From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:35491) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TDyim-0001dg-Kv for qemu-devel@nongnu.org; Tue, 18 Sep 2012 10:24:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TDyii-0002Jm-El for qemu-devel@nongnu.org; Tue, 18 Sep 2012 10:24:16 -0400 Received: from mail-pb0-f45.google.com ([209.85.160.45]:34846) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TDyii-0002Hy-89 for qemu-devel@nongnu.org; Tue, 18 Sep 2012 10:24:12 -0400 Received: by mail-pb0-f45.google.com with SMTP id rp12so94988pbb.4 for ; Tue, 18 Sep 2012 07:24:11 -0700 (PDT) Sender: Richard Henderson From: Richard Henderson Date: Tue, 18 Sep 2012 07:24:00 -0700 Message-Id: <1347978240-20260-6-git-send-email-rth@twiddle.net> In-Reply-To: <1347978240-20260-1-git-send-email-rth@twiddle.net> References: <1347978240-20260-1-git-send-email-rth@twiddle.net> Subject: [Qemu-devel] [PATCH 5/5] tcg: Optimize two-address commutative operations List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: aurelien@aurel32.net While swapping constants to the second operand, swap sources matching destinations to the first operand. Signed-off-by: Richard Henderson --- tcg/optimize.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) diff --git a/tcg/optimize.c b/tcg/optimize.c index 5b0a8ce..becc408 100644 --- a/tcg/optimize.c +++ b/tcg/optimize.c @@ -337,6 +337,8 @@ 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' @@ -363,7 +365,8 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, } } - /* For commutative operations make constant second argument */ + /* For commutative operations make constant second argument, or + if the destination is an input, make it the first argument. */ switch (op) { CASE_OP_32_64(add): CASE_OP_32_64(mul): @@ -373,7 +376,9 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, CASE_OP_32_64(eqv): CASE_OP_32_64(nand): CASE_OP_32_64(nor): - if (temps[args[1]].state == TCG_TEMP_CONST) { + if (temps[args[1]].state == TCG_TEMP_CONST + || (args[0] == args[2] + && temps[args[1]].state != TCG_TEMP_CONST)) { tmp = args[1]; args[1] = args[2]; args[2] = tmp; @@ -398,13 +403,24 @@ 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; } -- 1.7.11.4