Use the innermost lvalue instead of a reference when possible

vgvassilev · Jul 22, 2024 · c0ee0fb · c0ee0fb
1 parent 222f034
commit c0ee0fb
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Showing 2 changed files with 20 additions and 15 deletions.
diff --git a/lib/Differentiator/ReverseModeVisitor.cpp b/lib/Differentiator/ReverseModeVisitor.cpp
@@ -2335,8 +2335,15 @@ Expr* getArraySizeExpr(const ArrayType* AT, ASTContext& context,
 
       if (L->HasSideEffects(m_Context)) {
         Expr* E = Ldiff.getExpr();
-        auto* storeE = GlobalStoreAndRef(BuildOp(UO_AddrOf, E));
-        Ldiff.updateStmt(BuildOp(UO_Deref, storeE));
+        llvm::SmallVector<Expr*, 4> returnExprs;
+        utils::GetInnermostReturnExpr(E, returnExprs);
+        if (returnExprs.size() == 1) {
+          addToCurrentBlock(E, direction::forward);
+          Ldiff.updateStmt(returnExprs[0]);
+        } else {
+          auto* storeE = GlobalStoreAndRef(BuildOp(UO_AddrOf, E));
+          Ldiff.updateStmt(BuildOp(UO_Deref, storeE));
+        }
       }
 
       Stmts Lblock = EndBlockWithoutCreatingCS(direction::reverse);

diff --git a/test/Gradient/Assignments.C b/test/Gradient/Assignments.C
@@ -414,20 +414,19 @@ double f9(double x, double y) {
 //CHECK:   void f9_grad(double x, double y, double *_d_x, double *_d_y) {
 //CHECK-NEXT:       double _d_t = 0;
 //CHECK-NEXT:       double _t0;
-//CHECK-NEXT:       double *_t1;
-//CHECK-NEXT:       double _t2;
+//CHECK-NEXT:       double _t1;
 //CHECK-NEXT:       double t = x;
 //CHECK-NEXT:       _t0 = t;
-//CHECK-NEXT:       _t1 = &(t *= x);
-//CHECK-NEXT:       _t2 = *_t1;
-//CHECK-NEXT:       *_t1 *= y;
+//CHECK-NEXT:       (t *= x);
+//CHECK-NEXT:       _t1 = t;
+//CHECK-NEXT:       t *= y;
 //CHECK-NEXT:       _d_t += 1;
 //CHECK-NEXT:       {
-//CHECK-NEXT:           *_t1 = _t2;
+//CHECK-NEXT:           t = _t1;
 //CHECK-NEXT:           double _r_d1 = _d_t;
 //CHECK-NEXT:           _d_t = 0;
 //CHECK-NEXT:           _d_t += _r_d1 * y;
-//CHECK-NEXT:           *_d_y += *_t1 * _r_d1;
+//CHECK-NEXT:           *_d_y += t * _r_d1;
 //CHECK-NEXT:           t = _t0;
 //CHECK-NEXT:           double _r_d0 = _d_t;
 //CHECK-NEXT:           _d_t = 0;
@@ -474,16 +473,15 @@ double f11(double x, double y) {
 //CHECK:   void f11_grad(double x, double y, double *_d_x, double *_d_y) {
 //CHECK-NEXT:       double _d_t = 0;
 //CHECK-NEXT:       double _t0;
-//CHECK-NEXT:       double *_t1;
-//CHECK-NEXT:       double _t2;
+//CHECK-NEXT:       double _t1;
 //CHECK-NEXT:       double t = x;
 //CHECK-NEXT:       _t0 = t;
-//CHECK-NEXT:       _t1 = &(t = x);
-//CHECK-NEXT:       _t2 = *_t1;
-//CHECK-NEXT:       *_t1 = y;
+//CHECK-NEXT:       (t = x);
+//CHECK-NEXT:       _t1 = t;
+//CHECK-NEXT:       t = y;
 //CHECK-NEXT:       _d_t += 1;
 //CHECK-NEXT:       {
-//CHECK-NEXT:           *_t1 = _t2;
+//CHECK-NEXT:           t = _t1;
 //CHECK-NEXT:           double _r_d1 = _d_t;
 //CHECK-NEXT:           _d_t = 0;
 //CHECK-NEXT:           *_d_y += _r_d1;