From 50516fc8683cbd9147acafe05cac624920a7a2bd Mon Sep 17 00:00:00 2001 From: Atell Krasnopolski Date: Thu, 23 May 2024 19:56:04 +0200 Subject: [PATCH] Fix condition declarations & assignments, enable logical operators in for loops These changes fix the differentiation of variable declarations in for loop conditions that used to result into wrong derivatives. The commit also tackles the problem of having an assignment operator that affects the derivative in the for-loop condition, as well as adds support for logical operators in for-loops and allows to combine assignments with them. Fixes: #273 --- lib/Differentiator/BaseForwardModeVisitor.cpp | 93 +++++++++++++----- test/FirstDerivative/Loops.C | 94 ++++++++++++++++++- 2 files changed, 162 insertions(+), 25 deletions(-) diff --git a/lib/Differentiator/BaseForwardModeVisitor.cpp b/lib/Differentiator/BaseForwardModeVisitor.cpp index 5beab0cb3..9d80b1c54 100644 --- a/lib/Differentiator/BaseForwardModeVisitor.cpp +++ b/lib/Differentiator/BaseForwardModeVisitor.cpp @@ -668,18 +668,50 @@ StmtDiff BaseForwardModeVisitor::VisitForStmt(const ForStmt* FS) { const Stmt* init = FS->getInit(); StmtDiff initDiff = init ? Visit(init) : StmtDiff{}; addToCurrentBlock(initDiff.getStmt_dx()); - VarDecl* condVarDecl = FS->getConditionVariable(); - VarDecl* condVarClone = nullptr; - if (condVarDecl) { - DeclDiff condVarResult = DifferentiateVarDecl(condVarDecl); - condVarClone = condVarResult.getDecl(); - if (condVarResult.getDecl_dx()) - addToCurrentBlock(BuildDeclStmt(condVarResult.getDecl_dx())); + + StmtDiff condDiff = Clone(FS->getCond()); + Expr* cond = condDiff.getExpr(); + + // Declaration in the condition (if any) needs to be differentiated. + if (VarDecl* condVarDecl = FS->getConditionVariable()) { + // FIXME: here DifferentiateVarDecl is only used to clone the declaration + // properly because other ways have failed. + VarDecl* condVarClone = DifferentiateVarDecl(condVarDecl).getDecl(); + // Here we create a fictional cond that is equal to the assignment used in + // the declaration. The declaration itself is thrown before the for-loop + // without any init value. The fictional condition is then differentiated as + // normal condition (see below). + cond = + BuildOp(BO_Assign, BuildDeclRef(condVarClone), condVarClone->getInit()); + condVarClone->setInit(nullptr); + addToCurrentBlock(BuildDeclStmt(condVarClone)); + } + + // Condition differentiation. + // This adds support for assignments in conditions. + if (cond) { + while (CastExpr* condCast = dyn_cast(cond)) + cond = condCast->getSubExpr(); + while (ParenExpr* condParen = dyn_cast(cond)) + cond = condParen->getSubExpr(); + if (BinaryOperator* condBO = dyn_cast(cond)) { + // If it's an assignment operator or a binary logical operator we wrap it + // back into parentheses (as it is expected to be) and then visit. To + // ensure the correctness, a comma operator expression (cond_dx, cond) is + // generated and put instead of the condition. + if (condBO->isAssignmentOp() || condBO->getOpcode() == BO_LAnd || + condBO->getOpcode() == BO_LOr) { + condDiff = Visit(new (m_Context) ParenExpr(noLoc, noLoc, cond)); + cond = (condDiff.getExpr_dx()) + ? BuildOp(BO_Comma, BuildParens(condDiff.getExpr_dx()), + BuildParens(condDiff.getExpr())) + : condDiff.getExpr(); + } + } } - Expr* cond = FS->getCond() ? Clone(FS->getCond()) : nullptr; - const Expr* inc = FS->getInc(); // Differentiate the increment expression of the for loop + const Expr* inc = FS->getInc(); beginBlock(); StmtDiff incDiff = inc ? Visit(inc) : StmtDiff{}; CompoundStmt* decls = endBlock(); @@ -714,26 +746,23 @@ StmtDiff BaseForwardModeVisitor::VisitForStmt(const ForStmt* FS) { incResult = incDiff.getExpr(); } + // Build the derived for loop body. const Stmt* body = FS->getBody(); beginScope(Scope::DeclScope); Stmt* bodyResult = nullptr; - if (isa(body)) { - bodyResult = Visit(body).getStmt(); - } else { - beginBlock(); - StmtDiff Result = Visit(body); - for (Stmt* S : Result.getBothStmts()) - addToCurrentBlock(S); - CompoundStmt* Block = endBlock(); - if (Block->size() == 1) - bodyResult = Block->body_front(); - else - bodyResult = Block; - } + beginBlock(); + StmtDiff bodyVisited = Visit(body); + for (Stmt* S : bodyVisited.getBothStmts()) + addToCurrentBlock(S); + CompoundStmt* bodyResultCmpd = endBlock(); + if (bodyResultCmpd->size() == 1) + bodyResult = bodyResultCmpd->body_front(); + else + bodyResult = bodyResultCmpd; endScope(); Stmt* forStmtDiff = - new (m_Context) ForStmt(m_Context, initDiff.getStmt(), cond, condVarClone, + new (m_Context) ForStmt(m_Context, initDiff.getStmt(), cond, nullptr, incResult, bodyResult, noLoc, noLoc, noLoc); addToCurrentBlock(forStmtDiff); @@ -1366,6 +1395,24 @@ BaseForwardModeVisitor::VisitBinaryOperator(const BinaryOperator* BinOp) { } else opDiff = BuildOp(BO_Comma, BuildParens(Ldiff.getExpr()), BuildParens(Rdiff.getExpr_dx())); + } else if (opCode == BO_LAnd || opCode == BO_LOr) { + // For (A && B) return ((dA, A) && (dB, B)) to ensure correct evaluation and + // correct derivative execution. dLL = (dL, L) + Expr* dLL = BuildParens( + (Ldiff.getExpr_dx() ? BuildOp(BO_Comma, BuildParens(Ldiff.getExpr_dx()), + BuildParens(Ldiff.getExpr())) + : Ldiff.getExpr())); + // dRR = (dR, R) + Expr* dRR = BuildParens( + (Rdiff.getExpr_dx() ? BuildOp(BO_Comma, BuildParens(Rdiff.getExpr_dx()), + BuildParens(Rdiff.getExpr())) + : Rdiff.getExpr())); + opDiff = BuildOp(opCode, dLL, dRR); + + // Since the both parts are included in the opDiff, there's no point in + // including it as a Stmt_dx. Moreover, the fact that Stmt_dx is left + // nullptr is used for treating expressions like ((A && B) && C) correctly. + return StmtDiff(opDiff, nullptr); } if (!opDiff) { // FIXME: add support for other binary operators diff --git a/test/FirstDerivative/Loops.C b/test/FirstDerivative/Loops.C index 03257ff34..c1bdd8252 100644 --- a/test/FirstDerivative/Loops.C +++ b/test/FirstDerivative/Loops.C @@ -377,8 +377,8 @@ double fn10_darg0(double x, size_t n); // CHECK-NEXT: double res = 0; // CHECK-NEXT: { // CHECK-NEXT: size_t _d_count = 0; -// CHECK-NEXT: size_t _d_max_count = _d_n; -// CHECK-NEXT: for (size_t count = 0; {{.*}}max_count{{.*}}; ++count) { +// CHECK-NEXT: size_t max_count; +// CHECK-NEXT: for (size_t count = 0; (_d_max_count = _d_n) , (max_count = n); ++count) { // CHECK-NEXT: if (count >= max_count) // CHECK-NEXT: break; // CHECK-NEXT: { @@ -393,6 +393,81 @@ double fn10_darg0(double x, size_t n); // CHECK-NEXT: return _d_res; // CHECK-NEXT: } +double fn11(double x, double y) { + double r = 0; + for (int i = 0; (r = x); ++i) { + if (i == 3) break; + r += x; + } + return r; +} // fn11(x,y) == x + +double fn11_darg0(double x, double y); +// CHECK: double fn11_darg0(double x, double y) { +// CHECK-NEXT: double _d_x = 1; +// CHECK-NEXT: double _d_y = 0; +// CHECK-NEXT: double _d_r = 0; +// CHECK-NEXT: double r = 0; +// CHECK-NEXT: { +// CHECK-NEXT: int _d_i = 0; +// CHECK-NEXT: for (int i = 0; (_d_r = _d_x) , (r = x); ++i) { +// CHECK-NEXT: if (i == 3) +// CHECK-NEXT: break; +// CHECK-NEXT: _d_r += _d_x; +// CHECK-NEXT: r += x; +// CHECK-NEXT: } +// CHECK-NEXT: } +// CHECK-NEXT: return _d_r; +// CHECK-NEXT: } + +double fn12(double x, double y) { + double r = 0; + for (int i = 0; double c = x; ++i) { + if (i == 3) break; + c += x; + r = c; + } + return r; +} // fn11(x,y) == 2*x + +double fn12_darg0(double x, double y); +// CHECK: double fn12_darg0(double x, double y) { +// CHECK-NEXT: double _d_x = 1; +// CHECK-NEXT: double _d_y = 0; +// CHECK-NEXT: double _d_r = 0; +// CHECK-NEXT: double r = 0; +// CHECK-NEXT: { +// CHECK-NEXT: int _d_i = 0; +// CHECK-NEXT: double c; +// CHECK-NEXT: for (int i = 0; (_d_c = _d_x) , (c = x); ++i) { +// CHECK-NEXT: if (i == 3) +// CHECK-NEXT: break; +// CHECK-NEXT: _d_c += _d_x; +// CHECK-NEXT: c += x; +// CHECK-NEXT: _d_r = _d_c; +// CHECK-NEXT: r = c; +// CHECK-NEXT: } +// CHECK-NEXT: } +// CHECK-NEXT: return _d_r; +// CHECK-NEXT: } + +double fn13(double u, double v) { + double res = 0; + for (; (res = u * v) && (u = 0) ;) {} + return res; +} // = u*v + +double fn13_darg0(double u, double v); +// CHECK: double fn13_darg0(double u, double v) { +// CHECK-NEXT: double _d_u = 1; +// CHECK-NEXT: double _d_v = 0; +// CHECK-NEXT: double _d_res = 0; +// CHECK-NEXT: double res = 0; +// CHECK-NEXT: for (; (((_d_res = _d_u * v + u * _d_v) , (res = u * v)) && ((_d_u = 0) , (u = 0)));) { +// CHECK-NEXT: } +// CHECK-NEXT: return _d_res; +// CHECK-NEXT: } + #define TEST(fn)\ auto d_##fn = clad::differentiate(fn, "i");\ printf("%.2f\n", d_##fn.execute(3, 5)); @@ -430,4 +505,19 @@ int main() { clad::differentiate(fn10, 0); printf("Result is = %.2f\n", fn10_darg0(3, 5)); // CHECK-EXEC: Result is = 30.00 + + clad::differentiate(fn11, 0); + printf("Result is = %.2f\n", fn11_darg0(3, 5)); // CHECK-EXEC: Result is = 1.00 + printf("Result is = %.2f\n", fn11_darg0(-3, 6)); // CHECK-EXEC: Result is = 1.00 + printf("Result is = %.2f\n", fn11_darg0(1, 5)); // CHECK-EXEC: Result is = 1.00 + + clad::differentiate(fn12, 0); + printf("Result is = %.2f\n", fn12_darg0(3, 5)); // CHECK-EXEC: Result is = 2.00 + printf("Result is = %.2f\n", fn12_darg0(-3, 6)); // CHECK-EXEC: Result is = 2.00 + printf("Result is = %.2f\n", fn12_darg0(1, 5)); // CHECK-EXEC: Result is = 2.00 + + clad::differentiate(fn13, 0); + printf("Result is = %.2f\n", fn13_darg0(3, 4)); // CHECK-EXEC: Result is = 4.00 + printf("Result is = %.2f\n", fn13_darg0(-3, 5)); // CHECK-EXEC: Result is = 5.00 + printf("Result is = %.2f\n", fn13_darg0(1, 6)); // CHECK-EXEC: Result is = 6.00 }