================
@@ -14236,28 +14279,282 @@ bool SemaOpenMP::checkTransformableLoopNest(
return false;
},
[&OriginalInits](OMPLoopBasedDirective *Transform) {
- Stmt *DependentPreInits;
- if (auto *Dir = dyn_cast<OMPTileDirective>(Transform))
- DependentPreInits = Dir->getPreInits();
- else if (auto *Dir = dyn_cast<OMPStripeDirective>(Transform))
- DependentPreInits = Dir->getPreInits();
- else if (auto *Dir = dyn_cast<OMPUnrollDirective>(Transform))
- DependentPreInits = Dir->getPreInits();
- else if (auto *Dir = dyn_cast<OMPReverseDirective>(Transform))
- DependentPreInits = Dir->getPreInits();
- else if (auto *Dir = dyn_cast<OMPInterchangeDirective>(Transform))
- DependentPreInits = Dir->getPreInits();
- else
- llvm_unreachable("Unhandled loop transformation");
-
- appendFlattenedStmtList(OriginalInits.back(), DependentPreInits);
+ updatePreInits(Transform, OriginalInits.back());
});
assert(OriginalInits.back().empty() && "No preinit after innermost loop");
OriginalInits.pop_back();
return Result;
}
-/// Add preinit statements that need to be propageted from the selected loop.
+/// Counts the total number of nested loops, including the outermost loop (the
+/// original loop). PRECONDITION of this visitor is that it must be invoked
from
+/// the original loop to be analyzed. The traversal stops for Decl's and
+/// Expr's given that they may contain inner loops that must not be counted.
+///
+/// Example AST structure for the code:
+///
+/// int main() {
+/// #pragma omp fuse
+/// {
+/// for (int i = 0; i < 100; i++) { <-- Outer loop
+/// []() {
+/// for(int j = 0; j < 100; j++) {} <-- NOT A LOOP
+/// };
+/// for(int j = 0; j < 5; ++j) {} <-- Inner loop
+/// }
+/// for (int r = 0; i < 100; i++) { <-- Outer loop
+/// struct LocalClass {
+/// void bar() {
+/// for(int j = 0; j < 100; j++) {} <-- NOT A LOOP
+/// }
+/// };
+/// for(int k = 0; k < 10; ++k) {} <-- Inner loop
+/// {x = 5; for(k = 0; k < 10; ++k) x += k; x}; <-- NOT A LOOP
+/// }
+/// }
+/// }
+/// Result: Loop 'i' contains 2 loops, Loop 'r' also contains 2 loops.
+class NestedLoopCounterVisitor final : public DynamicRecursiveASTVisitor {
+private:
+ unsigned NestedLoopCount = 0;
+
+public:
+ explicit NestedLoopCounterVisitor() = default;
+
+ unsigned getNestedLoopCount() const { return NestedLoopCount; }
+
+ bool VisitForStmt(ForStmt *FS) override {
+ ++NestedLoopCount;
+ return true;
+ }
+
+ bool VisitCXXForRangeStmt(CXXForRangeStmt *FRS) override {
+ ++NestedLoopCount;
+ return true;
+ }
+
+ bool TraverseStmt(Stmt *S) override {
+ if (!S)
+ return true;
+
+ // Skip traversal of all expressions, including special cases like
+ // LambdaExpr, StmtExpr, BlockExpr, and RequiresExpr. These expressions
+ // may contain inner statements (and even loops), but they are not part
+ // of the syntactic body of the surrounding loop structure.
+ // Therefore must not be counted.
+ if (isa<Expr>(S))
+ return true;
+
+ // Only recurse into CompoundStmt (block {}) and loop bodies.
+ if (isa<CompoundStmt, ForStmt, CXXForRangeStmt>(S)) {
+ return DynamicRecursiveASTVisitor::TraverseStmt(S);
+ }
+
+ // Stop traversal of the rest of statements, that break perfect
+ // loop nesting, such as control flow (IfStmt, SwitchStmt...).
+ return true;
+ }
+
+ bool TraverseDecl(Decl *D) override {
+ // Stop in the case of finding a declaration, it is not important
+ // in order to find nested loops (Possible CXXRecordDecl, RecordDecl,
+ // FunctionDecl...).
+ return true;
+ }
+};
+
+bool SemaOpenMP::analyzeLoopSequence(Stmt *LoopSeqStmt,
+ LoopSequenceAnalysis &SeqAnalysis,
+ ASTContext &Context,
+ OpenMPDirectiveKind Kind) {
+
+ VarsWithInheritedDSAType TmpDSA;
+ /// Helper Lambda to handle storing initialization and body statements for
+ /// both ForStmt and CXXForRangeStmt.
+ auto StoreLoopStatements = [](LoopAnalysis &Analysis, Stmt *LoopStmt) {
+ if (auto *For = dyn_cast<ForStmt>(LoopStmt)) {
+ Analysis.OriginalInits.push_back(For->getInit());
+ Analysis.ForStmt = For;
+ } else {
+ auto *CXXFor = cast<CXXForRangeStmt>(LoopStmt);
+ Analysis.OriginalInits.push_back(CXXFor->getBeginStmt());
+ Analysis.ForStmt = CXXFor;
+ }
+ };
+
+ /// Helper lambda functions to encapsulate the processing of different
+ /// derivations of the canonical loop sequence grammar
+ /// Modularized code for handling loop generation and transformations.
+ auto AnalyzeLoopGeneration = [&](Stmt *Child) {
+ auto *LoopTransform = dyn_cast<OMPLoopTransformationDirective>(Child);
+ Stmt *TransformedStmt = LoopTransform->getTransformedStmt();
+ unsigned NumGeneratedLoopNests = LoopTransform->getNumGeneratedLoopNests();
+ unsigned NumGeneratedLoops = LoopTransform->getNumGeneratedLoops();
+ // Handle the case where transformed statement is not available due to
+ // dependent contexts
+ if (!TransformedStmt) {
+ if (NumGeneratedLoopNests > 0) {
+ SeqAnalysis.LoopSeqSize += NumGeneratedLoopNests;
+ SeqAnalysis.NumLoops += NumGeneratedLoops;
+ return true;
+ }
+ // Unroll full (0 loops produced)
+ Diag(Child->getBeginLoc(), diag::err_omp_not_for)
+ << 0 << getOpenMPDirectiveName(Kind);
+ return false;
+ }
+ // Handle loop transformations with multiple loop nests
+ // Unroll full
+ if (!NumGeneratedLoopNests) {
+ Diag(Child->getBeginLoc(), diag::err_omp_not_for)
+ << 0 << getOpenMPDirectiveName(Kind);
+ return false;
+ }
+ // Loop transformatons such as split or loopranged fuse
+ if (NumGeneratedLoopNests > 1) {
+ // Get the preinits related to this loop sequence generating
+ // loop transformation (i.e loopranged fuse, split...)
+ // These preinits differ slightly from regular inits/pre-inits related
+ // to single loop generating loop transformations (interchange, unroll)
+ // given that they are not bounded to a particular loop nest
+ // so they need to be treated independently
+ updatePreInits(LoopTransform, SeqAnalysis.LoopSequencePreInits);
+ return analyzeLoopSequence(TransformedStmt, SeqAnalysis, Context, Kind);
+ }
+ // Vast majority: (Tile, Unroll, Stripe, Reverse, Interchange, Fuse all)
+ // Process the transformed loop statement
+ LoopAnalysis &NewTransformedSingleLoop =
+ SeqAnalysis.Loops.emplace_back(OMPLoopCategory::TransformSingleLoop);
+ unsigned IsCanonical = checkOpenMPLoop(
+ Kind, nullptr, nullptr, TransformedStmt, SemaRef, *DSAStack, TmpDSA,
+ NewTransformedSingleLoop.HelperExprs);
+
+ if (!IsCanonical) {
+ Diag(TransformedStmt->getBeginLoc(), diag::err_omp_not_canonical_loop)
+ << getOpenMPDirectiveName(Kind);
+ return false;
+ }
+ StoreLoopStatements(NewTransformedSingleLoop, TransformedStmt);
+ updatePreInits(LoopTransform, NewTransformedSingleLoop.TransformsPreInits);
+
+ SeqAnalysis.NumLoops += NumGeneratedLoops;
+ SeqAnalysis.LoopSeqSize++;
+ return true;
+ };
+
+ /// Modularized code for handling regular canonical loops.
+ auto AnalyzeRegularLoop = [&](Stmt *Child) {
+ LoopAnalysis &NewRegularLoop =
+ SeqAnalysis.Loops.emplace_back(OMPLoopCategory::RegularLoop);
+ unsigned IsCanonical =
+ checkOpenMPLoop(Kind, nullptr, nullptr, Child, SemaRef, *DSAStack,
+ TmpDSA, NewRegularLoop.HelperExprs);
+
+ if (!IsCanonical) {
+ Diag(Child->getBeginLoc(), diag::err_omp_not_canonical_loop)
+ << getOpenMPDirectiveName(Kind);
+ return false;
+ }
+
+ StoreLoopStatements(NewRegularLoop, Child);
+ auto NLCV = NestedLoopCounterVisitor();
----------------
Meinersbur wrote:
```suggestion
NestedLoopCounterVisitor NLCV;
```
[style]
https://github.com/llvm/llvm-project/pull/139293
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