lib/Semantics/canonicalize-acc.cpp - llvm-project/flang - Git at Google

 //===-- lib/Semantics/canonicalize-acc.cpp --------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//

 #include "canonicalize-acc.h"
 #include "flang/Parser/parse-tree-visitor.h"
 #include "flang/Semantics/tools.h"

 // After Loop Canonicalization, rewrite OpenACC parse tree to make OpenACC
 // Constructs more structured which provide explicit scopes for later
 // structural checks and semantic analysis.
 //   1. move structured DoConstruct into
 //      OpenACCLoopConstruct. Compilation will not proceed in case of errors
 //      after this pass.
 //   2. move structured DoConstruct into OpenACCCombinedConstruct. Move
 //      AccEndCombinedConstruct into OpenACCCombinedConstruct if present.
 //      Compilation will not proceed in case of errors after this pass.
 namespace Fortran::semantics {

 using namespace parser::literals;

 class CanonicalizationOfAcc {
 public:
   template <typename T> bool Pre(T &) { return true; }
   template <typename T> void Post(T &) {}
   CanonicalizationOfAcc(parser::Messages &messages) : messages_{messages} {}

   void Post(parser::Block &block) {
     for (auto it{block.begin()}; it != block.end(); ++it) {
       if (auto *accLoop{parser::Unwrap<parser::OpenACCLoopConstruct>(*it)}) {
         RewriteOpenACCLoopConstruct(*accLoop, block, it);
       } else if (auto *accCombined{
                      parser::Unwrap<parser::OpenACCCombinedConstruct>(*it)}) {
         RewriteOpenACCCombinedConstruct(*accCombined, block, it);
       } else if (auto *endDir{
                      parser::Unwrap<parser::AccEndCombinedDirective>(*it)}) {
         // Unmatched AccEndCombinedDirective
         messages_.Say(endDir->v.source,
             "The %s directive must follow the DO loop associated with the "
             "loop construct"_err_en_US,
             parser::ToUpperCaseLetters(endDir->v.source.ToString()));
       }
     } // Block list
   }

 private:
   // Check constraint in 2.9.7
   // If there are n tile sizes in the list, the loop construct must be
   // immediately followed by n tightly-nested loops.
   template <typename C, typename D>
   void CheckTileClauseRestriction(const C &x) {
     const auto &beginLoopDirective = std::get<D>(x.t);
     const auto &accClauseList =
         std::get<parser::AccClauseList>(beginLoopDirective.t);
     for (const auto &clause : accClauseList.v) {
       if (const auto *tileClause =
               std::get_if<parser::AccClause::Tile>(&clause.u)) {
         const parser::AccTileExprList &tileExprList = tileClause->v;
         const std::list<parser::AccTileExpr> &listTileExpr = tileExprList.v;
         std::size_t tileArgNb = listTileExpr.size();

         const auto &outer{std::get<std::optional<parser::DoConstruct>>(x.t)};
         if (outer->IsDoConcurrent()) {
           return; // Tile is not allowed on DO CONURRENT
         }
         for (const parser::DoConstruct *loop{&*outer}; loop && tileArgNb > 0;
              --tileArgNb) {
           const auto &block{std::get<parser::Block>(loop->t)};
           const auto it{block.begin()};
           loop = it != block.end() ? parser::Unwrap<parser::DoConstruct>(*it)
                                    : nullptr;
         }

         if (tileArgNb > 0) {
           messages_.Say(beginLoopDirective.source,
               "The loop construct with the TILE clause must be followed by %d "
               "tightly-nested loops"_err_en_US,
               listTileExpr.size());
         }
       }
     }
   }

   // Check constraint on line 1835 in Section 2.9
   // A tile and collapse clause may not appear on loop that is associated with
   // do concurrent.
   template <typename C, typename D>
   void CheckDoConcurrentClauseRestriction(const C &x) {
     const auto &doCons{std::get<std::optional<parser::DoConstruct>>(x.t)};
     if (!doCons->IsDoConcurrent()) {
       return;
     }
     const auto &beginLoopDirective = std::get<D>(x.t);
     const auto &accClauseList =
         std::get<parser::AccClauseList>(beginLoopDirective.t);
     for (const auto &clause : accClauseList.v) {
       if (std::holds_alternative<parser::AccClause::Collapse>(clause.u) ||
           std::holds_alternative<parser::AccClause::Tile>(clause.u)) {
         messages_.Say(beginLoopDirective.source,
             "TILE and COLLAPSE clause may not appear on loop construct "
             "associated with DO CONCURRENT"_err_en_US);
       }
     }
   }

   void RewriteOpenACCLoopConstruct(parser::OpenACCLoopConstruct &x,
       parser::Block &block, parser::Block::iterator it) {
     // Check the sequence of DoConstruct in the same iteration
     //
     // Original:
     //   ExecutableConstruct -> OpenACCConstruct -> OpenACCLoopConstruct
     //     ACCBeginLoopDirective
     //   ExecutableConstruct -> DoConstruct
     //
     // After rewriting:
     //   ExecutableConstruct -> OpenACCConstruct -> OpenACCLoopConstruct
     //     AccBeginLoopDirective
     //     DoConstruct
     parser::Block::iterator nextIt;
     auto &beginDir{std::get<parser::AccBeginLoopDirective>(x.t)};
     auto &dir{std::get<parser::AccLoopDirective>(beginDir.t)};

     nextIt = it;
     if (++nextIt != block.end()) {
       if (auto *doCons{parser::Unwrap<parser::DoConstruct>(*nextIt)}) {
         if (doCons->GetLoopControl()) {
           // move DoConstruct
           std::get<std::optional<parser::DoConstruct>>(x.t) =
               std::move(*doCons);
           nextIt = block.erase(nextIt);
         } else {
           messages_.Say(dir.source,
               "DO loop after the %s directive must have loop control"_err_en_US,
               parser::ToUpperCaseLetters(dir.source.ToString()));
         }

         CheckDoConcurrentClauseRestriction<parser::OpenACCLoopConstruct,
             parser::AccBeginLoopDirective>(x);
         CheckTileClauseRestriction<parser::OpenACCLoopConstruct,
             parser::AccBeginLoopDirective>(x);

         return; // found do-loop
       }
     }
     messages_.Say(dir.source,
         "A DO loop must follow the %s directive"_err_en_US,
         parser::ToUpperCaseLetters(dir.source.ToString()));
   }

   void RewriteOpenACCCombinedConstruct(parser::OpenACCCombinedConstruct &x,
       parser::Block &block, parser::Block::iterator it) {
     // Check the sequence of DoConstruct in the same iteration
     //
     // Original:
     //   ExecutableConstruct -> OpenACCConstruct -> OpenACCCombinedConstruct
     //     ACCBeginCombinedDirective
     //   ExecutableConstruct -> DoConstruct
     //   ExecutableConstruct -> AccEndCombinedDirective (if available)
     //
     // After rewriting:
     //   ExecutableConstruct -> OpenACCConstruct -> OpenACCCombinedConstruct
     //     ACCBeginCombinedDirective
     //     DoConstruct
     //     AccEndCombinedDirective (if available)
     parser::Block::iterator nextIt;
     auto &beginDir{std::get<parser::AccBeginCombinedDirective>(x.t)};
     auto &dir{std::get<parser::AccCombinedDirective>(beginDir.t)};

     nextIt = it;
     if (++nextIt != block.end()) {
       if (auto *doCons{parser::Unwrap<parser::DoConstruct>(*nextIt)}) {
         if (doCons->GetLoopControl()) {
           // move DoConstruct
           std::get<std::optional<parser::DoConstruct>>(x.t) =
               std::move(*doCons);
           nextIt = block.erase(nextIt);
           // try to match AccEndCombinedDirective
           if (nextIt != block.end()) {
             if (auto *endDir{
                     parser::Unwrap<parser::AccEndCombinedDirective>(*nextIt)}) {
               std::get<std::optional<parser::AccEndCombinedDirective>>(x.t) =
                   std::move(*endDir);
               block.erase(nextIt);
             }
           }
         } else {
           messages_.Say(dir.source,
               "DO loop after the %s directive must have loop control"_err_en_US,
               parser::ToUpperCaseLetters(dir.source.ToString()));
         }

         CheckDoConcurrentClauseRestriction<parser::OpenACCCombinedConstruct,
             parser::AccBeginCombinedDirective>(x);
         CheckTileClauseRestriction<parser::OpenACCCombinedConstruct,
             parser::AccBeginCombinedDirective>(x);

         return; // found do-loop
       }
     }
     messages_.Say(dir.source,
         "A DO loop must follow the %s directive"_err_en_US,
         parser::ToUpperCaseLetters(dir.source.ToString()));
   }

   parser::Messages &messages_;
 };

 bool CanonicalizeAcc(parser::Messages &messages, parser::Program &program) {
   CanonicalizationOfAcc acc{messages};
   Walk(program, acc);
   return !messages.AnyFatalError();
 }
 } // namespace Fortran::semantics
	//===-- lib/Semantics/canonicalize-acc.cpp --------------------------------===//
	//
	// 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
	//
	//===----------------------------------------------------------------------===//

	#include "canonicalize-acc.h"
	#include "flang/Parser/parse-tree-visitor.h"
	#include "flang/Semantics/tools.h"

	// After Loop Canonicalization, rewrite OpenACC parse tree to make OpenACC
	// Constructs more structured which provide explicit scopes for later
	// structural checks and semantic analysis.
	// 1. move structured DoConstruct into
	// OpenACCLoopConstruct. Compilation will not proceed in case of errors
	// after this pass.
	// 2. move structured DoConstruct into OpenACCCombinedConstruct. Move
	// AccEndCombinedConstruct into OpenACCCombinedConstruct if present.
	// Compilation will not proceed in case of errors after this pass.
	namespace Fortran::semantics {

	using namespace parser::literals;

	class CanonicalizationOfAcc {
	public:
	template <typename T> bool Pre(T &) { return true; }
	template <typename T> void Post(T &) {}
	CanonicalizationOfAcc(parser::Messages &messages) : messages_{messages} {}

	void Post(parser::Block &block) {
	for (auto it{block.begin()}; it != block.end(); ++it) {
	if (auto accLoop{parser::Unwrap<parser::OpenACCLoopConstruct>(it)}) {
	RewriteOpenACCLoopConstruct(*accLoop, block, it);
	} else if (auto *accCombined{
	parser::Unwrap<parser::OpenACCCombinedConstruct>(*it)}) {
	RewriteOpenACCCombinedConstruct(*accCombined, block, it);
	} else if (auto *endDir{
	parser::Unwrap<parser::AccEndCombinedDirective>(*it)}) {
	// Unmatched AccEndCombinedDirective
	messages_.Say(endDir->v.source,
	"The %s directive must follow the DO loop associated with the "
	"loop construct"_err_en_US,
	parser::ToUpperCaseLetters(endDir->v.source.ToString()));
	}
	} // Block list
	}

	private:
	// Check constraint in 2.9.7
	// If there are n tile sizes in the list, the loop construct must be
	// immediately followed by n tightly-nested loops.
	template <typename C, typename D>
	void CheckTileClauseRestriction(const C &x) {
	const auto &beginLoopDirective = std::get<D>(x.t);
	const auto &accClauseList =
	std::get<parser::AccClauseList>(beginLoopDirective.t);
	for (const auto &clause : accClauseList.v) {
	if (const auto *tileClause =
	std::get_if<parser::AccClause::Tile>(&clause.u)) {
	const parser::AccTileExprList &tileExprList = tileClause->v;
	const std::list<parser::AccTileExpr> &listTileExpr = tileExprList.v;
	std::size_t tileArgNb = listTileExpr.size();

	const auto &outer{std::get<std::optional<parser::DoConstruct>>(x.t)};
	if (outer->IsDoConcurrent()) {
	return; // Tile is not allowed on DO CONURRENT
	}
	for (const parser::DoConstruct loop{&outer}; loop && tileArgNb > 0;
	--tileArgNb) {
	const auto &block{std::get<parser::Block>(loop->t)};
	const auto it{block.begin()};
	loop = it != block.end() ? parser::Unwrap<parser::DoConstruct>(*it)
	: nullptr;
	}

	if (tileArgNb > 0) {
	messages_.Say(beginLoopDirective.source,
	"The loop construct with the TILE clause must be followed by %d "
	"tightly-nested loops"_err_en_US,
	listTileExpr.size());
	}
	}
	}
	}

	// Check constraint on line 1835 in Section 2.9
	// A tile and collapse clause may not appear on loop that is associated with
	// do concurrent.
	template <typename C, typename D>
	void CheckDoConcurrentClauseRestriction(const C &x) {
	const auto &doCons{std::get<std::optional<parser::DoConstruct>>(x.t)};
	if (!doCons->IsDoConcurrent()) {
	return;
	}
	const auto &beginLoopDirective = std::get<D>(x.t);
	const auto &accClauseList =
	std::get<parser::AccClauseList>(beginLoopDirective.t);
	for (const auto &clause : accClauseList.v) {
	if (std::holds_alternative<parser::AccClause::Collapse>(clause.u) \|\|
	std::holds_alternative<parser::AccClause::Tile>(clause.u)) {
	messages_.Say(beginLoopDirective.source,
	"TILE and COLLAPSE clause may not appear on loop construct "
	"associated with DO CONCURRENT"_err_en_US);
	}
	}
	}

	void RewriteOpenACCLoopConstruct(parser::OpenACCLoopConstruct &x,
	parser::Block &block, parser::Block::iterator it) {
	// Check the sequence of DoConstruct in the same iteration
	//
	// Original:
	// ExecutableConstruct -> OpenACCConstruct -> OpenACCLoopConstruct
	// ACCBeginLoopDirective
	// ExecutableConstruct -> DoConstruct
	//
	// After rewriting:
	// ExecutableConstruct -> OpenACCConstruct -> OpenACCLoopConstruct
	// AccBeginLoopDirective
	// DoConstruct
	parser::Block::iterator nextIt;
	auto &beginDir{std::get<parser::AccBeginLoopDirective>(x.t)};
	auto &dir{std::get<parser::AccLoopDirective>(beginDir.t)};

	nextIt = it;
	if (++nextIt != block.end()) {
	if (auto doCons{parser::Unwrap<parser::DoConstruct>(nextIt)}) {
	if (doCons->GetLoopControl()) {
	// move DoConstruct
	std::get<std::optional<parser::DoConstruct>>(x.t) =
	std::move(*doCons);
	nextIt = block.erase(nextIt);
	} else {
	messages_.Say(dir.source,
	"DO loop after the %s directive must have loop control"_err_en_US,
	parser::ToUpperCaseLetters(dir.source.ToString()));
	}

	CheckDoConcurrentClauseRestriction<parser::OpenACCLoopConstruct,
	parser::AccBeginLoopDirective>(x);
	CheckTileClauseRestriction<parser::OpenACCLoopConstruct,
	parser::AccBeginLoopDirective>(x);

	return; // found do-loop
	}
	}
	messages_.Say(dir.source,
	"A DO loop must follow the %s directive"_err_en_US,
	parser::ToUpperCaseLetters(dir.source.ToString()));
	}

	void RewriteOpenACCCombinedConstruct(parser::OpenACCCombinedConstruct &x,
	parser::Block &block, parser::Block::iterator it) {
	// Check the sequence of DoConstruct in the same iteration
	//
	// Original:
	// ExecutableConstruct -> OpenACCConstruct -> OpenACCCombinedConstruct
	// ACCBeginCombinedDirective
	// ExecutableConstruct -> DoConstruct
	// ExecutableConstruct -> AccEndCombinedDirective (if available)
	//
	// After rewriting:
	// ExecutableConstruct -> OpenACCConstruct -> OpenACCCombinedConstruct
	// ACCBeginCombinedDirective
	// DoConstruct
	// AccEndCombinedDirective (if available)
	parser::Block::iterator nextIt;
	auto &beginDir{std::get<parser::AccBeginCombinedDirective>(x.t)};
	auto &dir{std::get<parser::AccCombinedDirective>(beginDir.t)};

	nextIt = it;
	if (++nextIt != block.end()) {
	if (auto doCons{parser::Unwrap<parser::DoConstruct>(nextIt)}) {
	if (doCons->GetLoopControl()) {
	// move DoConstruct
	std::get<std::optional<parser::DoConstruct>>(x.t) =
	std::move(*doCons);
	nextIt = block.erase(nextIt);
	// try to match AccEndCombinedDirective
	if (nextIt != block.end()) {
	if (auto *endDir{
	parser::Unwrap<parser::AccEndCombinedDirective>(*nextIt)}) {
	std::get<std::optional<parser::AccEndCombinedDirective>>(x.t) =
	std::move(*endDir);
	block.erase(nextIt);
	}
	}
	} else {
	messages_.Say(dir.source,
	"DO loop after the %s directive must have loop control"_err_en_US,
	parser::ToUpperCaseLetters(dir.source.ToString()));
	}

	CheckDoConcurrentClauseRestriction<parser::OpenACCCombinedConstruct,
	parser::AccBeginCombinedDirective>(x);
	CheckTileClauseRestriction<parser::OpenACCCombinedConstruct,
	parser::AccBeginCombinedDirective>(x);

	return; // found do-loop
	}
	}
	messages_.Say(dir.source,
	"A DO loop must follow the %s directive"_err_en_US,
	parser::ToUpperCaseLetters(dir.source.ToString()));
	}

	parser::Messages &messages_;
	};

	bool CanonicalizeAcc(parser::Messages &messages, parser::Program &program) {
	CanonicalizationOfAcc acc{messages};
	Walk(program, acc);
	return !messages.AnyFatalError();
	}
	} // namespace Fortran::semantics