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[50.233.235.3]) by smtp.gmail.com with ESMTPSA id i24-20020a635418000000b003c14af50622sm5798959pgb.58.2022.05.07.21.27.41 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 07 May 2022 21:27:41 -0700 (PDT) Message-ID: <461a810f-6ca0-98cc-4144-18062b165ad7@linaro.org> Date: Sat, 7 May 2022 23:27:39 -0500 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: [RFC PATCH v2 7/7] target/ppc: Implemented [pm]xvbf16ger2* Content-Language: en-US To: "Lucas Mateus Castro(alqotel)" , qemu-ppc@nongnu.org Cc: Joel Stanley , =?UTF-8?Q?C=c3=a9dric_Le_Goater?= , Daniel Henrique Barboza , David Gibson , Greg Kurz , "open list:All patches CC here" References: <20220506121844.18969-1-lucas.araujo@eldorado.org.br> <20220506121844.18969-8-lucas.araujo@eldorado.org.br> From: Richard Henderson In-Reply-To: <20220506121844.18969-8-lucas.araujo@eldorado.org.br> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=2607:f8b0:4864:20::635; envelope-from=richard.henderson@linaro.org; helo=mail-pl1-x635.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, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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" On 5/6/22 07:18, Lucas Mateus Castro(alqotel) wrote: > From: "Lucas Mateus Castro (alqotel)" > > Implement the following PowerISA v3.1 instructions: > xvbf16ger2: VSX Vector bfloat16 GER (rank-2 update) > xvbf16ger2nn: VSX Vector bfloat16 GER (rank-2 update) Negative multiply, > Negative accumulate > xvbf16ger2np: VSX Vector bfloat16 GER (rank-2 update) Negative multiply, > Positive accumulate > xvbf16ger2pn: VSX Vector bfloat16 GER (rank-2 update) Positive multiply, > Negative accumulate > xvbf16ger2pp: VSX Vector bfloat16 GER (rank-2 update) Positive multiply, > Positive accumulate > pmxvbf16ger2: Prefixed Masked VSX Vector bfloat16 GER (rank-2 update) > pmxvbf16ger2nn: Prefixed Masked VSX Vector bfloat16 GER (rank-2 update) > Negative multiply, Negative accumulate > pmxvbf16ger2np: Prefixed Masked VSX Vector bfloat16 GER (rank-2 update) > Negative multiply, Positive accumulate > pmxvbf16ger2pn: Prefixed Masked VSX Vector bfloat16 GER (rank-2 update) > Positive multiply, Negative accumulate > pmxvbf16ger2pp: Prefixed Masked VSX Vector bfloat16 GER (rank-2 update) > Positive multiply, Positive accumulate > > Signed-off-by: Lucas Mateus Castro (alqotel) > --- > There's a discrepancy between this implementation and mambo/the > hardware where implementing it with float64_mul then float64r32_muladd > sometimes results in an incorrect result after an underflow, but > implementing with float32_mul then float32_muladd results in incorrect > signal in some 0 or infinite results. I've not been able to solve this I did suggest that the float64_mul needs to be done in round-to-odd. Anyway, for this patch, Reviewed-by: Richard Henderson r~