qemu/0053-tcg-Optimize-two-address-commutative-operations.patch
2012-10-28 14:05:07 -04:00

58 lines
2.0 KiB
Diff

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