[01d433e] | 1 | // |
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| 2 | // Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo |
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| 3 | // |
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| 4 | // The contents of this file are covered under the licence agreement in the |
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| 5 | // file "LICENCE" distributed with Cforall. |
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| 6 | // |
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| 7 | // TupleExpansionNew.cpp -- |
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| 8 | // |
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| 9 | // Author : Henry Xue |
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| 10 | // Created On : Wed Aug 18 12:54:02 2021 |
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| 11 | // Last Modified By : Henry Xue |
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| 12 | // Last Modified On : Wed Aug 18 12:54:02 2021 |
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| 13 | // Update Count : 1 |
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| 14 | // |
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| 15 | |
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| 16 | // Currently not working due to unresolved issues with UniqueExpr |
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| 17 | |
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| 18 | #include "Tuples.h" |
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| 19 | |
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| 20 | namespace Tuples { |
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| 21 | namespace { |
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| 22 | struct UniqueExprExpander final : public ast::WithDeclsToAdd<> { |
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| 23 | const ast::Expr * postvisit( const ast::UniqueExpr * unqExpr ); |
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| 24 | std::map< int, const ast::Expr * > decls; // not vector, because order added may not be increasing order |
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| 25 | }; |
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| 26 | } // namespace |
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| 27 | |
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| 28 | void expandUniqueExpr( ast::TranslationUnit & translationUnit ) { |
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| 29 | ast::Pass< UniqueExprExpander >::run( translationUnit ); |
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| 30 | } |
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| 31 | |
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| 32 | namespace { |
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| 33 | const ast::Expr * UniqueExprExpander::postvisit( const ast::UniqueExpr * unqExpr ) { |
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| 34 | const CodeLocation loc = unqExpr->location; |
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| 35 | const int id = unqExpr->id; |
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| 36 | |
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| 37 | // on first time visiting a unique expr with a particular ID, generate the expression that replaces all UniqueExprs with that ID, |
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| 38 | // and lookup on subsequent hits. This ensures that all unique exprs with the same ID reference the same variable. |
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| 39 | if ( ! decls.count( id ) ) { |
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| 40 | ast::ptr< ast::Expr > assignUnq; |
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| 41 | ast::ptr< ast::VariableExpr > var = unqExpr->var; |
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| 42 | if ( unqExpr->object ) { |
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| 43 | // an object was generated to represent this unique expression -- it should be added to the list of declarations now |
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| 44 | declsToAddBefore.push_back( unqExpr->object.as< ast::Decl >() ); |
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| 45 | // deep copy required due to unresolved issues with UniqueExpr |
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| 46 | assignUnq = ast::UntypedExpr::createAssign( loc, var, ast::deepCopy( unqExpr->expr.get() ) ); |
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| 47 | } else { |
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| 48 | ast::ptr< ast::Expr > expr = unqExpr->expr; |
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| 49 | ast::ptr< ast::CommaExpr > commaExpr = expr.strict_as< ast::CommaExpr >(); |
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| 50 | assignUnq = commaExpr->arg1; |
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| 51 | } |
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| 52 | auto finished = new ast::ObjectDecl( loc, toString( "_unq", id, "_finished_" ), new ast::BasicType( ast::BasicType::Kind::Bool ), |
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| 53 | new ast::SingleInit( loc, ast::ConstantExpr::from_int( loc, 0 ) ), {}, ast::Linkage::Cforall ); |
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| 54 | declsToAddBefore.push_back( finished ); |
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| 55 | // (finished ? _unq_expr_N : (_unq_expr_N = <unqExpr->get_expr()>, finished = 1, _unq_expr_N)) |
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| 56 | // This pattern ensures that each unique expression is evaluated once, regardless of evaluation order of the generated C code. |
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| 57 | auto assignFinished = ast::UntypedExpr::createAssign( loc, new ast::VariableExpr( loc, finished ), |
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| 58 | ast::ConstantExpr::from_int( loc, 1 ) ); |
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| 59 | auto condExpr = new ast::ConditionalExpr( loc, new ast::VariableExpr( loc, finished ), var, |
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| 60 | new ast::CommaExpr( loc, new ast::CommaExpr( loc, assignUnq, assignFinished ), var ) ); |
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| 61 | condExpr->result = var->result; |
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| 62 | condExpr->env = unqExpr->env; |
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| 63 | decls[id] = condExpr; |
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| 64 | } |
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| 65 | //delete unqExpr; |
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| 66 | return decls[id]; |
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| 67 | } |
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| 68 | } // namespace |
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| 69 | } // namespace Tuples |
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