From 27821d7200beedd84a46c989e653a509ac1f7f7b Mon Sep 17 00:00:00 2001 From: Peter Collingbourne Date: Tue, 3 Mar 2015 00:49:28 +0000 Subject: [PATCH] LowerBitSets: Use byte arrays instead of bit sets to represent in-memory bit sets. By loading from indexed offsets into a byte array and applying a mask, a program can test bits from the bit set with a relatively short instruction sequence. For example, suppose we have 15 bit sets to lay out: A (16 bits), B (15 bits), C (14 bits), D (13 bits), E (12 bits), F (11 bits), G (10 bits), H (9 bits), I (7 bits), J (6 bits), K (5 bits), L (4 bits), M (3 bits), N (2 bits), O (1 bit) These bits can be laid out in a 16-byte array like this: Byte Offset 0123456789ABCDEF Bit 7 HHHHHHHHHIIIIIII 6 GGGGGGGGGGJJJJJJ 5 FFFFFFFFFFFKKKKK 4 EEEEEEEEEEEELLLL 3 DDDDDDDDDDDDDMMM 2 CCCCCCCCCCCCCCNN 1 BBBBBBBBBBBBBBBO 0 AAAAAAAAAAAAAAAA For example, to test bit X of A, we evaluate ((bits[X] & 1) != 0), or to test bit X of I, we evaluate ((bits[9 + X] & 0x80) != 0). This can be done in 1-2 machine instructions on x86, or 4-6 instructions on ARM. This uses the LPT multiprocessor scheduling algorithm to lay out the bits efficiently. Saves ~450KB of instructions in a recent build of Chromium. Differential Revision: http://reviews.llvm.org/D7954 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231043 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Transforms/IPO/LowerBitSets.h | 69 +++++-- lib/Transforms/IPO/LowerBitSets.cpp | 218 +++++++++++++++------ test/Transforms/LowerBitSets/simple.ll | 34 ++-- unittests/Transforms/IPO/LowerBitSets.cpp | 90 +++++++-- 4 files changed, 302 insertions(+), 109 deletions(-) diff --git a/include/llvm/Transforms/IPO/LowerBitSets.h b/include/llvm/Transforms/IPO/LowerBitSets.h index 0f606170545..9110dac9856 100644 --- a/include/llvm/Transforms/IPO/LowerBitSets.h +++ b/include/llvm/Transforms/IPO/LowerBitSets.h @@ -30,8 +30,8 @@ class GlobalVariable; class Value; struct BitSetInfo { - // The actual bitset. - std::vector Bits; + // The indices of the set bits in the bitset. + std::set Bits; // The byte offset into the combined global represented by the bitset. uint64_t ByteOffset; @@ -45,18 +45,11 @@ struct BitSetInfo { unsigned AlignLog2; bool isSingleOffset() const { - return Bits.size() == 1 && Bits[0] == 1; + return Bits.size() == 1; } bool isAllOnes() const { - for (unsigned I = 0; I != Bits.size() - 1; ++I) - if (Bits[I] != 0xFF) - return false; - - if (BitSize % 8 == 0) - return Bits[Bits.size() - 1] == 0xFF; - - return Bits[Bits.size() - 1] == (1 << (BitSize % 8)) - 1; + return Bits.size() == BitSize; } bool containsGlobalOffset(uint64_t Offset) const; @@ -64,7 +57,6 @@ struct BitSetInfo { bool containsValue(const DataLayout *DL, const DenseMap &GlobalLayout, Value *V, uint64_t COffset = 0) const; - }; struct BitSetBuilder { @@ -148,6 +140,59 @@ struct GlobalLayoutBuilder { void addFragment(const std::set &F); }; +/// This class is used to build a byte array containing overlapping bit sets. By +/// loading from indexed offsets into the byte array and applying a mask, a +/// program can test bits from the bit set with a relatively short instruction +/// sequence. For example, suppose we have 15 bit sets to lay out: +/// +/// A (16 bits), B (15 bits), C (14 bits), D (13 bits), E (12 bits), +/// F (11 bits), G (10 bits), H (9 bits), I (7 bits), J (6 bits), K (5 bits), +/// L (4 bits), M (3 bits), N (2 bits), O (1 bit) +/// +/// These bits can be laid out in a 16-byte array like this: +/// +/// Byte Offset +/// 0123456789ABCDEF +/// Bit +/// 7 HHHHHHHHHIIIIIII +/// 6 GGGGGGGGGGJJJJJJ +/// 5 FFFFFFFFFFFKKKKK +/// 4 EEEEEEEEEEEELLLL +/// 3 DDDDDDDDDDDDDMMM +/// 2 CCCCCCCCCCCCCCNN +/// 1 BBBBBBBBBBBBBBBO +/// 0 AAAAAAAAAAAAAAAA +/// +/// For example, to test bit X of A, we evaluate ((bits[X] & 1) != 0), or to +/// test bit X of I, we evaluate ((bits[9 + X] & 0x80) != 0). This can be done +/// in 1-2 machine instructions on x86, or 4-6 instructions on ARM. +/// +/// This is a byte array, rather than (say) a 2-byte array or a 4-byte array, +/// because for one thing it gives us better packing (the more bins there are, +/// the less evenly they will be filled), and for another, the instruction +/// sequences can be slightly shorter, both on x86 and ARM. +struct ByteArrayBuilder { + /// The byte array built so far. + std::vector Bytes; + + enum { BitsPerByte = 8 }; + + /// The number of bytes allocated so far for each of the bits. + uint64_t BitAllocs[BitsPerByte]; + + ByteArrayBuilder() { + memset(BitAllocs, 0, sizeof(BitAllocs)); + } + + /// Allocate BitSize bits in the byte array where Bits contains the bits to + /// set. AllocByteOffset is set to the offset within the byte array and + /// AllocMask is set to the bitmask for those bits. This uses the LPT (Longest + /// Processing Time) multiprocessor scheduling algorithm to lay out the bits + /// efficiently; the pass allocates bit sets in decreasing size order. + void allocate(const std::set &Bits, uint64_t BitSize, + uint64_t &AllocByteOffset, uint8_t &AllocMask); +}; + } // namespace llvm #endif diff --git a/lib/Transforms/IPO/LowerBitSets.cpp b/lib/Transforms/IPO/LowerBitSets.cpp index 0a22a809c53..f397c38a996 100644 --- a/lib/Transforms/IPO/LowerBitSets.cpp +++ b/lib/Transforms/IPO/LowerBitSets.cpp @@ -31,7 +31,9 @@ using namespace llvm; #define DEBUG_TYPE "lowerbitsets" -STATISTIC(NumBitSetsCreated, "Number of bitsets created"); +STATISTIC(ByteArraySizeBits, "Byte array size in bits"); +STATISTIC(ByteArraySizeBytes, "Byte array size in bytes"); +STATISTIC(NumByteArraysCreated, "Number of byte arrays created"); STATISTIC(NumBitSetCallsLowered, "Number of bitset calls lowered"); STATISTIC(NumBitSetDisjointSets, "Number of disjoint sets of bitsets"); @@ -46,7 +48,7 @@ bool BitSetInfo::containsGlobalOffset(uint64_t Offset) const { if (BitOffset >= BitSize) return false; - return (Bits[BitOffset / 8] >> (BitOffset % 8)) & 1; + return Bits.count(BitOffset); } bool BitSetInfo::containsValue( @@ -101,18 +103,15 @@ BitSetInfo BitSetBuilder::build() { BSI.ByteOffset = Min; BSI.AlignLog2 = 0; - // FIXME: Can probably do something smarter if all offsets are 0. if (Mask != 0) BSI.AlignLog2 = countTrailingZeros(Mask, ZB_Undefined); // Build the compressed bitset while normalizing the offsets against the // computed alignment. BSI.BitSize = ((Max - Min) >> BSI.AlignLog2) + 1; - uint64_t ByteSize = (BSI.BitSize + 7) / 8; - BSI.Bits.resize(ByteSize); for (uint64_t Offset : Offsets) { Offset >>= BSI.AlignLog2; - BSI.Bits[Offset / 8] |= 1 << (Offset % 8); + BSI.Bits.insert(Offset); } return BSI; @@ -147,14 +146,46 @@ void GlobalLayoutBuilder::addFragment(const std::set &F) { FragmentMap[ObjIndex] = FragmentIndex; } +void ByteArrayBuilder::allocate(const std::set &Bits, + uint64_t BitSize, uint64_t &AllocByteOffset, + uint8_t &AllocMask) { + // Find the smallest current allocation. + unsigned Bit = 0; + for (unsigned I = 1; I != BitsPerByte; ++I) + if (BitAllocs[I] < BitAllocs[Bit]) + Bit = I; + + AllocByteOffset = BitAllocs[Bit]; + + // Add our size to it. + unsigned ReqSize = AllocByteOffset + BitSize; + BitAllocs[Bit] = ReqSize; + if (Bytes.size() < ReqSize) + Bytes.resize(ReqSize); + + // Set our bits. + AllocMask = 1 << Bit; + for (uint64_t B : Bits) + Bytes[AllocByteOffset + B] |= AllocMask; +} + namespace { +struct ByteArrayInfo { + std::set Bits; + uint64_t BitSize; + GlobalVariable *ByteArray; + Constant *Mask; +}; + struct LowerBitSets : public ModulePass { static char ID; LowerBitSets() : ModulePass(ID) { initializeLowerBitSetsPass(*PassRegistry::getPassRegistry()); } + Module *M; + const DataLayout *DL; IntegerType *Int1Ty; IntegerType *Int8Ty; @@ -169,20 +200,23 @@ struct LowerBitSets : public ModulePass { // Mapping from bitset mdstrings to the call sites that test them. DenseMap> BitSetTestCallSites; + std::vector ByteArrayInfos; + BitSetInfo buildBitSet(MDString *BitSet, const DenseMap &GlobalLayout); - Value *createBitSetTest(IRBuilder<> &B, const BitSetInfo &BSI, - GlobalVariable *BitSetGlobal, Value *BitOffset); + ByteArrayInfo *createByteArray(BitSetInfo &BSI); + void allocateByteArrays(); + Value *createBitSetTest(IRBuilder<> &B, BitSetInfo &BSI, ByteArrayInfo *&BAI, + Value *BitOffset); Value * - lowerBitSetCall(CallInst *CI, const BitSetInfo &BSI, - GlobalVariable *BitSetGlobal, GlobalVariable *CombinedGlobal, + lowerBitSetCall(CallInst *CI, BitSetInfo &BSI, ByteArrayInfo *&BAI, + GlobalVariable *CombinedGlobal, const DenseMap &GlobalLayout); - void buildBitSetsFromGlobals(Module &M, - const std::vector &BitSets, + void buildBitSetsFromGlobals(const std::vector &BitSets, const std::vector &Globals); - bool buildBitSets(Module &M); - bool eraseBitSetMetadata(Module &M); + bool buildBitSets(); + bool eraseBitSetMetadata(); bool doInitialization(Module &M) override; bool runOnModule(Module &M) override; @@ -198,19 +232,21 @@ char LowerBitSets::ID = 0; ModulePass *llvm::createLowerBitSetsPass() { return new LowerBitSets; } -bool LowerBitSets::doInitialization(Module &M) { - DL = M.getDataLayout(); +bool LowerBitSets::doInitialization(Module &Mod) { + M = &Mod; + + DL = M->getDataLayout(); if (!DL) report_fatal_error("Data layout required"); - Int1Ty = Type::getInt1Ty(M.getContext()); - Int8Ty = Type::getInt8Ty(M.getContext()); - Int32Ty = Type::getInt32Ty(M.getContext()); + Int1Ty = Type::getInt1Ty(M->getContext()); + Int8Ty = Type::getInt8Ty(M->getContext()); + Int32Ty = Type::getInt32Ty(M->getContext()); Int32PtrTy = PointerType::getUnqual(Int32Ty); - Int64Ty = Type::getInt64Ty(M.getContext()); - IntPtrTy = DL->getIntPtrType(M.getContext(), 0); + Int64Ty = Type::getInt64Ty(M->getContext()); + IntPtrTy = DL->getIntPtrType(M->getContext(), 0); - BitSetNM = M.getNamedMetadata("llvm.bitsets"); + BitSetNM = M->getNamedMetadata("llvm.bitsets"); BitSetTestCallSites.clear(); @@ -259,52 +295,113 @@ static Value *createMaskedBitTest(IRBuilder<> &B, Value *Bits, return B.CreateICmpNE(MaskedBits, ConstantInt::get(BitsType, 0)); } +ByteArrayInfo *LowerBitSets::createByteArray(BitSetInfo &BSI) { + // Create globals to stand in for byte arrays and masks. These never actually + // get initialized, we RAUW and erase them later in allocateByteArrays() once + // we know the offset and mask to use. + auto ByteArrayGlobal = new GlobalVariable( + *M, Int8Ty, /*isConstant=*/true, GlobalValue::PrivateLinkage, nullptr); + auto MaskGlobal = new GlobalVariable( + *M, Int8Ty, /*isConstant=*/true, GlobalValue::PrivateLinkage, nullptr); + + ByteArrayInfos.emplace_back(); + ByteArrayInfo *BAI = &ByteArrayInfos.back(); + + BAI->Bits = BSI.Bits; + BAI->BitSize = BSI.BitSize; + BAI->ByteArray = ByteArrayGlobal; + BAI->Mask = ConstantExpr::getPtrToInt(MaskGlobal, Int8Ty); + return BAI; +} + +void LowerBitSets::allocateByteArrays() { + std::stable_sort(ByteArrayInfos.begin(), ByteArrayInfos.end(), + [](const ByteArrayInfo &BAI1, const ByteArrayInfo &BAI2) { + return BAI1.BitSize > BAI2.BitSize; + }); + + std::vector ByteArrayOffsets(ByteArrayInfos.size()); + + ByteArrayBuilder BAB; + for (unsigned I = 0; I != ByteArrayInfos.size(); ++I) { + ByteArrayInfo *BAI = &ByteArrayInfos[I]; + + uint8_t Mask; + BAB.allocate(BAI->Bits, BAI->BitSize, ByteArrayOffsets[I], Mask); + + BAI->Mask->replaceAllUsesWith(ConstantInt::get(Int8Ty, Mask)); + cast(BAI->Mask->getOperand(0))->eraseFromParent(); + } + + Constant *ByteArrayConst = ConstantDataArray::get(M->getContext(), BAB.Bytes); + auto ByteArray = + new GlobalVariable(*M, ByteArrayConst->getType(), /*isConstant=*/true, + GlobalValue::PrivateLinkage, ByteArrayConst); + + for (unsigned I = 0; I != ByteArrayInfos.size(); ++I) { + ByteArrayInfo *BAI = &ByteArrayInfos[I]; + + Constant *Idxs[] = {ConstantInt::get(IntPtrTy, 0), + ConstantInt::get(IntPtrTy, ByteArrayOffsets[I])}; + Constant *GEP = ConstantExpr::getInBoundsGetElementPtr(ByteArray, Idxs); + + // Create an alias instead of RAUW'ing the gep directly. On x86 this ensures + // that the pc-relative displacement is folded into the lea instead of the + // test instruction getting another displacement. + GlobalAlias *Alias = GlobalAlias::create( + Int8Ty, 0, GlobalValue::PrivateLinkage, "bits", GEP, M); + BAI->ByteArray->replaceAllUsesWith(Alias); + BAI->ByteArray->eraseFromParent(); + } + + ByteArraySizeBits = BAB.BitAllocs[0] + BAB.BitAllocs[1] + BAB.BitAllocs[2] + + BAB.BitAllocs[3] + BAB.BitAllocs[4] + BAB.BitAllocs[5] + + BAB.BitAllocs[6] + BAB.BitAllocs[7]; + ByteArraySizeBytes = BAB.Bytes.size(); +} + /// Build a test that bit BitOffset is set in BSI, where /// BitSetGlobal is a global containing the bits in BSI. -Value *LowerBitSets::createBitSetTest(IRBuilder<> &B, const BitSetInfo &BSI, - GlobalVariable *BitSetGlobal, - Value *BitOffset) { - if (BSI.Bits.size() <= 8) { +Value *LowerBitSets::createBitSetTest(IRBuilder<> &B, BitSetInfo &BSI, + ByteArrayInfo *&BAI, Value *BitOffset) { + if (BSI.BitSize <= 64) { // If the bit set is sufficiently small, we can avoid a load by bit testing // a constant. IntegerType *BitsTy; - if (BSI.Bits.size() <= 4) + if (BSI.BitSize <= 32) BitsTy = Int32Ty; else BitsTy = Int64Ty; uint64_t Bits = 0; - for (auto I = BSI.Bits.rbegin(), E = BSI.Bits.rend(); I != E; ++I) { - Bits <<= 8; - Bits |= *I; - } + for (auto Bit : BSI.Bits) + Bits |= uint64_t(1) << Bit; Constant *BitsConst = ConstantInt::get(BitsTy, Bits); return createMaskedBitTest(B, BitsConst, BitOffset); } else { - // TODO: We might want to use the memory variant of the bt instruction - // with the previously computed bit offset at -Os. This instruction does - // exactly what we want but has been benchmarked as being slower than open - // coding the load+bt. - Value *BitSetGlobalOffset = - B.CreateLShr(BitOffset, ConstantInt::get(IntPtrTy, 5)); - Value *BitSetEntryAddr = B.CreateGEP( - ConstantExpr::getBitCast(BitSetGlobal, Int32PtrTy), BitSetGlobalOffset); - Value *BitSetEntry = B.CreateLoad(BitSetEntryAddr); + if (!BAI) { + ++NumByteArraysCreated; + BAI = createByteArray(BSI); + } - return createMaskedBitTest(B, BitSetEntry, BitOffset); + Value *ByteAddr = B.CreateGEP(BAI->ByteArray, BitOffset); + Value *Byte = B.CreateLoad(ByteAddr); + + Value *ByteAndMask = B.CreateAnd(Byte, BAI->Mask); + return B.CreateICmpNE(ByteAndMask, ConstantInt::get(Int8Ty, 0)); } } /// Lower a llvm.bitset.test call to its implementation. Returns the value to /// replace the call with. Value *LowerBitSets::lowerBitSetCall( - CallInst *CI, const BitSetInfo &BSI, GlobalVariable *BitSetGlobal, + CallInst *CI, BitSetInfo &BSI, ByteArrayInfo *&BAI, GlobalVariable *CombinedGlobal, const DenseMap &GlobalLayout) { Value *Ptr = CI->getArgOperand(0); if (BSI.containsValue(DL, GlobalLayout, Ptr)) - return ConstantInt::getTrue(BitSetGlobal->getParent()->getContext()); + return ConstantInt::getTrue(CombinedGlobal->getParent()->getContext()); Constant *GlobalAsInt = ConstantExpr::getPtrToInt(CombinedGlobal, IntPtrTy); Constant *OffsetedGlobalAsInt = ConstantExpr::getAdd( @@ -353,7 +450,7 @@ Value *LowerBitSets::lowerBitSetCall( // Now that we know that the offset is in range and aligned, load the // appropriate bit from the bitset. - Value *Bit = createBitSetTest(ThenB, BSI, BitSetGlobal, BitOffset); + Value *Bit = createBitSetTest(ThenB, BSI, BAI, BitOffset); // The value we want is 0 if we came directly from the initial block // (having failed the range or alignment checks), or the loaded bit if @@ -368,7 +465,6 @@ Value *LowerBitSets::lowerBitSetCall( /// Given a disjoint set of bitsets and globals, layout the globals, build the /// bit sets and lower the llvm.bitset.test calls. void LowerBitSets::buildBitSetsFromGlobals( - Module &M, const std::vector &BitSets, const std::vector &Globals) { // Build a new global with the combined contents of the referenced globals. @@ -391,9 +487,9 @@ void LowerBitSets::buildBitSetsFromGlobals( } if (!GlobalInits.empty()) GlobalInits.pop_back(); - Constant *NewInit = ConstantStruct::getAnon(M.getContext(), GlobalInits); + Constant *NewInit = ConstantStruct::getAnon(M->getContext(), GlobalInits); auto CombinedGlobal = - new GlobalVariable(M, NewInit->getType(), /*isConstant=*/true, + new GlobalVariable(*M, NewInit->getType(), /*isConstant=*/true, GlobalValue::PrivateLinkage, NewInit); const StructLayout *CombinedGlobalLayout = @@ -410,18 +506,12 @@ void LowerBitSets::buildBitSetsFromGlobals( // Build the bitset. BitSetInfo BSI = buildBitSet(BS, GlobalLayout); - // Create a global in which to store it. - ++NumBitSetsCreated; - Constant *BitsConst = ConstantDataArray::get(M.getContext(), BSI.Bits); - auto BitSetGlobal = new GlobalVariable( - M, BitsConst->getType(), /*isConstant=*/true, - GlobalValue::PrivateLinkage, BitsConst, BS->getString() + ".bits"); + ByteArrayInfo *BAI = 0; // Lower each call to llvm.bitset.test for this bitset. for (CallInst *CI : BitSetTestCallSites[BS]) { ++NumBitSetCallsLowered; - Value *Lowered = - lowerBitSetCall(CI, BSI, BitSetGlobal, CombinedGlobal, GlobalLayout); + Value *Lowered = lowerBitSetCall(CI, BSI, BAI, CombinedGlobal, GlobalLayout); CI->replaceAllUsesWith(Lowered); CI->eraseFromParent(); } @@ -439,7 +529,7 @@ void LowerBitSets::buildBitSetsFromGlobals( GlobalAlias *GAlias = GlobalAlias::create( Globals[I]->getType()->getElementType(), Globals[I]->getType()->getAddressSpace(), Globals[I]->getLinkage(), - "", CombinedGlobalElemPtr, &M); + "", CombinedGlobalElemPtr, M); GAlias->takeName(Globals[I]); Globals[I]->replaceAllUsesWith(GAlias); Globals[I]->eraseFromParent(); @@ -447,9 +537,9 @@ void LowerBitSets::buildBitSetsFromGlobals( } /// Lower all bit sets in this module. -bool LowerBitSets::buildBitSets(Module &M) { +bool LowerBitSets::buildBitSets() { Function *BitSetTestFunc = - M.getFunction(Intrinsic::getName(Intrinsic::bitset_test)); + M->getFunction(Intrinsic::getName(Intrinsic::bitset_test)); if (!BitSetTestFunc) return false; @@ -591,22 +681,24 @@ bool LowerBitSets::buildBitSets(Module &M) { }); // Build the bitsets from this disjoint set. - buildBitSetsFromGlobals(M, BitSets, OrderedGlobals); + buildBitSetsFromGlobals(BitSets, OrderedGlobals); } + allocateByteArrays(); + return true; } -bool LowerBitSets::eraseBitSetMetadata(Module &M) { +bool LowerBitSets::eraseBitSetMetadata() { if (!BitSetNM) return false; - M.eraseNamedMetadata(BitSetNM); + M->eraseNamedMetadata(BitSetNM); return true; } bool LowerBitSets::runOnModule(Module &M) { - bool Changed = buildBitSets(M); - Changed |= eraseBitSetMetadata(M); + bool Changed = buildBitSets(); + Changed |= eraseBitSetMetadata(); return Changed; } diff --git a/test/Transforms/LowerBitSets/simple.ll b/test/Transforms/LowerBitSets/simple.ll index 704ab720cbf..75ef018b63d 100644 --- a/test/Transforms/LowerBitSets/simple.ll +++ b/test/Transforms/LowerBitSets/simple.ll @@ -9,8 +9,9 @@ target datalayout = "e-p:32:32" @c = constant i32 3 @d = constant [2 x i32] [i32 4, i32 5] +; CHECK: [[BA:@[^ ]*]] = private constant [68 x i8] c"\03\01\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\02\00\01" + ; Offset 0, 4 byte alignment -; CHECK: @bitset1.bits = private constant [9 x i8] c"\03\00\00\00\00\00\00\00\08" !0 = !{!"bitset1", i32* @a, i32 0} ; CHECK-NODISCARD-DAG: !{!"bitset1", i32* @a, i32 0} !1 = !{!"bitset1", [63 x i32]* @b, i32 0} @@ -19,14 +20,12 @@ target datalayout = "e-p:32:32" ; CHECK-NODISCARD-DAG: !{!"bitset1", [2 x i32]* @d, i32 4} ; Offset 4, 256 byte alignment -; CHECK: @bitset2.bits = private constant [1 x i8] c"\03" !3 = !{!"bitset2", [63 x i32]* @b, i32 0} ; CHECK-NODISCARD-DAG: !{!"bitset2", [63 x i32]* @b, i32 0} !4 = !{!"bitset2", i32* @c, i32 0} ; CHECK-NODISCARD-DAG: !{!"bitset2", i32* @c, i32 0} ; Offset 0, 4 byte alignment -; CHECK: @bitset3.bits = private constant [9 x i8] c"\01\00\00\00\00\00\00\00\02" !5 = !{!"bitset3", i32* @a, i32 0} ; CHECK-NODISCARD-DAG: !{!"bitset3", i32* @a, i32 0} !6 = !{!"bitset3", i32* @c, i32 0} @@ -43,6 +42,9 @@ target datalayout = "e-p:32:32" ; CHECK: @c = alias getelementptr inbounds ({ i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }* [[G]], i32 0, i32 4) ; CHECK: @d = alias getelementptr inbounds ({ i32, [0 x i8], [63 x i32], [4 x i8], i32, [0 x i8], [2 x i32] }* [[G]], i32 0, i32 6) +; CHECK: @bits = private alias getelementptr inbounds ([68 x i8]* [[BA]], i32 0, i32 0) +; CHECK: @bits1 = private alias getelementptr inbounds ([68 x i8]* [[BA]], i32 0, i32 0) + declare i1 @llvm.bitset.test(i8* %ptr, metadata %bitset) nounwind readnone ; CHECK: @foo(i32* [[A0:%[^ ]*]]) @@ -59,15 +61,12 @@ define i1 @foo(i32* %p) { ; CHECK: [[R6:%[^ ]*]] = icmp ult i32 [[R5]], 68 ; CHECK: br i1 [[R6]] - ; CHECK: [[R8:%[^ ]*]] = lshr i32 [[R5]], 5 - ; CHECK: [[R9:%[^ ]*]] = getelementptr i32, i32* bitcast ([9 x i8]* @bitset1.bits to i32*), i32 [[R8]] - ; CHECK: [[R10:%[^ ]*]] = load i32, i32* [[R9]] - ; CHECK: [[R11:%[^ ]*]] = and i32 [[R5]], 31 - ; CHECK: [[R12:%[^ ]*]] = shl i32 1, [[R11]] - ; CHECK: [[R13:%[^ ]*]] = and i32 [[R10]], [[R12]] - ; CHECK: [[R14:%[^ ]*]] = icmp ne i32 [[R13]], 0 + ; CHECK: [[R8:%[^ ]*]] = getelementptr i8, i8* @bits, i32 [[R5]] + ; CHECK: [[R9:%[^ ]*]] = load i8, i8* [[R8]] + ; CHECK: [[R10:%[^ ]*]] = and i8 [[R9]], 1 + ; CHECK: [[R11:%[^ ]*]] = icmp ne i8 [[R10]], 0 - ; CHECK: [[R16:%[^ ]*]] = phi i1 [ false, {{%[^ ]*}} ], [ [[R14]], {{%[^ ]*}} ] + ; CHECK: [[R16:%[^ ]*]] = phi i1 [ false, {{%[^ ]*}} ], [ [[R11]], {{%[^ ]*}} ] %x = call i1 @llvm.bitset.test(i8* %pi8, metadata !"bitset1") ; CHECK-NOT: llvm.bitset.test @@ -105,15 +104,12 @@ define i1 @baz(i32* %p) { ; CHECK: [[T6:%[^ ]*]] = icmp ult i32 [[T5]], 66 ; CHECK: br i1 [[T6]] - ; CHECK: [[T8:%[^ ]*]] = lshr i32 [[T5]], 5 - ; CHECK: [[T9:%[^ ]*]] = getelementptr i32, i32* bitcast ([9 x i8]* @bitset3.bits to i32*), i32 [[T8]] - ; CHECK: [[T10:%[^ ]*]] = load i32, i32* [[T9]] - ; CHECK: [[T11:%[^ ]*]] = and i32 [[T5]], 31 - ; CHECK: [[T12:%[^ ]*]] = shl i32 1, [[T11]] - ; CHECK: [[T13:%[^ ]*]] = and i32 [[T10]], [[T12]] - ; CHECK: [[T14:%[^ ]*]] = icmp ne i32 [[T13]], 0 + ; CHECK: [[T8:%[^ ]*]] = getelementptr i8, i8* @bits1, i32 [[T5]] + ; CHECK: [[T9:%[^ ]*]] = load i8, i8* [[T8]] + ; CHECK: [[T10:%[^ ]*]] = and i8 [[T9]], 2 + ; CHECK: [[T11:%[^ ]*]] = icmp ne i8 [[T10]], 0 - ; CHECK: [[T16:%[^ ]*]] = phi i1 [ false, {{%[^ ]*}} ], [ [[T14]], {{%[^ ]*}} ] + ; CHECK: [[T16:%[^ ]*]] = phi i1 [ false, {{%[^ ]*}} ], [ [[T11]], {{%[^ ]*}} ] %x = call i1 @llvm.bitset.test(i8* %pi8, metadata !"bitset3") ; CHECK: ret i1 [[T16]] ret i1 %x diff --git a/unittests/Transforms/IPO/LowerBitSets.cpp b/unittests/Transforms/IPO/LowerBitSets.cpp index 26a42528378..613a15fe0d0 100644 --- a/unittests/Transforms/IPO/LowerBitSets.cpp +++ b/unittests/Transforms/IPO/LowerBitSets.cpp @@ -15,27 +15,39 @@ using namespace llvm; TEST(LowerBitSets, BitSetBuilder) { struct { std::vector Offsets; - std::vector Bits; + std::set Bits; uint64_t ByteOffset; uint64_t BitSize; unsigned AlignLog2; bool IsSingleOffset; bool IsAllOnes; } BSBTests[] = { - {{}, {0}, 0, 1, 0, false, false}, - {{0}, {1}, 0, 1, 0, true, true}, - {{4}, {1}, 4, 1, 0, true, true}, - {{37}, {1}, 37, 1, 0, true, true}, - {{0, 1}, {3}, 0, 2, 0, false, true}, - {{0, 4}, {3}, 0, 2, 2, false, true}, - {{0, uint64_t(1) << 33}, {3}, 0, 2, 33, false, true}, - {{3, 7}, {3}, 3, 2, 2, false, true}, - {{0, 1, 7}, {131}, 0, 8, 0, false, false}, - {{0, 2, 14}, {131}, 0, 8, 1, false, false}, - {{0, 1, 8}, {3, 1}, 0, 9, 0, false, false}, - {{0, 2, 16}, {3, 1}, 0, 9, 1, false, false}, - {{0, 1, 2, 3, 4, 5, 6, 7}, {255}, 0, 8, 0, false, true}, - {{0, 1, 2, 3, 4, 5, 6, 7, 8}, {255, 1}, 0, 9, 0, false, true}, + {{}, {}, 0, 1, 0, false, false}, + {{0}, {0}, 0, 1, 0, true, true}, + {{4}, {0}, 4, 1, 0, true, true}, + {{37}, {0}, 37, 1, 0, true, true}, + {{0, 1}, {0, 1}, 0, 2, 0, false, true}, + {{0, 4}, {0, 1}, 0, 2, 2, false, true}, + {{0, uint64_t(1) << 33}, {0, 1}, 0, 2, 33, false, true}, + {{3, 7}, {0, 1}, 3, 2, 2, false, true}, + {{0, 1, 7}, {0, 1, 7}, 0, 8, 0, false, false}, + {{0, 2, 14}, {0, 1, 7}, 0, 8, 1, false, false}, + {{0, 1, 8}, {0, 1, 8}, 0, 9, 0, false, false}, + {{0, 2, 16}, {0, 1, 8}, 0, 9, 1, false, false}, + {{0, 1, 2, 3, 4, 5, 6, 7}, + {0, 1, 2, 3, 4, 5, 6, 7}, + 0, + 8, + 0, + false, + true}, + {{0, 1, 2, 3, 4, 5, 6, 7, 8}, + {0, 1, 2, 3, 4, 5, 6, 7, 8}, + 0, + 9, + 0, + false, + true}, }; for (auto &&T : BSBTests) { @@ -93,3 +105,51 @@ TEST(LowerBitSets, GlobalLayoutBuilder) { EXPECT_EQ(T.WantLayout, ComputedLayout); } } + +TEST(LowerBitSets, ByteArrayBuilder) { + struct BABAlloc { + std::set Bits; + uint64_t BitSize; + uint64_t WantByteOffset; + uint8_t WantMask; + }; + + struct { + std::vector Allocs; + std::vector WantBytes; + } BABTests[] = { + {{{{0}, 1, 0, 1}, {{0}, 1, 0, 2}}, {3}}, + {{{{0}, 16, 0, 1}, + {{1}, 15, 0, 2}, + {{2}, 14, 0, 4}, + {{3}, 13, 0, 8}, + {{4}, 12, 0, 0x10}, + {{5}, 11, 0, 0x20}, + {{6}, 10, 0, 0x40}, + {{7}, 9, 0, 0x80}, + {{0}, 7, 9, 0x80}, + {{0}, 6, 10, 0x40}, + {{0}, 5, 11, 0x20}, + {{0}, 4, 12, 0x10}, + {{0}, 3, 13, 8}, + {{0}, 2, 14, 4}, + {{0}, 1, 15, 2}}, + {1, 2, 4, 8, 0x10, 0x20, 0x40, 0x80, 0, 0x80, 0x40, 0x20, 0x10, 8, 4, + 2}}, + }; + + for (auto &&T : BABTests) { + ByteArrayBuilder BABuilder; + + for (auto &&A : T.Allocs) { + uint64_t GotByteOffset; + uint8_t GotMask; + + BABuilder.allocate(A.Bits, A.BitSize, GotByteOffset, GotMask); + EXPECT_EQ(A.WantByteOffset, GotByteOffset); + EXPECT_EQ(A.WantMask, GotMask); + } + + EXPECT_EQ(T.WantBytes, BABuilder.Bytes); + } +}