From af2bf6bcc6614622c87d28e9d763b57408c17500 Mon Sep 17 00:00:00 2001

From: Richard Henderson <rth@twiddle.net>

Date: Fri, 21 Sep 2012 10:13:38 -0700

Subject: [PATCH] tcg: Optimize two-address commutative operations

While swapping constants to the second operand, swap

sources matching destinations to the first operand.

Signed-off-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 | 15 ++++++++++++++-

 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/tcg/optimize.c b/tcg/optimize.c

index 26038a6..1be7631 100644

--- a/tcg/optimize.c

+++ b/tcg/optimize.c

@@ -334,6 +334,8 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,

     const TCGOpDef *def;

     TCGArg *gen_args;

     TCGArg tmp;

+    TCGCond cond;

+

     /* Array VALS has an element for each temp.

        If this temp holds a constant then its value is kept in VALS' element.

        If this temp is a copy of other ones then this equivalence class'

@@ -395,13 +397,24 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,

             }

             break;

         CASE_OP_32_64(movcond):

+            cond = args[5];

             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[5] = tcg_swap_cond(args[5]);

+                cond = tcg_swap_cond(cond);

+            }

+            /* For movcond, we canonicalize the "false" input reg to match

+               the destination reg so that the tcg backend can implement

+               a "move if true" operation.  */

+            if (args[0] == args[3]) {

+                tmp = args[3];

+                args[3] = args[4];

+                args[4] = tmp;

+                cond = tcg_invert_cond(cond);

             }

+            args[5] = cond;

         default:

             break;

         }

-- 

1.7.12.1