qemu/0018-tcg-optimize-split-expression-simplification.patch

From 16f29b266435c7eaffc5081c6bba4651d56a8ce8 Mon Sep 17 00:00:00 2001
From: Aurelien Jarno <aurelien@aurel32.net>
Date: Thu, 6 Sep 2012 16:47:13 +0200
Subject: [PATCH] tcg/optimize: split expression simplification

Split expression simplification in multiple parts so that a given op
can appear multiple times. This patch should not change anything.

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 | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/tcg/optimize.c b/tcg/optimize.c
index 9c65474..63f970d 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -322,7 +322,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
             break;
         }
 
-        /* Simplify expression if possible. */
+        /* Simplify expression for "op r, a, 0 => mov r, a" cases */
         switch (op) {
         CASE_OP_32_64(add):
         CASE_OP_32_64(sub):
@@ -352,6 +352,12 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
                 continue;
             }
             break;
+        default:
+            break;
+        }
+
+        /* Simplify expression for "op r, a, 0 => movi r, 0" cases */
+        switch (op) {
         CASE_OP_32_64(mul):
             if ((temps[args[2]].state == TCG_TEMP_CONST
                 && temps[args[2]].val == 0)) {
@@ -362,6 +368,12 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
                 continue;
             }
             break;
+        default:
+            break;
+        }
+
+        /* Simplify expression for "op r, a, a => mov r, a" cases */
+        switch (op) {
         CASE_OP_32_64(or):
         CASE_OP_32_64(and):
             if (args[1] == args[2]) {
-- 
1.8.0.2