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([172.56.177.223]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-2bd7daa37c7sm5958093eec.12.2026.02.23.21.44.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 23 Feb 2026 21:44:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1771911873; x=1772516673; 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=jL1s5SV3cubFpJlsGLlbrnPoja1OfqVMQ1g/z28whqY=; b=DvSXl3uddlyIfTVGdrHsG4N6KxCdPkk2/2q3EOLVQeU6amqHwiVSqZFYMqcFlwwcmx hX1BxI+/H8+5agBSFFAiHfSsocsMqTKotq2FeZs+IKGArhNdNl+Id6IUEAft0IxficwD pn6k+58ZUV38LN08NnxUBenlLVaIbMhEl/94lBQIjMsTcC4p+lRCG3a+27y7L4Yi+3OB LsRaXD4FmNCiwf3PripdQl0zMaIviibJ1p2XE2r2tb0JK4OyMuHYHP5d292RxnbnUJ2F AIqBGDLs0qHxOwKXyzX4VnlT6QFeoLsy2C+IR26rbT1TM86YpHDdI1T5SD8ay+MBrH8Y +CjA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1771911873; x=1772516673; 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=jL1s5SV3cubFpJlsGLlbrnPoja1OfqVMQ1g/z28whqY=; b=izm7ajbuCeLTBc0OYUUGMVnEDy+VehlDIvtk8djTuVDD/pIYiFC4NLhoK8PF5uDYf3 K/vP6iNgx2auG8zmv7CIq6JRP6WSFioJpdQkuRODWgfJ/fN1cabG+tVbKH1LKsmauBMl UvmbOycs+CppJxcpyw8CLJH2+fOjYuXXaV9wofrkZpdt0qTuQlGLQKCUfAY94xUIBJZr GJ1qqnnyEm36/SOqHJpoOVTUgFxEAIQUeHBBtZ3kAb8uSf2OCv5BLd6IBY9JApkEXAqJ BoZp2P5pRvIep1DZZxct8NX4Mj2hwUtGgEA9sovjBpW99/rDOJlCmQwLLfZRcNC8tVWu 37zQ== X-Gm-Message-State: AOJu0Yw4j6WQ1XkHrtlvIfqE6mnX2g15H/QvDTWkz6Z/3eDJwtkVM1s7 77zJe420rrjv7vzeXS0xc8tY09dryvfeER+wv82zzQBC9nZan5Ndydm0N4cRWP/bYUrmGVO1ev1 OSRD0j2Tjrw== X-Gm-Gg: ATEYQzwsP+mFHJT+pdyIpyah5AkOubj3vbgvqE7VEK+T4jyL3aVzYzcMOBUVhKr1caU 4Bx0Wqxu+snOPvDWZzT4hAm3e6fXnPscnb4V7YOb+kDZYuZoTUhVVDLUjeE3LW6txZJJCC5hit6 8JVrAR/f4xRn7kmI0IpCQdaHTjzt7CLmmFgZjbdUB3J/NLdqrTPrviNbFgOhcUTDBWc3lnk1nu5 SmOtXYu78praALpYjpNIsGvUE53Aln/3d2OjImssjbBpUTO3UW0fPn742MEsAafC46VJ8lMGjBT FHg+FZJJydoWXjSwnD5TP8N7xW97xXxT7AzZc2EPefkiUIVJ0Ox2JajsXHFQwZMCM/tAPYd+GUk iOeSyztERmlqAnyDQQL39L4rz7wPEpcFYYHYPdEwkEfK/pwbpSwPq5RtT6k+efWWGAvdg72oToa 50WNC5S1+SQWNLXrKIiq6k/qq/bOW6Ldh5I81bZsf4m+jrGiJ1EheF X-Received: by 2002:a05:693c:2c17:b0:2ba:8aa8:9bd4 with SMTP id 5a478bee46e88-2bd7b9d54a1mr4046033eec.5.1771911872771; Mon, 23 Feb 2026 21:44:32 -0800 (PST) From: Richard Henderson To: qemu-devel@nongnu.org Cc: Max Chou , Chao Liu Subject: [PULL 1/9] fpu/softfloat: Refactor IEEE format NaN classification to share code Date: Tue, 24 Feb 2026 16:44:09 +1100 Message-ID: <20260224054417.32430-2-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::1341; envelope-from=richard.henderson@linaro.org; helo=mail-dy1-x1341.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: 1771911893785158500 Content-Type: text/plain; charset="utf-8" From: Max Chou The floatN_is_[quiet|signaling]_nan functions for following formats (float16, bfloat16, float32, float64, float128) contain duplicated logic that should be shared. This commit introduces [float16|bfloat16|float32|float64|float128]_nan_is_snan that determine if a NaN is signaling. Suggested-by: Richard Henderson Signed-off-by: Max Chou Reviewed-by: Richard Henderson Reviewed-by: Chao Liu Signed-off-by: Richard Henderson Message-ID: <20260204051756.667397-3-max.chou@sifive.com> --- fpu/softfloat-specialize.c.inc | 192 ++++++++++++++------------------- 1 file changed, 80 insertions(+), 112 deletions(-) diff --git a/fpu/softfloat-specialize.c.inc b/fpu/softfloat-specialize.c.inc index ba4fa08b7b..7d2515c1fa 100644 --- a/fpu/softfloat-specialize.c.inc +++ b/fpu/softfloat-specialize.c.inc @@ -226,6 +226,19 @@ floatx80 floatx80_default_inf(bool zSign, float_status= *status) return packFloatx80(zSign, 0x7fff, z ? 0 : (1ULL << 63)); } =20 +/*------------------------------------------------------------------------= ---- +| Determine if a float16 NaN is signaling NaN. +*-------------------------------------------------------------------------= ---*/ + +static bool float16_nan_is_snan(float16 a, float_status *status) +{ + if (no_signaling_nans(status)) { + return false; + } + bool frac_msb_is_one =3D (a >> 9) & 1; + return frac_msb_is_one =3D=3D snan_bit_is_one(status); +} + /*------------------------------------------------------------------------= ---- | Returns 1 if the half-precision floating-point value `a' is a quiet | NaN; otherwise returns 0. @@ -233,36 +246,7 @@ floatx80 floatx80_default_inf(bool zSign, float_status= *status) =20 bool float16_is_quiet_nan(float16 a_, float_status *status) { - if (no_signaling_nans(status)) { - return float16_is_any_nan(a_); - } else { - uint16_t a =3D float16_val(a_); - if (snan_bit_is_one(status)) { - return (((a >> 9) & 0x3F) =3D=3D 0x3E) && (a & 0x1FF); - } else { - - return ((a >> 9) & 0x3F) =3D=3D 0x3F; - } - } -} - -/*------------------------------------------------------------------------= ---- -| Returns 1 if the bfloat16 value `a' is a quiet -| NaN; otherwise returns 0. -*-------------------------------------------------------------------------= ---*/ - -bool bfloat16_is_quiet_nan(bfloat16 a_, float_status *status) -{ - if (no_signaling_nans(status)) { - return bfloat16_is_any_nan(a_); - } else { - uint16_t a =3D a_; - if (snan_bit_is_one(status)) { - return (((a >> 6) & 0x1FF) =3D=3D 0x1FE) && (a & 0x3F); - } else { - return ((a >> 6) & 0x1FF) =3D=3D 0x1FF; - } - } + return float16_is_any_nan(a_) && !float16_nan_is_snan(a_, status); } =20 /*------------------------------------------------------------------------= ---- @@ -272,35 +256,51 @@ bool bfloat16_is_quiet_nan(bfloat16 a_, float_status = *status) =20 bool float16_is_signaling_nan(float16 a_, float_status *status) { - if (no_signaling_nans(status)) { - return 0; - } else { - uint16_t a =3D float16_val(a_); - if (snan_bit_is_one(status)) { - return ((a >> 9) & 0x3F) =3D=3D 0x3F; - } else { - return (((a >> 9) & 0x3F) =3D=3D 0x3E) && (a & 0x1FF); - } - } + return float16_is_any_nan(a_) && float16_nan_is_snan(a_, status); } =20 /*------------------------------------------------------------------------= ---- -| Returns 1 if the bfloat16 value `a' is a signaling -| NaN; otherwise returns 0. +| Determine if a bfloat16 NaN is signaling NaN. +*-------------------------------------------------------------------------= ---*/ + +static bool bfloat16_nan_is_snan(bfloat16 a, float_status *status) +{ + if (no_signaling_nans(status)) { + return false; + } + bool frac_msb_is_one =3D (a >> 6) & 1; + return frac_msb_is_one =3D=3D snan_bit_is_one(status); +} + +/*------------------------------------------------------------------------= ---- +| Returns 1 if the bfloat16 value `a' is a quiet NaN; otherwise returns 0. +*-------------------------------------------------------------------------= ---*/ + +bool bfloat16_is_quiet_nan(bfloat16 a_, float_status *status) +{ + return bfloat16_is_any_nan(a_) && !bfloat16_nan_is_snan(a_, status); +} + +/*------------------------------------------------------------------------= ---- +| Returns 1 if the bfloat16 value `a' is a signaling NaN; otherwise return= s 0. *-------------------------------------------------------------------------= ---*/ =20 bool bfloat16_is_signaling_nan(bfloat16 a_, float_status *status) +{ + return bfloat16_is_any_nan(a_) && bfloat16_nan_is_snan(a_, status); +} + +/*------------------------------------------------------------------------= ---- +| Determine if a float32 NaN is signaling NaN. +*-------------------------------------------------------------------------= ---*/ + +static bool float32_nan_is_snan(float32 a, float_status *status) { if (no_signaling_nans(status)) { - return 0; - } else { - uint16_t a =3D a_; - if (snan_bit_is_one(status)) { - return ((a >> 6) & 0x1FF) =3D=3D 0x1FF; - } else { - return (((a >> 6) & 0x1FF) =3D=3D 0x1FE) && (a & 0x3F); - } + return false; } + bool frac_msb_is_one =3D (a >> 22) & 1; + return frac_msb_is_one =3D=3D snan_bit_is_one(status); } =20 /*------------------------------------------------------------------------= ---- @@ -310,16 +310,7 @@ bool bfloat16_is_signaling_nan(bfloat16 a_, float_stat= us *status) =20 bool float32_is_quiet_nan(float32 a_, float_status *status) { - if (no_signaling_nans(status)) { - return float32_is_any_nan(a_); - } else { - uint32_t a =3D float32_val(a_); - if (snan_bit_is_one(status)) { - return (((a >> 22) & 0x1FF) =3D=3D 0x1FE) && (a & 0x003FFFFF); - } else { - return ((uint32_t)(a << 1) >=3D 0xFF800000); - } - } + return float32_is_any_nan(a_) && !float32_nan_is_snan(a_, status); } =20 /*------------------------------------------------------------------------= ---- @@ -328,17 +319,21 @@ bool float32_is_quiet_nan(float32 a_, float_status *s= tatus) *-------------------------------------------------------------------------= ---*/ =20 bool float32_is_signaling_nan(float32 a_, float_status *status) +{ + return float32_is_any_nan(a_) && float32_nan_is_snan(a_, status); +} + +/*------------------------------------------------------------------------= ---- +| Determine if a float64 NaN is signaling NaN. +*-------------------------------------------------------------------------= ---*/ + +static bool float64_nan_is_snan(float64 a, float_status *status) { if (no_signaling_nans(status)) { - return 0; - } else { - uint32_t a =3D float32_val(a_); - if (snan_bit_is_one(status)) { - return ((uint32_t)(a << 1) >=3D 0xFF800000); - } else { - return (((a >> 22) & 0x1FF) =3D=3D 0x1FE) && (a & 0x003FFFFF); - } + return false; } + bool frac_msb_is_one =3D (a >> 51) & 1; + return frac_msb_is_one =3D=3D snan_bit_is_one(status); } =20 /*------------------------------------------------------------------------= ---- @@ -348,17 +343,7 @@ bool float32_is_signaling_nan(float32 a_, float_status= *status) =20 bool float64_is_quiet_nan(float64 a_, float_status *status) { - if (no_signaling_nans(status)) { - return float64_is_any_nan(a_); - } else { - uint64_t a =3D float64_val(a_); - if (snan_bit_is_one(status)) { - return (((a >> 51) & 0xFFF) =3D=3D 0xFFE) - && (a & 0x0007FFFFFFFFFFFFULL); - } else { - return ((a << 1) >=3D 0xFFF0000000000000ULL); - } - } + return float64_is_any_nan(a_) && !float64_nan_is_snan(a_, status); } =20 /*------------------------------------------------------------------------= ---- @@ -368,17 +353,7 @@ bool float64_is_quiet_nan(float64 a_, float_status *st= atus) =20 bool float64_is_signaling_nan(float64 a_, float_status *status) { - if (no_signaling_nans(status)) { - return 0; - } else { - uint64_t a =3D float64_val(a_); - if (snan_bit_is_one(status)) { - return ((a << 1) >=3D 0xFFF0000000000000ULL); - } else { - return (((a >> 51) & 0xFFF) =3D=3D 0xFFE) - && (a & UINT64_C(0x0007FFFFFFFFFFFF)); - } - } + return float64_is_any_nan(a_) && float64_nan_is_snan(a_, status); } =20 /*------------------------------------------------------------------------= ---- @@ -444,6 +419,19 @@ floatx80 floatx80_silence_nan(floatx80 a, float_status= *status) return a; } =20 +/*------------------------------------------------------------------------= ---- +| Determine if a float128 NaN is signaling NaN. +*-------------------------------------------------------------------------= ---*/ + +static bool float128_nan_is_snan(float128 a, float_status *status) +{ + if (no_signaling_nans(status)) { + return false; + } + bool frac_msb_is_one =3D (a.high >> 47) & 1; + return frac_msb_is_one =3D=3D snan_bit_is_one(status); +} + /*------------------------------------------------------------------------= ---- | Returns 1 if the quadruple-precision floating-point value `a' is a quiet | NaN; otherwise returns 0. @@ -451,17 +439,7 @@ floatx80 floatx80_silence_nan(floatx80 a, float_status= *status) =20 bool float128_is_quiet_nan(float128 a, float_status *status) { - if (no_signaling_nans(status)) { - return float128_is_any_nan(a); - } else { - if (snan_bit_is_one(status)) { - return (((a.high >> 47) & 0xFFFF) =3D=3D 0xFFFE) - && (a.low || (a.high & 0x00007FFFFFFFFFFFULL)); - } else { - return ((a.high << 1) >=3D 0xFFFF000000000000ULL) - && (a.low || (a.high & 0x0000FFFFFFFFFFFFULL)); - } - } + return float128_is_any_nan(a) && !float128_nan_is_snan(a, status); } =20 /*------------------------------------------------------------------------= ---- @@ -471,15 +449,5 @@ bool float128_is_quiet_nan(float128 a, float_status *s= tatus) =20 bool float128_is_signaling_nan(float128 a, float_status *status) { - if (no_signaling_nans(status)) { - return 0; - } else { - if (snan_bit_is_one(status)) { - return ((a.high << 1) >=3D 0xFFFF000000000000ULL) - && (a.low || (a.high & 0x0000FFFFFFFFFFFFULL)); - } else { - return (((a.high >> 47) & 0xFFFF) =3D=3D 0xFFFE) - && (a.low || (a.high & UINT64_C(0x00007FFFFFFFFFFF))); - } - } + return float128_is_any_nan(a) && float128_nan_is_snan(a, status); } --=20 2.43.0