RE: [PATCH][combine][obvious] Use std::swap instead of manually swapping

["Kyrill Tkachov" <kyrylo.tkachov@arm.com>]

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On 27/04/15 15:37, Segher Boessenkool wrote:
> On Mon, Apr 27, 2015 at 10:55:17AM +0100, Kyrill Tkachov wrote:
>> Precedents suggest these changes are considered obvious.
>> So I'll commit this in a couple of days unless someone objects.
>
> Yes it's obvious.  One tiny thing...
>
>> @@ -9062,7 +9061,7 @@ known_cond (rtx x, enum rtx_code cond, rtx reg, rtx
val)
>>    else if (COMPARISON_P (x) || COMMUTATIVE_ARITH_P (x))
>>      {
>>        if (rtx_equal_p (XEXP (x, 0), val))
>> -	cond = swap_condition (cond), temp = val, val = reg, reg = temp;
>> +	cond = swap_condition (cond), std::swap (val, reg);
>>  
>>        if (rtx_equal_p (XEXP (x, 0), reg) && rtx_equal_p (XEXP (x, 1),
val))
>>  	{
>
> Might as well write this as two statements, like everywhere else, e.g.
>
>> @@ -11454,7 +11453,7 @@ simplify_comparison (enum rtx_code code, rtx
*pop0, rtx *pop1)
>>       is already a constant integer.  */
>>    if (swap_commutative_operands_p (op0, op1))
>>      {
>> -      tem = op0, op0 = op1, op1 = tem;
>> +      std::swap (op0, op1);
>>        code = swap_condition (code);
>>      }
>
> Thanks,

Thanks, here's what I committed with r222468.

Kyrill

>
>
>
> Segher
>

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commit 0f453edfd3d2aaa9414fa89eb3fea18adac1f319
Author: Kyrylo Tkachov <kyrylo.tkachov@arm.com>
Date:   Fri Apr 24 17:47:14 2015 +0100

    [combine][obvious] Use std::swap instead of manually swapping

diff --git a/gcc/combine.c b/gcc/combine.c
index 9f840cb..000188b 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -6185,7 +6185,7 @@ simplify_if_then_else (rtx x)
       if (false_code == EQ)
 	{
 	  swapped = 1, true_code = EQ, false_code = NE;
-	  temp = true_rtx, true_rtx = false_rtx, false_rtx = temp;
+	  std::swap (true_rtx, false_rtx);
 	}
 
       /* If we are comparing against zero and the expression being tested has
@@ -6250,7 +6250,7 @@ simplify_if_then_else (rtx x)
       SUBST (XEXP (x, 1), false_rtx);
       SUBST (XEXP (x, 2), true_rtx);
 
-      temp = true_rtx, true_rtx = false_rtx, false_rtx = temp;
+      std::swap (true_rtx, false_rtx);
       cond = XEXP (x, 0);
 
       /* It is possible that the conditional has been simplified out.  */
@@ -9022,7 +9022,6 @@ static rtx
 known_cond (rtx x, enum rtx_code cond, rtx reg, rtx val)
 {
   enum rtx_code code = GET_CODE (x);
-  rtx temp;
   const char *fmt;
   int i, j;
 
@@ -9062,7 +9061,10 @@ known_cond (rtx x, enum rtx_code cond, rtx reg, rtx val)
   else if (COMPARISON_P (x) || COMMUTATIVE_ARITH_P (x))
     {
       if (rtx_equal_p (XEXP (x, 0), val))
-	cond = swap_condition (cond), temp = val, val = reg, reg = temp;
+        {
+	  std::swap (val, reg);
+	  cond = swap_condition (cond);
+        }
 
       if (rtx_equal_p (XEXP (x, 0), reg) && rtx_equal_p (XEXP (x, 1), val))
 	{
@@ -11454,7 +11456,7 @@ simplify_comparison (enum rtx_code code, rtx *pop0, rtx *pop1)
      is already a constant integer.  */
   if (swap_commutative_operands_p (op0, op1))
     {
-      tem = op0, op0 = op1, op1 = tem;
+      std::swap (op0, op1);
       code = swap_condition (code);
     }
 
@@ -12341,7 +12343,7 @@ simplify_comparison (enum rtx_code code, rtx *pop0, rtx *pop1)
   /* We may have changed the comparison operands.  Re-canonicalize.  */
   if (swap_commutative_operands_p (op0, op1))
     {
-      tem = op0, op0 = op1, op1 = tem;
+      std::swap (op0, op1);
       code = swap_condition (code);
     }