From patchwork Tue May 7 08:42:15 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 13656411 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4B610C25B4F for ; Tue, 7 May 2024 08:44:09 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1s4GQS-00052h-GM; Tue, 07 May 2024 04:43:52 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1s4GQE-0004VG-Jp; Tue, 07 May 2024 04:43:40 -0400 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1s4GQB-0003Lb-8f; Tue, 07 May 2024 04:43:37 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 8CF2B64BD4; Tue, 7 May 2024 11:42:49 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id 7A946C85BD; Tue, 7 May 2024 11:42:30 +0300 (MSK) Received: (nullmailer pid 1026561 invoked by uid 1000); Tue, 07 May 2024 08:42:29 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , Paul Cercueil , Richard Henderson , Yoshinori Sato , Michael Tokarev Subject: [Stable-8.2.4 16/16] target/sh4: Fix SUBV opcode Date: Tue, 7 May 2024 11:42:15 +0300 Message-Id: <20240507084226.1026455-16-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Philippe Mathieu-Daudé The documentation says: SUBV Rm, Rn Rn - Rm -> Rn, underflow -> T The overflow / underflow can be calculated as: T = ((Rn ^ Rm) & (Result ^ Rn)) >> 31 However we were using the incorrect: T = ((Rn ^ Rm) & (Result ^ Rm)) >> 31 Fix by using the Rn register instead of Rm. Add tests provided by Paul Cercueil. Cc: qemu-stable@nongnu.org Fixes: ad8d25a11f ("target-sh4: implement addv and subv using TCG") Reported-by: Paul Cercueil Suggested-by: Paul Cercueil Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2318 Reviewed-by: Richard Henderson Signed-off-by: Philippe Mathieu-Daudé Reviewed-by: Yoshinori Sato Message-Id: <20240430163125.77430-3-philmd@linaro.org> (cherry picked from commit e88a856efd1d3c3ffa8e53da4831eff8da290808) Signed-off-by: Michael Tokarev diff --git a/target/sh4/translate.c b/target/sh4/translate.c index d8dcfc3a20..5c0a4cce7a 100644 --- a/target/sh4/translate.c +++ b/target/sh4/translate.c @@ -934,7 +934,7 @@ static void _decode_opc(DisasContext * ctx) t0 = tcg_temp_new(); tcg_gen_sub_i32(t0, REG(B11_8), REG(B7_4)); t1 = tcg_temp_new(); - tcg_gen_xor_i32(t1, t0, REG(B7_4)); + tcg_gen_xor_i32(t1, t0, REG(B11_8)); t2 = tcg_temp_new(); tcg_gen_xor_i32(t2, REG(B11_8), REG(B7_4)); tcg_gen_and_i32(t1, t1, t2); diff --git a/tests/tcg/sh4/Makefile.target b/tests/tcg/sh4/Makefile.target index 39751c41b2..a523a0d2c8 100644 --- a/tests/tcg/sh4/Makefile.target +++ b/tests/tcg/sh4/Makefile.target @@ -23,3 +23,6 @@ TESTS += test-macw test-addv: CFLAGS += -O -g TESTS += test-addv + +test-subv: CFLAGS += -O -g +TESTS += test-subv diff --git a/tests/tcg/sh4/test-subv.c b/tests/tcg/sh4/test-subv.c new file mode 100644 index 0000000000..a3c2db96e4 --- /dev/null +++ b/tests/tcg/sh4/test-subv.c @@ -0,0 +1,30 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ + +#include +#include +#include + +static void subv(const int a, const int b, const int res, const int carry) +{ + int o = a, c; + + asm volatile("subv %2,%0\n" + "movt %1\n" + : "+r"(o), "=r"(c) : "r"(b) : ); + + if (c != carry || o != res) { + printf("SUBV %d, %d = %d/%d [T = %d/%d]\n", a, b, o, res, c, carry); + abort(); + } +} + +int main(void) +{ + subv(INT_MIN, 1, INT_MAX, 1); + subv(INT_MAX, -1, INT_MIN, 1); + subv(INT_MAX, 1, INT_MAX - 1, 0); + subv(0, 1, -1, 0); + subv(-1, -1, 0, 0); + + return 0; +}