//===--- SPIRVUtils.cpp ---- SPIR-V Utility Functions -----------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains miscellaneous utility functions.
//
//===----------------------------------------------------------------------===//
#include "SPIRVUtils.h"
#include "MCTargetDesc/SPIRVBaseInfo.h"
#include "SPIRV.h"
#include "SPIRVInstrInfo.h"
#include "SPIRVSubtarget.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/CodeGen/GlobalISel/GenericMachineInstrs.h"
#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/Demangle/Demangle.h"
#include "llvm/IR/IntrinsicsSPIRV.h"
#include <queue>
#include <vector>
namespace llvm {
// The following functions are used to add these string literals as a series of
// 32-bit integer operands with the correct format, and unpack them if necessary
// when making string comparisons in compiler passes.
// SPIR-V requires null-terminated UTF-8 strings padded to 32-bit alignment.
static uint32_t convertCharsToWord(const StringRef &Str, unsigned i) {
uint32_t Word = 0u; // Build up this 32-bit word from 4 8-bit chars.
for (unsigned WordIndex = 0; WordIndex < 4; ++WordIndex) {
unsigned StrIndex = i + WordIndex;
uint8_t CharToAdd = 0; // Initilize char as padding/null.
if (StrIndex < Str.size()) { // If it's within the string, get a real char.
CharToAdd = Str[StrIndex];
}
Word |= (CharToAdd << (WordIndex * 8));
}
return Word;
}
// Get length including padding and null terminator.
static size_t getPaddedLen(const StringRef &Str) {
return (Str.size() + 4) & ~3;
}
void addStringImm(const StringRef &Str, MCInst &Inst) {
const size_t PaddedLen = getPaddedLen(Str);
for (unsigned i = 0; i < PaddedLen; i += 4) {
// Add an operand for the 32-bits of chars or padding.
Inst.addOperand(MCOperand::createImm(convertCharsToWord(Str, i)));
}
}
void addStringImm(const StringRef &Str, MachineInstrBuilder &MIB) {
const size_t PaddedLen = getPaddedLen(Str);
for (unsigned i = 0; i < PaddedLen; i += 4) {
// Add an operand for the 32-bits of chars or padding.
MIB.addImm(convertCharsToWord(Str, i));
}
}
void addStringImm(const StringRef &Str, IRBuilder<> &B,
std::vector<Value *> &Args) {
const size_t PaddedLen = getPaddedLen(Str);
for (unsigned i = 0; i < PaddedLen; i += 4) {
// Add a vector element for the 32-bits of chars or padding.
Args.push_back(B.getInt32(convertCharsToWord(Str, i)));
}
}
std::string getStringImm(const MachineInstr &MI, unsigned StartIndex) {
return getSPIRVStringOperand(MI, StartIndex);
}
void addNumImm(const APInt &Imm, MachineInstrBuilder &MIB) {
const auto Bitwidth = Imm.getBitWidth();
if (Bitwidth == 1)
return; // Already handled
else if (Bitwidth <= 32) {
MIB.addImm(Imm.getZExtValue());
// Asm Printer needs this info to print floating-type correctly
if (Bitwidth == 16)
MIB.getInstr()->setAsmPrinterFlag(SPIRV::ASM_PRINTER_WIDTH16);
return;
} else if (Bitwidth <= 64) {
uint64_t FullImm = Imm.getZExtValue();
uint32_t LowBits = FullImm & 0xffffffff;
uint32_t HighBits = (FullImm >> 32) & 0xffffffff;
MIB.addImm(LowBits).addImm(HighBits);
return;
}
report_fatal_error("Unsupported constant bitwidth");
}
void buildOpName(Register Target, const StringRef &Name,
MachineIRBuilder &MIRBuilder) {
if (!Name.empty()) {
auto MIB = MIRBuilder.buildInstr(SPIRV::OpName).addUse(Target);
addStringImm(Name, MIB);
}
}
static void finishBuildOpDecorate(MachineInstrBuilder &MIB,
const std::vector<uint32_t> &DecArgs,
StringRef StrImm) {
if (!StrImm.empty())
addStringImm(StrImm, MIB);
for (const auto &DecArg : DecArgs)
MIB.addImm(DecArg);
}
void buildOpDecorate(Register Reg, MachineIRBuilder &MIRBuilder,
SPIRV::Decoration::Decoration Dec,
const std::vector<uint32_t> &DecArgs, StringRef StrImm) {
auto MIB = MIRBuilder.buildInstr(SPIRV::OpDecorate)
.addUse(Reg)
.addImm(static_cast<uint32_t>(Dec));
finishBuildOpDecorate(MIB, DecArgs, StrImm);
}
void buildOpDecorate(Register Reg, MachineInstr &I, const SPIRVInstrInfo &TII,
SPIRV::Decoration::Decoration Dec,
const std::vector<uint32_t> &DecArgs, StringRef StrImm) {
MachineBasicBlock &MBB = *I.getParent();
auto MIB = BuildMI(MBB, I, I.getDebugLoc(), TII.get(SPIRV::OpDecorate))
.addUse(Reg)
.addImm(static_cast<uint32_t>(Dec));
finishBuildOpDecorate(MIB, DecArgs, StrImm);
}
void buildOpSpirvDecorations(Register Reg, MachineIRBuilder &MIRBuilder,
const MDNode *GVarMD) {
for (unsigned I = 0, E = GVarMD->getNumOperands(); I != E; ++I) {
auto *OpMD = dyn_cast<MDNode>(GVarMD->getOperand(I));
if (!OpMD)
report_fatal_error("Invalid decoration");
if (OpMD->getNumOperands() == 0)
report_fatal_error("Expect operand(s) of the decoration");
ConstantInt *DecorationId =
mdconst::dyn_extract<ConstantInt>(OpMD->getOperand(0));
if (!DecorationId)
report_fatal_error("Expect SPIR-V <Decoration> operand to be the first "
"element of the decoration");
auto MIB = MIRBuilder.buildInstr(SPIRV::OpDecorate)
.addUse(Reg)
.addImm(static_cast<uint32_t>(DecorationId->getZExtValue()));
for (unsigned OpI = 1, OpE = OpMD->getNumOperands(); OpI != OpE; ++OpI) {
if (ConstantInt *OpV =
mdconst::dyn_extract<ConstantInt>(OpMD->getOperand(OpI)))
MIB.addImm(static_cast<uint32_t>(OpV->getZExtValue()));
else if (MDString *OpV = dyn_cast<MDString>(OpMD->getOperand(OpI)))
addStringImm(OpV->getString(), MIB);
else
report_fatal_error("Unexpected operand of the decoration");
}
}
}
SPIRV::StorageClass::StorageClass
addressSpaceToStorageClass(unsigned AddrSpace, const SPIRVSubtarget &STI) {
switch (AddrSpace) {
case 0:
return SPIRV::StorageClass::Function;
case 1:
return SPIRV::StorageClass::CrossWorkgroup;
case 2:
return SPIRV::StorageClass::UniformConstant;
case 3:
return SPIRV::StorageClass::Workgroup;
case 4:
return SPIRV::StorageClass::Generic;
case 5:
return STI.canUseExtension(SPIRV::Extension::SPV_INTEL_usm_storage_classes)
? SPIRV::StorageClass::DeviceOnlyINTEL
: SPIRV::StorageClass::CrossWorkgroup;
case 6:
return STI.canUseExtension(SPIRV::Extension::SPV_INTEL_usm_storage_classes)
? SPIRV::StorageClass::HostOnlyINTEL
: SPIRV::StorageClass::CrossWorkgroup;
case 7:
return SPIRV::StorageClass::Input;
default:
report_fatal_error("Unknown address space");
}
}
SPIRV::MemorySemantics::MemorySemantics
getMemSemanticsForStorageClass(SPIRV::StorageClass::StorageClass SC) {
switch (SC) {
case SPIRV::StorageClass::StorageBuffer:
case SPIRV::StorageClass::Uniform:
return SPIRV::MemorySemantics::UniformMemory;
case SPIRV::StorageClass::Workgroup:
return SPIRV::MemorySemantics::WorkgroupMemory;
case SPIRV::StorageClass::CrossWorkgroup:
return SPIRV::MemorySemantics::CrossWorkgroupMemory;
case SPIRV::StorageClass::AtomicCounter:
return SPIRV::MemorySemantics::AtomicCounterMemory;
case SPIRV::StorageClass::Image:
return SPIRV::MemorySemantics::ImageMemory;
default:
return SPIRV::MemorySemantics::None;
}
}
SPIRV::MemorySemantics::MemorySemantics getMemSemantics(AtomicOrdering Ord) {
switch (Ord) {
case AtomicOrdering::Acquire:
return SPIRV::MemorySemantics::Acquire;
case AtomicOrdering::Release:
return SPIRV::MemorySemantics::Release;
case AtomicOrdering::AcquireRelease:
return SPIRV::MemorySemantics::AcquireRelease;
case AtomicOrdering::SequentiallyConsistent:
return SPIRV::MemorySemantics::SequentiallyConsistent;
case AtomicOrdering::Unordered:
case AtomicOrdering::Monotonic:
case AtomicOrdering::NotAtomic:
return SPIRV::MemorySemantics::None;
}
llvm_unreachable(nullptr);
}
SPIRV::Scope::Scope getMemScope(LLVMContext &Ctx, SyncScope::ID Id) {
// Named by
// https://registry.khronos.org/SPIR-V/specs/unified1/SPIRV.html#_scope_id.
// We don't need aliases for Invocation and CrossDevice, as we already have
// them covered by "singlethread" and "" strings respectively (see
// implementation of LLVMContext::LLVMContext()).
static const llvm::SyncScope::ID SubGroup =
Ctx.getOrInsertSyncScopeID("subgroup");
static const llvm::SyncScope::ID WorkGroup =
Ctx.getOrInsertSyncScopeID("workgroup");
static const llvm::SyncScope::ID Device =
Ctx.getOrInsertSyncScopeID("device");
if (Id == llvm::SyncScope::SingleThread)
return SPIRV::Scope::Invocation;
else if (Id == llvm::SyncScope::System)
return SPIRV::Scope::CrossDevice;
else if (Id == SubGroup)
return SPIRV::Scope::Subgroup;
else if (Id == WorkGroup)
return SPIRV::Scope::Workgroup;
else if (Id == Device)
return SPIRV::Scope::Device;
return SPIRV::Scope::CrossDevice;
}
MachineInstr *getDefInstrMaybeConstant(Register &ConstReg,
const MachineRegisterInfo *MRI) {
MachineInstr *MI = MRI->getVRegDef(ConstReg);
MachineInstr *ConstInstr =
MI->getOpcode() == SPIRV::G_TRUNC || MI->getOpcode() == SPIRV::G_ZEXT
? MRI->getVRegDef(MI->getOperand(1).getReg())
: MI;
if (auto *GI = dyn_cast<GIntrinsic>(ConstInstr)) {
if (GI->is(Intrinsic::spv_track_constant)) {
ConstReg = ConstInstr->getOperand(2).getReg();
return MRI->getVRegDef(ConstReg);
}
} else if (ConstInstr->getOpcode() == SPIRV::ASSIGN_TYPE) {
ConstReg = ConstInstr->getOperand(1).getReg();
return MRI->getVRegDef(ConstReg);
}
return MRI->getVRegDef(ConstReg);
}
uint64_t getIConstVal(Register ConstReg, const MachineRegisterInfo *MRI) {
const MachineInstr *MI = getDefInstrMaybeConstant(ConstReg, MRI);
assert(MI && MI->getOpcode() == TargetOpcode::G_CONSTANT);
return MI->getOperand(1).getCImm()->getValue().getZExtValue();
}
bool isSpvIntrinsic(const MachineInstr &MI, Intrinsic::ID IntrinsicID) {
if (const auto *GI = dyn_cast<GIntrinsic>(&MI))
return GI->is(IntrinsicID);
return false;
}
Type *getMDOperandAsType(const MDNode *N, unsigned I) {
Type *ElementTy = cast<ValueAsMetadata>(N->getOperand(I))->getType();
return toTypedPointer(ElementTy);
}
// The set of names is borrowed from the SPIR-V translator.
// TODO: may be implemented in SPIRVBuiltins.td.
static bool isPipeOrAddressSpaceCastBI(const StringRef MangledName) {
return MangledName == "write_pipe_2" || MangledName == "read_pipe_2" ||
MangledName == "write_pipe_2_bl" || MangledName == "read_pipe_2_bl" ||
MangledName == "write_pipe_4" || MangledName == "read_pipe_4" ||
MangledName == "reserve_write_pipe" ||
MangledName == "reserve_read_pipe" ||
MangledName == "commit_write_pipe" ||
MangledName == "commit_read_pipe" ||
MangledName == "work_group_reserve_write_pipe" ||
MangledName == "work_group_reserve_read_pipe" ||
MangledName == "work_group_commit_write_pipe" ||
MangledName == "work_group_commit_read_pipe" ||
MangledName == "get_pipe_num_packets_ro" ||
MangledName == "get_pipe_max_packets_ro" ||
MangledName == "get_pipe_num_packets_wo" ||
MangledName == "get_pipe_max_packets_wo" ||
MangledName == "sub_group_reserve_write_pipe" ||
MangledName == "sub_group_reserve_read_pipe" ||
MangledName == "sub_group_commit_write_pipe" ||
MangledName == "sub_group_commit_read_pipe" ||
MangledName == "to_global" || MangledName == "to_local" ||
MangledName == "to_private";
}
static bool isEnqueueKernelBI(const StringRef MangledName) {
return MangledName == "__enqueue_kernel_basic" ||
MangledName == "__enqueue_kernel_basic_events" ||
MangledName == "__enqueue_kernel_varargs" ||
MangledName == "__enqueue_kernel_events_varargs";
}
static bool isKernelQueryBI(const StringRef MangledName) {
return MangledName == "__get_kernel_work_group_size_impl" ||
MangledName == "__get_kernel_sub_group_count_for_ndrange_impl" ||
MangledName == "__get_kernel_max_sub_group_size_for_ndrange_impl" ||
MangledName == "__get_kernel_preferred_work_group_size_multiple_impl";
}
static bool isNonMangledOCLBuiltin(StringRef Name) {
if (!Name.starts_with("__"))
return false;
return isEnqueueKernelBI(Name) || isKernelQueryBI(Name) ||
isPipeOrAddressSpaceCastBI(Name.drop_front(2)) ||
Name == "__translate_sampler_initializer";
}
std::string getOclOrSpirvBuiltinDemangledName(StringRef Name) {
bool IsNonMangledOCL = isNonMangledOCLBuiltin(Name);
bool IsNonMangledSPIRV = Name.starts_with("__spirv_");
bool IsNonMangledHLSL = Name.starts_with("__hlsl_");
bool IsMangled = Name.starts_with("_Z");
// Otherwise use simple demangling to return the function name.
if (IsNonMangledOCL || IsNonMangledSPIRV || IsNonMangledHLSL || !IsMangled)
return Name.str();
// Try to use the itanium demangler.
if (char *DemangledName = itaniumDemangle(Name.data())) {
std::string Result = DemangledName;
free(DemangledName);
return Result;
}
// Autocheck C++, maybe need to do explicit check of the source language.
// OpenCL C++ built-ins are declared in cl namespace.
// TODO: consider using 'St' abbriviation for cl namespace mangling.
// Similar to ::std:: in C++.
size_t Start, Len = 0;
size_t DemangledNameLenStart = 2;
if (Name.starts_with("_ZN")) {
// Skip CV and ref qualifiers.
size_t NameSpaceStart = Name.find_first_not_of("rVKRO", 3);
// All built-ins are in the ::cl:: namespace.
if (Name.substr(NameSpaceStart, 11) != "2cl7__spirv")
return std::string();
DemangledNameLenStart = NameSpaceStart + 11;
}
Start = Name.find_first_not_of("0123456789", DemangledNameLenStart);
Name.substr(DemangledNameLenStart, Start - DemangledNameLenStart)
.getAsInteger(10, Len);
return Name.substr(Start, Len).str();
}
bool hasBuiltinTypePrefix(StringRef Name) {
if (Name.starts_with("opencl.") || Name.starts_with("ocl_") ||
Name.starts_with("spirv."))
return true;
return false;
}
bool isSpecialOpaqueType(const Type *Ty) {
if (const TargetExtType *EType = dyn_cast<TargetExtType>(Ty))
return hasBuiltinTypePrefix(EType->getName());
return false;
}
bool isEntryPoint(const Function &F) {
// OpenCL handling: any function with the SPIR_KERNEL
// calling convention will be a potential entry point.
if (F.getCallingConv() == CallingConv::SPIR_KERNEL)
return true;
// HLSL handling: special attribute are emitted from the
// front-end.
if (F.getFnAttribute("hlsl.shader").isValid())
return true;
return false;
}
Type *parseBasicTypeName(StringRef &TypeName, LLVMContext &Ctx) {
TypeName.consume_front("atomic_");
if (TypeName.consume_front("void"))
return Type::getVoidTy(Ctx);
else if (TypeName.consume_front("bool"))
return Type::getIntNTy(Ctx, 1);
else if (TypeName.consume_front("char") ||
TypeName.consume_front("unsigned char") ||
TypeName.consume_front("uchar"))
return Type::getInt8Ty(Ctx);
else if (TypeName.consume_front("short") ||
TypeName.consume_front("unsigned short") ||
TypeName.consume_front("ushort"))
return Type::getInt16Ty(Ctx);
else if (TypeName.consume_front("int") ||
TypeName.consume_front("unsigned int") ||
TypeName.consume_front("uint"))
return Type::getInt32Ty(Ctx);
else if (TypeName.consume_front("long") ||
TypeName.consume_front("unsigned long") ||
TypeName.consume_front("ulong"))
return Type::getInt64Ty(Ctx);
else if (TypeName.consume_front("half"))
return Type::getHalfTy(Ctx);
else if (TypeName.consume_front("float"))
return Type::getFloatTy(Ctx);
else if (TypeName.consume_front("double"))
return Type::getDoubleTy(Ctx);
// Unable to recognize SPIRV type name
return nullptr;
}
std::unordered_set<BasicBlock *>
PartialOrderingVisitor::getReachableFrom(BasicBlock *Start) {
std::queue<BasicBlock *> ToVisit;
ToVisit.push(Start);
std::unordered_set<BasicBlock *> Output;
while (ToVisit.size() != 0) {
BasicBlock *BB = ToVisit.front();
ToVisit.pop();
if (Output.count(BB) != 0)
continue;
Output.insert(BB);
for (BasicBlock *Successor : successors(BB)) {
if (DT.dominates(Successor, BB))
continue;
ToVisit.push(Successor);
}
}
return Output;
}
size_t PartialOrderingVisitor::visit(BasicBlock *BB, size_t Rank) {
if (Visited.count(BB) != 0)
return Rank;
Loop *L = LI.getLoopFor(BB);
const bool isLoopHeader = LI.isLoopHeader(BB);
if (BlockToOrder.count(BB) == 0) {
OrderInfo Info = {Rank, Visited.size()};
BlockToOrder.emplace(BB, Info);
} else {
BlockToOrder[BB].Rank = std::max(BlockToOrder[BB].Rank, Rank);
}
for (BasicBlock *Predecessor : predecessors(BB)) {
if (isLoopHeader && L->contains(Predecessor)) {
continue;
}
if (BlockToOrder.count(Predecessor) == 0) {
return Rank;
}
}
Visited.insert(BB);
SmallVector<BasicBlock *, 2> OtherSuccessors;
SmallVector<BasicBlock *, 2> LoopSuccessors;
for (BasicBlock *Successor : successors(BB)) {
// Ignoring back-edges.
if (DT.dominates(Successor, BB))
continue;
if (isLoopHeader && L->contains(Successor)) {
LoopSuccessors.push_back(Successor);
} else
OtherSuccessors.push_back(Successor);
}
for (BasicBlock *BB : LoopSuccessors)
Rank = std::max(Rank, visit(BB, Rank + 1));
size_t OutputRank = Rank;
for (BasicBlock *Item : OtherSuccessors)
OutputRank = std::max(OutputRank, visit(Item, Rank + 1));
return OutputRank;
}
PartialOrderingVisitor::PartialOrderingVisitor(Function &F) {
DT.recalculate(F);
LI = LoopInfo(DT);
visit(&*F.begin(), 0);
Order.reserve(F.size());
for (auto &[BB, Info] : BlockToOrder)
Order.emplace_back(BB);
std::sort(Order.begin(), Order.end(), [&](const auto &LHS, const auto &RHS) {
return compare(LHS, RHS);
});
}
bool PartialOrderingVisitor::compare(const BasicBlock *LHS,
const BasicBlock *RHS) const {
const OrderInfo &InfoLHS = BlockToOrder.at(const_cast<BasicBlock *>(LHS));
const OrderInfo &InfoRHS = BlockToOrder.at(const_cast<BasicBlock *>(RHS));
if (InfoLHS.Rank != InfoRHS.Rank)
return InfoLHS.Rank < InfoRHS.Rank;
return InfoLHS.TraversalIndex < InfoRHS.TraversalIndex;
}
void PartialOrderingVisitor::partialOrderVisit(
BasicBlock &Start, std::function<bool(BasicBlock *)> Op) {
std::unordered_set<BasicBlock *> Reachable = getReachableFrom(&Start);
assert(BlockToOrder.count(&Start) != 0);
// Skipping blocks with a rank inferior to |Start|'s rank.
auto It = Order.begin();
while (It != Order.end() && *It != &Start)
++It;
// This is unexpected. Worst case |Start| is the last block,
// so It should point to the last block, not past-end.
assert(It != Order.end());
// By default, there is no rank limit. Setting it to the maximum value.
std::optional<size_t> EndRank = std::nullopt;
for (; It != Order.end(); ++It) {
if (EndRank.has_value() && BlockToOrder[*It].Rank > *EndRank)
break;
if (Reachable.count(*It) == 0) {
continue;
}
if (!Op(*It)) {
EndRank = BlockToOrder[*It].Rank;
}
}
}
bool sortBlocks(Function &F) {
if (F.size() == 0)
return false;
bool Modified = false;
std::vector<BasicBlock *> Order;
Order.reserve(F.size());
PartialOrderingVisitor Visitor(F);
Visitor.partialOrderVisit(*F.begin(), [&Order](BasicBlock *Block) {
Order.push_back(Block);
return true;
});
assert(&*F.begin() == Order[0]);
BasicBlock *LastBlock = &*F.begin();
for (BasicBlock *BB : Order) {
if (BB != LastBlock && &*LastBlock->getNextNode() != BB) {
Modified = true;
BB->moveAfter(LastBlock);
}
LastBlock = BB;
}
return Modified;
}
MachineInstr *getVRegDef(MachineRegisterInfo &MRI, Register Reg) {
MachineInstr *MaybeDef = MRI.getVRegDef(Reg);
if (MaybeDef && MaybeDef->getOpcode() == SPIRV::ASSIGN_TYPE)
MaybeDef = MRI.getVRegDef(MaybeDef->getOperand(1).getReg());
return MaybeDef;
}
} // namespace llvm