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([172.56.177.223]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-2bd7daa37c7sm5958093eec.12.2026.02.23.21.44.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 23 Feb 2026 21:44:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1771911882; x=1772516682; darn=nongnu.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=7P4L6KRGUfnJuZGklnenZefdnYuPN4EZ2NjRTD5rCHQ=; b=U16My6skclzhMY8OQMMcJU53wUCgJ45X0DoqChxGCcY7L/kWiOsnZzZFjHTrzb21fA OvqUt5qRoZ0N9lwWhS8Okdpwwd8r64v6en2BOYbJfWCJL0XBQPjFCEQYeRCgkJctzVF2 Rcx0Aw3acu+/X2ItuIWP0eRWLALEzF3fSyL7LXKOR3e75ZgfWKS3gRCB2cywdxKXDgk2 PLILSGteLXx/JH0VY3/9TsoCR78S2KyoBXoCCvx4r33gUvHLeWSrRFhBNNbEOURsuMTm XKbccG5HV+yLCVjMqWTfEd9sytHmI9lgA2fHheHnNjgPsQI1dpnGWoNGIHhvfSCuCg1u kZnQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1771911882; x=1772516682; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=7P4L6KRGUfnJuZGklnenZefdnYuPN4EZ2NjRTD5rCHQ=; b=Ysb7PKeLgsK6Jo0WXKMp3zicsVPTI8T/cA38vHmfGpnRydJ5RCkMO6MmOhcXGDwiew oWWoc4eqPMGelBT/q4ZwakPShqfGT1CGKozjPXY51d/Ktynb9kGzn9CHZZfTz0644b4L boam4qPVGMO0foy4MbH/e1Uq1KEXcpySo18G9PA7zzos7xIczMnNsK/BhDu34m7Wnop4 hu7gXMWopeBqhGTP2oQCeHg2eebNI1bgRb9jhlJm+W+IbgGIbg02DdbXmiwVarC5JKDa foBCeRH4OAOncBx2d3w8BgXJ+6tOJFtw8cZBnTD9YQOda4AyJgp+CwPyptuh4YJd5zKs teOA== X-Gm-Message-State: AOJu0YwXjJpjC0OcIxTzsqKtMRRmKH2HBd9GvqeXMWy64WgaSqRy9jyz lDdfB1WECNlsmjyogjIt4a389liQQaBh31xCMwpFNbgO10EAYgxAA+jDsa4qzK6GgXhcrQuXDRI oGYE2qLg= X-Gm-Gg: ATEYQzxZ9gO4lyMqmBFy+EXlEMxS9M+C2nmffFxy7wHCcCNRsRWdm3GVPvzPoAaNnm4 YkN5F80JUeKgw7yMXmqzqctXYB0X7tAHIvO4cjjK6bDj+CcG+YTMaA7PAY2GrT8SrUEIRwghYPR dWP3N3FjfoUNzjvOU7zpU2oPHarr2yI5gDnSPnrPAscrB1SIzQAKDk2vL0MOoiwNVd7S8OIdd2i ZJH4844wqYAjLK1V3FVPffFwp2mP2LKIsGx1IAVdrV2bgrCtgOWRzviRkX/qWMdSvpglS22ctfH cjQj34EW+tTef8sbESB2G2IjQbUg18r+LNYuG+OhlC/Z9i0vAB0VByVE5aWocrxgGfCp2hR2qqT uZEPEd6Ppc4zONH02gtoycADTGHWGhs2BXm44Ttv0HFbR0HToKelaGR7cJF69D3+Pmo7ufH+At4 PlA5B6j1+sBOafJGbN5GUBDiBLdevYlMuZsy10J3Zmx9IgV3/xDj7g X-Received: by 2002:a05:693c:3944:b0:2ae:5e93:b69 with SMTP id 5a478bee46e88-2bd7bd24e03mr4123931eec.29.1771911881868; Mon, 23 Feb 2026 21:44:41 -0800 (PST) From: Richard Henderson To: qemu-devel@nongnu.org Cc: Max Chou , Chao Liu Subject: [PULL 3/9] target/i386: Fix pseudo-NaN handling in FPATAN/FYL2XP1/FYL2X helpers Date: Tue, 24 Feb 2026 16:44:11 +1100 Message-ID: <20260224054417.32430-4-richard.henderson@linaro.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260224054417.32430-1-richard.henderson@linaro.org> References: <20260224054417.32430-1-richard.henderson@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2607:f8b0:4864:20::132b; envelope-from=richard.henderson@linaro.org; helo=mail-dy1-x132b.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, 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: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @linaro.org) X-ZM-MESSAGEID: 1771911913644158500 Content-Type: text/plain; charset="utf-8" From: Max Chou According to Intel's x87 FPU specification (Table 8-10, Vol. 1), arithmetic operations on operands in unsupported formats (including pseudo-NaNs) must return the QNaN floating-point indefinite value. The helper functions for FPATAN, FYL2XP1, and FYL2X incorrectly check for signaling NaN before checking for invalid encodings. This causes pseudo-NaNs to be treated as valid signaling NaNs and silenced, rather than being rejected as unsupported formats. Reorder the checks to test floatx80_invalid_encoding before floatx80_is_signaling_nan, matching the correct behavior already implemented in helper_fscale. Signed-off-by: Max Chou Reviewed-by: Richard Henderson Reviewed-by: Chao Liu Signed-off-by: Richard Henderson Message-ID: <20260204051756.667397-5-max.chou@sifive.com> --- target/i386/tcg/fpu_helper.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/target/i386/tcg/fpu_helper.c b/target/i386/tcg/fpu_helper.c index b3b23823fd..37c83ded38 100644 --- a/target/i386/tcg/fpu_helper.c +++ b/target/i386/tcg/fpu_helper.c @@ -1377,16 +1377,16 @@ void helper_fpatan(CPUX86State *env) int32_t arg1_exp =3D extractFloatx80Exp(ST1); bool arg1_sign =3D extractFloatx80Sign(ST1); =20 - if (floatx80_is_signaling_nan(ST0, &env->fp_status)) { + if (floatx80_invalid_encoding(ST0, &env->fp_status) || + floatx80_invalid_encoding(ST1, &env->fp_status)) { + float_raise(float_flag_invalid, &env->fp_status); + ST1 =3D floatx80_default_nan(&env->fp_status); + } else if (floatx80_is_signaling_nan(ST0, &env->fp_status)) { float_raise(float_flag_invalid, &env->fp_status); ST1 =3D floatx80_silence_nan(ST0, &env->fp_status); } else if (floatx80_is_signaling_nan(ST1, &env->fp_status)) { float_raise(float_flag_invalid, &env->fp_status); ST1 =3D floatx80_silence_nan(ST1, &env->fp_status); - } else if (floatx80_invalid_encoding(ST0, &env->fp_status) || - floatx80_invalid_encoding(ST1, &env->fp_status)) { - float_raise(float_flag_invalid, &env->fp_status); - ST1 =3D floatx80_default_nan(&env->fp_status); } else if (floatx80_is_any_nan(ST0)) { ST1 =3D ST0; } else if (floatx80_is_any_nan(ST1)) { @@ -2061,16 +2061,16 @@ void helper_fyl2xp1(CPUX86State *env) int32_t arg1_exp =3D extractFloatx80Exp(ST1); bool arg1_sign =3D extractFloatx80Sign(ST1); =20 - if (floatx80_is_signaling_nan(ST0, &env->fp_status)) { + if (floatx80_invalid_encoding(ST0, &env->fp_status) || + floatx80_invalid_encoding(ST1, &env->fp_status)) { + float_raise(float_flag_invalid, &env->fp_status); + ST1 =3D floatx80_default_nan(&env->fp_status); + } else if (floatx80_is_signaling_nan(ST0, &env->fp_status)) { float_raise(float_flag_invalid, &env->fp_status); ST1 =3D floatx80_silence_nan(ST0, &env->fp_status); } else if (floatx80_is_signaling_nan(ST1, &env->fp_status)) { float_raise(float_flag_invalid, &env->fp_status); ST1 =3D floatx80_silence_nan(ST1, &env->fp_status); - } else if (floatx80_invalid_encoding(ST0, &env->fp_status) || - floatx80_invalid_encoding(ST1, &env->fp_status)) { - float_raise(float_flag_invalid, &env->fp_status); - ST1 =3D floatx80_default_nan(&env->fp_status); } else if (floatx80_is_any_nan(ST0)) { ST1 =3D ST0; } else if (floatx80_is_any_nan(ST1)) { @@ -2159,16 +2159,16 @@ void helper_fyl2x(CPUX86State *env) int32_t arg1_exp =3D extractFloatx80Exp(ST1); bool arg1_sign =3D extractFloatx80Sign(ST1); =20 - if (floatx80_is_signaling_nan(ST0, &env->fp_status)) { + if (floatx80_invalid_encoding(ST0, &env->fp_status) || + floatx80_invalid_encoding(ST1, &env->fp_status)) { + float_raise(float_flag_invalid, &env->fp_status); + ST1 =3D floatx80_default_nan(&env->fp_status); + } else if (floatx80_is_signaling_nan(ST0, &env->fp_status)) { float_raise(float_flag_invalid, &env->fp_status); ST1 =3D floatx80_silence_nan(ST0, &env->fp_status); } else if (floatx80_is_signaling_nan(ST1, &env->fp_status)) { float_raise(float_flag_invalid, &env->fp_status); ST1 =3D floatx80_silence_nan(ST1, &env->fp_status); - } else if (floatx80_invalid_encoding(ST0, &env->fp_status) || - floatx80_invalid_encoding(ST1, &env->fp_status)) { - float_raise(float_flag_invalid, &env->fp_status); - ST1 =3D floatx80_default_nan(&env->fp_status); } else if (floatx80_is_any_nan(ST0)) { ST1 =3D ST0; } else if (floatx80_is_any_nan(ST1)) { --=20 2.43.0