From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46555) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WVnl1-0006eS-Ig for qemu-devel@nongnu.org; Thu, 03 Apr 2014 15:57:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WVnkw-0004NQ-Im for qemu-devel@nongnu.org; Thu, 03 Apr 2014 15:57:03 -0400 Received: from mail-qc0-x22a.google.com ([2607:f8b0:400d:c01::22a]:60784) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WVnkw-0004NB-Bz for qemu-devel@nongnu.org; Thu, 03 Apr 2014 15:56:58 -0400 Received: by mail-qc0-f170.google.com with SMTP id x13so2515155qcv.29 for ; Thu, 03 Apr 2014 12:56:57 -0700 (PDT) Sender: Richard Henderson From: Richard Henderson Date: Thu, 3 Apr 2014 12:56:20 -0700 Message-Id: <1396555000-8205-7-git-send-email-rth@twiddle.net> In-Reply-To: <1396555000-8205-1-git-send-email-rth@twiddle.net> References: <1396555000-8205-1-git-send-email-rth@twiddle.net> Subject: [Qemu-devel] [PATCH v3 06/26] tcg-aarch64: Special case small constants in tcg_out_movi List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: claudio.fontana@gmail.com Reviewed-by: Claudio Fontana Signed-off-by: Richard Henderson --- tcg/aarch64/tcg-target.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/tcg/aarch64/tcg-target.c b/tcg/aarch64/tcg-target.c index c1d9895..a08f6c7 100644 --- a/tcg/aarch64/tcg-target.c +++ b/tcg/aarch64/tcg-target.c @@ -578,6 +578,16 @@ static void tcg_out_movi(TCGContext *s, TCGType type, TCGReg rd, type = TCG_TYPE_I32; } + /* Speed things up by handling the common case of small positive + and negative values specially. */ + if ((value & ~0xffffull) == 0) { + tcg_out_insn(s, 3405, MOVZ, type, rd, value, 0); + return; + } else if ((ivalue & ~0xffffull) == 0) { + tcg_out_insn(s, 3405, MOVN, type, rd, ivalue, 0); + return; + } + /* Check for bitfield immediates. For the benefit of 32-bit quantities, use the sign-extended value. That lets us match rotated values such as 0xff0000ff with the same 64-bit logic matching 0xffffffffff0000ff. */ -- 1.9.0