From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:52858) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TLyka-0005lb-Ij for qemu-devel@nongnu.org; Wed, 10 Oct 2012 12:03:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TLykP-0007eY-8w for qemu-devel@nongnu.org; Wed, 10 Oct 2012 12:03:12 -0400 Received: from mail-pa0-f45.google.com ([209.85.220.45]:38945) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TLykO-0007dw-PI for qemu-devel@nongnu.org; Wed, 10 Oct 2012 12:03:01 -0400 Received: by mail-pa0-f45.google.com with SMTP id fb10so744870pad.4 for ; Wed, 10 Oct 2012 09:03:00 -0700 (PDT) Sender: Richard Henderson From: Richard Henderson Date: Wed, 10 Oct 2012 09:02:40 -0700 Message-Id: <1349884967-4608-7-git-send-email-rth@twiddle.net> In-Reply-To: <1349884967-4608-1-git-send-email-rth@twiddle.net> References: <1349884967-4608-1-git-send-email-rth@twiddle.net> Subject: [Qemu-devel] [PATCH 06/13] tcg-sparc: Fix setcond List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Blue Swirl The set of comparisons that can immediately use the carry are LTU/GEU, not LTU/LEU. Don't swap operands when we need a temp register; the register may already be in use from setcond2. Signed-off-by: Richard Henderson --- tcg/sparc/tcg-target.c | 33 +++++++++++++++++++-------------- 1 file changed, 19 insertions(+), 14 deletions(-) diff --git a/tcg/sparc/tcg-target.c b/tcg/sparc/tcg-target.c index 3144044..31e8204 100644 --- a/tcg/sparc/tcg-target.c +++ b/tcg/sparc/tcg-target.c @@ -617,32 +617,37 @@ static void tcg_out_brcond2_i32(TCGContext *s, TCGCond cond, static void tcg_out_setcond_i32(TCGContext *s, TCGCond cond, TCGArg ret, TCGArg c1, TCGArg c2, int c2const) { - TCGArg t; - /* For 32-bit comparisons, we can play games with ADDX/SUBX. */ switch (cond) { + case TCG_COND_LTU: + case TCG_COND_GEU: + /* The result of the comparison is in the carry bit. */ + break; + case TCG_COND_EQ: case TCG_COND_NE: + /* For equality, we can transform to inequality vs zero. */ if (c2 != 0) { tcg_out_arithc(s, ret, c1, c2, c2const, ARITH_XOR); } c1 = TCG_REG_G0, c2 = ret, c2const = 0; - cond = (cond == TCG_COND_EQ ? TCG_COND_LEU : TCG_COND_LTU); + cond = (cond == TCG_COND_EQ ? TCG_COND_GEU : TCG_COND_LTU); break; case TCG_COND_GTU: - case TCG_COND_GEU: - if (c2const && c2 != 0) { - tcg_out_movi_imm13(s, TCG_REG_T1, c2); - c2 = TCG_REG_T1; - } - t = c1, c1 = c2, c2 = t, c2const = 0; - cond = tcg_swap_cond(cond); - break; - - case TCG_COND_LTU: case TCG_COND_LEU: - break; + /* If we don't need to load a constant into a register, we can + swap the operands on GTU/LEU. There's no benefit to loading + the constant into a temporary register. */ + if (!c2const || c2 == 0) { + TCGArg t = c1; + c1 = c2; + c2 = t; + c2const = 0; + cond = tcg_swap_cond(cond); + break; + } + /* FALLTHRU */ default: tcg_out_cmp(s, c1, c2, c2const); -- 1.7.11.4