From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:33269) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TE55G-0002fH-M1 for qemu-devel@nongnu.org; Tue, 18 Sep 2012 17:11:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TE55F-0004Wn-BZ for qemu-devel@nongnu.org; Tue, 18 Sep 2012 17:11:54 -0400 Received: from hall.aurel32.net ([88.191.126.93]:59618) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TE55F-0004WY-3g for qemu-devel@nongnu.org; Tue, 18 Sep 2012 17:11:53 -0400 Date: Tue, 18 Sep 2012 23:11:50 +0200 From: Aurelien Jarno Message-ID: <20120918211150.GA20986@ohm.aurel32.net> References: <1347978240-20260-1-git-send-email-rth@twiddle.net> <1347978240-20260-6-git-send-email-rth@twiddle.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1347978240-20260-6-git-send-email-rth@twiddle.net> Subject: Re: [Qemu-devel] [PATCH 5/5] tcg: Optimize two-address commutative operations List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Richard Henderson Cc: qemu-devel@nongnu.org On Tue, Sep 18, 2012 at 07:24:00AM -0700, Richard Henderson wrote: > 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]; Not directly related to movcond, and I also got that in my tree, but I guess it's fine. > 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 > Reviewed-by: Aurelien Jarno -- Aurelien Jarno GPG: 1024D/F1BCDB73 aurelien@aurel32.net http://www.aurel32.net