From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48804) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ekyPY-00058u-29 for qemu-devel@nongnu.org; Sun, 11 Feb 2018 15:39:46 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ekyPS-0006YA-Mi for qemu-devel@nongnu.org; Sun, 11 Feb 2018 15:39:44 -0500 Received: from mail-pl0-x242.google.com ([2607:f8b0:400e:c01::242]:41461) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1ekyPS-0006XH-Hd for qemu-devel@nongnu.org; Sun, 11 Feb 2018 15:39:38 -0500 Received: by mail-pl0-x242.google.com with SMTP id k8so4044676pli.8 for ; Sun, 11 Feb 2018 12:39:38 -0800 (PST) Received: from cloudburst.twiddle.net (174-21-6-47.tukw.qwest.net. [174.21.6.47]) by smtp.gmail.com with ESMTPSA id 10sm2327640pfo.69.2018.02.11.12.39.35 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sun, 11 Feb 2018 12:39:36 -0800 (PST) From: Richard Henderson Date: Sun, 11 Feb 2018 12:39:34 -0800 Message-Id: <20180211203934.15546-1-richard.henderson@linaro.org> Subject: [Qemu-devel] [PATCH] tcg: Improve tcg_gen_muli_i32/i64 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Convert multiplication by power of two to left shift. Signed-off-by: Richard Henderson --- tcg/tcg-op.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c index 3467787323..34b96d68f3 100644 --- a/tcg/tcg-op.c +++ b/tcg/tcg-op.c @@ -277,9 +277,15 @@ void tcg_gen_setcondi_i32(TCGCond cond, TCGv_i32 ret, void tcg_gen_muli_i32(TCGv_i32 ret, TCGv_i32 arg1, int32_t arg2) { - TCGv_i32 t0 = tcg_const_i32(arg2); - tcg_gen_mul_i32(ret, arg1, t0); - tcg_temp_free_i32(t0); + if (arg2 == 0) { + tcg_gen_movi_i32(ret, 0); + } else if (is_power_of_2(arg2)) { + tcg_gen_shli_i32(ret, arg1, ctz32(arg2)); + } else { + TCGv_i32 t0 = tcg_const_i32(arg2); + tcg_gen_mul_i32(ret, arg1, t0); + tcg_temp_free_i32(t0); + } } void tcg_gen_div_i32(TCGv_i32 ret, TCGv_i32 arg1, TCGv_i32 arg2) @@ -1430,9 +1436,15 @@ void tcg_gen_setcondi_i64(TCGCond cond, TCGv_i64 ret, void tcg_gen_muli_i64(TCGv_i64 ret, TCGv_i64 arg1, int64_t arg2) { - TCGv_i64 t0 = tcg_const_i64(arg2); - tcg_gen_mul_i64(ret, arg1, t0); - tcg_temp_free_i64(t0); + if (arg2 == 0) { + tcg_gen_movi_i64(ret, 0); + } else if (is_power_of_2(arg2)) { + tcg_gen_shli_i64(ret, arg1, ctz64(arg2)); + } else { + TCGv_i64 t0 = tcg_const_i64(arg2); + tcg_gen_mul_i64(ret, arg1, t0); + tcg_temp_free_i64(t0); + } } void tcg_gen_div_i64(TCGv_i64 ret, TCGv_i64 arg1, TCGv_i64 arg2) -- 2.14.3