[OpenMP][Part 2] Use reusable OpenMP context/traits handling
This patch implements an almost complete handling of OpenMP
contexts/traits such that we can reuse most of the logic in Flang
through the OMPContext.{h,cpp} in llvm/Frontend/OpenMP.
All but construct SIMD specifiers, e.g., inbranch, and the device ISA
selector are define in `llvm/lib/Frontend/OpenMP/OMPKinds.def`. From
these definitions we generate the enum classes `TraitSet`,
`TraitSelector`, and `TraitProperty` as well as conversion and helper
functions in `llvm/lib/Frontend/OpenMP/OMPContext.{h,cpp}`.
The above enum classes are used in the parser, sema, and the AST
attribute. The latter is not a collection of multiple primitive variant
arguments that contain encodings via numbers and strings but instead a
tree that mirrors the `match` clause (see `struct OpenMPTraitInfo`).
The changes to the parser make it more forgiving when wrong syntax is
read and they also resulted in more specialized diagnostics. The tests
are updated and the core issues are detected as before. Here and
elsewhere this patch tries to be generic, thus we do not distinguish
what selector set, selector, or property is parsed except if they do
behave exceptionally, as for example `user={condition(EXPR)}` does.
The sema logic changed in two ways: First, the OMPDeclareVariantAttr
representation changed, as mentioned above, and the sema was adjusted to
work with the new `OpenMPTraitInfo`. Second, the matching and scoring
logic moved into `OMPContext.{h,cpp}`. It is implemented on a flat
representation of the `match` clause that is not tied to clang.
`OpenMPTraitInfo` provides a method to generate this flat structure (see
`struct VariantMatchInfo`) by computing integer score values and boolean
user conditions from the `clang::Expr` we keep for them.
The OpenMP context is now an explicit object (see `struct OMPContext`).
This is in anticipation of construct traits that need to be tracked. The
OpenMP context, as well as the `VariantMatchInfo`, are basically made up
of a set of active or respectively required traits, e.g., 'host', and an
ordered container of constructs which allows duplication. Matching and
scoring is kept as generic as possible to allow easy extension in the
future.
---
Test changes:
The messages checked in `OpenMP/declare_variant_messages.{c,cpp}` have
been auto generated to match the new warnings and notes of the parser.
The "subset" checks were reversed causing the wrong version to be
picked. The tests have been adjusted to correct this.
We do not print scores if the user did not provide one.
We print spaces to make lists in the `match` clause more legible.
Reviewers: kiranchandramohan, ABataev, RaviNarayanaswamy, gtbercea, grokos, sdmitriev, JonChesterfield, hfinkel, fghanim
Subscribers: merge_guards_bot, rampitec, mgorny, hiraditya, aheejin, fedor.sergeev, simoncook, bollu, guansong, dexonsmith, jfb, s.egerton, llvm-commits, cfe-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D71830
diff --git a/clang/lib/CodeGen/CGOpenMPRuntime.cpp b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
index 7440434..60b8149 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
@@ -11065,257 +11065,34 @@
return Address(Addr, Align);
}
-namespace {
-using OMPContextSelectorData =
- OpenMPCtxSelectorData<ArrayRef<StringRef>, llvm::APSInt>;
-using CompleteOMPContextSelectorData = SmallVector<OMPContextSelectorData, 4>;
-} // anonymous namespace
-
-/// Checks current context and returns true if it matches the context selector.
-template <OpenMPContextSelectorSetKind CtxSet, OpenMPContextSelectorKind Ctx,
- typename... Arguments>
-static bool checkContext(const OMPContextSelectorData &Data,
- Arguments... Params) {
- assert(Data.CtxSet != OMP_CTX_SET_unknown && Data.Ctx != OMP_CTX_unknown &&
- "Unknown context selector or context selector set.");
- return false;
-}
-
-/// Checks for implementation={vendor(<vendor>)} context selector.
-/// \returns true iff <vendor>="llvm", false otherwise.
-template <>
-bool checkContext<OMP_CTX_SET_implementation, OMP_CTX_vendor>(
- const OMPContextSelectorData &Data) {
- return llvm::all_of(Data.Names,
- [](StringRef S) { return !S.compare_lower("llvm"); });
-}
-
-/// Checks for device={kind(<kind>)} context selector.
-/// \returns true if <kind>="host" and compilation is for host.
-/// true if <kind>="nohost" and compilation is for device.
-/// true if <kind>="cpu" and compilation is for Arm, X86 or PPC CPU.
-/// true if <kind>="gpu" and compilation is for NVPTX or AMDGCN.
-/// false otherwise.
-template <>
-bool checkContext<OMP_CTX_SET_device, OMP_CTX_kind, CodeGenModule &>(
- const OMPContextSelectorData &Data, CodeGenModule &CGM) {
- for (StringRef Name : Data.Names) {
- if (!Name.compare_lower("host")) {
- if (CGM.getLangOpts().OpenMPIsDevice)
- return false;
- continue;
- }
- if (!Name.compare_lower("nohost")) {
- if (!CGM.getLangOpts().OpenMPIsDevice)
- return false;
- continue;
- }
- switch (CGM.getTriple().getArch()) {
- case llvm::Triple::arm:
- case llvm::Triple::armeb:
- case llvm::Triple::aarch64:
- case llvm::Triple::aarch64_be:
- case llvm::Triple::aarch64_32:
- case llvm::Triple::ppc:
- case llvm::Triple::ppc64:
- case llvm::Triple::ppc64le:
- case llvm::Triple::x86:
- case llvm::Triple::x86_64:
- if (Name.compare_lower("cpu"))
- return false;
- break;
- case llvm::Triple::amdgcn:
- case llvm::Triple::nvptx:
- case llvm::Triple::nvptx64:
- if (Name.compare_lower("gpu"))
- return false;
- break;
- case llvm::Triple::UnknownArch:
- case llvm::Triple::arc:
- case llvm::Triple::avr:
- case llvm::Triple::bpfel:
- case llvm::Triple::bpfeb:
- case llvm::Triple::hexagon:
- case llvm::Triple::mips:
- case llvm::Triple::mipsel:
- case llvm::Triple::mips64:
- case llvm::Triple::mips64el:
- case llvm::Triple::msp430:
- case llvm::Triple::r600:
- case llvm::Triple::riscv32:
- case llvm::Triple::riscv64:
- case llvm::Triple::sparc:
- case llvm::Triple::sparcv9:
- case llvm::Triple::sparcel:
- case llvm::Triple::systemz:
- case llvm::Triple::tce:
- case llvm::Triple::tcele:
- case llvm::Triple::thumb:
- case llvm::Triple::thumbeb:
- case llvm::Triple::xcore:
- case llvm::Triple::le32:
- case llvm::Triple::le64:
- case llvm::Triple::amdil:
- case llvm::Triple::amdil64:
- case llvm::Triple::hsail:
- case llvm::Triple::hsail64:
- case llvm::Triple::spir:
- case llvm::Triple::spir64:
- case llvm::Triple::kalimba:
- case llvm::Triple::shave:
- case llvm::Triple::lanai:
- case llvm::Triple::wasm32:
- case llvm::Triple::wasm64:
- case llvm::Triple::renderscript32:
- case llvm::Triple::renderscript64:
- case llvm::Triple::ve:
- return false;
- }
- }
- return true;
-}
-
-static bool matchesContext(CodeGenModule &CGM,
- const CompleteOMPContextSelectorData &ContextData) {
- for (const OMPContextSelectorData &Data : ContextData) {
- switch (Data.Ctx) {
- case OMP_CTX_vendor:
- assert(Data.CtxSet == OMP_CTX_SET_implementation &&
- "Expected implementation context selector set.");
- if (!checkContext<OMP_CTX_SET_implementation, OMP_CTX_vendor>(Data))
- return false;
- break;
- case OMP_CTX_kind:
- assert(Data.CtxSet == OMP_CTX_SET_device &&
- "Expected device context selector set.");
- if (!checkContext<OMP_CTX_SET_device, OMP_CTX_kind, CodeGenModule &>(Data,
- CGM))
- return false;
- break;
- case OMP_CTX_unknown:
- llvm_unreachable("Unknown context selector kind.");
- }
- }
- return true;
-}
-
-static CompleteOMPContextSelectorData
-translateAttrToContextSelectorData(ASTContext &C,
- const OMPDeclareVariantAttr *A) {
- CompleteOMPContextSelectorData Data;
- for (unsigned I = 0, E = A->scores_size(); I < E; ++I) {
- Data.emplace_back();
- auto CtxSet = static_cast<OpenMPContextSelectorSetKind>(
- *std::next(A->ctxSelectorSets_begin(), I));
- auto Ctx = static_cast<OpenMPContextSelectorKind>(
- *std::next(A->ctxSelectors_begin(), I));
- Data.back().CtxSet = CtxSet;
- Data.back().Ctx = Ctx;
- const Expr *Score = *std::next(A->scores_begin(), I);
- Data.back().Score = Score->EvaluateKnownConstInt(C);
- switch (Ctx) {
- case OMP_CTX_vendor:
- assert(CtxSet == OMP_CTX_SET_implementation &&
- "Expected implementation context selector set.");
- Data.back().Names =
- llvm::makeArrayRef(A->implVendors_begin(), A->implVendors_end());
- break;
- case OMP_CTX_kind:
- assert(CtxSet == OMP_CTX_SET_device &&
- "Expected device context selector set.");
- Data.back().Names =
- llvm::makeArrayRef(A->deviceKinds_begin(), A->deviceKinds_end());
- break;
- case OMP_CTX_unknown:
- llvm_unreachable("Unknown context selector kind.");
- }
- }
- return Data;
-}
-
-static bool isStrictSubset(const CompleteOMPContextSelectorData &LHS,
- const CompleteOMPContextSelectorData &RHS) {
- llvm::SmallDenseMap<std::pair<int, int>, llvm::StringSet<>, 4> RHSData;
- for (const OMPContextSelectorData &D : RHS) {
- auto &Pair = RHSData.FindAndConstruct(std::make_pair(D.CtxSet, D.Ctx));
- Pair.getSecond().insert(D.Names.begin(), D.Names.end());
- }
- bool AllSetsAreEqual = true;
- for (const OMPContextSelectorData &D : LHS) {
- auto It = RHSData.find(std::make_pair(D.CtxSet, D.Ctx));
- if (It == RHSData.end())
- return false;
- if (D.Names.size() > It->getSecond().size())
- return false;
- if (llvm::set_union(It->getSecond(), D.Names))
- return false;
- AllSetsAreEqual =
- AllSetsAreEqual && (D.Names.size() == It->getSecond().size());
- }
-
- return LHS.size() != RHS.size() || !AllSetsAreEqual;
-}
-
-static bool greaterCtxScore(const CompleteOMPContextSelectorData &LHS,
- const CompleteOMPContextSelectorData &RHS) {
- // Score is calculated as sum of all scores + 1.
- llvm::APSInt LHSScore(llvm::APInt(64, 1), /*isUnsigned=*/false);
- bool RHSIsSubsetOfLHS = isStrictSubset(RHS, LHS);
- if (RHSIsSubsetOfLHS) {
- LHSScore = llvm::APSInt::get(0);
- } else {
- for (const OMPContextSelectorData &Data : LHS) {
- if (Data.Score.getBitWidth() > LHSScore.getBitWidth()) {
- LHSScore = LHSScore.extend(Data.Score.getBitWidth()) + Data.Score;
- } else if (Data.Score.getBitWidth() < LHSScore.getBitWidth()) {
- LHSScore += Data.Score.extend(LHSScore.getBitWidth());
- } else {
- LHSScore += Data.Score;
- }
- }
- }
- llvm::APSInt RHSScore(llvm::APInt(64, 1), /*isUnsigned=*/false);
- if (!RHSIsSubsetOfLHS && isStrictSubset(LHS, RHS)) {
- RHSScore = llvm::APSInt::get(0);
- } else {
- for (const OMPContextSelectorData &Data : RHS) {
- if (Data.Score.getBitWidth() > RHSScore.getBitWidth()) {
- RHSScore = RHSScore.extend(Data.Score.getBitWidth()) + Data.Score;
- } else if (Data.Score.getBitWidth() < RHSScore.getBitWidth()) {
- RHSScore += Data.Score.extend(RHSScore.getBitWidth());
- } else {
- RHSScore += Data.Score;
- }
- }
- }
- return llvm::APSInt::compareValues(LHSScore, RHSScore) >= 0;
-}
-
/// Finds the variant function that matches current context with its context
/// selector.
static const FunctionDecl *getDeclareVariantFunction(CodeGenModule &CGM,
const FunctionDecl *FD) {
if (!FD->hasAttrs() || !FD->hasAttr<OMPDeclareVariantAttr>())
return FD;
- // Iterate through all DeclareVariant attributes and check context selectors.
- const OMPDeclareVariantAttr *TopMostAttr = nullptr;
- CompleteOMPContextSelectorData TopMostData;
+
+ SmallVector<Expr *, 8> VariantExprs;
+ SmallVector<VariantMatchInfo, 8> VMIs;
for (const auto *A : FD->specific_attrs<OMPDeclareVariantAttr>()) {
- CompleteOMPContextSelectorData Data =
- translateAttrToContextSelectorData(CGM.getContext(), A);
- if (!matchesContext(CGM, Data))
+ const OMPTraitInfo *TI = A->getTraitInfos();
+ if (!TI)
continue;
- // If the attribute matches the context, find the attribute with the highest
- // score.
- if (!TopMostAttr || !greaterCtxScore(TopMostData, Data)) {
- TopMostAttr = A;
- TopMostData.swap(Data);
- }
+ VMIs.push_back(VariantMatchInfo());
+ TI->getAsVariantMatchInfo(CGM.getContext(), VMIs.back());
+ VariantExprs.push_back(A->getVariantFuncRef());
}
- if (!TopMostAttr)
+
+ OMPContext Ctx(CGM.getLangOpts().OpenMPIsDevice, CGM.getTriple());
+ // FIXME: Keep the context in the OMPIRBuilder so we can add constructs as we
+ // build them.
+
+ int BestMatchIdx = getBestVariantMatchForContext(VMIs, Ctx);
+ if (BestMatchIdx < 0)
return FD;
+
return cast<FunctionDecl>(
- cast<DeclRefExpr>(TopMostAttr->getVariantFuncRef()->IgnoreParenImpCasts())
+ cast<DeclRefExpr>(VariantExprs[BestMatchIdx]->IgnoreParenImpCasts())
->getDecl());
}