From 1127ad0d084f0cef11b5658b3dbbf8505d8d3af0 Mon Sep 17 00:00:00 2001
From: Aurelien Jarno <aurelien@aurel32.net>
Date: Thu, 6 Sep 2012 16:47:14 +0200
Subject: [PATCH] tcg/optimize: swap brcond/setcond arguments when possible

brcond and setcond ops are not commutative, but it's easy to compute the
new condition after swapping the arguments. Try to always put the constant
argument in second position like for commutative ops, to help backends to
generate better code.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 tcg/optimize.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/tcg/optimize.c b/tcg/optimize.c
index 1698ba3..7debc8a 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -318,6 +318,24 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
                 args[2] = tmp;
             }
             break;
+        CASE_OP_32_64(brcond):
+            if (temps[args[0]].state == TCG_TEMP_CONST
+                && temps[args[1]].state != TCG_TEMP_CONST) {
+                tmp = args[0];
+                args[0] = args[1];
+                args[1] = tmp;
+                args[2] = tcg_swap_cond(args[2]);
+            }
+            break;
+        CASE_OP_32_64(setcond):
+            if (temps[args[1]].state == TCG_TEMP_CONST
+                && temps[args[2]].state != TCG_TEMP_CONST) {
+                tmp = args[1];
+                args[1] = args[2];
+                args[2] = tmp;
+                args[3] = tcg_swap_cond(args[3]);
+            }
+            break;
         default:
             break;
         }