Use std::swap instead of manual swaps.

gcc/
	* auto-inc-dec.c (reverse_mem, reverse_inc): Remove.
	(parse_add_or_inc): Use std::swap instead of reverse_{mem,inc}.
	(find_inc): Likewise.
	* combine.c (combine_simplify_rtx): Use std::swap instead of manually
	swapping.
	* df-core.c (df_worklist_dataflow_doublequeue): Likewise.
	* df-scan.c (df_swap_refs): Remove.
	(df_sort_and_compress_refs): Use std::swap instead of df_swap_refs.
	* dominance.c (link_roots): Use std::swap instead of manually swapping.
	* expr.c (expand_expr_real_2, do_store_flag): Likewise.
	* fold-const.c (fold_relational_const): Likewise.
	* genattrtab.c (simplify_test_exp): Likewise.
	* gimple-match-head.c (gimple_resimplify2, gimple_resimplify3,
	gimple_simplify): Likewise.
	* ifcvt.c (noce_try_abs, find_if_header): Likewise.
	* internal-fn.c (expand_addsub_overflow, expand_mul_overflow): Likewise.
	* ipa-devirt.c (add_type_duplicate): Likewise.
	* loop-iv.c (get_biv_step_1, iv_number_of_iterations): Likewise.
	* lra-lives.c (lra_setup_reload_pseudo_preferenced_hard_reg): Likewise.
	* lra.c (lra_create_copy): Likewise.
	* lto-streamer-out.c (DFS::DFS): Likewise.
	* modulo-sched.c (get_sched_window): Likewise.
	* omega.c (omega_pretty_print_problem): Likewise.
	* optabs.c (prepare_float_lib_cmp, expand_mult_highpart): Likewise.
	* reload1.c (reloads_unique_chain_p): Likewise.
	* sel-sched-ir.c (exchange_lv_sets, exchange_av_sets): Remove.
	(exchange_data_sets): Move logic from exchange_{av,lv}_sets here and
	use std::swap.
	* simplify-rtx.c (simplify_unary_operation_1): Use std::swap instead of
	manually swapping.
	* tree-if-conv.c (is_cond_scalar_reduction, predicate_scalar_phi,
	predicate_mem_writes): Likewise.
	* tree-loop-distribution.c (pg_add_dependence_edges): Likewise.
	* tree-predcom.c (combine_chains): Likewise.
	* tree-ssa-alias.c (nonoverlapping_component_refs_p,
	refs_may_alias_p_1): Likewise.
	* tree-ssa-ifcombine.c (recognize_if_then_else): Likewise.
	* tree-ssa-loop-ivopts.c (extract_cond_operands): Likewise.
	* tree-ssa-loop-niter.c (refine_bounds_using_guard,
	number_of_iterations_cond): Likewise.
	* tree-ssa-phiopt.c (tree_ssa_phiopt_worker): Likewise.
	* tree-ssa-sccvn.c (vn_nary_op_compute_hash): Likewise.
	* tree-vect-slp.c (vect_build_slp_tree): Likewise.
	* tree-vect-stmts.c (supportable_widening_operation): Likewise.
	* tree-vrp.c (extract_range_from_binary_expr_1,
	extract_range_from_unary_expr_1): Likewise.

gcc/cp/
	* pt.c (maybe_adjust_types_for_deduction): Use std::swap instead of
	manually swapping.
	* semantics.c (finish_omp_atomic): Likewise.
	* typeck.c (cp_build_array_ref): Likewise.

gcc/c-family/
	* c-common.c (scalar_to_vector): Use std::swap instead of manually
	swapping.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@224718 138bc75d-0d04-0410-961f-82ee72b054a4

41 files changed, 162 insertions, 350 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 2b5568504d9..737178ca0ca 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,52 @@
+2015-06-22  Mikhail Maltsev  <maltsevm@gmail.com>
+
+	* auto-inc-dec.c (reverse_mem, reverse_inc): Remove.
+	(parse_add_or_inc): Use std::swap instead of reverse_{mem,inc}.
+	(find_inc): Likewise.
+	* combine.c (combine_simplify_rtx): Use std::swap instead of manually
+	swapping.
+	* df-core.c (df_worklist_dataflow_doublequeue): Likewise.
+	* df-scan.c (df_swap_refs): Remove.
+	(df_sort_and_compress_refs): Use std::swap instead of df_swap_refs.
+	* dominance.c (link_roots): Use std::swap instead of manually swapping.
+	* expr.c (expand_expr_real_2, do_store_flag): Likewise.
+	* fold-const.c (fold_relational_const): Likewise.
+	* genattrtab.c (simplify_test_exp): Likewise.
+	* gimple-match-head.c (gimple_resimplify2, gimple_resimplify3,
+	gimple_simplify): Likewise.
+	* ifcvt.c (noce_try_abs, find_if_header): Likewise.
+	* internal-fn.c (expand_addsub_overflow, expand_mul_overflow): Likewise.
+	* ipa-devirt.c (add_type_duplicate): Likewise.
+	* loop-iv.c (get_biv_step_1, iv_number_of_iterations): Likewise.
+	* lra-lives.c (lra_setup_reload_pseudo_preferenced_hard_reg): Likewise.
+	* lra.c (lra_create_copy): Likewise.
+	* lto-streamer-out.c (DFS::DFS): Likewise.
+	* modulo-sched.c (get_sched_window): Likewise.
+	* omega.c (omega_pretty_print_problem): Likewise.
+	* optabs.c (prepare_float_lib_cmp, expand_mult_highpart): Likewise.
+	* reload1.c (reloads_unique_chain_p): Likewise.
+	* sel-sched-ir.c (exchange_lv_sets, exchange_av_sets): Remove.
+	(exchange_data_sets): Move logic from exchange_{av,lv}_sets here and
+	use std::swap.
+	* simplify-rtx.c (simplify_unary_operation_1): Use std::swap instead of
+	manually swapping.
+	* tree-if-conv.c (is_cond_scalar_reduction, predicate_scalar_phi,
+	predicate_mem_writes): Likewise.
+	* tree-loop-distribution.c (pg_add_dependence_edges): Likewise.
+	* tree-predcom.c (combine_chains): Likewise.
+	* tree-ssa-alias.c (nonoverlapping_component_refs_p,
+	refs_may_alias_p_1): Likewise.
+	* tree-ssa-ifcombine.c (recognize_if_then_else): Likewise.
+	* tree-ssa-loop-ivopts.c (extract_cond_operands): Likewise.
+	* tree-ssa-loop-niter.c (refine_bounds_using_guard,
+	number_of_iterations_cond): Likewise.
+	* tree-ssa-phiopt.c (tree_ssa_phiopt_worker): Likewise.
+	* tree-ssa-sccvn.c (vn_nary_op_compute_hash): Likewise.
+	* tree-vect-slp.c (vect_build_slp_tree): Likewise.
+	* tree-vect-stmts.c (supportable_widening_operation): Likewise.
+	* tree-vrp.c (extract_range_from_binary_expr_1,
+	extract_range_from_unary_expr_1): Likewise.
+
 2015-06-20  Marek Polacek  <polacek@redhat.com>
 
 	* common.opt (fsanitize-undefined-trap-on-error): Add Driver.
diff --git a/gcc/auto-inc-dec.c b/gcc/auto-inc-dec.c
index 3241ed7c1e2..df52229322d 100644
--- a/gcc/auto-inc-dec.c
+++ b/gcc/auto-inc-dec.c
@@ -767,28 +767,6 @@ get_next_ref (int regno, basic_block bb, rtx_insn **next_array)
 }
 
 
-/* Reverse the operands in a mem insn.  */
-
-static void
-reverse_mem (void)
-{
-  rtx tmp = mem_insn.reg1;
-  mem_insn.reg1 = mem_insn.reg0;
-  mem_insn.reg0 = tmp;
-}
-
-
-/* Reverse the operands in a inc insn.  */
-
-static void
-reverse_inc (void)
-{
-  rtx tmp = inc_insn.reg1;
-  inc_insn.reg1 = inc_insn.reg0;
-  inc_insn.reg0 = tmp;
-}
-
-
 /* Return true if INSN is of a form "a = b op c" where a and b are
    regs.  op is + if c is a reg and +|- if c is a const.  Fill in
    INC_INSN with what is found.
@@ -857,7 +835,7 @@ parse_add_or_inc (rtx_insn *insn, bool before_mem)
 	{
 	  /* Reverse the two operands and turn *_ADD into *_INC since
 	     a = c + a.  */
-	  reverse_inc ();
+	  std::swap (inc_insn.reg0, inc_insn.reg1);
 	  inc_insn.form = before_mem ? FORM_PRE_INC : FORM_POST_INC;
 	  return true;
 	}
@@ -1017,7 +995,7 @@ find_inc (bool first_try)
 	 find this.  Only try it once though.  */
       if (first_try && !mem_insn.reg1_is_const)
 	{
-	  reverse_mem ();
+	  std::swap (mem_insn.reg0, mem_insn.reg1);
 	  return find_inc (false);
 	}
       else
@@ -1118,7 +1096,7 @@ find_inc (bool first_try)
 		    return false;
 
 		  if (!rtx_equal_p (mem_insn.reg0, inc_insn.reg0))
-		    reverse_inc ();
+		    std::swap (inc_insn.reg0, inc_insn.reg1);
 		}
 
 	      other_insn
@@ -1168,7 +1146,7 @@ find_inc (bool first_try)
 		  /* See comment above on find_inc (false) call.  */
 		  if (first_try)
 		    {
-		      reverse_mem ();
+		      std::swap (mem_insn.reg0, mem_insn.reg1);
 		      return find_inc (false);
 		    }
 		  else
@@ -1187,7 +1165,7 @@ find_inc (bool first_try)
 	    {
 	      /* We know that mem_insn.reg0 must equal inc_insn.reg1
 		 or else we would not have found the inc insn.  */
-	      reverse_mem ();
+	      std::swap (mem_insn.reg0, mem_insn.reg1);
 	      if (!rtx_equal_p (mem_insn.reg0, inc_insn.reg0))
 		{
 		  /* See comment above on find_inc (false) call.  */
@@ -1226,7 +1204,7 @@ find_inc (bool first_try)
 	    {
 	      if (first_try)
 		{
-		  reverse_mem ();
+		  std::swap (mem_insn.reg0, mem_insn.reg1);
 		  return find_inc (false);
 		}
 	      else
diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog
index 33cf7690bb6..39de58a9ea5 100644
--- a/gcc/c-family/ChangeLog
+++ b/gcc/c-family/ChangeLog
@@ -1,3 +1,8 @@
+2015-06-22  Mikhail Maltsev  <maltsevm@gmail.com>
+
+	* c-common.c (scalar_to_vector): Use std::swap instead of manually
+	swapping.
+
 2015-06-17  Andrew MacLeod  <amacleod@redhat.com>
 
 	* array-notation-common.c: Do not include input.h, line-map.h or is-a.h.
diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index dc2bf00ebbc..c39a36deb30 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -12605,11 +12605,9 @@ scalar_to_vector (location_t loc, enum tree_code code, tree op0, tree op1,
       /* What about UNLT_EXPR?  */
 	if (TREE_CODE (type0) == VECTOR_TYPE)
 	  {
-	    tree tmp;
 	    ret = stv_secondarg;
-	    /* Swap TYPE0 with TYPE1 and OP0 with OP1  */
-	    tmp = type0; type0 = type1; type1 = tmp;
-	    tmp = op0; op0 = op1; op1 = tmp;
+	    std::swap (type0, type1);
+	    std::swap (op0, op1);
 	  }
 
 	if (TREE_CODE (type0) == INTEGER_TYPE
diff --git a/gcc/combine.c b/gcc/combine.c
index 171e51dc4c7..f3802d7379a 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -5684,11 +5684,7 @@ combine_simplify_rtx (rtx x, machine_mode op0_mode, int in_dest,
 	  /* Make sure we pass the constant operand if any as the second
 	     one if this is a commutative operation.  */
 	  if (CONSTANT_P (inner_op0) && COMMUTATIVE_ARITH_P (x))
-	    {
-	      rtx tem = inner_op0;
-	      inner_op0 = inner_op1;
-	      inner_op1 = tem;
-	    }
+	    std::swap (inner_op0, inner_op1);
 	  inner = simplify_binary_operation (code == MINUS ? PLUS
 					     : code == DIV ? MULT
 					     : code,
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 66564419fc0..7b3cd2ce720 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,10 @@
+2015-06-22  Mikhail Maltsev  <maltsevm@gmail.com>
+
+	* pt.c (maybe_adjust_types_for_deduction): Use std::swap instead of
+	manually swapping.
+	* semantics.c (finish_omp_atomic): Likewise.
+	* typeck.c (cp_build_array_ref): Likewise.
+
 2015-06-20  Mikhail Maltsev  <maltsevm@gmail.com>
 
 	PR c++/65882
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index efb90e46f0f..8800af819ec 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -16545,15 +16545,11 @@ maybe_adjust_types_for_deduction (unification_kind_t strict,
       break;
 
     case DEDUCE_CONV:
-      {
-	/* Swap PARM and ARG throughout the remainder of this
-	   function; the handling is precisely symmetric since PARM
-	   will initialize ARG rather than vice versa.  */
-	tree* temp = parm;
-	parm = arg;
-	arg = temp;
-	break;
-      }
+      /* Swap PARM and ARG throughout the remainder of this
+	 function; the handling is precisely symmetric since PARM
+	 will initialize ARG rather than vice versa.  */
+      std::swap (parm, arg);
+      break;
 
     case DEDUCE_EXACT:
       /* Core issue #873: Do the DR606 thing (see below) for these cases,
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 9b5f050dfa4..aeb5f7ba298 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -6870,9 +6870,7 @@ finish_omp_atomic (enum tree_code code, enum tree_code opcode, tree lhs,
       bool swapped = false;
       if (rhs1 && cp_tree_equal (lhs, rhs))
 	{
-	  tree tem = rhs;
-	  rhs = rhs1;
-	  rhs1 = tem;
+	  std::swap (rhs, rhs1);
 	  swapped = !commutative_tree_code (opcode);
 	}
       if (rhs1 && !cp_tree_equal (lhs, rhs1))
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index 22fbb6e2389..5b3fdfbf76b 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -3179,11 +3179,7 @@ cp_build_array_ref (location_t loc, tree array, tree idx,
 
     /* Put the integer in IND to simplify error checking.  */
     if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
-      {
-	tree temp = ar;
-	ar = ind;
-	ind = temp;
-      }
+      std::swap (ar, ind);
 
     if (ar == error_mark_node || ind == error_mark_node)
       return error_mark_node;
diff --git a/gcc/df-core.c b/gcc/df-core.c
index 68d18497133..ea1f16842a2 100644
--- a/gcc/df-core.c
+++ b/gcc/df-core.c
@@ -1043,10 +1043,7 @@ df_worklist_dataflow_doublequeue (struct dataflow *dataflow,
       bitmap_iterator bi;
       unsigned int index;
 
-      /* Swap pending and worklist. */
-      bitmap temp = worklist;
-      worklist = pending;
-      pending = temp;
+      std::swap (pending, worklist);
 
       EXECUTE_IF_SET_IN_BITMAP (worklist, 0, index, bi)
 	{
diff --git a/gcc/df-scan.c b/gcc/df-scan.c
index 07e6ad5de51..ef9cdbbbe32 100644
--- a/gcc/df-scan.c
+++ b/gcc/df-scan.c
@@ -2133,14 +2133,6 @@ df_ref_ptr_compare (const void *r1, const void *r2)
   return df_ref_compare (*(const df_ref *) r1, *(const df_ref *) r2);
 }
 
-static void
-df_swap_refs (vec<df_ref, va_heap> *ref_vec, int i, int j)
-{
-  df_ref tmp = (*ref_vec)[i];
-  (*ref_vec)[i] = (*ref_vec)[j];
-  (*ref_vec)[j] = tmp;
-}
-
 /* Sort and compress a set of refs.  */
 
 static void
@@ -2160,7 +2152,7 @@ df_sort_and_compress_refs (vec<df_ref, va_heap> *ref_vec)
       df_ref r0 = (*ref_vec)[0];
       df_ref r1 = (*ref_vec)[1];
       if (df_ref_compare (r0, r1) > 0)
-        df_swap_refs (ref_vec, 0, 1);
+	std::swap ((*ref_vec)[0], (*ref_vec)[1]);
     }
   else
     {
diff --git a/gcc/dominance.c b/gcc/dominance.c
index b39cd799225..a9e042ef4b5 100644
--- a/gcc/dominance.c
+++ b/gcc/dominance.c
@@ -484,11 +484,7 @@ link_roots (struct dom_info *di, TBB v, TBB w)
   di->path_min[s] = di->path_min[w];
   di->set_size[v] += di->set_size[w];
   if (di->set_size[v] < 2 * di->set_size[w])
-    {
-      TBB tmp = s;
-      s = di->set_child[v];
-      di->set_child[v] = tmp;
-    }
+    std::swap (di->set_child[v], s);
 
   /* Merge all subtrees.  */
   while (s)
diff --git a/gcc/expr.c b/gcc/expr.c
index 4eb1ab32c2f..78904c24bf2 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -8426,11 +8426,7 @@ expand_expr_real_2 (sepops ops, rtx target, machine_mode tmode,
 	 Thus the following special case checks need only
 	 check the second operand.  */
       if (TREE_CODE (treeop0) == INTEGER_CST)
-	{
-	  tree t1 = treeop0;
-	  treeop0 = treeop1;
-	  treeop1 = t1;
-	}
+	std::swap (treeop0, treeop1);
 
       /* First, check if we have a multiplication of one signed and one
 	 unsigned operand.  */
@@ -8555,11 +8551,7 @@ expand_expr_real_2 (sepops ops, rtx target, machine_mode tmode,
 	    def0 = get_def_for_expr (treeop1, NEGATE_EXPR);
 	    /* Swap operands if the 2nd operand is fed by a negate.  */
 	    if (def0)
-	      {
-		tree tem = treeop0;
-		treeop0 = treeop1;
-		treeop1 = tem;
-	      }
+	      std::swap (treeop0, treeop1);
 	  }
 	def2 = get_def_for_expr (treeop2, NEGATE_EXPR);
 
@@ -8606,11 +8598,7 @@ expand_expr_real_2 (sepops ops, rtx target, machine_mode tmode,
 	 Thus the following special case checks need only
 	 check the second operand.  */
       if (TREE_CODE (treeop0) == INTEGER_CST)
-	{
-	  tree t1 = treeop0;
-	  treeop0 = treeop1;
-	  treeop1 = t1;
-	}
+	std::swap (treeop0, treeop1);
 
       /* Attempt to return something suitable for generating an
 	 indexed address, for machines that support that.  */
@@ -10910,7 +10898,6 @@ do_store_flag (sepops ops, rtx target, machine_mode mode)
 {
   enum rtx_code code;
   tree arg0, arg1, type;
-  tree tem;
   machine_mode operand_mode;
   int unsignedp;
   rtx op0, op1;
@@ -11033,7 +11020,7 @@ do_store_flag (sepops ops, rtx target, machine_mode mode)
   if (TREE_CODE (arg0) == REAL_CST || TREE_CODE (arg0) == INTEGER_CST
       || TREE_CODE (arg0) == FIXED_CST)
     {
-      tem = arg0; arg0 = arg1; arg1 = tem;
+      std::swap (arg0, arg1);
       code = swap_condition (code);
     }
 
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index e61d9463462..60aa2104960 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -15664,9 +15664,7 @@ fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
 
   if (code == LE_EXPR || code == GT_EXPR)
     {
-      tree tem = op0;
-      op0 = op1;
-      op1 = tem;
+      std::swap (op0, op1);
       code = swap_tree_comparison (code);
     }
 
diff --git a/gcc/genattrtab.c b/gcc/genattrtab.c
index 2ec02c366eb..85ec738a9a4 100644
--- a/gcc/genattrtab.c
+++ b/gcc/genattrtab.c
@@ -2532,11 +2532,7 @@ simplify_test_exp (rtx exp, int insn_code, int insn_index)
 	  && compute_alternative_mask (right, IOR))
 	{
 	  if (GET_CODE (left) == IOR)
-	    {
-	      rtx tem = left;
-	      left = right;
-	      right = tem;
-	    }
+	    std::swap (left, right);
 
 	  newexp = attr_rtx (IOR,
 			     attr_rtx (AND, left, XEXP (right, 0)),
diff --git a/gcc/gimple-match-head.c b/gcc/gimple-match-head.c
index 86ba78bab80..7b1f1ace8f9 100644
--- a/gcc/gimple-match-head.c
+++ b/gcc/gimple-match-head.c
@@ -190,9 +190,7 @@ gimple_resimplify2 (gimple_seq *seq,
 	  || commutative_tree_code (*res_code))
       && tree_swap_operands_p (res_ops[0], res_ops[1], false))
     {
-      tree tem = res_ops[0];
-      res_ops[0] = res_ops[1];
-      res_ops[1] = tem;
+      std::swap (res_ops[0], res_ops[1]);
       if (TREE_CODE_CLASS ((enum tree_code) *res_code) == tcc_comparison)
 	*res_code = swap_tree_comparison (*res_code);
       canonicalized = true;
@@ -262,9 +260,7 @@ gimple_resimplify3 (gimple_seq *seq,
       && commutative_ternary_tree_code (*res_code)
       && tree_swap_operands_p (res_ops[0], res_ops[1], false))
     {
-      tree tem = res_ops[0];
-      res_ops[0] = res_ops[1];
-      res_ops[1] = tem;
+      std::swap (res_ops[0], res_ops[1]);
       canonicalized = true;
     }
 
@@ -427,9 +423,7 @@ gimple_simplify (enum tree_code code, tree type,
        || TREE_CODE_CLASS (code) == tcc_comparison)
       && tree_swap_operands_p (op0, op1, false))
     {
-      tree tem = op0;
-      op0 = op1;
-      op1 = tem;
+      std::swap (op0, op1);
       if (TREE_CODE_CLASS (code) == tcc_comparison)
 	code = swap_tree_comparison (code);
     }
@@ -462,11 +456,7 @@ gimple_simplify (enum tree_code code, tree type,
      generation.  */
   if (commutative_ternary_tree_code (code)
       && tree_swap_operands_p (op0, op1, false))
-    {
-      tree tem = op0;
-      op0 = op1;
-      op1 = tem;
-    }
+    std::swap (op0, op1);
 
   code_helper rcode;
   tree ops[3] = {};
diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c
index 648965c4208..7d4ad934003 100644
--- a/gcc/ifcvt.c
+++ b/gcc/ifcvt.c
@@ -2065,7 +2065,7 @@ noce_try_abs (struct noce_if_info *if_info)
     negate = 0;
   else if (GET_CODE (b) == NEG && rtx_equal_p (XEXP (b, 0), a))
     {
-      c = a; a = b; b = c;
+      std::swap (a, b);
       negate = 1;
     }
   else if (GET_CODE (a) == NOT && rtx_equal_p (XEXP (a, 0), b))
@@ -2075,7 +2075,7 @@ noce_try_abs (struct noce_if_info *if_info)
     }
   else if (GET_CODE (b) == NOT && rtx_equal_p (XEXP (b, 0), a))
     {
-      c = a; a = b; b = c;
+      std::swap (a, b);
       negate = 1;
       one_cmpl = true;
     }
@@ -3390,11 +3390,7 @@ find_if_header (basic_block test_bb, int pass)
   if (then_edge->flags & EDGE_FALLTHRU)
     ;
   else if (else_edge->flags & EDGE_FALLTHRU)
-    {
-      edge e = else_edge;
-      else_edge = then_edge;
-      then_edge = e;
-    }
+    std::swap (then_edge, else_edge);
   else
     /* Otherwise this must be a multiway branch of some sort.  */
     return NULL;
diff --git a/gcc/internal-fn.c b/gcc/internal-fn.c
index 64ce8e34f4d..c398c125bcf 100644
--- a/gcc/internal-fn.c
+++ b/gcc/internal-fn.c
@@ -526,14 +526,10 @@ expand_addsub_overflow (location_t loc, tree_code code, tree lhs,
       /* PLUS_EXPR is commutative, if operand signedness differs,
 	 canonicalize to the first operand being signed and second
 	 unsigned to simplify following code.  */
-      rtx tem = op1;
-      op1 = op0;
-      op0 = tem;
-      tree t = arg1;
-      arg1 = arg0;
-      arg0 = t;
-      uns0_p = 0;
-      uns1_p = 1;
+      std::swap (op0, op1);
+      std::swap (arg0, arg1);
+      uns0_p = false;
+      uns1_p = true;
     }
 
   /* u1 +- u2 -> ur  */
@@ -674,9 +670,7 @@ expand_addsub_overflow (location_t loc, tree_code code, tree lhs,
 	  int pos_neg0 = get_range_pos_neg (arg0);
 	  if (pos_neg0 != 3 && pos_neg == 3)
 	    {
-	      rtx tem = op1;
-	      op1 = op0;
-	      op0 = tem;
+	      std::swap (op0, op1);
 	      pos_neg = pos_neg0;
 	    }
 	}
@@ -781,22 +775,14 @@ expand_addsub_overflow (location_t loc, tree_code code, tree lhs,
 	 do_compare_rtx_and_jump will be just folded.  Otherwise try
 	 to use range info if available.  */
       if (code == PLUS_EXPR && CONST_INT_P (op0))
-	{
-	  rtx tem = op0;
-	  op0 = op1;
-	  op1 = tem;
-	}
+	std::swap (op0, op1);
       else if (CONST_INT_P (op1))
 	;
       else if (code == PLUS_EXPR && TREE_CODE (arg0) == SSA_NAME)
 	{
 	  pos_neg = get_range_pos_neg (arg0);
 	  if (pos_neg != 3)
-	    {
-	      rtx tem = op0;
-	      op0 = op1;
-	      op1 = tem;
-	    }
+	    std::swap (op0, op1);
 	}
       if (pos_neg == 3 && !CONST_INT_P (op1) && TREE_CODE (arg1) == SSA_NAME)
 	pos_neg = get_range_pos_neg (arg1);
@@ -1023,14 +1009,10 @@ expand_mul_overflow (location_t loc, tree lhs, tree arg0, tree arg1,
       /* Multiplication is commutative, if operand signedness differs,
 	 canonicalize to the first operand being signed and second
 	 unsigned to simplify following code.  */
-      rtx tem = op1;
-      op1 = op0;
-      op0 = tem;
-      tree t = arg1;
-      arg1 = arg0;
-      arg0 = t;
-      uns0_p = 0;
-      uns1_p = 1;
+      std::swap (op0, op1);
+      std::swap (arg0, arg1);
+      uns0_p = false;
+      uns1_p = true;
     }
 
   int pos_neg0 = get_range_pos_neg (arg0);
diff --git a/gcc/ipa-devirt.c b/gcc/ipa-devirt.c
index 6fba692577f..1bf4b1acb6b 100644
--- a/gcc/ipa-devirt.c
+++ b/gcc/ipa-devirt.c
@@ -1846,12 +1846,7 @@ add_type_duplicate (odr_type val, tree type)
     }
 
   if (prevail)
-    {
-      tree tmp = type;
-
-      type = val->type;
-      val->type = tmp;
-    }
+    std::swap (val->type, type);
 
   val->types_set->add (type);
 
diff --git a/gcc/loop-iv.c b/gcc/loop-iv.c
index 141b43672ce..c0d6a1d3f3f 100644
--- a/gcc/loop-iv.c
+++ b/gcc/loop-iv.c
@@ -664,7 +664,7 @@ get_biv_step_1 (df_ref def, rtx reg,
 		rtx *outer_step)
 {
   rtx set, rhs, op0 = NULL_RTX, op1 = NULL_RTX;
-  rtx next, nextr, tmp;
+  rtx next, nextr;
   enum rtx_code code;
   rtx_insn *insn = DF_REF_INSN (def);
   df_ref next_def;
@@ -694,9 +694,7 @@ get_biv_step_1 (df_ref def, rtx reg,
       op1 = XEXP (rhs, 1);
 
       if (code == PLUS && CONSTANT_P (op0))
-	{
-	  tmp = op0; op0 = op1; op1 = tmp;
-	}
+	std::swap (op0, op1);
 
       if (!simple_reg_p (op0)
 	  || !CONSTANT_P (op1))
@@ -2347,7 +2345,7 @@ iv_number_of_iterations (struct loop *loop, rtx_insn *insn, rtx condition,
 			 struct niter_desc *desc)
 {
   rtx op0, op1, delta, step, bound, may_xform, tmp, tmp0, tmp1;
-  struct rtx_iv iv0, iv1, tmp_iv;
+  struct rtx_iv iv0, iv1;
   rtx assumption, may_not_xform;
   enum rtx_code cond;
   machine_mode mode, comp_mode;
@@ -2410,7 +2408,7 @@ iv_number_of_iterations (struct loop *loop, rtx_insn *insn, rtx condition,
       case GT:
       case GEU:
       case GTU:
-	tmp_iv = iv0; iv0 = iv1; iv1 = tmp_iv;
+	std::swap (iv0, iv1);
 	cond = swap_condition (cond);
 	break;
       case NE:
diff --git a/gcc/lra-lives.c b/gcc/lra-lives.c
index 8bf217f6865..16e1f386b3e 100644
--- a/gcc/lra-lives.c
+++ b/gcc/lra-lives.c
@@ -572,16 +572,10 @@ lra_setup_reload_pseudo_preferenced_hard_reg (int regno,
       && (lra_reg_info[regno].preferred_hard_regno_profit2
 	  > lra_reg_info[regno].preferred_hard_regno_profit1))
     {
-      int temp;
-
-      temp = lra_reg_info[regno].preferred_hard_regno1;
-      lra_reg_info[regno].preferred_hard_regno1
-	= lra_reg_info[regno].preferred_hard_regno2;
-      lra_reg_info[regno].preferred_hard_regno2 = temp;
-      temp = lra_reg_info[regno].preferred_hard_regno_profit1;
-      lra_reg_info[regno].preferred_hard_regno_profit1
-	= lra_reg_info[regno].preferred_hard_regno_profit2;
-      lra_reg_info[regno].preferred_hard_regno_profit2 = temp;
+      std::swap (lra_reg_info[regno].preferred_hard_regno1,
+		 lra_reg_info[regno].preferred_hard_regno2);
+      std::swap (lra_reg_info[regno].preferred_hard_regno_profit1,
+		 lra_reg_info[regno].preferred_hard_regno_profit2);
     }
   if (lra_dump_file != NULL)
     {
diff --git a/gcc/lra.c b/gcc/lra.c
index 15e65f7b02f..5d1f429658f 100644
--- a/gcc/lra.c
+++ b/gcc/lra.c
@@ -1377,11 +1377,8 @@ lra_create_copy (int regno1, int regno2, int freq)
   regno1_dest_p = true;
   if (regno1 > regno2)
     {
-      int temp = regno2;
-
+      std::swap (regno1, regno2);
       regno1_dest_p = false;
-      regno2 = regno1;
-      regno1 = temp;
     }
   cp = new lra_copy ();
   copy_vec.safe_push (cp);
diff --git a/gcc/lto-streamer-out.c b/gcc/lto-streamer-out.c
index 4671702d249..363da4c02d7 100644
--- a/gcc/lto-streamer-out.c
+++ b/gcc/lto-streamer-out.c
@@ -608,11 +608,8 @@ DFS::DFS (struct output_block *ob, tree expr, bool ref_p, bool this_ref_p,
 		    }
 		}
 	      for (unsigned i = 0; i < scc_entry_len; ++i)
-		{
-		  scc_entry tem = sccstack[first + i];
-		  sccstack[first + i] = sccstack[first + entry_start + i];
-		  sccstack[first + entry_start + i] = tem;
-		}
+		std::swap (sccstack[first + i],
+			   sccstack[first + entry_start + i]);
 
 	      if (scc_entry_len == 1)
 		; /* We already sorted SCC deterministically in hash_scc.  */
diff --git a/gcc/modulo-sched.c b/gcc/modulo-sched.c
index db76095fb65..60b39f81d18 100644
--- a/gcc/modulo-sched.c
+++ b/gcc/modulo-sched.c
@@ -2006,9 +2006,7 @@ get_sched_window (partial_schedule_ptr ps, ddg_node_ptr u_node,
      node close to its successors.  */
   if (pss_not_empty && count_succs >= count_preds)
     {
-      int tmp = end;
-      end = start;
-      start = tmp;
+      std::swap (start, end);
       step = -1;
     }
 
diff --git a/gcc/omega.c b/gcc/omega.c
index 4654df8cccd..829520a338a 100644
--- a/gcc/omega.c
+++ b/gcc/omega.c
@@ -547,11 +547,7 @@ omega_pretty_print_problem (FILE *file, omega_pb pb)
 		else
 		  {
 		    if (pb->geqs[e].coef[v1] == 1)
-		      {
-			v3 = v2;
-			v2 = v1;
-			v1 = v3;
-		      }
+		      std::swap (v1, v2);
 
 		    /* Relation is v1 <= v2 or v1 < v2.  */
 		    po[v1][v2] = ((pb->geqs[e].coef[0] == 0) ? le : lt);
diff --git a/gcc/optabs.c b/gcc/optabs.c
index 94739a945bc..491341b8887 100644
--- a/gcc/optabs.c
+++ b/gcc/optabs.c
@@ -4383,8 +4383,7 @@ prepare_float_lib_cmp (rtx x, rtx y, enum rtx_code comparison,
       if (code_to_optab (swapped)
 	  && (libfunc = optab_libfunc (code_to_optab (swapped), mode)))
 	{
-	  rtx tmp;
-	  tmp = x; x = y; y = tmp;
+	  std::swap (x, y);
 	  comparison = swapped;
 	  break;
 	}
@@ -6967,11 +6966,7 @@ expand_mult_highpart (machine_mode mode, rtx op0, rtx op1,
       tab1 = uns_p ? vec_widen_umult_lo_optab : vec_widen_smult_lo_optab;
       tab2 = uns_p ? vec_widen_umult_hi_optab : vec_widen_smult_hi_optab;
       if (BYTES_BIG_ENDIAN)
-	{
-	  optab t = tab1;
-	  tab1 = tab2;
-	  tab2 = t;
-	}
+	std::swap (tab1, tab2);
       break;
     default:
       gcc_unreachable ();
diff --git a/gcc/reload1.c b/gcc/reload1.c
index a86084a8e29..57837a1fc90 100644
--- a/gcc/reload1.c
+++ b/gcc/reload1.c
@@ -5612,11 +5612,7 @@ reloads_unique_chain_p (int r1, int r2)
 
   /* The following loop assumes that r1 is the reload that feeds r2.  */
   if (r1 > r2)
-    {
-      int tmp = r2;
-      r2 = r1;
-      r1 = tmp;
-    }
+    std::swap (r1, r2);
 
   for (i = 0; i < n_reloads; i ++)
     /* Look for input reloads that aren't our two */
diff --git a/gcc/sel-sched-ir.c b/gcc/sel-sched-ir.c
index bb55e3ddfa8..f9b7655af12 100644
--- a/gcc/sel-sched-ir.c
+++ b/gcc/sel-sched-ir.c
@@ -4414,51 +4414,17 @@ free_data_sets (basic_block bb)
   free_av_set (bb);
 }
 
-/* Exchange lv sets of TO and FROM.  */
-static void
-exchange_lv_sets (basic_block to, basic_block from)
-{
-  {
-    regset to_lv_set = BB_LV_SET (to);
-
-    BB_LV_SET (to) = BB_LV_SET (from);
-    BB_LV_SET (from) = to_lv_set;
-  }
-
-  {
-    bool to_lv_set_valid_p = BB_LV_SET_VALID_P (to);
-
-    BB_LV_SET_VALID_P (to) = BB_LV_SET_VALID_P (from);
-    BB_LV_SET_VALID_P (from) = to_lv_set_valid_p;
-  }
-}
-
-
-/* Exchange av sets of TO and FROM.  */
-static void
-exchange_av_sets (basic_block to, basic_block from)
-{
-  {
-    av_set_t to_av_set = BB_AV_SET (to);
-
-    BB_AV_SET (to) = BB_AV_SET (from);
-    BB_AV_SET (from) = to_av_set;
-  }
-
-  {
-    int to_av_level = BB_AV_LEVEL (to);
-
-    BB_AV_LEVEL (to) = BB_AV_LEVEL (from);
-    BB_AV_LEVEL (from) = to_av_level;
-  }
-}
-
 /* Exchange data sets of TO and FROM.  */
 void
 exchange_data_sets (basic_block to, basic_block from)
 {
-  exchange_lv_sets (to, from);
-  exchange_av_sets (to, from);
+  /* Exchange lv sets of TO and FROM.  */
+  std::swap (BB_LV_SET (from), BB_LV_SET (to));
+  std::swap (BB_LV_SET_VALID_P (from), BB_LV_SET_VALID_P (to));
+
+  /* Exchange av sets of TO and FROM.  */
+  std::swap (BB_AV_SET (from), BB_AV_SET (to));
+  std::swap (BB_AV_LEVEL (from), BB_AV_LEVEL (to));
 }
 
 /* Copy data sets of FROM to TO.  */
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index a5731e83595..521fecf566e 100644
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -944,10 +944,7 @@ simplify_unary_operation_1 (enum rtx_code code, machine_mode mode, rtx op)
 	  in2 = simplify_gen_unary (NOT, op_mode, in2, op_mode);
 
 	  if (GET_CODE (in2) == NOT && GET_CODE (in1) != NOT)
-	    {
-	      rtx tem = in2;
-	      in2 = in1; in1 = tem;
-	    }
+	    std::swap (in1, in2);
 
 	  return gen_rtx_fmt_ee (GET_CODE (op) == IOR ? AND : IOR,
 				 mode, in1, in2);
diff --git a/gcc/tree-if-conv.c b/gcc/tree-if-conv.c
index a5e17b85b08..e0ac936d72c 100644
--- a/gcc/tree-if-conv.c
+++ b/gcc/tree-if-conv.c
@@ -1510,11 +1510,7 @@ is_cond_scalar_reduction (gimple phi, gimple *reduc, tree arg_0, tree arg_1,
   /* Make R_OP1 to hold reduction variable.  */
   if (r_op2 == PHI_RESULT (header_phi)
       && reduction_op == PLUS_EXPR)
-    {
-      tree tmp = r_op1;
-      r_op1 = r_op2;
-      r_op2 = tmp;
-    }
+    std::swap (r_op1, r_op2);
   else if (r_op1 != PHI_RESULT (header_phi))
     return false;
 
@@ -1708,11 +1704,7 @@ predicate_scalar_phi (gphi *phi, gimple_stmt_iterator *gsi)
       second_edge = EDGE_PRED (bb, 1);
       cond = bb_predicate (first_edge->src);
       if (TREE_CODE (cond) == TRUTH_NOT_EXPR)
-	{
-	  edge tmp_edge = first_edge;
-	  first_edge = second_edge;
-	  second_edge = tmp_edge;
-	}
+	std::swap (first_edge, second_edge);
       if (EDGE_COUNT (first_edge->src->succs) > 1)
 	{
 	  cond = bb_predicate (second_edge->src);
@@ -1795,11 +1787,7 @@ predicate_scalar_phi (gphi *phi, gimple_stmt_iterator *gsi)
 
   /* Put element with max number of occurences to the end of ARGS.  */
   if (max_ind != -1 && max_ind +1 != (int) args_len)
-    {
-      tree tmp = args[args_len - 1];
-      args[args_len - 1] = args[max_ind];
-      args[max_ind] = tmp;
-    }
+    std::swap (args[args_len - 1], args[max_ind]);
 
   /* Handle one special case when number of arguments with different values
      is equal 2 and one argument has the only occurrence.  Such PHI can be
@@ -2174,11 +2162,7 @@ predicate_mem_writes (loop_p loop)
 	    lhs = ifc_temp_var (type, unshare_expr (lhs), &gsi);
 	    rhs = ifc_temp_var (type, unshare_expr (rhs), &gsi);
 	    if (swap)
-	      {
-		tree tem = lhs;
-		lhs = rhs;
-		rhs = tem;
-	      }
+	      std::swap (lhs, rhs);
 	    cond = force_gimple_operand_gsi_1 (&gsi, unshare_expr (cond),
 					       is_gimple_condexpr, NULL_TREE,
 					       true, GSI_SAME_STMT);
diff --git a/gcc/tree-loop-distribution.c b/gcc/tree-loop-distribution.c
index 96fbc3620f5..19523b941d2 100644
--- a/gcc/tree-loop-distribution.c
+++ b/gcc/tree-loop-distribution.c
@@ -1360,9 +1360,7 @@ pg_add_dependence_edges (struct graph *rdg, vec<loop_p> loops, int dir,
 	if (rdg_vertex_for_stmt (rdg, DR_STMT (dr1))
 	    > rdg_vertex_for_stmt (rdg, DR_STMT (dr2)))
 	  {
-	    data_reference_p tem = dr1;
-	    dr1 = dr2;
-	    dr2 = tem;
+	    std::swap (dr1, dr2);
 	    this_dir = -this_dir;
 	  }
 	ddr = initialize_data_dependence_relation (dr1, dr2, loops);
@@ -1373,9 +1371,7 @@ pg_add_dependence_edges (struct graph *rdg, vec<loop_p> loops, int dir,
 	  {
 	    if (DDR_REVERSED_P (ddr))
 	      {
-		data_reference_p tem = dr1;
-		dr1 = dr2;
-		dr2 = tem;
+		std::swap (dr1, dr2);
 		this_dir = -this_dir;
 	      }
 	    /* Known dependences can still be unordered througout the
diff --git a/gcc/tree-predcom.c b/gcc/tree-predcom.c
index 341bcc77a8e..eadad7e0ad2 100644
--- a/gcc/tree-predcom.c
+++ b/gcc/tree-predcom.c
@@ -2301,11 +2301,7 @@ combine_chains (chain_p ch1, chain_p ch2)
     }
 
   if (swap)
-    {
-      chain_p tmp = ch1;
-      ch1 = ch2;
-      ch2 = tmp;
-    }
+    std::swap (ch1, ch2);
 
   new_chain = XCNEW (struct chain);
   new_chain->type = CT_COMBINATION;
diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index d9aae421fbc..a1f0beeae63 100644
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -953,11 +953,7 @@ nonoverlapping_component_refs_p (const_tree x, const_tree y)
   if (fieldsx.length () == 2)
     {
       if (ncr_compar (&fieldsx[0], &fieldsx[1]) == 1)
-	{
-	  const_tree tem = fieldsx[0];
-	  fieldsx[0] = fieldsx[1];
-	  fieldsx[1] = tem;
-	}
+	std::swap (fieldsx[0], fieldsx[1]);
     }
   else
     fieldsx.qsort (ncr_compar);
@@ -965,11 +961,7 @@ nonoverlapping_component_refs_p (const_tree x, const_tree y)
   if (fieldsy.length () == 2)
     {
       if (ncr_compar (&fieldsy[0], &fieldsy[1]) == 1)
-	{
-	  const_tree tem = fieldsy[0];
-	  fieldsy[0] = fieldsy[1];
-	  fieldsy[1] = tem;
-	}
+	std::swap (fieldsy[0], fieldsy[1]);
     }
   else
     fieldsy.qsort (ncr_compar);
@@ -1426,13 +1418,10 @@ refs_may_alias_p_1 (ao_ref *ref1, ao_ref *ref2, bool tbaa_p)
   /* Canonicalize the pointer-vs-decl case.  */
   if (ind1_p && var2_p)
     {
-      HOST_WIDE_INT tmp1;
-      tree tmp2;
-      ao_ref *tmp3;
-      tmp1 = offset1; offset1 = offset2; offset2 = tmp1;
-      tmp1 = max_size1; max_size1 = max_size2; max_size2 = tmp1;
-      tmp2 = base1; base1 = base2; base2 = tmp2;
-      tmp3 = ref1; ref1 = ref2; ref2 = tmp3;
+      std::swap (offset1, offset2);
+      std::swap (max_size1, max_size2);
+      std::swap (base1, base2);
+      std::swap (ref1, ref2);
       var1_p = true;
       ind1_p = false;
       var2_p = false;
diff --git a/gcc/tree-ssa-ifcombine.c b/gcc/tree-ssa-ifcombine.c
index 650624e49f3..f55a4528d49 100644
--- a/gcc/tree-ssa-ifcombine.c
+++ b/gcc/tree-ssa-ifcombine.c
@@ -98,11 +98,7 @@ recognize_if_then_else (basic_block cond_bb,
   t = EDGE_SUCC (cond_bb, 0);
   e = EDGE_SUCC (cond_bb, 1);
   if (!(t->flags & EDGE_TRUE_VALUE))
-    {
-      edge tmp = t;
-      t = e;
-      e = tmp;
-    }
+    std::swap (t, e);
   if (!(t->flags & EDGE_TRUE_VALUE)
       || !(e->flags & EDGE_FALSE_VALUE))
     return false;
diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c
index cb5f054720d..cab5acfc8d5 100644
--- a/gcc/tree-ssa-loop-ivopts.c
+++ b/gcc/tree-ssa-loop-ivopts.c
@@ -1485,8 +1485,8 @@ extract_cond_operands (struct ivopts_data *data, gimple stmt,
   /* The objects returned when COND has constant operands.  */
   static struct iv const_iv;
   static tree zero;
-  tree *op0 = &zero, *op1 = &zero, *tmp_op;
-  struct iv *iv0 = &const_iv, *iv1 = &const_iv, *tmp_iv;
+  tree *op0 = &zero, *op1 = &zero;
+  struct iv *iv0 = &const_iv, *iv1 = &const_iv;
   bool ret = false;
 
   if (gimple_code (stmt) == GIMPLE_COND)
@@ -1517,8 +1517,8 @@ extract_cond_operands (struct ivopts_data *data, gimple stmt,
   if (integer_zerop (iv0->step))
     {
       /* Control variable may be on the other side.  */
-      tmp_op = op0; op0 = op1; op1 = tmp_op;
-      tmp_iv = iv0; iv0 = iv1; iv1 = tmp_iv;
+      std::swap (op0, op1);
+      std::swap (iv0, iv1);
     }
   ret = !integer_zerop (iv0->step) && integer_zerop (iv1->step);
 
diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c
index 64c9a73e03f..213d72e3dc4 100644
--- a/gcc/tree-ssa-loop-niter.c
+++ b/gcc/tree-ssa-loop-niter.c
@@ -73,8 +73,6 @@ along with GCC; see the file COPYING3.  If not see
 #include "wide-int-print.h"
 
 
-#define SWAP(X, Y) do { affine_iv *tmp = (X); (X) = (Y); (Y) = tmp; } while (0)
-
 /* The maximum number of dominator BBs we search for conditions
    of loop header copies we use for simplifying a conditional
    expression.  */
@@ -301,7 +299,7 @@ refine_bounds_using_guard (tree type, tree varx, mpz_t offx,
 			   tree c0, enum tree_code cmp, tree c1,
 			   bounds *bnds)
 {
-  tree varc0, varc1, tmp, ctype;
+  tree varc0, varc1, ctype;
   mpz_t offc0, offc1, loffx, loffy, bnd;
   bool lbound = false;
   bool no_wrap = nowrap_type_p (type);
@@ -371,7 +369,7 @@ refine_bounds_using_guard (tree type, tree varx, mpz_t offx,
 
   if (operand_equal_p (varx, varc1, 0))
     {
-      tmp = varc0; varc0 = varc1; varc1 = tmp;
+      std::swap (varc0, varc1);
       mpz_swap (offc0, offc1);
       cmp = swap_tree_comparison (cmp);
     }
@@ -385,7 +383,7 @@ refine_bounds_using_guard (tree type, tree varx, mpz_t offx,
 
   if (cmp == GT_EXPR || cmp == GE_EXPR)
     {
-      tmp = varx; varx = vary; vary = tmp;
+      std::swap (varx, vary);
       mpz_swap (offc0, offc1);
       mpz_swap (loffx, loffy);
       cmp = swap_tree_comparison (cmp);
@@ -1365,7 +1363,7 @@ number_of_iterations_cond (struct loop *loop,
   if (code == GE_EXPR || code == GT_EXPR
       || (code == NE_EXPR && integer_zerop (iv0->step)))
     {
-      SWAP (iv0, iv1);
+      std::swap (iv0, iv1);
       code = swap_tree_comparison (code);
     }
 
diff --git a/gcc/tree-ssa-phiopt.c b/gcc/tree-ssa-phiopt.c
index 098a02868e2..d2a5cee2329 100644
--- a/gcc/tree-ssa-phiopt.c
+++ b/gcc/tree-ssa-phiopt.c
@@ -237,12 +237,8 @@ tree_ssa_phiopt_worker (bool do_store_elim, bool do_hoist_loads)
         ;
       else if (EDGE_SUCC (bb2, 0)->dest == bb1)
         {
-	  basic_block bb_tmp = bb1;
-	  edge e_tmp = e1;
-	  bb1 = bb2;
-	  bb2 = bb_tmp;
-	  e1 = e2;
-	  e2 = e_tmp;
+	  std::swap (bb1, bb2);
+	  std::swap (e1, e2);
 	}
       else if (do_store_elim
 	       && EDGE_SUCC (bb1, 0)->dest == EDGE_SUCC (bb2, 0)->dest)
diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index 3db42b03bbb..ccfa6b603ec 100644
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -2389,11 +2389,7 @@ vn_nary_op_compute_hash (const vn_nary_op_t vno1)
   if (vno1->length == 2
       && commutative_tree_code (vno1->opcode)
       && tree_swap_operands_p (vno1->op[0], vno1->op[1], false))
-    {
-      tree temp = vno1->op[0];
-      vno1->op[0] = vno1->op[1];
-      vno1->op[1] = temp;
-    }
+    std::swap (vno1->op[0], vno1->op[1]);
 
   hstate.add_int (vno1->opcode);
   for (i = 0; i < vno1->length; ++i)
diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c
index 47d8a42474e..91ddc0fc444 100644
--- a/gcc/tree-vect-slp.c
+++ b/gcc/tree-vect-slp.c
@@ -1124,9 +1124,8 @@ vect_build_slp_tree (loop_vec_info loop_vinfo, bb_vec_info bb_vinfo,
 	  for (j = 0; j < group_size; ++j)
 	    if (!matches[j])
 	      {
-		gimple tem = oprnds_info[0]->def_stmts[j];
-		oprnds_info[0]->def_stmts[j] = oprnds_info[1]->def_stmts[j];
-		oprnds_info[1]->def_stmts[j] = tem;
+		std::swap (oprnds_info[0]->def_stmts[j],
+			   oprnds_info[1]->def_stmts[j]);
 		dump_printf (MSG_NOTE, "%d ", j);
 	      }
 	  dump_printf (MSG_NOTE, "\n");
diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
index 9760d9a471f..0b9c8d6e1f9 100644
--- a/gcc/tree-vect-stmts.c
+++ b/gcc/tree-vect-stmts.c
@@ -8259,11 +8259,7 @@ supportable_widening_operation (enum tree_code code, gimple stmt,
     }
 
   if (BYTES_BIG_ENDIAN && c1 != VEC_WIDEN_MULT_EVEN_EXPR)
-    {
-      enum tree_code ctmp = c1;
-      c1 = c2;
-      c2 = ctmp;
-    }
+    std::swap (c1, c2);
 
   if (code == FIX_TRUNC_EXPR)
     {
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index a7e66f14f2b..fdaebe4c2fc 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -2914,33 +2914,17 @@ extract_range_from_binary_expr_1 (value_range_t *vr,
 	     prod3.  */
 	  /* min0min1 > max0max1 */
 	  if (wi::gts_p (prod0, prod3))
-	    {
-	      vrp_int tmp = prod3;
-	      prod3 = prod0;
-	      prod0 = tmp;
-	    }
+	    std::swap (prod0, prod3);
 
 	  /* min0max1 > max0min1 */
 	  if (wi::gts_p (prod1, prod2))
-	    {
-	      vrp_int tmp = prod2;
-	      prod2 = prod1;
-	      prod1 = tmp;
-	    }
+	    std::swap (prod1, prod2);
 
 	  if (wi::gts_p (prod0, prod1))
-	    {
-	      vrp_int tmp = prod1;
-	      prod1 = prod0;
-	      prod0 = tmp;
-	    }
+	    std::swap (prod0, prod1);
 
 	  if (wi::gts_p (prod2, prod3))
-	    {
-	      vrp_int tmp = prod3;
-	      prod3 = prod2;
-	      prod2 = tmp;
-	    }
+	    std::swap (prod2, prod3);
 
 	  /* diff = max - min.  */
 	  prod2 = prod3 - prod0;
@@ -3723,11 +3707,7 @@ extract_range_from_unary_expr_1 (value_range_t *vr,
 	{
           /* If the range was reversed, swap MIN and MAX.  */
 	  if (cmp == 1)
-	    {
-	      tree t = min;
-	      min = max;
-	      max = t;
-	    }
+	    std::swap (min, max);
 	}
 
       cmp = compare_values (min, max);