[ARM] Replacing variable swaps that use a temporary variable with a call to…

[ARM] Replacing variable swaps that use a temporary variable with a call to std::swap in gcc/config/arm/arm.c

On behalf of <bilyan.borisov@arm.com>

2015-09-21  Bilyan Borisov  <bilyan.borisov@arm.com>

	* config/arm/arm.c (thumb_output_move_mem_multiple): Replaced
	operands[4] operands[5] swap with std::swap, removed tmp variable.
	(arm_evpc_neon_vzip): Replaced in0/in1 and
	out0/out1 swaps with std::swap, removed x variable.
	(arm_evpc_neon_vtrn): Replaced in0/int1 and
	out0/out1 swaos with std::swap, removed x variable.
	(arm_expand_vec_perm_const_1): Replaced
	d->op0/d->op1 swap with std::swap, removed x variable.
	(arm_evpc_neon_vuzp): Replaced in0/in1 and
	out0/out1 swaps with std::swap, removed x variable.

From-SVN: r227963

gcc/ChangeLog

+2015-09-21  Bilyan Borisov  <bilyan.borisov@arm.com>
+
+	* config/arm/arm.c (thumb_output_move_mem_multiple): Replaced
+	operands[4] operands[5] swap with std::swap, removed tmp variable.
+	(arm_evpc_neon_vzip): Replaced in0/in1 and
+	out0/out1 swaps with std::swap, removed x variable.
+	(arm_evpc_neon_vtrn): Replaced in0/int1 and
+	out0/out1 swaos with std::swap, removed x variable.
+	(arm_expand_vec_perm_const_1): Replaced
+	d->op0/d->op1 swap with std::swap, removed x variable.
+	(arm_evpc_neon_vuzp): Replaced in0/in1 and
+	out0/out1 swaps with std::swap, removed x variable.
+
 2015-09-21  Jonathan Yong  <10walls@gmail.com>
 
 	* config/i386/cygwin.h (STARTFILE_SPEC): Explicitly search

gcc/config/arm/arm.c

@@ -25656,17 +25656,12 @@ thumb_load_double_from_address (rtx *operands)
 const char *
 thumb_output_move_mem_multiple (int n, rtx *operands)
 {
-  rtx tmp;
-
   switch (n)
     {
     case 2:
       if (REGNO (operands[4]) > REGNO (operands[5]))
-	{
-	  tmp = operands[4];
-	  operands[4] = operands[5];
-	  operands[5] = tmp;
-	}
+	std::swap (operands[4], operands[5]);
+
       output_asm_insn ("ldmia\t%1!, {%4, %5}", operands);
       output_asm_insn ("stmia\t%0!, {%4, %5}", operands);
       break;
@@ -28216,7 +28211,7 @@ static bool
 arm_evpc_neon_vuzp (struct expand_vec_perm_d *d)
 {
   unsigned int i, odd, mask, nelt = d->nelt;
-  rtx out0, out1, in0, in1, x;
+  rtx out0, out1, in0, in1;
   rtx (*gen)(rtx, rtx, rtx, rtx);
 
   if (GET_MODE_UNIT_SIZE (d->vmode) >= 8)
@@ -28260,14 +28255,14 @@ arm_evpc_neon_vuzp (struct expand_vec_perm_d *d)
   in1 = d->op1;
   if (BYTES_BIG_ENDIAN)
     {
-      x = in0, in0 = in1, in1 = x;
+      std::swap (in0, in1);
       odd = !odd;
     }
 
   out0 = d->target;
   out1 = gen_reg_rtx (d->vmode);
   if (odd)
-    x = out0, out0 = out1, out1 = x;
+    std::swap (out0, out1);
 
   emit_insn (gen (out0, in0, in1, out1));
   return true;
@@ -28279,7 +28274,7 @@ static bool
 arm_evpc_neon_vzip (struct expand_vec_perm_d *d)
 {
   unsigned int i, high, mask, nelt = d->nelt;
-  rtx out0, out1, in0, in1, x;
+  rtx out0, out1, in0, in1;
   rtx (*gen)(rtx, rtx, rtx, rtx);
 
   if (GET_MODE_UNIT_SIZE (d->vmode) >= 8)
@@ -28327,14 +28322,14 @@ arm_evpc_neon_vzip (struct expand_vec_perm_d *d)
   in1 = d->op1;
   if (BYTES_BIG_ENDIAN)
     {
-      x = in0, in0 = in1, in1 = x;
+      std::swap (in0, in1);
       high = !high;
     }
 
   out0 = d->target;
   out1 = gen_reg_rtx (d->vmode);
   if (high)
-    x = out0, out0 = out1, out1 = x;
+    std::swap (out0, out1);
 
   emit_insn (gen (out0, in0, in1, out1));
   return true;
@@ -28420,7 +28415,7 @@ static bool
 arm_evpc_neon_vtrn (struct expand_vec_perm_d *d)
 {
   unsigned int i, odd, mask, nelt = d->nelt;
-  rtx out0, out1, in0, in1, x;
+  rtx out0, out1, in0, in1;
   rtx (*gen)(rtx, rtx, rtx, rtx);
 
   if (GET_MODE_UNIT_SIZE (d->vmode) >= 8)
@@ -28465,14 +28460,14 @@ arm_evpc_neon_vtrn (struct expand_vec_perm_d *d)
   in1 = d->op1;
   if (BYTES_BIG_ENDIAN)
     {
-      x = in0, in0 = in1, in1 = x;
+      std::swap (in0, in1);
       odd = !odd;
     }
 
   out0 = d->target;
   out1 = gen_reg_rtx (d->vmode);
   if (odd)
-    x = out0, out0 = out1, out1 = x;
+    std::swap (out0, out1);
 
   emit_insn (gen (out0, in0, in1, out1));
   return true;
@@ -28595,14 +28590,11 @@ arm_expand_vec_perm_const_1 (struct expand_vec_perm_d *d)
   if (d->perm[0] >= d->nelt)
     {
       unsigned i, nelt = d->nelt;
-      rtx x;
 
       for (i = 0; i < nelt; ++i)
 	d->perm[i] = (d->perm[i] + nelt) & (2 * nelt - 1);
 
-      x = d->op0;
-      d->op0 = d->op1;
-      d->op1 = x;
+      std::swap (d->op0, d->op1);
     }
 
   if (TARGET_NEON)