From patchwork Thu Aug 7 13:09:41 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Stubbs X-Patchwork-Id: 118013 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 7A34A3858D21 for ; Thu, 7 Aug 2025 13:10:34 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 7A34A3858D21 Authentication-Results: sourceware.org; dkim=pass (2048-bit key, unprotected) header.d=baylibre-com.20230601.gappssmtp.com header.i=@baylibre-com.20230601.gappssmtp.com header.a=rsa-sha256 header.s=20230601 header.b=nsFhTwvf X-Original-To: newlib@sourceware.org Delivered-To: newlib@sourceware.org Received: from mail-wm1-x336.google.com (mail-wm1-x336.google.com [IPv6:2a00:1450:4864:20::336]) by sourceware.org (Postfix) with ESMTPS id 766653858408 for ; Thu, 7 Aug 2025 13:09:46 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 766653858408 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=baylibre.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=baylibre.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 766653858408 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=2a00:1450:4864:20::336 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1754572186; cv=none; b=tI2FWr3jlj9zPf/sBTXu9X4Dx1QkgXF0fKLTx7EaWCOp4Y61fryVmSmc7uFDkSBs1VIBp55rzvp+Y0z7Hgiv+x0mSr5Lb414o9lMZPMEtonwooyz5Cqhu9CNx/8Ek6nBGd2rxTVvMUwwJMRUcHXtZL/JMhJv7kfjgMnoebDTvz0= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1754572186; c=relaxed/simple; bh=qSaQQOjshOSJLty0/MubomgsZDi+DNHrFnFXI/SxfkE=; h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version; b=QZGzUYx/2wkRhGx12j+4Ey7IB0nI2eTKoSs9iiSevoP97WqqTCXCPcpCBXMzNsya0nQS5EKrStMUpDbZPr2bAgzKuLoOUp1EUldkRhbELM8P5L1r/vst657o6Rclq4J70LHeCb3f7jx0ZxqyP48ZuSsWrEjFcdB8LWCG61UL0x8= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 766653858408 Received: by mail-wm1-x336.google.com with SMTP id 5b1f17b1804b1-459eb4ae596so8913495e9.1 for ; Thu, 07 Aug 2025 06:09:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20230601.gappssmtp.com; s=20230601; t=1754572185; x=1755176985; darn=sourceware.org; h=content-transfer-encoding:mime-version:message-id:date:subject:to :from:from:to:cc:subject:date:message-id:reply-to; bh=evIl15+sRpAdCv/UxZOgSBFVkk4fJEeo2VZpNthGBGQ=; b=nsFhTwvfUVwKRzEgn2EyBHoLNJx0mkLGoDPqnEGk/9m+C1L9JhxRHGmqaHnEAIhXKY 10D1LAMDVTdBsszXGhhbC8M1LfV0aTPzbrEKMWuGYIUzi4VpxPdFmspFQSv2nACA2a1x l9GQrd0JaL7nj9B3PbByWLYAdGBQ27JCP9aO8maSa+ZyS4eANNDq4x8g2UFccLQPKKjy PgJz/9MeFLPVEhJstQRcQJy9jYK+YP5TPfwceVlm5SaL5Apc5T2ehJLw5WY4k4mBZTtK t+ugUVuF062A/weKBMFhxyRnNQrkMatEwEKlaxOogiUGgF6KEO+4Gyrc5UR422iyt8Mc pUnA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1754572185; x=1755176985; h=content-transfer-encoding:mime-version:message-id:date:subject:to :from:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=evIl15+sRpAdCv/UxZOgSBFVkk4fJEeo2VZpNthGBGQ=; b=Ad1f1/FIASLT24iZk7GvAkr52xkETwVUy7z8mWsZikIvBYchjEVBar2YLRcg9VcptU yD1xd0NDAC2pDRgg3FCNBA+b+MyYrGvA8RBjvXZ4ScE5O74ViekvhXSy5v2YlxLLtJVZ i966fXy69MPN/ihy9p0i6Utv6pOdVkztIojysDcTUk22lnNiZScpnmqSzZjfCmjuanDe A1c6RreCVMFuQO48Bl/PUyQzNHnVT7OceqOq5S7I5UP32hWQdW70iFeNk3r8D1qN3EB+ XHuPFdLs7+gT+4jxP1cmaTWyzKNTQTh1r5CUvr28kV6kmkibMN9GpV6ITUpl3jTnvNzs qiOw== X-Gm-Message-State: AOJu0YxN17VdFozSSEgHEfSa1OUUmwjEQnjz6gisnzYd+9eoe4NdST0/ ha4AWsUMhGaVgpE4+PvGWL/pSQyksNRZ4TGDzMjCkyB7u+uVMme2MILfMFJXexvVKXLthKUHosl NbK8Y X-Gm-Gg: ASbGncs9eq7hl+tF4qxAvFdqQt54nZXi7BheO3jt/+rz6B7ic8I4bk56LzpIKt7tM8d Ybf08o9su1IJmHSzLQQkO+AYUdbntxuoBujhKbJlBAlX5BqamUKrHcA0fLoaQKy9TaudUSdtMUe AFwmtH5A7CMcxH8BbbnovdV3iXjwUvboCVvy3d0JBg3mvTauMEZldjwOoO2Cu9YexiyhT1K0qU2 Or7Wc1zbDPTadJNzdCp63H3Z0EKBGJw753HPIRjVct7db2ednTbT8xeOfRBaTSZ5ZfvDF1h1h57 QOuwSyQ1aFbfoL80D4bNCINbDzkHy1scal7FHSrD/Ry60DO1Q/3QVpMzwjv2Lku+6rLQy2ak0aQ L2Rx509AICepWy+LdgOQmjYeXeQ== X-Google-Smtp-Source: AGHT+IE/gI3XbaV6i2IRzDw5gon7/s+naDMa3PDMXOZVUOteQ4mmUjdfT6MEdUP9/ds/CRNUsxhTGg== X-Received: by 2002:a05:600c:1c18:b0:456:19be:5cc with SMTP id 5b1f17b1804b1-459e741fcebmr73402275e9.14.1754572184583; Thu, 07 Aug 2025 06:09:44 -0700 (PDT) Received: from vbuild-02.baylibre ([217.13.61.132]) by smtp.googlemail.com with ESMTPSA id 5b1f17b1804b1-459e5843021sm104773455e9.3.2025.08.07.06.09.43 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Aug 2025 06:09:44 -0700 (PDT) From: Andrew Stubbs To: newlib@sourceware.org Subject: [PATCH] amdgcn, libm: fix infinite loop Date: Thu, 7 Aug 2025 13:09:41 +0000 Message-ID: <20250807130941.363722-1-ams@baylibre.com> X-Mailer: git-send-email 2.50.0 MIME-Version: 1.0 X-Spam-Status: No, score=-10.8 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: newlib@sourceware.org X-Mailman-Version: 2.1.30 Precedence: list List-Id: Newlib mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: newlib-bounces~patchwork=sourceware.org@sourceware.org The end condition on this loop, unlike all the other similar loops, is "i >= 0", which is a problem because "i <<= 1" can go negative and then zero if you continue shifting, and so back to true, again. This isn't a problem for the loop in the scalar implementation, but it means we need to mask the shift in the vector implementation. This fixes GCC PR#121392. --- newlib/libm/machine/amdgcn/v64sf_fmod.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/newlib/libm/machine/amdgcn/v64sf_fmod.c b/newlib/libm/machine/amdgcn/v64sf_fmod.c index 7302420ad..b62b81929 100644 --- a/newlib/libm/machine/amdgcn/v64sf_fmod.c +++ b/newlib/libm/machine/amdgcn/v64sf_fmod.c @@ -70,8 +70,11 @@ DEF_VS_MATH_FUNC (v64sf, fmodf, v64sf x, v64sf y) v64si iy; VECTOR_IF (hy < 0x00800000, cond) // subnormal y iy = VECTOR_INIT (-126); - for (v64si i = (hy << 8); !ALL_ZEROES_P (cond & (i >= 0)); i <<= 1) - VECTOR_COND_MOVE (iy, iy - 1, cond & (i >= 0)); + for (v64si i = (hy << 8); !ALL_ZEROES_P (cond & (i >= 0)); /* i <<= 1 */) + { + VECTOR_COND_MOVE (iy, iy - 1, cond & (i >= 0)); + VECTOR_COND_MOVE (i, i << 1, cond & (i >= 0)); + } VECTOR_ELSE (cond) VECTOR_COND_MOVE (iy, (hy >> 23) - 127, cond); VECTOR_ENDIF