update local copy move return to fix compiler warning

Author: tqchen

apps/hexagon_launcher/launcher_util.cc

@@ -47,7 +47,7 @@ std::string load_text_file(const std::string& file_name) {
   std::string buffer(file_size + 1, 0);
 
   in_file.read(&buffer[0], file_size);
-  return std::move(buffer);
+  return buffer;
 }
 
 void* load_binary_file(const std::string& file_name, void* buffer, size_t buffer_size) {

src/arith/canonical_simplify.cc

@@ -752,7 +752,7 @@ PrimExpr CanonicalSimplifier::Impl::VisitExpr_(const AddNode* op) {
   } else {
     ret.CopyOnWrite()->AddToSelf(ToSplitExpr(b), 1);
   }
-  return std::move(ret);
+  return ret;
 }
 
 PrimExpr CanonicalSimplifier::Impl::VisitExpr_(const SubNode* op) {
@@ -776,7 +776,7 @@ PrimExpr CanonicalSimplifier::Impl::VisitExpr_(const SubNode* op) {
   } else {
     ret.CopyOnWrite()->AddToSelf(ToSplitExpr(b), -1);
   }
-  return std::move(ret);
+  return ret;
 }
 
 PrimExpr CanonicalSimplifier::Impl::VisitExpr_(const MulNode* op) {
@@ -798,11 +798,12 @@ PrimExpr CanonicalSimplifier::Impl::VisitExpr_(const MulNode* op) {
     if (a.as<SumExprNode>()) {
       SumExpr ret = Downcast<SumExpr>(std::move(a));
       ret.CopyOnWrite()->MulToSelf(bconst->value);
-      return std::move(ret);
+      return ret;
+
     } else {
       SplitExpr ret = ToSplitExpr(std::move(a));
       ret.CopyOnWrite()->MulToSelf(bconst->value);
-      return std::move(ret);
+      return ret;
     }
   }
 
@@ -969,7 +970,7 @@ PrimExpr CanonicalSimplifier::Impl::VisitExpr_(const DivNode* op) {
       // can be divided by cval
       if (extra->IsZero()) {
         lhs.CopyOnWrite()->DivideBy(cval);
-        return std::move(lhs);
+        return lhs;
       }
       // both lhs and extra are non-negative
       if (analyzer_->CanProveGreaterEqual(lhs->Normalize(), 0) &&
@@ -984,7 +985,7 @@ PrimExpr CanonicalSimplifier::Impl::VisitExpr_(const DivNode* op) {
             lhs.CopyOnWrite()->AddToSelf(SplitDivConst(ToSplitExpr(temp), cval, kTruncDiv), 1);
           }
         }
-        return std::move(lhs);
+        return lhs;
       }
     } else {
       // if a >= 0 && a < cval, then result == 0
@@ -1031,7 +1032,7 @@ PrimExpr CanonicalSimplifier::Impl::VisitExpr_(const FloorDivNode* op) {
       SeparateDivisibleParts(psum, cval, &lhs, &extra);
       if (extra->IsZero()) {
         lhs.CopyOnWrite()->DivideBy(cval);
-        return std::move(lhs);
+        return lhs;
       }
       // continue simplification.
       lhs.CopyOnWrite()->DivideBy(cval);
@@ -1045,7 +1046,8 @@ PrimExpr CanonicalSimplifier::Impl::VisitExpr_(const FloorDivNode* op) {
           lhs.CopyOnWrite()->AddToSelf(SplitDivConst(ToSplitExpr(temp), cval, kFloorDiv), 1);
         }
       }
-      return std::move(lhs);
+      return lhs;
+
     } else {
       // if a >= 0 && a < cval, then result == 0
       auto cbound = analyzer_->const_int_bound(Normalize(a));
@@ -1371,14 +1373,14 @@ PrimExpr CanonicalSimplifier::Impl::VisitExpr_(const CastNode* op) {
     SumExpr se = Downcast<SumExpr>(value);
     if (se->CanPushCastToChildren(op->dtype, analyzer_)) {
       se.CopyOnWrite()->PushCastToChildren(op->dtype);
-      return std::move(se);
+      return se;
     }
   }
   if (value.as<SplitExprNode>()) {
     SplitExpr se = Downcast<SplitExpr>(value);
     if (se->CanPushCastToChildren(op->dtype, analyzer_)) {
       se.CopyOnWrite()->PushCastToChildren(op->dtype);
-      return std::move(se);
+      return se;
     }
   }
   return Rewriter::VisitExpr_(op);

src/arith/int_set.cc

@@ -1001,7 +1001,7 @@ IntSet EvalSet(Range r, const Map<Var, IntSet>& dom_map) {
   // Simplifying first can give tighter bounds if r->min and r->extent share variables
   PrimExpr sum = r->min + r->extent - 1;
   auto res = m.Eval(IntervalSet(r->min, ana.Simplify(sum)));
-  return std::move(res);
+  return res;
 }
 
 IntSet EvalSet(Range r, const std::unordered_map<const VarNode*, IntSet>& dom_map) {

src/arith/iter_affine_map.cc

@@ -1555,7 +1555,7 @@ PrimExpr IterMapRewriter::VisitExpr_(const VarNode* op) {
   auto var = GetRef<Var>(op);
   auto it = var_map_.find(var);
   if (it != var_map_.end()) return it->second;
-  return std::move(var);
+  return var;
 }
 
 PrimExpr IterMapRewriter::VisitExpr_(const AddNode* op) {
@@ -1588,7 +1588,7 @@ PrimExpr IterMapRewriter::VisitExpr_(const AddNode* op) {
   } else {
     AddToLhs(ret.CopyOnWrite(), ToIterSumExpr(b), 1);
   }
-  return std::move(ret);
+  return ret;
 }
 
 PrimExpr IterMapRewriter::VisitExpr_(const SubNode* op) {
@@ -1623,7 +1623,7 @@ PrimExpr IterMapRewriter::VisitExpr_(const SubNode* op) {
   } else {
     AddToLhs(ret.CopyOnWrite(), ToIterSumExpr(b), -1);
   }
-  return std::move(ret);
+  return ret;
 }
 
 PrimExpr IterMapRewriter::VisitExpr_(const MulNode* op) {
@@ -1660,12 +1660,13 @@ PrimExpr IterMapRewriter::VisitExpr_(const MulNode* op) {
   if (a->IsInstance<IterSumExprNode>()) {
     IterSumExpr ret = Downcast<IterSumExpr>(std::move(a));
     MulToLhs(ret.CopyOnWrite(), b);
-    return std::move(ret);
+    return ret;
+
   } else {
     ICHECK(a->IsInstance<IterSplitExprNode>());
     IterSplitExpr ret = Downcast<IterSplitExpr>(std::move(a));
     ret.CopyOnWrite()->scale *= b;
-    return std::move(ret);
+    return ret;
   }
 }
 
@@ -1854,7 +1855,8 @@ PrimExpr IterMapRewriter::SplitFloorDivConst(IterSplitExpr lhs, PrimExpr base, P
   if (is_one(rhs)) {
     if (is_zero(base)) {
       // floordiv(x, 1) = x
-      return std::move(lhs);
+      return lhs;
+
     } else {
       // floordiv(x+y, 1) = x+y
       return IterSumExpr({lhs}, base);
@@ -1865,7 +1867,8 @@ PrimExpr IterMapRewriter::SplitFloorDivConst(IterSplitExpr lhs, PrimExpr base, P
     if (CanProveDivisible(lhs->scale, rhs) && is_zero(base)) {
       // floordiv(x*c1*c2, c2) = x*c1, c1=scale/rhs
       lhs.CopyOnWrite()->scale = floordiv(lhs->scale, rhs);
-      return std::move(lhs);
+      return lhs;
+
     } else if (CanProveDivisible(lhs->scale, rhs) && CanProveDivisible(base, rhs)) {
       // floordiv(x*c1*c2 + y*c2, c2) = x*c1 + y, c1=scale/rhs
       lhs.CopyOnWrite()->scale = floordiv(lhs->scale, rhs);
@@ -1929,7 +1932,8 @@ PrimExpr IterMapRewriter::SplitFloorDivConst(IterSplitExpr lhs, PrimExpr base, P
 
   auto new_base = analyzer_->Simplify(floordiv(base - left_pad, rhs), 6);
   if (is_zero(new_base)) {
-    return std::move(new_split);
+    return new_split;
+
   } else {
     return IterSumExpr({new_split}, new_base);
   }

src/arith/narrow_predicate_expression.cc

@@ -83,7 +83,8 @@ class ExpressionNarrower : public tir::ExprMutator {
       contains_unknown_expr_ = false;
       return Bool(CurrentContext() == Context::Minimize);
     } else if (a.same_as(t->a) && b.same_as(t->b)) {
-      return std::move(t);
+      return t;
+
     } else {
       return T(a, b);
     }

src/arith/rewrite_simplify.cc

@@ -1720,7 +1720,7 @@ PrimExpr RewriteSimplifier::Impl::ApplyRewriteRules(EQ ret) {
     // supported path.
     TVM_TRY_REWRITE_IF(x == x, ctrue, SideEffect(x.Eval()) <= CallEffectKind::kReadState);
   }
-  return std::move(ret);
+  return ret;
 }
 
 PrimExpr RewriteSimplifier::Impl::VisitExpr_(const NENode* op) {
@@ -1981,7 +1981,7 @@ PrimExpr RewriteSimplifier::Impl::ApplyRewriteRules(LT ret) {
       return RecursiveRewrite(floordiv(ret->a, common_factor) < floordiv(ret->b, common_factor));
     }
   }
-  return std::move(ret);
+  return ret;
 }
 
 PrimExpr RewriteSimplifier::Impl::VisitExpr_(const NotNode* op) {
@@ -2009,7 +2009,7 @@ PrimExpr RewriteSimplifier::Impl::ApplyRewriteRules(Not ret) {
   TVM_TRY_REWRITE(!(x != y), x == y);
   TVM_TRY_RECURSIVE_REWRITE(!(x || y), (!x) && (!y));
   TVM_TRY_RECURSIVE_REWRITE(!(x && y), (!x) || (!y));
-  return std::move(ret);
+  return ret;
 }
 
 PrimExpr RewriteSimplifier::Impl::VisitExpr_(const AndNode* op) {

src/relax/ir/transform.cc

@@ -283,7 +283,7 @@ class DataflowBlockMutator : public ExprMutator {
     ICHECK(global_scope_vars.empty() && symbolic_vars.empty())
         << "Error: DataflowBlock Pass should not delete any GlobalScope/Symbolic Var.";
 
-    return std::move(updated_block);
+    return updated_block;
   }
 
  private:

src/relax/op/op.cc

@@ -528,7 +528,7 @@ Expr NormalizeCallTIR(const BlockBuilder& ctx, Call call) {
     call.CopyOnWrite()->args = new_args;
   }
 
-  return std::move(call);
+  return call;
 }
 
 void ValidateCallTIR(Call call) {
@@ -750,7 +750,7 @@ Expr NormalizeCallTIRInPlace(const BlockBuilder& ctx, Call call) {
     }
   }
 
-  return std::move(call);
+  return call;
 }
 
 TVM_REGISTER_NODE_TYPE(CallTIRInplaceAttrs);

src/relax/transform/convert_layout.cc

@@ -157,7 +157,7 @@ class LayoutConvertMutator : public ExprMutator {
       new_args.push_back(arg);
     }
 
-    return std::move(new_args);
+    return new_args;
   }
 
   void VisitBinding(const Binding& binding) final {

src/relax/transform/fold_constant.cc

@@ -301,7 +301,7 @@ class ConstantFolder : public ExprMutator {
       }
     }
 
-    return std::move(post_call);
+    return post_call;
   }
 
   Expr VisitExpr_(const VarNode* op) final {