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authorRichard Henderson <rth@twiddle.net>2012-09-21 10:13:38 -0700
committerAurelien Jarno <aurelien@aurel32.net>2012-09-21 19:53:17 +0200
commit5d8f53630011f93dc774f1b2dc9557c7eac3ad89 (patch)
treee29018e75d97047230513066afc7d473d8165b2f
parentfa01a2084e5643504b28ebba2d9dbdb73d2f74a4 (diff)
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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>
-rw-r--r--tcg/optimize.c15
1 files changed, 14 insertions, 1 deletions
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;
}