blame] | 148 | } else if (!ArgsToPromote.count(&*I)) { |
Matthijs Kooijman | fd30704 | 2008-07-29 10:00:13 +0000 | [diff] [blame] | 149 | // Unchanged argument |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 150 | Params.push_back(I->getType()); |
Reid Kleckner | 6652a52 | 2017-04-28 18:37:16 +0000 | [diff] [blame] | 151 | ArgAttrVec.push_back(PAL.getParamAttributes(ArgNo)); |
Chris Lattner | 254f8f8 | 2004-05-23 21:21:17 +0000 | [diff] [blame] | 152 | } else if (I->use_empty()) { |
Matthijs Kooijman | fd30704 | 2008-07-29 10:00:13 +0000 | [diff] [blame] | 153 | // Dead argument (which are always marked as promotable) |
Chris Lattner | 254f8f8 | 2004-05-23 21:21:17 +0000 | [diff] [blame] | 154 | ++NumArgumentsDead; |
Mikael Holmen | e0ced14 | 2017-07-10 06:07:24 +0000 | [diff] [blame] | 155 | |
| 156 | // There may be remaining metadata uses of the argument for things like |
| 157 | // llvm.dbg.value. Replace them with undef. |
| 158 | I->replaceAllUsesWith(UndefValue::get(I->getType())); |
Chris Lattner | 254f8f8 | 2004-05-23 21:21:17 +0000 | [diff] [blame] | 159 | } else { |
Matthijs Kooijman | fd30704 | 2008-07-29 10:00:13 +0000 | [diff] [blame] | 160 | // Okay, this is being promoted. This means that the only uses are loads |
| 161 | // or GEPs which are only used by loads |
| 162 | |
| 163 | // In this table, we will track which indices are loaded from the argument |
| 164 | // (where direct loads are tracked as no indices). |
Duncan P. N. Exon Smith | 1732340 | 2015-10-13 17:51:03 +0000 | [diff] [blame] | 165 | ScalarizeTable &ArgIndices = ScalarizedElements[&*I]; |
Chandler Carruth | cdf4788 | 2014-03-09 03:16:01 +0000 | [diff] [blame] | 166 | for (User *U : I->users()) { |
| 167 | Instruction *UI = cast<Instruction>(U); |
David Blaikie | 7682663 | 2015-03-14 21:11:26 +0000 | [diff] [blame] | 168 | Type *SrcTy; |
| 169 | if (LoadInst *L = dyn_cast<LoadInst>(UI)) |
| 170 | SrcTy = L->getType(); |
| 171 | else |
| 172 | SrcTy = cast<GetElementPtrInst>(UI)->getSourceElementType(); |
Matthijs Kooijman | fd30704 | 2008-07-29 10:00:13 +0000 | [diff] [blame] | 173 | IndicesVector Indices; |
Chandler Carruth | cdf4788 | 2014-03-09 03:16:01 +0000 | [diff] [blame] | 174 | Indices.reserve(UI->getNumOperands() - 1); |
Matthijs Kooijman | fd30704 | 2008-07-29 10:00:13 +0000 | [diff] [blame] | 175 | // Since loads will only have a single operand, and GEPs only a single |
| 176 | // non-index operand, this will record direct loads without any indices, |
| 177 | // and gep+loads with the GEP indices. |
Chandler Carruth | cdf4788 | 2014-03-09 03:16:01 +0000 | [diff] [blame] | 178 | for (User::op_iterator II = UI->op_begin() + 1, IE = UI->op_end(); |
Matthijs Kooijman | fd30704 | 2008-07-29 10:00:13 +0000 | [diff] [blame] | 179 | II != IE; ++II) |
| 180 | Indices.push_back(cast<ConstantInt>(*II)->getSExtValue()); |
| 181 | // GEPs with a single 0 index can be merged with direct loads |
| 182 | if (Indices.size() == 1 && Indices.front() == 0) |
| 183 | Indices.clear(); |
David Blaikie | 7682663 | 2015-03-14 21:11:26 +0000 | [diff] [blame] | 184 | ArgIndices.insert(std::make_pair(SrcTy, Indices)); |
Owen Anderson | edadd3f | 2006-09-15 05:22:51 +0000 | [diff] [blame] | 185 | LoadInst *OrigLoad; |
Chandler Carruth | cdf4788 | 2014-03-09 03:16:01 +0000 | [diff] [blame] | 186 | if (LoadInst *L = dyn_cast<LoadInst>(UI)) |
Owen Anderson | edadd3f | 2006-09-15 05:22:51 +0000 | [diff] [blame] | 187 | OrigLoad = L; |
| 188 | else |
Matthijs Kooijman | fd30704 | 2008-07-29 10:00:13 +0000 | [diff] [blame] | 189 | // Take any load, we will use it only to update Alias Analysis |
Chandler Carruth | cdf4788 | 2014-03-09 03:16:01 +0000 | [diff] [blame] | 190 | OrigLoad = cast<LoadInst>(UI->user_back()); |
Duncan P. N. Exon Smith | 1732340 | 2015-10-13 17:51:03 +0000 | [diff] [blame] | 191 | OriginalLoads[std::make_pair(&*I, Indices)] = OrigLoad; |
Chris Lattner | fe6f2e3 | 2004-03-08 01:04:36 +0000 | [diff] [blame] | 192 | } |
| 193 | |
| 194 | // Add a parameter to the function for each element passed in. |
Benjamin Kramer | 135f735 | 2016-06-26 12:28:59 +0000 | [diff] [blame] | 195 | for (const auto &ArgIndex : ArgIndices) { |
Torok Edwin | 026259f | 2008-11-16 17:21:25 +0000 | [diff] [blame] | 196 | // not allowed to dereference ->begin() if size() is 0 |
David Blaikie | d288fb8 | 2015-03-30 21:41:43 +0000 | [diff] [blame] | 197 | Params.push_back(GetElementPtrInst::getIndexedType( |
| 198 | cast<PointerType>(I->getType()->getScalarType())->getElementType(), |
Benjamin Kramer | 135f735 | 2016-06-26 12:28:59 +0000 | [diff] [blame] | 199 | ArgIndex.second)); |
Reid Kleckner | 7f72033 | 2017-04-13 00:58:09 +0000 | [diff] [blame] | 200 | ArgAttrVec.push_back(AttributeSet()); |
Matthijs Kooijman | fd30704 | 2008-07-29 10:00:13 +0000 | [diff] [blame] | 201 | assert(Params.back()); |
| 202 | } |
Chris Lattner | fe6f2e3 | 2004-03-08 01:04:36 +0000 | [diff] [blame] | 203 | |
David Blaikie | 7682663 | 2015-03-14 21:11:26 +0000 | [diff] [blame] | 204 | if (ArgIndices.size() == 1 && ArgIndices.begin()->second.empty()) |
Chris Lattner | fe6f2e3 | 2004-03-08 01:04:36 +0000 | [diff] [blame] | 205 | ++NumArgumentsPromoted; |
| 206 | else |
| 207 | ++NumAggregatesPromoted; |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 208 | } |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 209 | } |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 210 | |
Chris Lattner | 229907c | 2011-07-18 04:54:35 +0000 | [diff] [blame] | 211 | Type *RetTy = FTy->getReturnType(); |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 212 | |
Duncan Sands | ad0ea2d | 2007-11-27 13:23:08 +0000 | [diff] [blame] | 213 | // Construct the new function type using the new arguments. |
Owen Anderson | 4056ca9 | 2009-07-29 22:17:13 +0000 | [diff] [blame] | 214 | FunctionType *NFTy = FunctionType::get(RetTy, Params, FTy->isVarArg()); |
Misha Brukman | b1c9317 | 2005-04-21 23:48:37 +0000 | [diff] [blame] | 215 | |
Chris Lattner | e098721 | 2009-09-15 05:40:35 +0000 | [diff] [blame] | 216 | // Create the new function body and insert it into the module. |
Dylan McKay | f920da0 | 2018-12-18 09:52:52 +0000 | [diff] [blame] | 217 | Function *NF = Function::Create(NFTy, F->getLinkage(), F->getAddressSpace(), |
| 218 | F->getName()); |
Duncan Sands | dd7daee | 2008-05-26 19:58:59 +0000 | [diff] [blame] | 219 | NF->copyAttributesFrom(F); |
Chris Lattner | 5630c4f | 2008-01-17 01:17:03 +0000 | [diff] [blame] | 220 | |
David Blaikie | e844cd5 | 2014-07-01 21:13:37 +0000 | [diff] [blame] | 221 | // Patch the pointer to LLVM function in debug info descriptor. |
Peter Collingbourne | d4bff30 | 2015-11-05 22:03:56 +0000 | [diff] [blame] | 222 | NF->setSubprogram(F->getSubprogram()); |
| 223 | F->setSubprogram(nullptr); |
David Blaikie | 8e9cfa5 | 2014-07-23 22:09:29 +0000 | [diff] [blame] | 224 | |
Nicola Zaghen | d34e60c | 2018-05-14 12:53:11 +0000 | [diff] [blame] | 225 | LLVM_DEBUG(dbgs() << "ARG PROMOTION: Promoting to:" << *NF << "\n" |
| 226 | << "From: " << *F); |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 227 | |
Chris Lattner | 5630c4f | 2008-01-17 01:17:03 +0000 | [diff] [blame] | 228 | // Recompute the parameter attributes list based on the new arguments for |
| 229 | // the function. |
Reid Kleckner | 7f72033 | 2017-04-13 00:58:09 +0000 | [diff] [blame] | 230 | NF->setAttributes(AttributeList::get(F->getContext(), PAL.getFnAttributes(), |
| 231 | PAL.getRetAttributes(), ArgAttrVec)); |
| 232 | ArgAttrVec.clear(); |
Duncan Sands | dd7daee | 2008-05-26 19:58:59 +0000 | [diff] [blame] | 233 | |
Duncan P. N. Exon Smith | 1732340 | 2015-10-13 17:51:03 +0000 | [diff] [blame] | 234 | F->getParent()->getFunctionList().insert(F->getIterator(), NF); |
Zhou Sheng | a30cdb9 | 2008-03-20 08:05:05 +0000 | [diff] [blame] | 235 | NF->takeName(F); |
Chris Lattner | 254f8f8 | 2004-05-23 21:21:17 +0000 | [diff] [blame] | 236 | |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 237 | // Loop over all of the callers of the function, transforming the call sites |
| 238 | // to pass in the loaded pointers. |
| 239 | // |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 240 | SmallVector<Value *, 16> Args; |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 241 | while (!F->use_empty()) { |
Chandler Carruth | cdf4788 | 2014-03-09 03:16:01 +0000 | [diff] [blame] | 242 | CallSite CS(F->user_back()); |
Gabor Greif | 161cb04 | 2010-03-23 14:40:20 +0000 | [diff] [blame] | 243 | assert(CS.getCalledFunction() == F); |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 244 | Instruction *Call = CS.getInstruction(); |
Reid Kleckner | b518054 | 2017-03-21 16:57:19 +0000 | [diff] [blame] | 245 | const AttributeList &CallPAL = CS.getAttributes(); |
Duncan Sands | 1ea0d2e | 2008-09-07 09:54:09 +0000 | [diff] [blame] | 246 | |
Chris Lattner | 254f8f8 | 2004-05-23 21:21:17 +0000 | [diff] [blame] | 247 | // Loop over the operands, inserting GEP and loads in the caller as |
| 248 | // appropriate. |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 249 | CallSite::arg_iterator AI = CS.arg_begin(); |
Reid Kleckner | 6652a52 | 2017-04-28 18:37:16 +0000 | [diff] [blame] | 250 | ArgNo = 0; |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 251 | for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; |
Reid Kleckner | 6652a52 | 2017-04-28 18:37:16 +0000 | [diff] [blame] | 252 | ++I, ++AI, ++ArgNo) |
Duncan P. N. Exon Smith | 1732340 | 2015-10-13 17:51:03 +0000 | [diff] [blame] | 253 | if (!ArgsToPromote.count(&*I) && !ByValArgsToTransform.count(&*I)) { |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 254 | Args.push_back(*AI); // Unmodified argument |
Reid Kleckner | 6652a52 | 2017-04-28 18:37:16 +0000 | [diff] [blame] | 255 | ArgAttrVec.push_back(CallPAL.getParamAttributes(ArgNo)); |
Duncan P. N. Exon Smith | 1732340 | 2015-10-13 17:51:03 +0000 | [diff] [blame] | 256 | } else if (ByValArgsToTransform.count(&*I)) { |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 257 | // Emit a GEP and load for each element of the struct. |
Chris Lattner | 229907c | 2011-07-18 04:54:35 +0000 | [diff] [blame] | 258 | Type *AgTy = cast<PointerType>(I->getType())->getElementType(); |
| 259 | StructType *STy = cast<StructType>(AgTy); |
Owen Anderson | 55f1c09 | 2009-08-13 21:58:54 +0000 | [diff] [blame] | 260 | Value *Idxs[2] = { |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 261 | ConstantInt::get(Type::getInt32Ty(F->getContext()), 0), nullptr}; |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 262 | for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { |
Owen Anderson | 55f1c09 | 2009-08-13 21:58:54 +0000 | [diff] [blame] | 263 | Idxs[1] = ConstantInt::get(Type::getInt32Ty(F->getContext()), i); |
David Blaikie | 7682663 | 2015-03-14 21:11:26 +0000 | [diff] [blame] | 264 | Value *Idx = GetElementPtrInst::Create( |
Benjamin Kramer | dba7ee9 | 2015-05-28 11:24:24 +0000 | [diff] [blame] | 265 | STy, *AI, Idxs, (*AI)->getName() + "." + Twine(i), Call); |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 266 | // TODO: Tell AA about the new values? |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 267 | Args.push_back(new LoadInst(Idx, Idx->getName() + ".val", Call)); |
Reid Kleckner | 7f72033 | 2017-04-13 00:58:09 +0000 | [diff] [blame] | 268 | ArgAttrVec.push_back(AttributeSet()); |
Duncan Sands | 1ea0d2e | 2008-09-07 09:54:09 +0000 | [diff] [blame] | 269 | } |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 270 | } else if (!I->use_empty()) { |
Chris Lattner | 254f8f8 | 2004-05-23 21:21:17 +0000 | [diff] [blame] | 271 | // Non-dead argument: insert GEPs and loads as appropriate. |
Duncan P. N. Exon Smith | 1732340 | 2015-10-13 17:51:03 +0000 | [diff] [blame] | 272 | ScalarizeTable &ArgIndices = ScalarizedElements[&*I]; |
Matthijs Kooijman | fd30704 | 2008-07-29 10:00:13 +0000 | [diff] [blame] | 273 | // Store the Value* version of the indices in here, but declare it now |
Gabor Greif | 161cb04 | 2010-03-23 14:40:20 +0000 | [diff] [blame] | 274 | // for reuse. |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 275 | std::vector<Value *> Ops; |
Benjamin Kramer | 135f735 | 2016-06-26 12:28:59 +0000 | [diff] [blame] | 276 | for (const auto &ArgIndex : ArgIndices) { |
Chris Lattner | fe6f2e3 | 2004-03-08 01:04:36 +0000 | [diff] [blame] | 277 | Value *V = *AI; |
Benjamin Kramer | 135f735 | 2016-06-26 12:28:59 +0000 | [diff] [blame] | 278 | LoadInst *OrigLoad = |
| 279 | OriginalLoads[std::make_pair(&*I, ArgIndex.second)]; |
| 280 | if (!ArgIndex.second.empty()) { |
| 281 | Ops.reserve(ArgIndex.second.size()); |
Chris Lattner | 229907c | 2011-07-18 04:54:35 +0000 | [diff] [blame] | 282 | Type *ElTy = V->getType(); |
Martin Storsjo | e81233d | 2017-05-04 10:54:35 +0000 | [diff] [blame] | 283 | for (auto II : ArgIndex.second) { |
Matthijs Kooijman | fd30704 | 2008-07-29 10:00:13 +0000 | [diff] [blame] | 284 | // Use i32 to index structs, and i64 for others (pointers/arrays). |
| 285 | // This satisfies GEP constraints. |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 286 | Type *IdxTy = |
| 287 | (ElTy->isStructTy() ? Type::getInt32Ty(F->getContext()) |
| 288 | : Type::getInt64Ty(F->getContext())); |
Benjamin Kramer | 135f735 | 2016-06-26 12:28:59 +0000 | [diff] [blame] | 289 | Ops.push_back(ConstantInt::get(IdxTy, II)); |
Gabor Greif | 161cb04 | 2010-03-23 14:40:20 +0000 | [diff] [blame] | 290 | // Keep track of the type we're currently indexing. |
Peter Collingbourne | 4568158 | 2016-12-02 03:05:41 +0000 | [diff] [blame] | 291 | if (auto *ElPTy = dyn_cast<PointerType>(ElTy)) |
| 292 | ElTy = ElPTy->getElementType(); |
| 293 | else |
| 294 | ElTy = cast<CompositeType>(ElTy)->getTypeAtIndex(II); |
Matthijs Kooijman | fd30704 | 2008-07-29 10:00:13 +0000 | [diff] [blame] | 295 | } |
Gabor Greif | 161cb04 | 2010-03-23 14:40:20 +0000 | [diff] [blame] | 296 | // And create a GEP to extract those indices. |
Benjamin Kramer | 135f735 | 2016-06-26 12:28:59 +0000 | [diff] [blame] | 297 | V = GetElementPtrInst::Create(ArgIndex.first, V, Ops, |
David Blaikie | 72edd88 | 2015-03-14 21:40:12 +0000 | [diff] [blame] | 298 | V->getName() + ".idx", Call); |
Matthijs Kooijman | fd30704 | 2008-07-29 10:00:13 +0000 | [diff] [blame] | 299 | Ops.clear(); |
Chris Lattner | 254f8f8 | 2004-05-23 21:21:17 +0000 | [diff] [blame] | 300 | } |
Eric Christopher | 81c0344 | 2010-03-27 01:54:00 +0000 | [diff] [blame] | 301 | // Since we're replacing a load make sure we take the alignment |
| 302 | // of the previous load. |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 303 | LoadInst *newLoad = new LoadInst(V, V->getName() + ".val", Call); |
Eric Christopher | 81c0344 | 2010-03-27 01:54:00 +0000 | [diff] [blame] | 304 | newLoad->setAlignment(OrigLoad->getAlignment()); |
Hal Finkel | cc39b67 | 2014-07-24 12:16:19 +0000 | [diff] [blame] | 305 | // Transfer the AA info too. |
| 306 | AAMDNodes AAInfo; |
| 307 | OrigLoad->getAAMetadata(AAInfo); |
| 308 | newLoad->setAAMetadata(AAInfo); |
| 309 | |
Eric Christopher | 81c0344 | 2010-03-27 01:54:00 +0000 | [diff] [blame] | 310 | Args.push_back(newLoad); |
Reid Kleckner | 7f72033 | 2017-04-13 00:58:09 +0000 | [diff] [blame] | 311 | ArgAttrVec.push_back(AttributeSet()); |
Chris Lattner | fe6f2e3 | 2004-03-08 01:04:36 +0000 | [diff] [blame] | 312 | } |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 313 | } |
| 314 | |
Gabor Greif | 161cb04 | 2010-03-23 14:40:20 +0000 | [diff] [blame] | 315 | // Push any varargs arguments on the list. |
Reid Kleckner | 6652a52 | 2017-04-28 18:37:16 +0000 | [diff] [blame] | 316 | for (; AI != CS.arg_end(); ++AI, ++ArgNo) { |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 317 | Args.push_back(*AI); |
Reid Kleckner | 6652a52 | 2017-04-28 18:37:16 +0000 | [diff] [blame] | 318 | ArgAttrVec.push_back(CallPAL.getParamAttributes(ArgNo)); |
Chris Lattner | 5630c4f | 2008-01-17 01:17:03 +0000 | [diff] [blame] | 319 | } |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 320 | |
David Majnemer | cd24bb1 | 2016-04-29 04:56:12 +0000 | [diff] [blame] | 321 | SmallVector<OperandBundleDef, 1> OpBundles; |
| 322 | CS.getOperandBundlesAsDefs(OpBundles); |
| 323 | |
Reid Kleckner | 7f72033 | 2017-04-13 00:58:09 +0000 | [diff] [blame] | 324 | CallSite NewCS; |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 325 | if (InvokeInst *II = dyn_cast<InvokeInst>(Call)) { |
Reid Kleckner | 7f72033 | 2017-04-13 00:58:09 +0000 | [diff] [blame] | 326 | NewCS = InvokeInst::Create(NF, II->getNormalDest(), II->getUnwindDest(), |
Reid Kleckner | 3a11503 | 2017-04-13 18:10:30 +0000 | [diff] [blame] | 327 | Args, OpBundles, "", Call); |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 328 | } else { |
Reid Kleckner | 7f72033 | 2017-04-13 00:58:09 +0000 | [diff] [blame] | 329 | auto *NewCall = CallInst::Create(NF, Args, OpBundles, "", Call); |
| 330 | NewCall->setTailCallKind(cast<CallInst>(Call)->getTailCallKind()); |
| 331 | NewCS = NewCall; |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 332 | } |
Reid Kleckner | 7f72033 | 2017-04-13 00:58:09 +0000 | [diff] [blame] | 333 | NewCS.setCallingConv(CS.getCallingConv()); |
| 334 | NewCS.setAttributes( |
| 335 | AttributeList::get(F->getContext(), CallPAL.getFnAttributes(), |
| 336 | CallPAL.getRetAttributes(), ArgAttrVec)); |
| 337 | NewCS->setDebugLoc(Call->getDebugLoc()); |
Reid Kleckner | 3a11503 | 2017-04-13 18:10:30 +0000 | [diff] [blame] | 338 | uint64_t W; |
| 339 | if (Call->extractProfTotalWeight(W)) |
| 340 | NewCS->setProfWeight(W); |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 341 | Args.clear(); |
Reid Kleckner | 7f72033 | 2017-04-13 00:58:09 +0000 | [diff] [blame] | 342 | ArgAttrVec.clear(); |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 343 | |
Duncan Sands | 3cf7d86 | 2008-09-08 11:07:35 +0000 | [diff] [blame] | 344 | // Update the callgraph to know that the callsite has been transformed. |
Chandler Carruth | addcda4 | 2017-02-09 23:46:27 +0000 | [diff] [blame] | 345 | if (ReplaceCallSite) |
Reid Kleckner | 7f72033 | 2017-04-13 00:58:09 +0000 | [diff] [blame] | 346 | (*ReplaceCallSite)(CS, NewCS); |
Duncan Sands | 3cf7d86 | 2008-09-08 11:07:35 +0000 | [diff] [blame] | 347 | |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 348 | if (!Call->use_empty()) { |
Reid Kleckner | 7f72033 | 2017-04-13 00:58:09 +0000 | [diff] [blame] | 349 | Call->replaceAllUsesWith(NewCS.getInstruction()); |
| 350 | NewCS->takeName(Call); |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 351 | } |
Misha Brukman | b1c9317 | 2005-04-21 23:48:37 +0000 | [diff] [blame] | 352 | |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 353 | // Finally, remove the old call from the program, reducing the use-count of |
| 354 | // F. |
Chris Lattner | 4062a62 | 2008-01-11 19:20:39 +0000 | [diff] [blame] | 355 | Call->eraseFromParent(); |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 356 | } |
| 357 | |
Matt Arsenault | 3c1fc76 | 2017-04-10 22:27:50 +0000 | [diff] [blame] | 358 | const DataLayout &DL = F->getParent()->getDataLayout(); |
| 359 | |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 360 | // Since we have now created the new function, splice the body of the old |
| 361 | // function right into the new function, leaving the old rotting hulk of the |
| 362 | // function empty. |
| 363 | NF->getBasicBlockList().splice(NF->begin(), F->getBasicBlockList()); |
| 364 | |
Chris Lattner | 0ab5e2c | 2011-04-15 05:18:47 +0000 | [diff] [blame] | 365 | // Loop over the argument list, transferring uses of the old arguments over to |
| 366 | // the new arguments, also transferring over the names as well. |
Chris Lattner | a06a8fd | 2007-02-13 02:10:56 +0000 | [diff] [blame] | 367 | for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(), |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 368 | I2 = NF->arg_begin(); |
| 369 | I != E; ++I) { |
Duncan P. N. Exon Smith | 1732340 | 2015-10-13 17:51:03 +0000 | [diff] [blame] | 370 | if (!ArgsToPromote.count(&*I) && !ByValArgsToTransform.count(&*I)) { |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 371 | // If this is an unmodified argument, move the name and users over to the |
| 372 | // new version. |
Duncan P. N. Exon Smith | 1732340 | 2015-10-13 17:51:03 +0000 | [diff] [blame] | 373 | I->replaceAllUsesWith(&*I2); |
| 374 | I2->takeName(&*I); |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 375 | ++I2; |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 376 | continue; |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 377 | } |
Duncan Sands | 1ea0d2e | 2008-09-07 09:54:09 +0000 | [diff] [blame] | 378 | |
Duncan P. N. Exon Smith | 1732340 | 2015-10-13 17:51:03 +0000 | [diff] [blame] | 379 | if (ByValArgsToTransform.count(&*I)) { |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 380 | // In the callee, we create an alloca, and store each of the new incoming |
| 381 | // arguments into the alloca. |
Duncan P. N. Exon Smith | 1732340 | 2015-10-13 17:51:03 +0000 | [diff] [blame] | 382 | Instruction *InsertPt = &NF->begin()->front(); |
Duncan Sands | 1ea0d2e | 2008-09-07 09:54:09 +0000 | [diff] [blame] | 383 | |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 384 | // Just add all the struct element types. |
Chris Lattner | 229907c | 2011-07-18 04:54:35 +0000 | [diff] [blame] | 385 | Type *AgTy = cast<PointerType>(I->getType())->getElementType(); |
Matt Arsenault | 3c1fc76 | 2017-04-10 22:27:50 +0000 | [diff] [blame] | 386 | Value *TheAlloca = new AllocaInst(AgTy, DL.getAllocaAddrSpace(), nullptr, |
Reid Kleckner | da748f1 | 2017-08-04 17:09:11 +0000 | [diff] [blame] | 387 | I->getParamAlignment(), "", InsertPt); |
Chris Lattner | 229907c | 2011-07-18 04:54:35 +0000 | [diff] [blame] | 388 | StructType *STy = cast<StructType>(AgTy); |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 389 | Value *Idxs[2] = {ConstantInt::get(Type::getInt32Ty(F->getContext()), 0), |
| 390 | nullptr}; |
Duncan Sands | 1ea0d2e | 2008-09-07 09:54:09 +0000 | [diff] [blame] | 391 | |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 392 | for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { |
Owen Anderson | 55f1c09 | 2009-08-13 21:58:54 +0000 | [diff] [blame] | 393 | Idxs[1] = ConstantInt::get(Type::getInt32Ty(F->getContext()), i); |
David Blaikie | 096b1da | 2015-03-14 19:53:33 +0000 | [diff] [blame] | 394 | Value *Idx = GetElementPtrInst::Create( |
| 395 | AgTy, TheAlloca, Idxs, TheAlloca->getName() + "." + Twine(i), |
| 396 | InsertPt); |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 397 | I2->setName(I->getName() + "." + Twine(i)); |
Duncan P. N. Exon Smith | 1732340 | 2015-10-13 17:51:03 +0000 | [diff] [blame] | 398 | new StoreInst(&*I2++, Idx, InsertPt); |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 399 | } |
Duncan Sands | 1ea0d2e | 2008-09-07 09:54:09 +0000 | [diff] [blame] | 400 | |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 401 | // Anything that used the arg should now use the alloca. |
| 402 | I->replaceAllUsesWith(TheAlloca); |
Duncan P. N. Exon Smith | 1732340 | 2015-10-13 17:51:03 +0000 | [diff] [blame] | 403 | TheAlloca->takeName(&*I); |
Rafael Espindola | 2a05ea5 | 2014-01-23 17:19:42 +0000 | [diff] [blame] | 404 | |
| 405 | // If the alloca is used in a call, we must clear the tail flag since |
| 406 | // the callee now uses an alloca from the caller. |
Chandler Carruth | cdf4788 | 2014-03-09 03:16:01 +0000 | [diff] [blame] | 407 | for (User *U : TheAlloca->users()) { |
| 408 | CallInst *Call = dyn_cast<CallInst>(U); |
Rafael Espindola | 2a05ea5 | 2014-01-23 17:19:42 +0000 | [diff] [blame] | 409 | if (!Call) |
| 410 | continue; |
| 411 | Call->setTailCall(false); |
| 412 | } |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 413 | continue; |
Duncan Sands | 1ea0d2e | 2008-09-07 09:54:09 +0000 | [diff] [blame] | 414 | } |
| 415 | |
Chandler Carruth | a1032a0 | 2015-07-22 09:49:59 +0000 | [diff] [blame] | 416 | if (I->use_empty()) |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 417 | continue; |
Duncan Sands | 1ea0d2e | 2008-09-07 09:54:09 +0000 | [diff] [blame] | 418 | |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 419 | // Otherwise, if we promoted this argument, then all users are load |
Matthijs Kooijman | fd30704 | 2008-07-29 10:00:13 +0000 | [diff] [blame] | 420 | // instructions (or GEPs with only load users), and all loads should be |
| 421 | // using the new argument that we added. |
Duncan P. N. Exon Smith | 1732340 | 2015-10-13 17:51:03 +0000 | [diff] [blame] | 422 | ScalarizeTable &ArgIndices = ScalarizedElements[&*I]; |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 423 | |
| 424 | while (!I->use_empty()) { |
Chandler Carruth | cdf4788 | 2014-03-09 03:16:01 +0000 | [diff] [blame] | 425 | if (LoadInst *LI = dyn_cast<LoadInst>(I->user_back())) { |
David Blaikie | 7682663 | 2015-03-14 21:11:26 +0000 | [diff] [blame] | 426 | assert(ArgIndices.begin()->second.empty() && |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 427 | "Load element should sort to front!"); |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 428 | I2->setName(I->getName() + ".val"); |
Duncan P. N. Exon Smith | 1732340 | 2015-10-13 17:51:03 +0000 | [diff] [blame] | 429 | LI->replaceAllUsesWith(&*I2); |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 430 | LI->eraseFromParent(); |
Nicola Zaghen | d34e60c | 2018-05-14 12:53:11 +0000 | [diff] [blame] | 431 | LLVM_DEBUG(dbgs() << "*** Promoted load of argument '" << I->getName() |
| 432 | << "' in function '" << F->getName() << "'\n"); |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 433 | } else { |
Chandler Carruth | cdf4788 | 2014-03-09 03:16:01 +0000 | [diff] [blame] | 434 | GetElementPtrInst *GEP = cast<GetElementPtrInst>(I->user_back()); |
Matthijs Kooijman | fd30704 | 2008-07-29 10:00:13 +0000 | [diff] [blame] | 435 | IndicesVector Operands; |
| 436 | Operands.reserve(GEP->getNumIndices()); |
| 437 | for (User::op_iterator II = GEP->idx_begin(), IE = GEP->idx_end(); |
| 438 | II != IE; ++II) |
| 439 | Operands.push_back(cast<ConstantInt>(*II)->getSExtValue()); |
| 440 | |
| 441 | // GEPs with a single 0 index can be merged with direct loads |
| 442 | if (Operands.size() == 1 && Operands.front() == 0) |
| 443 | Operands.clear(); |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 444 | |
| 445 | Function::arg_iterator TheArg = I2; |
| 446 | for (ScalarizeTable::iterator It = ArgIndices.begin(); |
David Blaikie | 7682663 | 2015-03-14 21:11:26 +0000 | [diff] [blame] | 447 | It->second != Operands; ++It, ++TheArg) { |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 448 | assert(It != ArgIndices.end() && "GEP not handled??"); |
| 449 | } |
| 450 | |
| 451 | std::string NewName = I->getName(); |
Matthijs Kooijman | fd30704 | 2008-07-29 10:00:13 +0000 | [diff] [blame] | 452 | for (unsigned i = 0, e = Operands.size(); i != e; ++i) { |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 453 | NewName += "." + utostr(Operands[i]); |
Matthijs Kooijman | fd30704 | 2008-07-29 10:00:13 +0000 | [diff] [blame] | 454 | } |
| 455 | NewName += ".val"; |
| 456 | TheArg->setName(NewName); |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 457 | |
Nicola Zaghen | d34e60c | 2018-05-14 12:53:11 +0000 | [diff] [blame] | 458 | LLVM_DEBUG(dbgs() << "*** Promoted agg argument '" << TheArg->getName() |
| 459 | << "' of function '" << NF->getName() << "'\n"); |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 460 | |
| 461 | // All of the uses must be load instructions. Replace them all with |
| 462 | // the argument specified by ArgNo. |
| 463 | while (!GEP->use_empty()) { |
Chandler Carruth | cdf4788 | 2014-03-09 03:16:01 +0000 | [diff] [blame] | 464 | LoadInst *L = cast<LoadInst>(GEP->user_back()); |
Duncan P. N. Exon Smith | 1732340 | 2015-10-13 17:51:03 +0000 | [diff] [blame] | 465 | L->replaceAllUsesWith(&*TheArg); |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 466 | L->eraseFromParent(); |
| 467 | } |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 468 | GEP->eraseFromParent(); |
| 469 | } |
| 470 | } |
| 471 | |
| 472 | // Increment I2 past all of the arguments added for this promoted pointer. |
Benjamin Kramer | 8403625 | 2012-09-30 17:31:56 +0000 | [diff] [blame] | 473 | std::advance(I2, ArgIndices.size()); |
Chris Lattner | b5bd924 | 2008-01-11 22:31:41 +0000 | [diff] [blame] | 474 | } |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 475 | |
Chandler Carruth | addcda4 | 2017-02-09 23:46:27 +0000 | [diff] [blame] | 476 | return NF; |
Chris Lattner | 483ae01 | 2004-03-07 21:29:54 +0000 | [diff] [blame] | 477 | } |
David Blaikie | e844cd5 | 2014-07-01 21:13:37 +0000 | [diff] [blame] | 478 | |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 479 | /// AllCallersPassInValidPointerForArgument - Return true if we can prove that |
| 480 | /// all callees pass in a valid pointer for the specified function argument. |
Chandler Carruth | 8e9c0a8 | 2017-01-29 08:03:21 +0000 | [diff] [blame] | 481 | static bool allCallersPassInValidPointerForArgument(Argument *Arg) { |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 482 | Function *Callee = Arg->getParent(); |
| 483 | const DataLayout &DL = Callee->getParent()->getDataLayout(); |
| 484 | |
| 485 | unsigned ArgNo = Arg->getArgNo(); |
| 486 | |
| 487 | // Look at all call sites of the function. At this point we know we only have |
| 488 | // direct callees. |
| 489 | for (User *U : Callee->users()) { |
| 490 | CallSite CS(U); |
| 491 | assert(CS && "Should only have direct calls!"); |
| 492 | |
| 493 | if (!isDereferenceablePointer(CS.getArgument(ArgNo), DL)) |
| 494 | return false; |
| 495 | } |
| 496 | return true; |
| 497 | } |
| 498 | |
| 499 | /// Returns true if Prefix is a prefix of longer. That means, Longer has a size |
| 500 | /// that is greater than or equal to the size of prefix, and each of the |
| 501 | /// elements in Prefix is the same as the corresponding elements in Longer. |
| 502 | /// |
| 503 | /// This means it also returns true when Prefix and Longer are equal! |
Chandler Carruth | 8e9c0a8 | 2017-01-29 08:03:21 +0000 | [diff] [blame] | 504 | static bool isPrefix(const IndicesVector &Prefix, const IndicesVector &Longer) { |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 505 | if (Prefix.size() > Longer.size()) |
| 506 | return false; |
| 507 | return std::equal(Prefix.begin(), Prefix.end(), Longer.begin()); |
| 508 | } |
| 509 | |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 510 | /// Checks if Indices, or a prefix of Indices, is in Set. |
Chandler Carruth | 8e9c0a8 | 2017-01-29 08:03:21 +0000 | [diff] [blame] | 511 | static bool prefixIn(const IndicesVector &Indices, |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 512 | std::set<IndicesVector> &Set) { |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 513 | std::set<IndicesVector>::iterator Low; |
| 514 | Low = Set.upper_bound(Indices); |
| 515 | if (Low != Set.begin()) |
| 516 | Low--; |
| 517 | // Low is now the last element smaller than or equal to Indices. This means |
| 518 | // it points to a prefix of Indices (possibly Indices itself), if such |
| 519 | // prefix exists. |
| 520 | // |
| 521 | // This load is safe if any prefix of its operands is safe to load. |
Chandler Carruth | 8e9c0a8 | 2017-01-29 08:03:21 +0000 | [diff] [blame] | 522 | return Low != Set.end() && isPrefix(*Low, Indices); |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 523 | } |
| 524 | |
| 525 | /// Mark the given indices (ToMark) as safe in the given set of indices |
| 526 | /// (Safe). Marking safe usually means adding ToMark to Safe. However, if there |
| 527 | /// is already a prefix of Indices in Safe, Indices are implicitely marked safe |
| 528 | /// already. Furthermore, any indices that Indices is itself a prefix of, are |
| 529 | /// removed from Safe (since they are implicitely safe because of Indices now). |
Chandler Carruth | 8e9c0a8 | 2017-01-29 08:03:21 +0000 | [diff] [blame] | 530 | static void markIndicesSafe(const IndicesVector &ToMark, |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 531 | std::set<IndicesVector> &Safe) { |
| 532 | std::set<IndicesVector>::iterator Low; |
| 533 | Low = Safe.upper_bound(ToMark); |
| 534 | // Guard against the case where Safe is empty |
| 535 | if (Low != Safe.begin()) |
| 536 | Low--; |
| 537 | // Low is now the last element smaller than or equal to Indices. This |
| 538 | // means it points to a prefix of Indices (possibly Indices itself), if |
| 539 | // such prefix exists. |
| 540 | if (Low != Safe.end()) { |
Chandler Carruth | 8e9c0a8 | 2017-01-29 08:03:21 +0000 | [diff] [blame] | 541 | if (isPrefix(*Low, ToMark)) |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 542 | // If there is already a prefix of these indices (or exactly these |
| 543 | // indices) marked a safe, don't bother adding these indices |
| 544 | return; |
| 545 | |
| 546 | // Increment Low, so we can use it as a "insert before" hint |
| 547 | ++Low; |
| 548 | } |
| 549 | // Insert |
| 550 | Low = Safe.insert(Low, ToMark); |
| 551 | ++Low; |
| 552 | // If there we're a prefix of longer index list(s), remove those |
| 553 | std::set<IndicesVector>::iterator End = Safe.end(); |
Chandler Carruth | 8e9c0a8 | 2017-01-29 08:03:21 +0000 | [diff] [blame] | 554 | while (Low != End && isPrefix(ToMark, *Low)) { |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 555 | std::set<IndicesVector>::iterator Remove = Low; |
| 556 | ++Low; |
| 557 | Safe.erase(Remove); |
| 558 | } |
| 559 | } |
| 560 | |
| 561 | /// isSafeToPromoteArgument - As you might guess from the name of this method, |
| 562 | /// it checks to see if it is both safe and useful to promote the argument. |
| 563 | /// This method limits promotion of aggregates to only promote up to three |
| 564 | /// elements of the aggregate in order to avoid exploding the number of |
| 565 | /// arguments passed in. |
| 566 | static bool isSafeToPromoteArgument(Argument *Arg, bool isByValOrInAlloca, |
| 567 | AAResults &AAR, unsigned MaxElements) { |
Eugene Zelenko | f27d161 | 2017-10-19 21:21:30 +0000 | [diff] [blame] | 568 | using GEPIndicesSet = std::set<IndicesVector>; |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 569 | |
| 570 | // Quick exit for unused arguments |
| 571 | if (Arg->use_empty()) |
| 572 | return true; |
| 573 | |
| 574 | // We can only promote this argument if all of the uses are loads, or are GEP |
| 575 | // instructions (with constant indices) that are subsequently loaded. |
| 576 | // |
| 577 | // Promoting the argument causes it to be loaded in the caller |
| 578 | // unconditionally. This is only safe if we can prove that either the load |
| 579 | // would have happened in the callee anyway (ie, there is a load in the entry |
| 580 | // block) or the pointer passed in at every call site is guaranteed to be |
| 581 | // valid. |
| 582 | // In the former case, invalid loads can happen, but would have happened |
| 583 | // anyway, in the latter case, invalid loads won't happen. This prevents us |
| 584 | // from introducing an invalid load that wouldn't have happened in the |
| 585 | // original code. |
| 586 | // |
| 587 | // This set will contain all sets of indices that are loaded in the entry |
| 588 | // block, and thus are safe to unconditionally load in the caller. |
| 589 | // |
| 590 | // This optimization is also safe for InAlloca parameters, because it verifies |
| 591 | // that the address isn't captured. |
| 592 | GEPIndicesSet SafeToUnconditionallyLoad; |
| 593 | |
| 594 | // This set contains all the sets of indices that we are planning to promote. |
| 595 | // This makes it possible to limit the number of arguments added. |
| 596 | GEPIndicesSet ToPromote; |
| 597 | |
| 598 | // If the pointer is always valid, any load with first index 0 is valid. |
Chandler Carruth | 8e9c0a8 | 2017-01-29 08:03:21 +0000 | [diff] [blame] | 599 | if (isByValOrInAlloca || allCallersPassInValidPointerForArgument(Arg)) |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 600 | SafeToUnconditionallyLoad.insert(IndicesVector(1, 0)); |
| 601 | |
| 602 | // First, iterate the entry block and mark loads of (geps of) arguments as |
| 603 | // safe. |
| 604 | BasicBlock &EntryBlock = Arg->getParent()->front(); |
| 605 | // Declare this here so we can reuse it |
| 606 | IndicesVector Indices; |
| 607 | for (Instruction &I : EntryBlock) |
| 608 | if (LoadInst *LI = dyn_cast<LoadInst>(&I)) { |
| 609 | Value *V = LI->getPointerOperand(); |
| 610 | if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(V)) { |
| 611 | V = GEP->getPointerOperand(); |
| 612 | if (V == Arg) { |
| 613 | // This load actually loads (part of) Arg? Check the indices then. |
| 614 | Indices.reserve(GEP->getNumIndices()); |
| 615 | for (User::op_iterator II = GEP->idx_begin(), IE = GEP->idx_end(); |
| 616 | II != IE; ++II) |
| 617 | if (ConstantInt *CI = dyn_cast<ConstantInt>(*II)) |
| 618 | Indices.push_back(CI->getSExtValue()); |
| 619 | else |
| 620 | // We found a non-constant GEP index for this argument? Bail out |
| 621 | // right away, can't promote this argument at all. |
| 622 | return false; |
| 623 | |
| 624 | // Indices checked out, mark them as safe |
Chandler Carruth | 8e9c0a8 | 2017-01-29 08:03:21 +0000 | [diff] [blame] | 625 | markIndicesSafe(Indices, SafeToUnconditionallyLoad); |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 626 | Indices.clear(); |
| 627 | } |
| 628 | } else if (V == Arg) { |
| 629 | // Direct loads are equivalent to a GEP with a single 0 index. |
Chandler Carruth | 8e9c0a8 | 2017-01-29 08:03:21 +0000 | [diff] [blame] | 630 | markIndicesSafe(IndicesVector(1, 0), SafeToUnconditionallyLoad); |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 631 | } |
| 632 | } |
| 633 | |
| 634 | // Now, iterate all uses of the argument to see if there are any uses that are |
| 635 | // not (GEP+)loads, or any (GEP+)loads that are not safe to promote. |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 636 | SmallVector<LoadInst *, 16> Loads; |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 637 | IndicesVector Operands; |
| 638 | for (Use &U : Arg->uses()) { |
| 639 | User *UR = U.getUser(); |
| 640 | Operands.clear(); |
| 641 | if (LoadInst *LI = dyn_cast<LoadInst>(UR)) { |
| 642 | // Don't hack volatile/atomic loads |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 643 | if (!LI->isSimple()) |
| 644 | return false; |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 645 | Loads.push_back(LI); |
| 646 | // Direct loads are equivalent to a GEP with a zero index and then a load. |
| 647 | Operands.push_back(0); |
| 648 | } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(UR)) { |
| 649 | if (GEP->use_empty()) { |
| 650 | // Dead GEP's cause trouble later. Just remove them if we run into |
| 651 | // them. |
| 652 | GEP->eraseFromParent(); |
| 653 | // TODO: This runs the above loop over and over again for dead GEPs |
| 654 | // Couldn't we just do increment the UI iterator earlier and erase the |
| 655 | // use? |
| 656 | return isSafeToPromoteArgument(Arg, isByValOrInAlloca, AAR, |
| 657 | MaxElements); |
| 658 | } |
| 659 | |
| 660 | // Ensure that all of the indices are constants. |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 661 | for (User::op_iterator i = GEP->idx_begin(), e = GEP->idx_end(); i != e; |
| 662 | ++i) |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 663 | if (ConstantInt *C = dyn_cast<ConstantInt>(*i)) |
| 664 | Operands.push_back(C->getSExtValue()); |
| 665 | else |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 666 | return false; // Not a constant operand GEP! |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 667 | |
| 668 | // Ensure that the only users of the GEP are load instructions. |
| 669 | for (User *GEPU : GEP->users()) |
| 670 | if (LoadInst *LI = dyn_cast<LoadInst>(GEPU)) { |
| 671 | // Don't hack volatile/atomic loads |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 672 | if (!LI->isSimple()) |
| 673 | return false; |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 674 | Loads.push_back(LI); |
| 675 | } else { |
| 676 | // Other uses than load? |
| 677 | return false; |
| 678 | } |
| 679 | } else { |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 680 | return false; // Not a load or a GEP. |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 681 | } |
| 682 | |
| 683 | // Now, see if it is safe to promote this load / loads of this GEP. Loading |
| 684 | // is safe if Operands, or a prefix of Operands, is marked as safe. |
Chandler Carruth | 8e9c0a8 | 2017-01-29 08:03:21 +0000 | [diff] [blame] | 685 | if (!prefixIn(Operands, SafeToUnconditionallyLoad)) |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 686 | return false; |
| 687 | |
| 688 | // See if we are already promoting a load with these indices. If not, check |
| 689 | // to make sure that we aren't promoting too many elements. If so, nothing |
| 690 | // to do. |
| 691 | if (ToPromote.find(Operands) == ToPromote.end()) { |
| 692 | if (MaxElements > 0 && ToPromote.size() == MaxElements) { |
Nicola Zaghen | d34e60c | 2018-05-14 12:53:11 +0000 | [diff] [blame] | 693 | LLVM_DEBUG(dbgs() << "argpromotion not promoting argument '" |
| 694 | << Arg->getName() |
| 695 | << "' because it would require adding more " |
| 696 | << "than " << MaxElements |
| 697 | << " arguments to the function.\n"); |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 698 | // We limit aggregate promotion to only promoting up to a fixed number |
| 699 | // of elements of the aggregate. |
| 700 | return false; |
| 701 | } |
| 702 | ToPromote.insert(std::move(Operands)); |
| 703 | } |
| 704 | } |
| 705 | |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 706 | if (Loads.empty()) |
| 707 | return true; // No users, this is a dead argument. |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 708 | |
| 709 | // Okay, now we know that the argument is only used by load instructions and |
| 710 | // it is safe to unconditionally perform all of them. Use alias analysis to |
| 711 | // check to see if the pointer is guaranteed to not be modified from entry of |
| 712 | // the function to each of the load instructions. |
| 713 | |
| 714 | // Because there could be several/many load instructions, remember which |
| 715 | // blocks we know to be transparent to the load. |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 716 | df_iterator_default_set<BasicBlock *, 16> TranspBlocks; |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 717 | |
| 718 | for (LoadInst *Load : Loads) { |
| 719 | // Check to see if the load is invalidated from the start of the block to |
| 720 | // the load itself. |
| 721 | BasicBlock *BB = Load->getParent(); |
| 722 | |
| 723 | MemoryLocation Loc = MemoryLocation::get(Load); |
Alina Sbirlea | 193429f | 2017-12-07 22:41:34 +0000 | [diff] [blame] | 724 | if (AAR.canInstructionRangeModRef(BB->front(), *Load, Loc, ModRefInfo::Mod)) |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 725 | return false; // Pointer is invalidated! |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 726 | |
| 727 | // Now check every path from the entry block to the load for transparency. |
| 728 | // To do this, we perform a depth first search on the inverse CFG from the |
| 729 | // loading block. |
| 730 | for (BasicBlock *P : predecessors(BB)) { |
| 731 | for (BasicBlock *TranspBB : inverse_depth_first_ext(P, TranspBlocks)) |
| 732 | if (AAR.canBasicBlockModify(*TranspBB, Loc)) |
| 733 | return false; |
| 734 | } |
| 735 | } |
| 736 | |
| 737 | // If the path from the entry of the function to each load is free of |
| 738 | // instructions that potentially invalidate the load, we can make the |
| 739 | // transformation! |
| 740 | return true; |
| 741 | } |
| 742 | |
Adrian Prantl | 5f8f34e4 | 2018-05-01 15:54:18 +0000 | [diff] [blame] | 743 | /// Checks if a type could have padding bytes. |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 744 | static bool isDenselyPacked(Type *type, const DataLayout &DL) { |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 745 | // There is no size information, so be conservative. |
| 746 | if (!type->isSized()) |
| 747 | return false; |
| 748 | |
| 749 | // If the alloc size is not equal to the storage size, then there are padding |
| 750 | // bytes. For x86_fp80 on x86-64, size: 80 alloc size: 128. |
| 751 | if (DL.getTypeSizeInBits(type) != DL.getTypeAllocSizeInBits(type)) |
| 752 | return false; |
| 753 | |
| 754 | if (!isa<CompositeType>(type)) |
| 755 | return true; |
| 756 | |
| 757 | // For homogenous sequential types, check for padding within members. |
| 758 | if (SequentialType *seqTy = dyn_cast<SequentialType>(type)) |
| 759 | return isDenselyPacked(seqTy->getElementType(), DL); |
| 760 | |
| 761 | // Check for padding within and between elements of a struct. |
| 762 | StructType *StructTy = cast<StructType>(type); |
| 763 | const StructLayout *Layout = DL.getStructLayout(StructTy); |
| 764 | uint64_t StartPos = 0; |
| 765 | for (unsigned i = 0, E = StructTy->getNumElements(); i < E; ++i) { |
| 766 | Type *ElTy = StructTy->getElementType(i); |
| 767 | if (!isDenselyPacked(ElTy, DL)) |
| 768 | return false; |
| 769 | if (StartPos != Layout->getElementOffsetInBits(i)) |
| 770 | return false; |
| 771 | StartPos += DL.getTypeAllocSizeInBits(ElTy); |
| 772 | } |
| 773 | |
| 774 | return true; |
| 775 | } |
| 776 | |
Adrian Prantl | 5f8f34e4 | 2018-05-01 15:54:18 +0000 | [diff] [blame] | 777 | /// Checks if the padding bytes of an argument could be accessed. |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 778 | static bool canPaddingBeAccessed(Argument *arg) { |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 779 | assert(arg->hasByValAttr()); |
| 780 | |
| 781 | // Track all the pointers to the argument to make sure they are not captured. |
| 782 | SmallPtrSet<Value *, 16> PtrValues; |
| 783 | PtrValues.insert(arg); |
| 784 | |
| 785 | // Track all of the stores. |
| 786 | SmallVector<StoreInst *, 16> Stores; |
| 787 | |
| 788 | // Scan through the uses recursively to make sure the pointer is always used |
| 789 | // sanely. |
| 790 | SmallVector<Value *, 16> WorkList; |
| 791 | WorkList.insert(WorkList.end(), arg->user_begin(), arg->user_end()); |
| 792 | while (!WorkList.empty()) { |
| 793 | Value *V = WorkList.back(); |
| 794 | WorkList.pop_back(); |
| 795 | if (isa<GetElementPtrInst>(V) || isa<PHINode>(V)) { |
| 796 | if (PtrValues.insert(V).second) |
| 797 | WorkList.insert(WorkList.end(), V->user_begin(), V->user_end()); |
| 798 | } else if (StoreInst *Store = dyn_cast<StoreInst>(V)) { |
| 799 | Stores.push_back(Store); |
| 800 | } else if (!isa<LoadInst>(V)) { |
| 801 | return true; |
| 802 | } |
| 803 | } |
| 804 | |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 805 | // Check to make sure the pointers aren't captured |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 806 | for (StoreInst *Store : Stores) |
| 807 | if (PtrValues.count(Store->getValueOperand())) |
| 808 | return true; |
| 809 | |
| 810 | return false; |
| 811 | } |
| 812 | |
Tom Stellard | 3d36e5c | 2019-01-16 05:15:31 +0000 | [diff] [blame] | 813 | static bool areFunctionArgsABICompatible( |
| 814 | const Function &F, const TargetTransformInfo &TTI, |
| 815 | SmallPtrSetImpl<Argument *> &ArgsToPromote, |
| 816 | SmallPtrSetImpl<Argument *> &ByValArgsToTransform) { |
| 817 | for (const Use &U : F.uses()) { |
| 818 | CallSite CS(U.getUser()); |
| 819 | const Function *Caller = CS.getCaller(); |
| 820 | const Function *Callee = CS.getCalledFunction(); |
| 821 | if (!TTI.areFunctionArgsABICompatible(Caller, Callee, ArgsToPromote) || |
| 822 | !TTI.areFunctionArgsABICompatible(Caller, Callee, ByValArgsToTransform)) |
| 823 | return false; |
| 824 | } |
| 825 | return true; |
| 826 | } |
| 827 | |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 828 | /// PromoteArguments - This method checks the specified function to see if there |
| 829 | /// are any promotable arguments and if it is safe to promote the function (for |
| 830 | /// example, all callers are direct). If safe to promote some arguments, it |
| 831 | /// calls the DoPromotion method. |
Chandler Carruth | addcda4 | 2017-02-09 23:46:27 +0000 | [diff] [blame] | 832 | static Function * |
| 833 | promoteArguments(Function *F, function_ref<AAResults &(Function &F)> AARGetter, |
| 834 | unsigned MaxElements, |
| 835 | Optional<function_ref<void(CallSite OldCS, CallSite NewCS)>> |
Tom Stellard | 3d36e5c | 2019-01-16 05:15:31 +0000 | [diff] [blame] | 836 | ReplaceCallSite, |
| 837 | const TargetTransformInfo &TTI) { |
Luke Cheeseman | 6c1e6bb | 2018-02-22 14:42:08 +0000 | [diff] [blame] | 838 | // Don't perform argument promotion for naked functions; otherwise we can end |
| 839 | // up removing parameters that are seemingly 'not used' as they are referred |
| 840 | // to in the assembly. |
| 841 | if(F->hasFnAttribute(Attribute::Naked)) |
| 842 | return nullptr; |
| 843 | |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 844 | // Make sure that it is local to this module. |
Chandler Carruth | addcda4 | 2017-02-09 23:46:27 +0000 | [diff] [blame] | 845 | if (!F->hasLocalLinkage()) |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 846 | return nullptr; |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 847 | |
| 848 | // Don't promote arguments for variadic functions. Adding, removing, or |
| 849 | // changing non-pack parameters can change the classification of pack |
| 850 | // parameters. Frontends encode that classification at the call site in the |
| 851 | // IR, while in the callee the classification is determined dynamically based |
| 852 | // on the number of registers consumed so far. |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 853 | if (F->isVarArg()) |
| 854 | return nullptr; |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 855 | |
| 856 | // First check: see if there are any pointer arguments! If not, quick exit. |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 857 | SmallVector<Argument *, 16> PointerArgs; |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 858 | for (Argument &I : F->args()) |
| 859 | if (I.getType()->isPointerTy()) |
| 860 | PointerArgs.push_back(&I); |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 861 | if (PointerArgs.empty()) |
| 862 | return nullptr; |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 863 | |
| 864 | // Second check: make sure that all callers are direct callers. We can't |
| 865 | // transform functions that have indirect callers. Also see if the function |
Tom Stellard | 3d36e5c | 2019-01-16 05:15:31 +0000 | [diff] [blame] | 866 | // is self-recursive and check that target features are compatible. |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 867 | bool isSelfRecursive = false; |
| 868 | for (Use &U : F->uses()) { |
| 869 | CallSite CS(U.getUser()); |
| 870 | // Must be a direct call. |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 871 | if (CS.getInstruction() == nullptr || !CS.isCallee(&U)) |
| 872 | return nullptr; |
| 873 | |
Fedor Indutny | 1571b12 | 2018-03-02 00:59:27 +0000 | [diff] [blame] | 874 | // Can't change signature of musttail callee |
| 875 | if (CS.isMustTailCall()) |
| 876 | return nullptr; |
| 877 | |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 878 | if (CS.getInstruction()->getParent()->getParent() == F) |
| 879 | isSelfRecursive = true; |
| 880 | } |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 881 | |
Fedor Indutny | 1571b12 | 2018-03-02 00:59:27 +0000 | [diff] [blame] | 882 | // Can't change signature of musttail caller |
| 883 | // FIXME: Support promoting whole chain of musttail functions |
| 884 | for (BasicBlock &BB : *F) |
| 885 | if (BB.getTerminatingMustTailCall()) |
| 886 | return nullptr; |
| 887 | |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 888 | const DataLayout &DL = F->getParent()->getDataLayout(); |
| 889 | |
| 890 | AAResults &AAR = AARGetter(*F); |
| 891 | |
| 892 | // Check to see which arguments are promotable. If an argument is promotable, |
| 893 | // add it to ArgsToPromote. |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 894 | SmallPtrSet<Argument *, 8> ArgsToPromote; |
| 895 | SmallPtrSet<Argument *, 8> ByValArgsToTransform; |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 896 | for (Argument *PtrArg : PointerArgs) { |
| 897 | Type *AgTy = cast<PointerType>(PtrArg->getType())->getElementType(); |
| 898 | |
| 899 | // Replace sret attribute with noalias. This reduces register pressure by |
| 900 | // avoiding a register copy. |
| 901 | if (PtrArg->hasStructRetAttr()) { |
| 902 | unsigned ArgNo = PtrArg->getArgNo(); |
Reid Kleckner | a0b45f4 | 2017-05-03 18:17:31 +0000 | [diff] [blame] | 903 | F->removeParamAttr(ArgNo, Attribute::StructRet); |
| 904 | F->addParamAttr(ArgNo, Attribute::NoAlias); |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 905 | for (Use &U : F->uses()) { |
| 906 | CallSite CS(U.getUser()); |
Reid Kleckner | a0b45f4 | 2017-05-03 18:17:31 +0000 | [diff] [blame] | 907 | CS.removeParamAttr(ArgNo, Attribute::StructRet); |
| 908 | CS.addParamAttr(ArgNo, Attribute::NoAlias); |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 909 | } |
| 910 | } |
| 911 | |
| 912 | // If this is a byval argument, and if the aggregate type is small, just |
| 913 | // pass the elements, which is always safe, if the passed value is densely |
| 914 | // packed or if we can prove the padding bytes are never accessed. This does |
| 915 | // not apply to inalloca. |
| 916 | bool isSafeToPromote = |
| 917 | PtrArg->hasByValAttr() && |
| 918 | (isDenselyPacked(AgTy, DL) || !canPaddingBeAccessed(PtrArg)); |
| 919 | if (isSafeToPromote) { |
| 920 | if (StructType *STy = dyn_cast<StructType>(AgTy)) { |
| 921 | if (MaxElements > 0 && STy->getNumElements() > MaxElements) { |
Nicola Zaghen | d34e60c | 2018-05-14 12:53:11 +0000 | [diff] [blame] | 922 | LLVM_DEBUG(dbgs() << "argpromotion disable promoting argument '" |
| 923 | << PtrArg->getName() |
| 924 | << "' because it would require adding more" |
| 925 | << " than " << MaxElements |
| 926 | << " arguments to the function.\n"); |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 927 | continue; |
| 928 | } |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 929 | |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 930 | // If all the elements are single-value types, we can promote it. |
| 931 | bool AllSimple = true; |
| 932 | for (const auto *EltTy : STy->elements()) { |
| 933 | if (!EltTy->isSingleValueType()) { |
| 934 | AllSimple = false; |
| 935 | break; |
| 936 | } |
| 937 | } |
| 938 | |
| 939 | // Safe to transform, don't even bother trying to "promote" it. |
| 940 | // Passing the elements as a scalar will allow sroa to hack on |
| 941 | // the new alloca we introduce. |
| 942 | if (AllSimple) { |
| 943 | ByValArgsToTransform.insert(PtrArg); |
| 944 | continue; |
| 945 | } |
| 946 | } |
| 947 | } |
| 948 | |
| 949 | // If the argument is a recursive type and we're in a recursive |
| 950 | // function, we could end up infinitely peeling the function argument. |
| 951 | if (isSelfRecursive) { |
| 952 | if (StructType *STy = dyn_cast<StructType>(AgTy)) { |
| 953 | bool RecursiveType = false; |
| 954 | for (const auto *EltTy : STy->elements()) { |
| 955 | if (EltTy == PtrArg->getType()) { |
| 956 | RecursiveType = true; |
| 957 | break; |
| 958 | } |
| 959 | } |
| 960 | if (RecursiveType) |
| 961 | continue; |
| 962 | } |
| 963 | } |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 964 | |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 965 | // Otherwise, see if we can promote the pointer to its value. |
| 966 | if (isSafeToPromoteArgument(PtrArg, PtrArg->hasByValOrInAllocaAttr(), AAR, |
| 967 | MaxElements)) |
| 968 | ArgsToPromote.insert(PtrArg); |
| 969 | } |
| 970 | |
| 971 | // No promotable pointer arguments. |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 972 | if (ArgsToPromote.empty() && ByValArgsToTransform.empty()) |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 973 | return nullptr; |
| 974 | |
Tom Stellard | 3d36e5c | 2019-01-16 05:15:31 +0000 | [diff] [blame] | 975 | if (!areFunctionArgsABICompatible(*F, TTI, ArgsToPromote, |
| 976 | ByValArgsToTransform)) |
| 977 | return nullptr; |
| 978 | |
Chandler Carruth | addcda4 | 2017-02-09 23:46:27 +0000 | [diff] [blame] | 979 | return doPromotion(F, ArgsToPromote, ByValArgsToTransform, ReplaceCallSite); |
| 980 | } |
| 981 | |
| 982 | PreservedAnalyses ArgumentPromotionPass::run(LazyCallGraph::SCC &C, |
| 983 | CGSCCAnalysisManager &AM, |
| 984 | LazyCallGraph &CG, |
| 985 | CGSCCUpdateResult &UR) { |
| 986 | bool Changed = false, LocalChange; |
| 987 | |
| 988 | // Iterate until we stop promoting from this SCC. |
| 989 | do { |
| 990 | LocalChange = false; |
| 991 | |
| 992 | for (LazyCallGraph::Node &N : C) { |
| 993 | Function &OldF = N.getFunction(); |
| 994 | |
| 995 | FunctionAnalysisManager &FAM = |
| 996 | AM.getResult<FunctionAnalysisManagerCGSCCProxy>(C, CG).getManager(); |
| 997 | // FIXME: This lambda must only be used with this function. We should |
| 998 | // skip the lambda and just get the AA results directly. |
| 999 | auto AARGetter = [&](Function &F) -> AAResults & { |
| 1000 | assert(&F == &OldF && "Called with an unexpected function!"); |
| 1001 | return FAM.getResult<AAManager>(F); |
| 1002 | }; |
| 1003 | |
Tom Stellard | 3d36e5c | 2019-01-16 05:15:31 +0000 | [diff] [blame] | 1004 | const TargetTransformInfo &TTI = FAM.getResult<TargetIRAnalysis>(OldF); |
| 1005 | Function *NewF = |
| 1006 | promoteArguments(&OldF, AARGetter, MaxElements, None, TTI); |
Chandler Carruth | addcda4 | 2017-02-09 23:46:27 +0000 | [diff] [blame] | 1007 | if (!NewF) |
| 1008 | continue; |
| 1009 | LocalChange = true; |
| 1010 | |
| 1011 | // Directly substitute the functions in the call graph. Note that this |
| 1012 | // requires the old function to be completely dead and completely |
| 1013 | // replaced by the new function. It does no call graph updates, it merely |
| 1014 | // swaps out the particular function mapped to a particular node in the |
| 1015 | // graph. |
| 1016 | C.getOuterRefSCC().replaceNodeFunction(N, *NewF); |
| 1017 | OldF.eraseFromParent(); |
| 1018 | } |
| 1019 | |
| 1020 | Changed |= LocalChange; |
| 1021 | } while (LocalChange); |
| 1022 | |
| 1023 | if (!Changed) |
| 1024 | return PreservedAnalyses::all(); |
| 1025 | |
| 1026 | return PreservedAnalyses::none(); |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 1027 | } |
| 1028 | |
| 1029 | namespace { |
Eugene Zelenko | f27d161 | 2017-10-19 21:21:30 +0000 | [diff] [blame] | 1030 | |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 1031 | /// ArgPromotion - The 'by reference' to 'by value' argument promotion pass. |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 1032 | struct ArgPromotion : public CallGraphSCCPass { |
Eugene Zelenko | f27d161 | 2017-10-19 21:21:30 +0000 | [diff] [blame] | 1033 | // Pass identification, replacement for typeid |
| 1034 | static char ID; |
| 1035 | |
| 1036 | explicit ArgPromotion(unsigned MaxElements = 3) |
| 1037 | : CallGraphSCCPass(ID), MaxElements(MaxElements) { |
| 1038 | initializeArgPromotionPass(*PassRegistry::getPassRegistry()); |
| 1039 | } |
| 1040 | |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 1041 | void getAnalysisUsage(AnalysisUsage &AU) const override { |
| 1042 | AU.addRequired<AssumptionCacheTracker>(); |
| 1043 | AU.addRequired<TargetLibraryInfoWrapperPass>(); |
Tom Stellard | 3d36e5c | 2019-01-16 05:15:31 +0000 | [diff] [blame] | 1044 | AU.addRequired<TargetTransformInfoWrapperPass>(); |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 1045 | getAAResultsAnalysisUsage(AU); |
| 1046 | CallGraphSCCPass::getAnalysisUsage(AU); |
| 1047 | } |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 1048 | |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 1049 | bool runOnSCC(CallGraphSCC &SCC) override; |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 1050 | |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 1051 | private: |
| 1052 | using llvm::Pass::doInitialization; |
Eugene Zelenko | f27d161 | 2017-10-19 21:21:30 +0000 | [diff] [blame] | 1053 | |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 1054 | bool doInitialization(CallGraph &CG) override; |
Eugene Zelenko | f27d161 | 2017-10-19 21:21:30 +0000 | [diff] [blame] | 1055 | |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 1056 | /// The maximum number of elements to expand, or 0 for unlimited. |
| 1057 | unsigned MaxElements; |
| 1058 | }; |
Eugene Zelenko | f27d161 | 2017-10-19 21:21:30 +0000 | [diff] [blame] | 1059 | |
| 1060 | } // end anonymous namespace |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 1061 | |
| 1062 | char ArgPromotion::ID = 0; |
Eugene Zelenko | f27d161 | 2017-10-19 21:21:30 +0000 | [diff] [blame] | 1063 | |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 1064 | INITIALIZE_PASS_BEGIN(ArgPromotion, "argpromotion", |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 1065 | "Promote 'by reference' arguments to scalars", false, |
| 1066 | false) |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 1067 | INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker) |
| 1068 | INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass) |
| 1069 | INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass) |
Tom Stellard | 3d36e5c | 2019-01-16 05:15:31 +0000 | [diff] [blame] | 1070 | INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass) |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 1071 | INITIALIZE_PASS_END(ArgPromotion, "argpromotion", |
Chandler Carruth | ae9ce3d | 2017-01-29 08:03:19 +0000 | [diff] [blame] | 1072 | "Promote 'by reference' arguments to scalars", false, false) |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 1073 | |
| 1074 | Pass *llvm::createArgumentPromotionPass(unsigned MaxElements) { |
| 1075 | return new ArgPromotion(MaxElements); |
| 1076 | } |
| 1077 | |
| 1078 | bool ArgPromotion::runOnSCC(CallGraphSCC &SCC) { |
| 1079 | if (skipSCC(SCC)) |
| 1080 | return false; |
| 1081 | |
| 1082 | // Get the callgraph information that we need to update to reflect our |
| 1083 | // changes. |
| 1084 | CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph(); |
| 1085 | |
Peter Collingbourne | cea1e4e | 2017-02-09 23:11:52 +0000 | [diff] [blame] | 1086 | LegacyAARGetter AARGetter(*this); |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 1087 | |
| 1088 | bool Changed = false, LocalChange; |
| 1089 | |
| 1090 | // Iterate until we stop promoting from this SCC. |
| 1091 | do { |
| 1092 | LocalChange = false; |
| 1093 | // Attempt to promote arguments from all functions in this SCC. |
| 1094 | for (CallGraphNode *OldNode : SCC) { |
Chandler Carruth | addcda4 | 2017-02-09 23:46:27 +0000 | [diff] [blame] | 1095 | Function *OldF = OldNode->getFunction(); |
| 1096 | if (!OldF) |
| 1097 | continue; |
| 1098 | |
| 1099 | auto ReplaceCallSite = [&](CallSite OldCS, CallSite NewCS) { |
| 1100 | Function *Caller = OldCS.getInstruction()->getParent()->getParent(); |
| 1101 | CallGraphNode *NewCalleeNode = |
| 1102 | CG.getOrInsertFunction(NewCS.getCalledFunction()); |
| 1103 | CallGraphNode *CallerNode = CG[Caller]; |
| 1104 | CallerNode->replaceCallEdge(OldCS, NewCS, NewCalleeNode); |
| 1105 | }; |
| 1106 | |
Tom Stellard | 3d36e5c | 2019-01-16 05:15:31 +0000 | [diff] [blame] | 1107 | const TargetTransformInfo &TTI = |
| 1108 | getAnalysis<TargetTransformInfoWrapperPass>().getTTI(*OldF); |
Chandler Carruth | addcda4 | 2017-02-09 23:46:27 +0000 | [diff] [blame] | 1109 | if (Function *NewF = promoteArguments(OldF, AARGetter, MaxElements, |
Tom Stellard | 3d36e5c | 2019-01-16 05:15:31 +0000 | [diff] [blame] | 1110 | {ReplaceCallSite}, TTI)) { |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 1111 | LocalChange = true; |
Chandler Carruth | addcda4 | 2017-02-09 23:46:27 +0000 | [diff] [blame] | 1112 | |
| 1113 | // Update the call graph for the newly promoted function. |
| 1114 | CallGraphNode *NewNode = CG.getOrInsertFunction(NewF); |
| 1115 | NewNode->stealCalledFunctionsFrom(OldNode); |
| 1116 | if (OldNode->getNumReferences() == 0) |
| 1117 | delete CG.removeFunctionFromModule(OldNode); |
| 1118 | else |
| 1119 | OldF->setLinkage(Function::ExternalLinkage); |
| 1120 | |
| 1121 | // And updat ethe SCC we're iterating as well. |
Chandler Carruth | cd836cd | 2017-01-29 08:03:16 +0000 | [diff] [blame] | 1122 | SCC.ReplaceNode(OldNode, NewNode); |
| 1123 | } |
| 1124 | } |
| 1125 | // Remember that we changed something. |
| 1126 | Changed |= LocalChange; |
| 1127 | } while (LocalChange); |
| 1128 | |
| 1129 | return Changed; |
| 1130 | } |
| 1131 | |
David Blaikie | e844cd5 | 2014-07-01 21:13:37 +0000 | [diff] [blame] | 1132 | bool ArgPromotion::doInitialization(CallGraph &CG) { |
David Blaikie | e844cd5 | 2014-07-01 21:13:37 +0000 | [diff] [blame] | 1133 | return CallGraphSCCPass::doInitialization(CG); |
| 1134 | } |