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[37.158.79.165]) by smtp.gmail.com with ESMTPSA id q84sm14044877wme.3.2021.11.19.08.06.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Nov 2021 08:06:18 -0800 (PST) From: Richard Henderson To: qemu-devel@nongnu.org Subject: [PATCH 33/35] target/ppc: Update fres to new flags and float64r32 Date: Fri, 19 Nov 2021 17:05:00 +0100 Message-Id: <20211119160502.17432-34-richard.henderson@linaro.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211119160502.17432-1-richard.henderson@linaro.org> References: <20211119160502.17432-1-richard.henderson@linaro.org> MIME-Version: 1.0 X-Host-Lookup-Failed: Reverse DNS lookup failed for 2a00:1450:4864:20::32f (failed) Received-SPF: pass client-ip=2a00:1450:4864:20::32f; envelope-from=richard.henderson@linaro.org; helo=mail-wm1-x32f.google.com X-Spam_score_int: -12 X-Spam_score: -1.3 X-Spam_bar: - X-Spam_report: (-1.3 / 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, PDS_HP_HELO_NORDNS=0.001, RCVD_IN_DNSWL_NONE=-0.0001, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-ppc@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-ppc@nongnu.org, danielhb413@gmail.com, alex.bennee@linaro.org, clg@kaod.org Errors-To: qemu-ppc-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-ppc" There is no double-rounding bug here, because the result is merely an estimate to within 1 part in 256, but perform the operation with float64r32_div for consistency. Use float_flag_invalid_snan instead of recomputing the snan-ness of the operand. Signed-off-by: Richard Henderson --- target/ppc/fpu_helper.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/target/ppc/fpu_helper.c b/target/ppc/fpu_helper.c index cb511f2050..ea238929da 100644 --- a/target/ppc/fpu_helper.c +++ b/target/ppc/fpu_helper.c @@ -813,20 +813,20 @@ float64 helper_fre(CPUPPCState *env, float64 arg) /* fres - fres. */ uint64_t helper_fres(CPUPPCState *env, uint64_t arg) { - CPU_DoubleU farg; - float32 f32; + /* "Estimate" the reciprocal with actual division. */ + float64 ret = float64r32_div(float64_one, arg, &env->fp_status); + int flags = get_float_exception_flags(&env->fp_status); - farg.ll = arg; - - if (unlikely(float64_is_signaling_nan(farg.d, &env->fp_status))) { - /* sNaN reciprocal */ + if (unlikely(flags & float_flag_invalid_snan)) { float_invalid_op_vxsnan(env, GETPC()); } - farg.d = float64_div(float64_one, farg.d, &env->fp_status); - f32 = float64_to_float32(farg.d, &env->fp_status); - farg.d = float32_to_float64(f32, &env->fp_status); + if (unlikely(flags & float_flag_divbyzero)) { + float_zero_divide_excp(env, GETPC()); + /* For FPSCR.ZE == 0, the result is 1/2. */ + ret = float64_set_sign(float64_half, float64_is_neg(arg)); + } - return farg.ll; + return ret; } /* frsqrte - frsqrte. */