From patchwork Mon Dec 11 12:56:59 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Alex_Benn=C3=A9e?= X-Patchwork-Id: 121399 Delivered-To: patch@linaro.org Received: by 10.140.22.227 with SMTP id 90csp2760440qgn; Mon, 11 Dec 2017 05:02:17 -0800 (PST) X-Google-Smtp-Source: ACJfBot2lzdeMRcLkTiq8vYZf+/dk41qQ/NJ1KGgtCURrI3mstMDHrtBd/65D5iIJg+jLYcsnO6u X-Received: by 10.37.81.6 with SMTP id f6mr202238ybb.62.1512997337233; Mon, 11 Dec 2017 05:02:17 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1512997337; cv=none; d=google.com; s=arc-20160816; b=VQHyBa1keBOWBPhpSoORj/stFKH5YLtWxE40jiUWR26Dh8o1cdoctKwL4dREVIlO9y 5O2swAYutlE7+eqHZtpZhzJKnzdzjS50M82TdJulUXJpIVGTIFenfz9uugFq0yOC9mVK oGDEFqZqhVpW0ob75C2EXuPPxeqZL3gQ7M2w3cGPJuPXrCpW/4mjCd3OJVWLCH93sPTI ZtUaS2N7blFlpXYkzV3/aI6MG6Eu3XJ9g/1eFDWuh2qLI+v+TXYYCEgDxNrqJZ8Qs+0x NsTrAJFGOWne9/L9smoj9a4A89wLRRdDHhwvsmDeI6ADbfgTDcfJQMOV3IAYwKoL7jlg Kc8Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:cc:list-subscribe:list-help:list-post:list-archive :list-unsubscribe:list-id:precedence:subject :content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:to:from:dkim-signature:arc-authentication-results; bh=5t1m3meS4KvstcFcWlNP1dTrxEuOocu5zOe+N5EdqD8=; b=aN3YlcihksGPFwF2wJIjyh8uJvhGfEyUJRnJxSZs8SuYxQP0qVBpys1ol4xqcYmkRs qAiNYJKNo3URKYfJNIBWcKAnJLelqKnuHEiOWMTUGsn7aIs7Dm8JTZByaB/SbRb2RVkX 9kHTSR+dNB+aJhljUWm4hZUL5fhCvhnCOvUbyEwQNAKg20wWRXSFnAhbGGYlmQV9mbJE +SmQL2Yu0RarqcMZkf7Y/MQG58+ttWHsjQI9gDUv2W+rxBye/08B/SI80j6sN4mgYx91 wXKxg2nJ/W/Q4I7QS/OyOR6IltrAZ/aXgxsHU/fHqujoXjfkmJYnMIjemKQntSuInBXS vfUg== ARC-Authentication-Results: i=1; mx.google.com; dkim=fail header.i=@linaro.org header.s=google header.b=S62GJzBs; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) smtp.mailfrom=qemu-devel-bounces+patch=linaro.org@nongnu.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linaro.org Return-Path: Received: from lists.gnu.org (lists.gnu.org. [2001:4830:134:3::11]) by mx.google.com with ESMTPS id k5si2850672ybm.46.2017.12.11.05.02.17 for (version=TLS1 cipher=AES128-SHA bits=128/128); Mon, 11 Dec 2017 05:02:17 -0800 (PST) Received-SPF: pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) client-ip=2001:4830:134:3::11; Authentication-Results: mx.google.com; dkim=fail header.i=@linaro.org header.s=google header.b=S62GJzBs; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) smtp.mailfrom=qemu-devel-bounces+patch=linaro.org@nongnu.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: from localhost ([::1]:52612 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eONiq-0006Rq-Mf for patch@linaro.org; Mon, 11 Dec 2017 08:02:16 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51690) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eONeA-0002VS-HG for qemu-devel@nongnu.org; Mon, 11 Dec 2017 07:57:29 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eONe6-0007n5-OF for qemu-devel@nongnu.org; Mon, 11 Dec 2017 07:57:26 -0500 Received: from mail-wr0-x22c.google.com ([2a00:1450:400c:c0c::22c]:41589) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1eONe6-0007lp-A9 for qemu-devel@nongnu.org; Mon, 11 Dec 2017 07:57:22 -0500 Received: by mail-wr0-x22c.google.com with SMTP id z18so17479254wrb.8 for ; Mon, 11 Dec 2017 04:57:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=5t1m3meS4KvstcFcWlNP1dTrxEuOocu5zOe+N5EdqD8=; b=S62GJzBsL7PNcMScQAT6uqfaziE0kmOYUC+kt5Xij5Z0ykURiKRJ6ClryL7bGyaEM0 ekkpSMs5+jH8ZzD21eoLKjR+TFZ8CvPZoPyLwjJ7F4e7RAWSOgJtQ2VJW3Es20gfXMhg xUfD/nN3E61TjpCBoiET297qh7ebIHHMCuzRo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=5t1m3meS4KvstcFcWlNP1dTrxEuOocu5zOe+N5EdqD8=; b=gQtehC/ZBEIlBDc92NyUNrCCRSuN7Ec8PJkv2vAKNIL+6dDTbOMlPBhLKEhdMQyILQ fodJ8mD1/w0hRXVFQdeRjlKtvjeJ5nb5KPGqOLKP8AxN98UwwZQnZMAeUeV0/xmJ1aRN h2ssF30Idr7dCbSNYPtffFfgtjxjFh4xRu67knG20ax/vLgeuuKVOtyXhh/XVoRIuqLQ 2eGhsEILXiifDTWY+xuNVUTbmYqMFGbg6GSI8o2aNZkHca2+FnSRvRFbQTH29s7ZlqlU X7fv54rv+x0h6PR2O895JAuqHWqFkPqEQdUeTu3Ds+qobx6x1NAQIy0QcIrCDisSIIqZ ddrw== X-Gm-Message-State: AKGB3mLQv+5nVbU2VeZluYYB9akEtm6tg5u2dH6xSqH61oR/yUs9Q2xT n8VO8/mL90rmhQIwiyhp9Jm93Q== X-Received: by 10.223.139.149 with SMTP id o21mr289568wra.87.1512997040539; Mon, 11 Dec 2017 04:57:20 -0800 (PST) Received: from zen.linaro.local ([81.128.185.34]) by smtp.gmail.com with ESMTPSA id w76sm19581562wrc.79.2017.12.11.04.57.11 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Dec 2017 04:57:13 -0800 (PST) Received: from zen.linaroharston (localhost [127.0.0.1]) by zen.linaro.local (Postfix) with ESMTP id 5B50D3E0C02; Mon, 11 Dec 2017 12:57:06 +0000 (GMT) From: =?utf-8?q?Alex_Benn=C3=A9e?= To: richard.henderson@linaro.org, peter.maydell@linaro.org, laurent@vivier.eu, bharata@linux.vnet.ibm.com, andrew@andrewdutcher.com, aleksandar.markovic@imgtec.com Date: Mon, 11 Dec 2017 12:56:59 +0000 Message-Id: <20171211125705.16120-14-alex.bennee@linaro.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20171211125705.16120-1-alex.bennee@linaro.org> References: <20171211125705.16120-1-alex.bennee@linaro.org> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2a00:1450:400c:c0c::22c Subject: [Qemu-devel] [PATCH v1 13/19] fpu/softfloat: re-factor muladd X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: =?utf-8?q?Alex_Benn=C3=A9e?= , qemu-devel@nongnu.org, Aurelien Jarno Errors-To: qemu-devel-bounces+patch=linaro.org@nongnu.org Sender: "Qemu-devel" We can now add float16_muladd and use the common decompose and canonicalize functions to have a single implementation for float16/32/64 muladd functions. Signed-off-by: Alex Bennée --- fpu/softfloat-specialize.h | 104 ------- fpu/softfloat.c | 756 +++++++++++++++++---------------------------- include/fpu/softfloat.h | 1 + 3 files changed, 286 insertions(+), 575 deletions(-) -- 2.15.1 Signed-off-by: Richard Henderson diff --git a/fpu/softfloat-specialize.h b/fpu/softfloat-specialize.h index 3d507d8c77..98fb0e7001 100644 --- a/fpu/softfloat-specialize.h +++ b/fpu/softfloat-specialize.h @@ -729,58 +729,6 @@ static float32 propagateFloat32NaN(float32 a, float32 b, float_status *status) } } -/*---------------------------------------------------------------------------- -| Takes three single-precision floating-point values `a', `b' and `c', one of -| which is a NaN, and returns the appropriate NaN result. If any of `a', -| `b' or `c' is a signaling NaN, the invalid exception is raised. -| The input infzero indicates whether a*b was 0*inf or inf*0 (in which case -| obviously c is a NaN, and whether to propagate c or some other NaN is -| implementation defined). -*----------------------------------------------------------------------------*/ - -static float32 propagateFloat32MulAddNaN(float32 a, float32 b, - float32 c, flag infzero, - float_status *status) -{ - flag aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN, - cIsQuietNaN, cIsSignalingNaN; - int which; - - aIsQuietNaN = float32_is_quiet_nan(a, status); - aIsSignalingNaN = float32_is_signaling_nan(a, status); - bIsQuietNaN = float32_is_quiet_nan(b, status); - bIsSignalingNaN = float32_is_signaling_nan(b, status); - cIsQuietNaN = float32_is_quiet_nan(c, status); - cIsSignalingNaN = float32_is_signaling_nan(c, status); - - if (aIsSignalingNaN | bIsSignalingNaN | cIsSignalingNaN) { - float_raise(float_flag_invalid, status); - } - - which = pickNaNMulAdd(aIsQuietNaN, aIsSignalingNaN, - bIsQuietNaN, bIsSignalingNaN, - cIsQuietNaN, cIsSignalingNaN, infzero, status); - - if (status->default_nan_mode) { - /* Note that this check is after pickNaNMulAdd so that function - * has an opportunity to set the Invalid flag. - */ - return float32_default_nan(status); - } - - switch (which) { - case 0: - return float32_maybe_silence_nan(a, status); - case 1: - return float32_maybe_silence_nan(b, status); - case 2: - return float32_maybe_silence_nan(c, status); - case 3: - default: - return float32_default_nan(status); - } -} - #ifdef NO_SIGNALING_NANS int float64_is_quiet_nan(float64 a_, float_status *status) { @@ -936,58 +884,6 @@ static float64 propagateFloat64NaN(float64 a, float64 b, float_status *status) } } -/*---------------------------------------------------------------------------- -| Takes three double-precision floating-point values `a', `b' and `c', one of -| which is a NaN, and returns the appropriate NaN result. If any of `a', -| `b' or `c' is a signaling NaN, the invalid exception is raised. -| The input infzero indicates whether a*b was 0*inf or inf*0 (in which case -| obviously c is a NaN, and whether to propagate c or some other NaN is -| implementation defined). -*----------------------------------------------------------------------------*/ - -static float64 propagateFloat64MulAddNaN(float64 a, float64 b, - float64 c, flag infzero, - float_status *status) -{ - flag aIsQuietNaN, aIsSignalingNaN, bIsQuietNaN, bIsSignalingNaN, - cIsQuietNaN, cIsSignalingNaN; - int which; - - aIsQuietNaN = float64_is_quiet_nan(a, status); - aIsSignalingNaN = float64_is_signaling_nan(a, status); - bIsQuietNaN = float64_is_quiet_nan(b, status); - bIsSignalingNaN = float64_is_signaling_nan(b, status); - cIsQuietNaN = float64_is_quiet_nan(c, status); - cIsSignalingNaN = float64_is_signaling_nan(c, status); - - if (aIsSignalingNaN | bIsSignalingNaN | cIsSignalingNaN) { - float_raise(float_flag_invalid, status); - } - - which = pickNaNMulAdd(aIsQuietNaN, aIsSignalingNaN, - bIsQuietNaN, bIsSignalingNaN, - cIsQuietNaN, cIsSignalingNaN, infzero, status); - - if (status->default_nan_mode) { - /* Note that this check is after pickNaNMulAdd so that function - * has an opportunity to set the Invalid flag. - */ - return float64_default_nan(status); - } - - switch (which) { - case 0: - return float64_maybe_silence_nan(a, status); - case 1: - return float64_maybe_silence_nan(b, status); - case 2: - return float64_maybe_silence_nan(c, status); - case 3: - default: - return float64_default_nan(status); - } -} - #ifdef NO_SIGNALING_NANS int floatx80_is_quiet_nan(floatx80 a_, float_status *status) { diff --git a/fpu/softfloat.c b/fpu/softfloat.c index 2b703c12ed..bf37f23f6a 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -561,6 +561,50 @@ static decomposed_parts pick_nan_parts(decomposed_parts a, decomposed_parts b, return a; } +static decomposed_parts pick_nan_muladd_parts(decomposed_parts a, + decomposed_parts b, + decomposed_parts c, + bool inf_zero, + float_status *s) +{ + if (a.cls == float_class_snan + || + b.cls == float_class_snan + || + c.cls == float_class_snan) { + s->float_exception_flags |= float_flag_invalid; + } + + if (s->default_nan_mode) { + a.cls = float_class_dnan; + } else { + switch (pickNaNMulAdd(a.cls == float_class_qnan, + a.cls == float_class_snan, + b.cls == float_class_qnan, + b.cls == float_class_snan, + c.cls == float_class_qnan, + c.cls == float_class_snan, + inf_zero, s)) { + case 0: + break; + case 1: + a = b; + break; + case 2: + a = c; + break; + case 3: + a.cls = float_class_dnan; + return a; + default: + g_assert_not_reached(); + } + + a.cls = float_class_msnan; + } + return a; +} + /* * Returns the result of adding the absolute values of the @@ -809,6 +853,247 @@ float64 float64_mul(float64 a, float64 b, float_status *status) return float64_round_pack_canonical(pr, status); } +/* + * Returns the result of multiplying the floating-point values `a' and + * `b' then adding 'c', with no intermediate rounding step after the + * multiplication. The operation is performed according to the + * IEC/IEEE Standard for Binary Floating-Point Arithmetic 754-2008. + * The flags argument allows the caller to select negation of the + * addend, the intermediate product, or the final result. (The + * difference between this and having the caller do a separate + * negation is that negating externally will flip the sign bit on + * NaNs.) + */ + +static decomposed_parts muladd_decomposed(decomposed_parts a, + decomposed_parts b, + decomposed_parts c, int flags, + float_status *s) +{ + bool inf_zero = ((1 << a.cls) | (1 << b.cls)) == + ((1 << float_class_inf) | (1 << float_class_zero)); + bool p_sign; + bool sign_flip = flags & float_muladd_negate_result; + float_class p_class; + uint64_t hi, lo; + int p_exp; + + /* It is implementation-defined whether the cases of (0,inf,qnan) + * and (inf,0,qnan) raise InvalidOperation or not (and what QNaN + * they return if they do), so we have to hand this information + * off to the target-specific pick-a-NaN routine. + */ + if (a.cls >= float_class_qnan || + b.cls >= float_class_qnan || + c.cls >= float_class_qnan) { + return pick_nan_muladd_parts(a, b, c, inf_zero, s); + } + + if (inf_zero) { + s->float_exception_flags |= float_flag_invalid; + a.cls = float_class_dnan; + return a; + } + + if (flags & float_muladd_negate_c) { + c.sign ^= 1; + } + + p_sign = a.sign ^ b.sign; + + if (flags & float_muladd_negate_product) { + p_sign ^= 1; + } + + if (a.cls == float_class_inf || b.cls == float_class_inf) { + p_class = float_class_inf; + } else if (a.cls == float_class_zero || b.cls == float_class_zero) { + p_class = float_class_zero; + } else { + p_class = float_class_normal; + } + + if (c.cls == float_class_inf) { + if (p_class == float_class_inf && p_sign != c.sign) { + s->float_exception_flags |= float_flag_invalid; + a.cls = float_class_dnan; + } else { + a.cls = float_class_inf; + a.sign = c.sign ^ sign_flip; + } + return a; + } + + if (p_class == float_class_inf) { + a.cls = float_class_inf; + a.sign = p_sign ^ sign_flip; + return a; + } + + if (p_class == float_class_zero) { + if (c.cls == float_class_zero) { + if (p_sign != c.sign) { + p_sign = s->float_rounding_mode == float_round_down; + } + c.sign = p_sign; + } else if (flags & float_muladd_halve_result) { + c.exp -= 1; + } + c.sign ^= sign_flip; + return c; + } + + /* a & b should be normals now... */ + assert(a.cls == float_class_normal && + b.cls == float_class_normal); + + p_exp = a.exp + b.exp; + + /* Multiply of 2 62-bit numbers produces a (2*62) == 124-bit + * result. + */ + mul64To128(a.frac, b.frac, &hi, &lo); + /* binary point now at bit 124 */ + + /* check for overflow */ + if (hi & (1ULL << (DECOMPOSED_BINARY_POINT * 2 + 1 - 64))) { + shift128RightJamming(hi, lo, 1, &hi, &lo); + p_exp += 1; + } + + /* + add/sub */ + if (c.cls == float_class_zero) { + /* move binary point back to 62 */ + shift128RightJamming(hi, lo, DECOMPOSED_BINARY_POINT, &hi, &lo); + } else { + int exp_diff = p_exp - c.exp; + if (p_sign == c.sign) { + /* Addition */ + if (exp_diff <= 0) { + shift128RightJamming(hi, lo, + DECOMPOSED_BINARY_POINT - exp_diff, + &hi, &lo); + lo += c.frac; + p_exp = c.exp; + } else { + uint64_t c_hi, c_lo; + /* shift c to the same binary point as the product (124) */ + c_hi = c.frac >> 2; + c_lo = 0; + shift128RightJamming(c_hi, c_lo, + exp_diff, + &c_hi, &c_lo); + add128(hi, lo, c_hi, c_lo, &hi, &lo); + /* move binary point back to 62 */ + shift128RightJamming(hi, lo, DECOMPOSED_BINARY_POINT, &hi, &lo); + } + + if (lo & DECOMPOSED_OVERFLOW_BIT) { + shift64RightJamming(lo, 1, &lo); + p_exp += 1; + } + + } else { + /* Subtraction */ + uint64_t c_hi, c_lo; + /* make C binary point match product at bit 124 */ + c_hi = c.frac >> 2; + c_lo = 0; + + if (exp_diff <= 0) { + shift128RightJamming(hi, lo, -exp_diff, &hi, &lo); + if (exp_diff == 0 + && + (hi > c_hi || (hi == c_hi && lo >= c_lo))) { + sub128(hi, lo, c_hi, c_lo, &hi, &lo); + } else { + sub128(c_hi, c_lo, hi, lo, &hi, &lo); + p_sign ^= 1; + p_exp = c.exp; + } + } else { + shift128RightJamming(c_hi, c_lo, + exp_diff, + &c_hi, &c_lo); + sub128(hi, lo, c_hi, c_lo, &hi, &lo); + } + + if (hi == 0 && lo == 0) { + a.cls = float_class_zero; + a.sign = s->float_rounding_mode == float_round_down; + a.sign ^= sign_flip; + return a; + } else { + int shift; + if (hi != 0) { + shift = clz64(hi); + } else { + shift = clz64(lo) + 64; + } + /* Normalizing to a binary point of 124 is the + correct adjust for the exponent. However since we're + shifting, we might as well put the binary point back + at 62 where we really want it. Therefore shift as + if we're leaving 1 bit at the top of the word, but + adjust the exponent as if we're leaving 3 bits. */ + shift -= 1; + if (shift >= 64) { + lo = lo << (shift - 64); + } else { + hi = (hi << shift) | (lo >> (64 - shift)); + lo = hi | ((lo << shift) != 0); + } + p_exp -= shift - 2; + } + } + } + + if (flags & float_muladd_halve_result) { + p_exp -= 1; + } + + /* finally prepare our result */ + a.cls = float_class_normal; + a.sign = p_sign ^ sign_flip; + a.exp = p_exp; + a.frac = lo; + + return a; +} + +float16 float16_muladd(float16 a, float16 b, float16 c, int flags, + float_status *status) +{ + decomposed_parts pa = float16_unpack_canonical(a, status); + decomposed_parts pb = float16_unpack_canonical(b, status); + decomposed_parts pc = float16_unpack_canonical(c, status); + decomposed_parts pr = muladd_decomposed(pa, pb, pc, flags, status); + + return float16_round_pack_canonical(pr, status); +} + +float32 float32_muladd(float32 a, float32 b, float32 c, int flags, + float_status *status) +{ + decomposed_parts pa = float32_unpack_canonical(a, status); + decomposed_parts pb = float32_unpack_canonical(b, status); + decomposed_parts pc = float32_unpack_canonical(c, status); + decomposed_parts pr = muladd_decomposed(pa, pb, pc, flags, status); + + return float32_round_pack_canonical(pr, status); +} + +float64 float64_muladd(float64 a, float64 b, float64 c, int flags, + float_status *status) +{ + decomposed_parts pa = float64_unpack_canonical(a, status); + decomposed_parts pb = float64_unpack_canonical(b, status); + decomposed_parts pc = float64_unpack_canonical(c, status); + decomposed_parts pr = muladd_decomposed(pa, pb, pc, flags, status); + + return float64_round_pack_canonical(pr, status); +} + /* * Returns the result of dividing the floating-point value `a' by the * corresponding value `b'. The operation is performed according to @@ -2814,231 +3099,6 @@ float32 float32_rem(float32 a, float32 b, float_status *status) return normalizeRoundAndPackFloat32(aSign ^ zSign, bExp, aSig, status); } -/*---------------------------------------------------------------------------- -| Returns the result of multiplying the single-precision floating-point values -| `a' and `b' then adding 'c', with no intermediate rounding step after the -| multiplication. The operation is performed according to the IEC/IEEE -| Standard for Binary Floating-Point Arithmetic 754-2008. -| The flags argument allows the caller to select negation of the -| addend, the intermediate product, or the final result. (The difference -| between this and having the caller do a separate negation is that negating -| externally will flip the sign bit on NaNs.) -*----------------------------------------------------------------------------*/ - -float32 float32_muladd(float32 a, float32 b, float32 c, int flags, - float_status *status) -{ - flag aSign, bSign, cSign, zSign; - int aExp, bExp, cExp, pExp, zExp, expDiff; - uint32_t aSig, bSig, cSig; - flag pInf, pZero, pSign; - uint64_t pSig64, cSig64, zSig64; - uint32_t pSig; - int shiftcount; - flag signflip, infzero; - - a = float32_squash_input_denormal(a, status); - b = float32_squash_input_denormal(b, status); - c = float32_squash_input_denormal(c, status); - aSig = extractFloat32Frac(a); - aExp = extractFloat32Exp(a); - aSign = extractFloat32Sign(a); - bSig = extractFloat32Frac(b); - bExp = extractFloat32Exp(b); - bSign = extractFloat32Sign(b); - cSig = extractFloat32Frac(c); - cExp = extractFloat32Exp(c); - cSign = extractFloat32Sign(c); - - infzero = ((aExp == 0 && aSig == 0 && bExp == 0xff && bSig == 0) || - (aExp == 0xff && aSig == 0 && bExp == 0 && bSig == 0)); - - /* It is implementation-defined whether the cases of (0,inf,qnan) - * and (inf,0,qnan) raise InvalidOperation or not (and what QNaN - * they return if they do), so we have to hand this information - * off to the target-specific pick-a-NaN routine. - */ - if (((aExp == 0xff) && aSig) || - ((bExp == 0xff) && bSig) || - ((cExp == 0xff) && cSig)) { - return propagateFloat32MulAddNaN(a, b, c, infzero, status); - } - - if (infzero) { - float_raise(float_flag_invalid, status); - return float32_default_nan(status); - } - - if (flags & float_muladd_negate_c) { - cSign ^= 1; - } - - signflip = (flags & float_muladd_negate_result) ? 1 : 0; - - /* Work out the sign and type of the product */ - pSign = aSign ^ bSign; - if (flags & float_muladd_negate_product) { - pSign ^= 1; - } - pInf = (aExp == 0xff) || (bExp == 0xff); - pZero = ((aExp | aSig) == 0) || ((bExp | bSig) == 0); - - if (cExp == 0xff) { - if (pInf && (pSign ^ cSign)) { - /* addition of opposite-signed infinities => InvalidOperation */ - float_raise(float_flag_invalid, status); - return float32_default_nan(status); - } - /* Otherwise generate an infinity of the same sign */ - return packFloat32(cSign ^ signflip, 0xff, 0); - } - - if (pInf) { - return packFloat32(pSign ^ signflip, 0xff, 0); - } - - if (pZero) { - if (cExp == 0) { - if (cSig == 0) { - /* Adding two exact zeroes */ - if (pSign == cSign) { - zSign = pSign; - } else if (status->float_rounding_mode == float_round_down) { - zSign = 1; - } else { - zSign = 0; - } - return packFloat32(zSign ^ signflip, 0, 0); - } - /* Exact zero plus a denorm */ - if (status->flush_to_zero) { - float_raise(float_flag_output_denormal, status); - return packFloat32(cSign ^ signflip, 0, 0); - } - } - /* Zero plus something non-zero : just return the something */ - if (flags & float_muladd_halve_result) { - if (cExp == 0) { - normalizeFloat32Subnormal(cSig, &cExp, &cSig); - } - /* Subtract one to halve, and one again because roundAndPackFloat32 - * wants one less than the true exponent. - */ - cExp -= 2; - cSig = (cSig | 0x00800000) << 7; - return roundAndPackFloat32(cSign ^ signflip, cExp, cSig, status); - } - return packFloat32(cSign ^ signflip, cExp, cSig); - } - - if (aExp == 0) { - normalizeFloat32Subnormal(aSig, &aExp, &aSig); - } - if (bExp == 0) { - normalizeFloat32Subnormal(bSig, &bExp, &bSig); - } - - /* Calculate the actual result a * b + c */ - - /* Multiply first; this is easy. */ - /* NB: we subtract 0x7e where float32_mul() subtracts 0x7f - * because we want the true exponent, not the "one-less-than" - * flavour that roundAndPackFloat32() takes. - */ - pExp = aExp + bExp - 0x7e; - aSig = (aSig | 0x00800000) << 7; - bSig = (bSig | 0x00800000) << 8; - pSig64 = (uint64_t)aSig * bSig; - if ((int64_t)(pSig64 << 1) >= 0) { - pSig64 <<= 1; - pExp--; - } - - zSign = pSign ^ signflip; - - /* Now pSig64 is the significand of the multiply, with the explicit bit in - * position 62. - */ - if (cExp == 0) { - if (!cSig) { - /* Throw out the special case of c being an exact zero now */ - shift64RightJamming(pSig64, 32, &pSig64); - pSig = pSig64; - if (flags & float_muladd_halve_result) { - pExp--; - } - return roundAndPackFloat32(zSign, pExp - 1, - pSig, status); - } - normalizeFloat32Subnormal(cSig, &cExp, &cSig); - } - - cSig64 = (uint64_t)cSig << (62 - 23); - cSig64 |= LIT64(0x4000000000000000); - expDiff = pExp - cExp; - - if (pSign == cSign) { - /* Addition */ - if (expDiff > 0) { - /* scale c to match p */ - shift64RightJamming(cSig64, expDiff, &cSig64); - zExp = pExp; - } else if (expDiff < 0) { - /* scale p to match c */ - shift64RightJamming(pSig64, -expDiff, &pSig64); - zExp = cExp; - } else { - /* no scaling needed */ - zExp = cExp; - } - /* Add significands and make sure explicit bit ends up in posn 62 */ - zSig64 = pSig64 + cSig64; - if ((int64_t)zSig64 < 0) { - shift64RightJamming(zSig64, 1, &zSig64); - } else { - zExp--; - } - } else { - /* Subtraction */ - if (expDiff > 0) { - shift64RightJamming(cSig64, expDiff, &cSig64); - zSig64 = pSig64 - cSig64; - zExp = pExp; - } else if (expDiff < 0) { - shift64RightJamming(pSig64, -expDiff, &pSig64); - zSig64 = cSig64 - pSig64; - zExp = cExp; - zSign ^= 1; - } else { - zExp = pExp; - if (cSig64 < pSig64) { - zSig64 = pSig64 - cSig64; - } else if (pSig64 < cSig64) { - zSig64 = cSig64 - pSig64; - zSign ^= 1; - } else { - /* Exact zero */ - zSign = signflip; - if (status->float_rounding_mode == float_round_down) { - zSign ^= 1; - } - return packFloat32(zSign, 0, 0); - } - } - --zExp; - /* Normalize to put the explicit bit back into bit 62. */ - shiftcount = countLeadingZeros64(zSig64) - 1; - zSig64 <<= shiftcount; - zExp -= shiftcount; - } - if (flags & float_muladd_halve_result) { - zExp--; - } - - shift64RightJamming(zSig64, 32, &zSig64); - return roundAndPackFloat32(zSign, zExp, zSig64, status); -} - /*---------------------------------------------------------------------------- | Returns the square root of the single-precision floating-point value `a'. @@ -4262,252 +4322,6 @@ float64 float64_rem(float64 a, float64 b, float_status *status) } -/*---------------------------------------------------------------------------- -| Returns the result of multiplying the double-precision floating-point values -| `a' and `b' then adding 'c', with no intermediate rounding step after the -| multiplication. The operation is performed according to the IEC/IEEE -| Standard for Binary Floating-Point Arithmetic 754-2008. -| The flags argument allows the caller to select negation of the -| addend, the intermediate product, or the final result. (The difference -| between this and having the caller do a separate negation is that negating -| externally will flip the sign bit on NaNs.) -*----------------------------------------------------------------------------*/ - -float64 float64_muladd(float64 a, float64 b, float64 c, int flags, - float_status *status) -{ - flag aSign, bSign, cSign, zSign; - int aExp, bExp, cExp, pExp, zExp, expDiff; - uint64_t aSig, bSig, cSig; - flag pInf, pZero, pSign; - uint64_t pSig0, pSig1, cSig0, cSig1, zSig0, zSig1; - int shiftcount; - flag signflip, infzero; - - a = float64_squash_input_denormal(a, status); - b = float64_squash_input_denormal(b, status); - c = float64_squash_input_denormal(c, status); - aSig = extractFloat64Frac(a); - aExp = extractFloat64Exp(a); - aSign = extractFloat64Sign(a); - bSig = extractFloat64Frac(b); - bExp = extractFloat64Exp(b); - bSign = extractFloat64Sign(b); - cSig = extractFloat64Frac(c); - cExp = extractFloat64Exp(c); - cSign = extractFloat64Sign(c); - - infzero = ((aExp == 0 && aSig == 0 && bExp == 0x7ff && bSig == 0) || - (aExp == 0x7ff && aSig == 0 && bExp == 0 && bSig == 0)); - - /* It is implementation-defined whether the cases of (0,inf,qnan) - * and (inf,0,qnan) raise InvalidOperation or not (and what QNaN - * they return if they do), so we have to hand this information - * off to the target-specific pick-a-NaN routine. - */ - if (((aExp == 0x7ff) && aSig) || - ((bExp == 0x7ff) && bSig) || - ((cExp == 0x7ff) && cSig)) { - return propagateFloat64MulAddNaN(a, b, c, infzero, status); - } - - if (infzero) { - float_raise(float_flag_invalid, status); - return float64_default_nan(status); - } - - if (flags & float_muladd_negate_c) { - cSign ^= 1; - } - - signflip = (flags & float_muladd_negate_result) ? 1 : 0; - - /* Work out the sign and type of the product */ - pSign = aSign ^ bSign; - if (flags & float_muladd_negate_product) { - pSign ^= 1; - } - pInf = (aExp == 0x7ff) || (bExp == 0x7ff); - pZero = ((aExp | aSig) == 0) || ((bExp | bSig) == 0); - - if (cExp == 0x7ff) { - if (pInf && (pSign ^ cSign)) { - /* addition of opposite-signed infinities => InvalidOperation */ - float_raise(float_flag_invalid, status); - return float64_default_nan(status); - } - /* Otherwise generate an infinity of the same sign */ - return packFloat64(cSign ^ signflip, 0x7ff, 0); - } - - if (pInf) { - return packFloat64(pSign ^ signflip, 0x7ff, 0); - } - - if (pZero) { - if (cExp == 0) { - if (cSig == 0) { - /* Adding two exact zeroes */ - if (pSign == cSign) { - zSign = pSign; - } else if (status->float_rounding_mode == float_round_down) { - zSign = 1; - } else { - zSign = 0; - } - return packFloat64(zSign ^ signflip, 0, 0); - } - /* Exact zero plus a denorm */ - if (status->flush_to_zero) { - float_raise(float_flag_output_denormal, status); - return packFloat64(cSign ^ signflip, 0, 0); - } - } - /* Zero plus something non-zero : just return the something */ - if (flags & float_muladd_halve_result) { - if (cExp == 0) { - normalizeFloat64Subnormal(cSig, &cExp, &cSig); - } - /* Subtract one to halve, and one again because roundAndPackFloat64 - * wants one less than the true exponent. - */ - cExp -= 2; - cSig = (cSig | 0x0010000000000000ULL) << 10; - return roundAndPackFloat64(cSign ^ signflip, cExp, cSig, status); - } - return packFloat64(cSign ^ signflip, cExp, cSig); - } - - if (aExp == 0) { - normalizeFloat64Subnormal(aSig, &aExp, &aSig); - } - if (bExp == 0) { - normalizeFloat64Subnormal(bSig, &bExp, &bSig); - } - - /* Calculate the actual result a * b + c */ - - /* Multiply first; this is easy. */ - /* NB: we subtract 0x3fe where float64_mul() subtracts 0x3ff - * because we want the true exponent, not the "one-less-than" - * flavour that roundAndPackFloat64() takes. - */ - pExp = aExp + bExp - 0x3fe; - aSig = (aSig | LIT64(0x0010000000000000))<<10; - bSig = (bSig | LIT64(0x0010000000000000))<<11; - mul64To128(aSig, bSig, &pSig0, &pSig1); - if ((int64_t)(pSig0 << 1) >= 0) { - shortShift128Left(pSig0, pSig1, 1, &pSig0, &pSig1); - pExp--; - } - - zSign = pSign ^ signflip; - - /* Now [pSig0:pSig1] is the significand of the multiply, with the explicit - * bit in position 126. - */ - if (cExp == 0) { - if (!cSig) { - /* Throw out the special case of c being an exact zero now */ - shift128RightJamming(pSig0, pSig1, 64, &pSig0, &pSig1); - if (flags & float_muladd_halve_result) { - pExp--; - } - return roundAndPackFloat64(zSign, pExp - 1, - pSig1, status); - } - normalizeFloat64Subnormal(cSig, &cExp, &cSig); - } - - /* Shift cSig and add the explicit bit so [cSig0:cSig1] is the - * significand of the addend, with the explicit bit in position 126. - */ - cSig0 = cSig << (126 - 64 - 52); - cSig1 = 0; - cSig0 |= LIT64(0x4000000000000000); - expDiff = pExp - cExp; - - if (pSign == cSign) { - /* Addition */ - if (expDiff > 0) { - /* scale c to match p */ - shift128RightJamming(cSig0, cSig1, expDiff, &cSig0, &cSig1); - zExp = pExp; - } else if (expDiff < 0) { - /* scale p to match c */ - shift128RightJamming(pSig0, pSig1, -expDiff, &pSig0, &pSig1); - zExp = cExp; - } else { - /* no scaling needed */ - zExp = cExp; - } - /* Add significands and make sure explicit bit ends up in posn 126 */ - add128(pSig0, pSig1, cSig0, cSig1, &zSig0, &zSig1); - if ((int64_t)zSig0 < 0) { - shift128RightJamming(zSig0, zSig1, 1, &zSig0, &zSig1); - } else { - zExp--; - } - shift128RightJamming(zSig0, zSig1, 64, &zSig0, &zSig1); - if (flags & float_muladd_halve_result) { - zExp--; - } - return roundAndPackFloat64(zSign, zExp, zSig1, status); - } else { - /* Subtraction */ - if (expDiff > 0) { - shift128RightJamming(cSig0, cSig1, expDiff, &cSig0, &cSig1); - sub128(pSig0, pSig1, cSig0, cSig1, &zSig0, &zSig1); - zExp = pExp; - } else if (expDiff < 0) { - shift128RightJamming(pSig0, pSig1, -expDiff, &pSig0, &pSig1); - sub128(cSig0, cSig1, pSig0, pSig1, &zSig0, &zSig1); - zExp = cExp; - zSign ^= 1; - } else { - zExp = pExp; - if (lt128(cSig0, cSig1, pSig0, pSig1)) { - sub128(pSig0, pSig1, cSig0, cSig1, &zSig0, &zSig1); - } else if (lt128(pSig0, pSig1, cSig0, cSig1)) { - sub128(cSig0, cSig1, pSig0, pSig1, &zSig0, &zSig1); - zSign ^= 1; - } else { - /* Exact zero */ - zSign = signflip; - if (status->float_rounding_mode == float_round_down) { - zSign ^= 1; - } - return packFloat64(zSign, 0, 0); - } - } - --zExp; - /* Do the equivalent of normalizeRoundAndPackFloat64() but - * starting with the significand in a pair of uint64_t. - */ - if (zSig0) { - shiftcount = countLeadingZeros64(zSig0) - 1; - shortShift128Left(zSig0, zSig1, shiftcount, &zSig0, &zSig1); - if (zSig1) { - zSig0 |= 1; - } - zExp -= shiftcount; - } else { - shiftcount = countLeadingZeros64(zSig1); - if (shiftcount == 0) { - zSig0 = (zSig1 >> 1) | (zSig1 & 1); - zExp -= 63; - } else { - shiftcount--; - zSig0 = zSig1 << shiftcount; - zExp -= (shiftcount + 64); - } - } - if (flags & float_muladd_halve_result) { - zExp--; - } - return roundAndPackFloat64(zSign, zExp, zSig0, status); - } -} /*---------------------------------------------------------------------------- | Returns the square root of the double-precision floating-point value `a'. diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h index d2b8d29f22..102cf4b1e1 100644 --- a/include/fpu/softfloat.h +++ b/include/fpu/softfloat.h @@ -349,6 +349,7 @@ float64 float16_to_float64(float16 a, flag ieee, float_status *status); float16 float16_add(float16, float16, float_status *status); float16 float16_sub(float16, float16, float_status *status); float16 float16_mul(float16, float16, float_status *status); +float16 float16_muladd(float16, float16, float16, int, float_status *status); float16 float16_div(float16, float16, float_status *status); int float16_is_quiet_nan(float16, float_status *status);