From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49534) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fCkM7-0005DL-RB for qemu-devel@nongnu.org; Sun, 29 Apr 2018 07:19:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fCkM2-0006Tb-W6 for qemu-devel@nongnu.org; Sun, 29 Apr 2018 07:18:59 -0400 Received: from mail.uni-paderborn.de ([131.234.142.9]:48004) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fCkM2-0006TH-IM for qemu-devel@nongnu.org; Sun, 29 Apr 2018 07:18:54 -0400 References: <7366cfc5-e37f-483d-917b-2aae41d1e59e@gmail.com> From: Bastian Koppelmann Message-ID: <7a5d09e7-3e30-3683-41ae-076bd4532786@mail.uni-paderborn.de> Date: Sun, 29 Apr 2018 13:18:50 +0200 MIME-Version: 1.0 In-Reply-To: <7366cfc5-e37f-483d-917b-2aae41d1e59e@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] Difference between tcg_gen_ld_i64 and tcg_gen_qemu_ld_i64. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Rafael Kioji , qemu-devel@nongnu.org On 04/29/2018 12:15 PM, Rafael Kioji wrote: > Dear all, > > What is the difference between these two functions? They are located in the file > "tcg/tcg-op.c". Here is their header: > > 1. static inline void tcg_gen_ld_i64(TCGv_i64 ret, TCGv_ptr arg2, >    tcg_target_long offset) This is used to access fields of qemu data structures from generated code, e.g. CPUArmState. > 2. void tcg_gen_qemu_ld_i64(TCGv_i64 val, TCGv addr, TCGArg idx, >    TCGMemOp memop) This actually generates a load to guest memory. > > I don't quite understand the need for function (1). Especially because it is > usually passed "cpu_env" for arg2. Like in target/arm/translate-a64.c:595: cpu_env is a pointer to CPUArmState. Cheers, Bastian