| /* |
| * QEMU float support |
| * |
| * The code in this source file is derived from release 2a of the SoftFloat |
| * IEC/IEEE Floating-point Arithmetic Package. Those parts of the code (and |
| * some later contributions) are provided under that license, as detailed below. |
| * It has subsequently been modified by contributors to the QEMU Project, |
| * so some portions are provided under: |
| * the SoftFloat-2a license |
| * the BSD license |
| * GPL-v2-or-later |
| * |
| * Any future contributions to this file after December 1st 2014 will be |
| * taken to be licensed under the Softfloat-2a license unless specifically |
| * indicated otherwise. |
| */ |
| |
| /* |
| =============================================================================== |
| This C source fragment is part of the SoftFloat IEC/IEEE Floating-point |
| Arithmetic Package, Release 2a. |
| |
| Written by John R. Hauser. This work was made possible in part by the |
| International Computer Science Institute, located at Suite 600, 1947 Center |
| Street, Berkeley, California 94704. Funding was partially provided by the |
| National Science Foundation under grant MIP-9311980. The original version |
| of this code was written as part of a project to build a fixed-point vector |
| processor in collaboration with the University of California at Berkeley, |
| overseen by Profs. Nelson Morgan and John Wawrzynek. More information |
| is available through the Web page `http://HTTP.CS.Berkeley.EDU/~jhauser/ |
| arithmetic/SoftFloat.html'. |
| |
| THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE. Although reasonable effort |
| has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT |
| TIMES RESULT IN INCORRECT BEHAVIOR. USE OF THIS SOFTWARE IS RESTRICTED TO |
| PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY |
| AND ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE. |
| |
| Derivative works are acceptable, even for commercial purposes, so long as |
| (1) they include prominent notice that the work is derivative, and (2) they |
| include prominent notice akin to these four paragraphs for those parts of |
| this code that are retained. |
| |
| =============================================================================== |
| */ |
| |
| /* BSD licensing: |
| * Copyright (c) 2006, Fabrice Bellard |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright notice, |
| * this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright notice, |
| * this list of conditions and the following disclaimer in the documentation |
| * and/or other materials provided with the distribution. |
| * |
| * 3. Neither the name of the copyright holder nor the names of its contributors |
| * may be used to endorse or promote products derived from this software without |
| * specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE |
| * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF |
| * THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /* Portions of this work are licensed under the terms of the GNU GPL, |
| * version 2 or later. See the COPYING file in the top-level directory. |
| */ |
| |
| /* |
| * Define whether architecture deviates from IEEE in not supporting |
| * signaling NaNs (so all NaNs are treated as quiet). |
| */ |
| static inline bool no_signaling_nans(float_status *status) |
| { |
| #if defined(TARGET_XTENSA) |
| return status->no_signaling_nans; |
| #else |
| return false; |
| #endif |
| } |
| |
| /* Define how the architecture discriminates signaling NaNs. |
| * This done with the most significant bit of the fraction. |
| * In IEEE 754-1985 this was implementation defined, but in IEEE 754-2008 |
| * the msb must be zero. MIPS is (so far) unique in supporting both the |
| * 2008 revision and backward compatibility with their original choice. |
| * Thus for MIPS we must make the choice at runtime. |
| */ |
| static inline bool snan_bit_is_one(float_status *status) |
| { |
| #if defined(TARGET_MIPS) |
| return status->snan_bit_is_one; |
| #elif defined(TARGET_HPPA) || defined(TARGET_SH4) |
| return 1; |
| #else |
| return 0; |
| #endif |
| } |
| |
| /*---------------------------------------------------------------------------- |
| | For the deconstructed floating-point with fraction FRAC, return true |
| | if the fraction represents a signalling NaN; otherwise false. |
| *----------------------------------------------------------------------------*/ |
| |
| static bool parts_is_snan_frac(uint64_t frac, float_status *status) |
| { |
| if (no_signaling_nans(status)) { |
| return false; |
| } else { |
| bool msb = extract64(frac, DECOMPOSED_BINARY_POINT - 1, 1); |
| return msb == snan_bit_is_one(status); |
| } |
| } |
| |
| /*---------------------------------------------------------------------------- |
| | The pattern for a default generated deconstructed floating-point NaN. |
| *----------------------------------------------------------------------------*/ |
| |
| static void parts64_default_nan(FloatParts64 *p, float_status *status) |
| { |
| bool sign = 0; |
| uint64_t frac; |
| |
| #if defined(TARGET_SPARC) || defined(TARGET_M68K) |
| /* !snan_bit_is_one, set all bits */ |
| frac = (1ULL << DECOMPOSED_BINARY_POINT) - 1; |
| #elif defined(TARGET_I386) || defined(TARGET_X86_64) \ |
| || defined(TARGET_MICROBLAZE) |
| /* !snan_bit_is_one, set sign and msb */ |
| frac = 1ULL << (DECOMPOSED_BINARY_POINT - 1); |
| sign = 1; |
| #elif defined(TARGET_HPPA) |
| /* snan_bit_is_one, set msb-1. */ |
| frac = 1ULL << (DECOMPOSED_BINARY_POINT - 2); |
| #elif defined(TARGET_HEXAGON) |
| sign = 1; |
| frac = ~0ULL; |
| #else |
| /* |
| * This case is true for Alpha, ARM, MIPS, OpenRISC, PPC, RISC-V, |
| * S390, SH4, TriCore, and Xtensa. Our other supported targets, |
| * such CRIS, do not have floating-point. |
| */ |
| if (snan_bit_is_one(status)) { |
| /* set all bits other than msb */ |
| frac = (1ULL << (DECOMPOSED_BINARY_POINT - 1)) - 1; |
| } else { |
| /* set msb */ |
| frac = 1ULL << (DECOMPOSED_BINARY_POINT - 1); |
| } |
| #endif |
| |
| *p = (FloatParts64) { |
| .cls = float_class_qnan, |
| .sign = sign, |
| .exp = INT_MAX, |
| .frac = frac |
| }; |
| } |
| |
| static void parts128_default_nan(FloatParts128 *p, float_status *status) |
| { |
| /* |
| * Extrapolate from the choices made by parts64_default_nan to fill |
| * in the quad-floating format. If the low bit is set, assume we |
| * want to set all non-snan bits. |
| */ |
| FloatParts64 p64; |
| parts64_default_nan(&p64, status); |
| |
| *p = (FloatParts128) { |
| .cls = float_class_qnan, |
| .sign = p64.sign, |
| .exp = INT_MAX, |
| .frac_hi = p64.frac, |
| .frac_lo = -(p64.frac & 1) |
| }; |
| } |
| |
| /*---------------------------------------------------------------------------- |
| | Returns a quiet NaN from a signalling NaN for the deconstructed |
| | floating-point parts. |
| *----------------------------------------------------------------------------*/ |
| |
| static uint64_t parts_silence_nan_frac(uint64_t frac, float_status *status) |
| { |
| g_assert(!no_signaling_nans(status)); |
| |
| /* The only snan_bit_is_one target without default_nan_mode is HPPA. */ |
| if (snan_bit_is_one(status)) { |
| frac &= ~(1ULL << (DECOMPOSED_BINARY_POINT - 1)); |
| frac |= 1ULL << (DECOMPOSED_BINARY_POINT - 2); |
| } else { |
| frac |= 1ULL << (DECOMPOSED_BINARY_POINT - 1); |
| } |
| return frac; |
| } |
| |
| static void parts64_silence_nan(FloatParts64 *p, float_status *status) |
| { |
| p->frac = parts_silence_nan_frac(p->frac, status); |
| p->cls = float_class_qnan; |
| } |
| |
| static void parts128_silence_nan(FloatParts128 *p, float_status *status) |
| { |
| p->frac_hi = parts_silence_nan_frac(p->frac_hi, status); |
| p->cls = float_class_qnan; |
| } |
| |
| /*---------------------------------------------------------------------------- |
| | The pattern for a default generated extended double-precision NaN. |
| *----------------------------------------------------------------------------*/ |
| floatx80 floatx80_default_nan(float_status *status) |
| { |
| floatx80 r; |
| |
| /* None of the targets that have snan_bit_is_one use floatx80. */ |
| assert(!snan_bit_is_one(status)); |
| #if defined(TARGET_M68K) |
| r.low = UINT64_C(0xFFFFFFFFFFFFFFFF); |
| r.high = 0x7FFF; |
| #else |
| /* X86 */ |
| r.low = UINT64_C(0xC000000000000000); |
| r.high = 0xFFFF; |
| #endif |
| return r; |
| } |
| |
| /*---------------------------------------------------------------------------- |
| | The pattern for a default generated extended double-precision inf. |
| *----------------------------------------------------------------------------*/ |
| |
| #define floatx80_infinity_high 0x7FFF |
| #if defined(TARGET_M68K) |
| #define floatx80_infinity_low UINT64_C(0x0000000000000000) |
| #else |
| #define floatx80_infinity_low UINT64_C(0x8000000000000000) |
| #endif |
| |
| const floatx80 floatx80_infinity |
| = make_floatx80_init(floatx80_infinity_high, floatx80_infinity_low); |
| |
| /*---------------------------------------------------------------------------- |
| | Returns 1 if the half-precision floating-point value `a' is a quiet |
| | NaN; otherwise returns 0. |
| *----------------------------------------------------------------------------*/ |
| |
| 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 = float16_val(a_); |
| if (snan_bit_is_one(status)) { |
| return (((a >> 9) & 0x3F) == 0x3E) && (a & 0x1FF); |
| } else { |
| |
| return ((a >> 9) & 0x3F) == 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 = a_; |
| if (snan_bit_is_one(status)) { |
| return (((a >> 6) & 0x1FF) == 0x1FE) && (a & 0x3F); |
| } else { |
| return ((a >> 6) & 0x1FF) == 0x1FF; |
| } |
| } |
| } |
| |
| /*---------------------------------------------------------------------------- |
| | Returns 1 if the half-precision floating-point value `a' is a signaling |
| | NaN; otherwise returns 0. |
| *----------------------------------------------------------------------------*/ |
| |
| bool float16_is_signaling_nan(float16 a_, float_status *status) |
| { |
| if (no_signaling_nans(status)) { |
| return 0; |
| } else { |
| uint16_t a = float16_val(a_); |
| if (snan_bit_is_one(status)) { |
| return ((a >> 9) & 0x3F) == 0x3F; |
| } else { |
| return (((a >> 9) & 0x3F) == 0x3E) && (a & 0x1FF); |
| } |
| } |
| } |
| |
| /*---------------------------------------------------------------------------- |
| | Returns 1 if the bfloat16 value `a' is a signaling |
| | NaN; otherwise returns 0. |
| *----------------------------------------------------------------------------*/ |
| |
| bool bfloat16_is_signaling_nan(bfloat16 a_, float_status *status) |
| { |
| if (no_signaling_nans(status)) { |
| return 0; |
| } else { |
| uint16_t a = a_; |
| if (snan_bit_is_one(status)) { |
| return ((a >> 6) & 0x1FF) == 0x1FF; |
| } else { |
| return (((a >> 6) & 0x1FF) == 0x1FE) && (a & 0x3F); |
| } |
| } |
| } |
| |
| /*---------------------------------------------------------------------------- |
| | Returns 1 if the single-precision floating-point value `a' is a quiet |
| | NaN; otherwise returns 0. |
| *----------------------------------------------------------------------------*/ |
| |
| 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 = float32_val(a_); |
| if (snan_bit_is_one(status)) { |
| return (((a >> 22) & 0x1FF) == 0x1FE) && (a & 0x003FFFFF); |
| } else { |
| return ((uint32_t)(a << 1) >= 0xFF800000); |
| } |
| } |
| } |
| |
| /*---------------------------------------------------------------------------- |
| | Returns 1 if the single-precision floating-point value `a' is a signaling |
| | NaN; otherwise returns 0. |
| *----------------------------------------------------------------------------*/ |
| |
| bool float32_is_signaling_nan(float32 a_, float_status *status) |
| { |
| if (no_signaling_nans(status)) { |
| return 0; |
| } else { |
| uint32_t a = float32_val(a_); |
| if (snan_bit_is_one(status)) { |
| return ((uint32_t)(a << 1) >= 0xFF800000); |
| } else { |
| return (((a >> 22) & 0x1FF) == 0x1FE) && (a & 0x003FFFFF); |
| } |
| } |
| } |
| |
| /*---------------------------------------------------------------------------- |
| | Select which NaN to propagate for a two-input operation. |
| | IEEE754 doesn't specify all the details of this, so the |
| | algorithm is target-specific. |
| | The routine is passed various bits of information about the |
| | two NaNs and should return 0 to select NaN a and 1 for NaN b. |
| | Note that signalling NaNs are always squashed to quiet NaNs |
| | by the caller, by calling floatXX_silence_nan() before |
| | returning them. |
| | |
| | aIsLargerSignificand is only valid if both a and b are NaNs |
| | of some kind, and is true if a has the larger significand, |
| | or if both a and b have the same significand but a is |
| | positive but b is negative. It is only needed for the x87 |
| | tie-break rule. |
| *----------------------------------------------------------------------------*/ |
| |
| static int pickNaN(FloatClass a_cls, FloatClass b_cls, |
| bool aIsLargerSignificand, float_status *status) |
| { |
| #if defined(TARGET_ARM) || defined(TARGET_MIPS) || defined(TARGET_HPPA) || \ |
| defined(TARGET_LOONGARCH64) || defined(TARGET_S390X) |
| /* ARM mandated NaN propagation rules (see FPProcessNaNs()), take |
| * the first of: |
| * 1. A if it is signaling |
| * 2. B if it is signaling |
| * 3. A (quiet) |
| * 4. B (quiet) |
| * A signaling NaN is always quietened before returning it. |
| */ |
| /* According to MIPS specifications, if one of the two operands is |
| * a sNaN, a new qNaN has to be generated. This is done in |
| * floatXX_silence_nan(). For qNaN inputs the specifications |
| * says: "When possible, this QNaN result is one of the operand QNaN |
| * values." In practice it seems that most implementations choose |
| * the first operand if both operands are qNaN. In short this gives |
| * the following rules: |
| * 1. A if it is signaling |
| * 2. B if it is signaling |
| * 3. A (quiet) |
| * 4. B (quiet) |
| * A signaling NaN is always silenced before returning it. |
| */ |
| if (is_snan(a_cls)) { |
| return 0; |
| } else if (is_snan(b_cls)) { |
| return 1; |
| } else if (is_qnan(a_cls)) { |
| return 0; |
| } else { |
| return 1; |
| } |
| #elif defined(TARGET_PPC) || defined(TARGET_M68K) |
| /* PowerPC propagation rules: |
| * 1. A if it sNaN or qNaN |
| * 2. B if it sNaN or qNaN |
| * A signaling NaN is always silenced before returning it. |
| */ |
| /* M68000 FAMILY PROGRAMMER'S REFERENCE MANUAL |
| * 3.4 FLOATING-POINT INSTRUCTION DETAILS |
| * If either operand, but not both operands, of an operation is a |
| * nonsignaling NaN, then that NaN is returned as the result. If both |
| * operands are nonsignaling NaNs, then the destination operand |
| * nonsignaling NaN is returned as the result. |
| * If either operand to an operation is a signaling NaN (SNaN), then the |
| * SNaN bit is set in the FPSR EXC byte. If the SNaN exception enable bit |
| * is set in the FPCR ENABLE byte, then the exception is taken and the |
| * destination is not modified. If the SNaN exception enable bit is not |
| * set, setting the SNaN bit in the operand to a one converts the SNaN to |
| * a nonsignaling NaN. The operation then continues as described in the |
| * preceding paragraph for nonsignaling NaNs. |
| */ |
| if (is_nan(a_cls)) { |
| return 0; |
| } else { |
| return 1; |
| } |
| #elif defined(TARGET_XTENSA) |
| /* |
| * Xtensa has two NaN propagation modes. |
| * Which one is active is controlled by float_status::use_first_nan. |
| */ |
| if (status->use_first_nan) { |
| if (is_nan(a_cls)) { |
| return 0; |
| } else { |
| return 1; |
| } |
| } else { |
| if (is_nan(b_cls)) { |
| return 1; |
| } else { |
| return 0; |
| } |
| } |
| #else |
| /* This implements x87 NaN propagation rules: |
| * SNaN + QNaN => return the QNaN |
| * two SNaNs => return the one with the larger significand, silenced |
| * two QNaNs => return the one with the larger significand |
| * SNaN and a non-NaN => return the SNaN, silenced |
| * QNaN and a non-NaN => return the QNaN |
| * |
| * If we get down to comparing significands and they are the same, |
| * return the NaN with the positive sign bit (if any). |
| */ |
| if (is_snan(a_cls)) { |
| if (is_snan(b_cls)) { |
| return aIsLargerSignificand ? 0 : 1; |
| } |
| return is_qnan(b_cls) ? 1 : 0; |
| } else if (is_qnan(a_cls)) { |
| if (is_snan(b_cls) || !is_qnan(b_cls)) { |
| return 0; |
| } else { |
| return aIsLargerSignificand ? 0 : 1; |
| } |
| } else { |
| return 1; |
| } |
| #endif |
| } |
| |
| /*---------------------------------------------------------------------------- |
| | Select which NaN to propagate for a three-input operation. |
| | For the moment we assume that no CPU needs the 'larger significand' |
| | information. |
| | Return values : 0 : a; 1 : b; 2 : c; 3 : default-NaN |
| *----------------------------------------------------------------------------*/ |
| static int pickNaNMulAdd(FloatClass a_cls, FloatClass b_cls, FloatClass c_cls, |
| bool infzero, float_status *status) |
| { |
| #if defined(TARGET_ARM) |
| /* For ARM, the (inf,zero,qnan) case sets InvalidOp and returns |
| * the default NaN |
| */ |
| if (infzero && is_qnan(c_cls)) { |
| float_raise(float_flag_invalid | float_flag_invalid_imz, status); |
| return 3; |
| } |
| |
| /* This looks different from the ARM ARM pseudocode, because the ARM ARM |
| * puts the operands to a fused mac operation (a*b)+c in the order c,a,b. |
| */ |
| if (is_snan(c_cls)) { |
| return 2; |
| } else if (is_snan(a_cls)) { |
| return 0; |
| } else if (is_snan(b_cls)) { |
| return 1; |
| } else if (is_qnan(c_cls)) { |
| return 2; |
| } else if (is_qnan(a_cls)) { |
| return 0; |
| } else { |
| return 1; |
| } |
| #elif defined(TARGET_MIPS) |
| if (snan_bit_is_one(status)) { |
| /* |
| * For MIPS systems that conform to IEEE754-1985, the (inf,zero,nan) |
| * case sets InvalidOp and returns the default NaN |
| */ |
| if (infzero) { |
| float_raise(float_flag_invalid | float_flag_invalid_imz, status); |
| return 3; |
| } |
| /* Prefer sNaN over qNaN, in the a, b, c order. */ |
| if (is_snan(a_cls)) { |
| return 0; |
| } else if (is_snan(b_cls)) { |
| return 1; |
| } else if (is_snan(c_cls)) { |
| return 2; |
| } else if (is_qnan(a_cls)) { |
| return 0; |
| } else if (is_qnan(b_cls)) { |
| return 1; |
| } else { |
| return 2; |
| } |
| } else { |
| /* |
| * For MIPS systems that conform to IEEE754-2008, the (inf,zero,nan) |
| * case sets InvalidOp and returns the input value 'c' |
| */ |
| if (infzero) { |
| float_raise(float_flag_invalid | float_flag_invalid_imz, status); |
| return 2; |
| } |
| /* Prefer sNaN over qNaN, in the c, a, b order. */ |
| if (is_snan(c_cls)) { |
| return 2; |
| } else if (is_snan(a_cls)) { |
| return 0; |
| } else if (is_snan(b_cls)) { |
| return 1; |
| } else if (is_qnan(c_cls)) { |
| return 2; |
| } else if (is_qnan(a_cls)) { |
| return 0; |
| } else { |
| return 1; |
| } |
| } |
| #elif defined(TARGET_LOONGARCH64) |
| /* |
| * For LoongArch systems that conform to IEEE754-2008, the (inf,zero,nan) |
| * case sets InvalidOp and returns the input value 'c' |
| */ |
| if (infzero) { |
| float_raise(float_flag_invalid | float_flag_invalid_imz, status); |
| return 2; |
| } |
| /* Prefer sNaN over qNaN, in the c, a, b order. */ |
| if (is_snan(c_cls)) { |
| return 2; |
| } else if (is_snan(a_cls)) { |
| return 0; |
| } else if (is_snan(b_cls)) { |
| return 1; |
| } else if (is_qnan(c_cls)) { |
| return 2; |
| } else if (is_qnan(a_cls)) { |
| return 0; |
| } else { |
| return 1; |
| } |
| #elif defined(TARGET_PPC) |
| /* For PPC, the (inf,zero,qnan) case sets InvalidOp, but we prefer |
| * to return an input NaN if we have one (ie c) rather than generating |
| * a default NaN |
| */ |
| if (infzero) { |
| float_raise(float_flag_invalid | float_flag_invalid_imz, status); |
| return 2; |
| } |
| |
| /* If fRA is a NaN return it; otherwise if fRB is a NaN return it; |
| * otherwise return fRC. Note that muladd on PPC is (fRA * fRC) + frB |
| */ |
| if (is_nan(a_cls)) { |
| return 0; |
| } else if (is_nan(c_cls)) { |
| return 2; |
| } else { |
| return 1; |
| } |
| #elif defined(TARGET_RISCV) |
| /* For RISC-V, InvalidOp is set when multiplicands are Inf and zero */ |
| if (infzero) { |
| float_raise(float_flag_invalid | float_flag_invalid_imz, status); |
| } |
| return 3; /* default NaN */ |
| #elif defined(TARGET_XTENSA) |
| /* |
| * For Xtensa, the (inf,zero,nan) case sets InvalidOp and returns |
| * an input NaN if we have one (ie c). |
| */ |
| if (infzero) { |
| float_raise(float_flag_invalid | float_flag_invalid_imz, status); |
| return 2; |
| } |
| if (status->use_first_nan) { |
| if (is_nan(a_cls)) { |
| return 0; |
| } else if (is_nan(b_cls)) { |
| return 1; |
| } else { |
| return 2; |
| } |
| } else { |
| if (is_nan(c_cls)) { |
| return 2; |
| } else if (is_nan(b_cls)) { |
| return 1; |
| } else { |
| return 0; |
| } |
| } |
| #else |
| /* A default implementation: prefer a to b to c. |
| * This is unlikely to actually match any real implementation. |
| */ |
| if (is_nan(a_cls)) { |
| return 0; |
| } else if (is_nan(b_cls)) { |
| return 1; |
| } else { |
| return 2; |
| } |
| #endif |
| } |
| |
| /*---------------------------------------------------------------------------- |
| | Returns 1 if the double-precision floating-point value `a' is a quiet |
| | NaN; otherwise returns 0. |
| *----------------------------------------------------------------------------*/ |
| |
| 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 = float64_val(a_); |
| if (snan_bit_is_one(status)) { |
| return (((a >> 51) & 0xFFF) == 0xFFE) |
| && (a & 0x0007FFFFFFFFFFFFULL); |
| } else { |
| return ((a << 1) >= 0xFFF0000000000000ULL); |
| } |
| } |
| } |
| |
| /*---------------------------------------------------------------------------- |
| | Returns 1 if the double-precision floating-point value `a' is a signaling |
| | NaN; otherwise returns 0. |
| *----------------------------------------------------------------------------*/ |
| |
| bool float64_is_signaling_nan(float64 a_, float_status *status) |
| { |
| if (no_signaling_nans(status)) { |
| return 0; |
| } else { |
| uint64_t a = float64_val(a_); |
| if (snan_bit_is_one(status)) { |
| return ((a << 1) >= 0xFFF0000000000000ULL); |
| } else { |
| return (((a >> 51) & 0xFFF) == 0xFFE) |
| && (a & UINT64_C(0x0007FFFFFFFFFFFF)); |
| } |
| } |
| } |
| |
| /*---------------------------------------------------------------------------- |
| | Returns 1 if the extended double-precision floating-point value `a' is a |
| | quiet NaN; otherwise returns 0. This slightly differs from the same |
| | function for other types as floatx80 has an explicit bit. |
| *----------------------------------------------------------------------------*/ |
| |
| int floatx80_is_quiet_nan(floatx80 a, float_status *status) |
| { |
| if (no_signaling_nans(status)) { |
| return floatx80_is_any_nan(a); |
| } else { |
| if (snan_bit_is_one(status)) { |
| uint64_t aLow; |
| |
| aLow = a.low & ~0x4000000000000000ULL; |
| return ((a.high & 0x7FFF) == 0x7FFF) |
| && (aLow << 1) |
| && (a.low == aLow); |
| } else { |
| return ((a.high & 0x7FFF) == 0x7FFF) |
| && (UINT64_C(0x8000000000000000) <= ((uint64_t)(a.low << 1))); |
| } |
| } |
| } |
| |
| /*---------------------------------------------------------------------------- |
| | Returns 1 if the extended double-precision floating-point value `a' is a |
| | signaling NaN; otherwise returns 0. This slightly differs from the same |
| | function for other types as floatx80 has an explicit bit. |
| *----------------------------------------------------------------------------*/ |
| |
| int floatx80_is_signaling_nan(floatx80 a, float_status *status) |
| { |
| if (no_signaling_nans(status)) { |
| return 0; |
| } else { |
| if (snan_bit_is_one(status)) { |
| return ((a.high & 0x7FFF) == 0x7FFF) |
| && ((a.low << 1) >= 0x8000000000000000ULL); |
| } else { |
| uint64_t aLow; |
| |
| aLow = a.low & ~UINT64_C(0x4000000000000000); |
| return ((a.high & 0x7FFF) == 0x7FFF) |
| && (uint64_t)(aLow << 1) |
| && (a.low == aLow); |
| } |
| } |
| } |
| |
| /*---------------------------------------------------------------------------- |
| | Returns a quiet NaN from a signalling NaN for the extended double-precision |
| | floating point value `a'. |
| *----------------------------------------------------------------------------*/ |
| |
| floatx80 floatx80_silence_nan(floatx80 a, float_status *status) |
| { |
| /* None of the targets that have snan_bit_is_one use floatx80. */ |
| assert(!snan_bit_is_one(status)); |
| a.low |= UINT64_C(0xC000000000000000); |
| return a; |
| } |
| |
| /*---------------------------------------------------------------------------- |
| | Takes two extended double-precision floating-point values `a' and `b', one |
| | of which is a NaN, and returns the appropriate NaN result. If either `a' or |
| | `b' is a signaling NaN, the invalid exception is raised. |
| *----------------------------------------------------------------------------*/ |
| |
| floatx80 propagateFloatx80NaN(floatx80 a, floatx80 b, float_status *status) |
| { |
| bool aIsLargerSignificand; |
| FloatClass a_cls, b_cls; |
| |
| /* This is not complete, but is good enough for pickNaN. */ |
| a_cls = (!floatx80_is_any_nan(a) |
| ? float_class_normal |
| : floatx80_is_signaling_nan(a, status) |
| ? float_class_snan |
| : float_class_qnan); |
| b_cls = (!floatx80_is_any_nan(b) |
| ? float_class_normal |
| : floatx80_is_signaling_nan(b, status) |
| ? float_class_snan |
| : float_class_qnan); |
| |
| if (is_snan(a_cls) || is_snan(b_cls)) { |
| float_raise(float_flag_invalid, status); |
| } |
| |
| if (status->default_nan_mode) { |
| return floatx80_default_nan(status); |
| } |
| |
| if (a.low < b.low) { |
| aIsLargerSignificand = 0; |
| } else if (b.low < a.low) { |
| aIsLargerSignificand = 1; |
| } else { |
| aIsLargerSignificand = (a.high < b.high) ? 1 : 0; |
| } |
| |
| if (pickNaN(a_cls, b_cls, aIsLargerSignificand, status)) { |
| if (is_snan(b_cls)) { |
| return floatx80_silence_nan(b, status); |
| } |
| return b; |
| } else { |
| if (is_snan(a_cls)) { |
| return floatx80_silence_nan(a, status); |
| } |
| return a; |
| } |
| } |
| |
| /*---------------------------------------------------------------------------- |
| | Returns 1 if the quadruple-precision floating-point value `a' is a quiet |
| | NaN; otherwise returns 0. |
| *----------------------------------------------------------------------------*/ |
| |
| 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) == 0xFFFE) |
| && (a.low || (a.high & 0x00007FFFFFFFFFFFULL)); |
| } else { |
| return ((a.high << 1) >= 0xFFFF000000000000ULL) |
| && (a.low || (a.high & 0x0000FFFFFFFFFFFFULL)); |
| } |
| } |
| } |
| |
| /*---------------------------------------------------------------------------- |
| | Returns 1 if the quadruple-precision floating-point value `a' is a |
| | signaling NaN; otherwise returns 0. |
| *----------------------------------------------------------------------------*/ |
| |
| 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) >= 0xFFFF000000000000ULL) |
| && (a.low || (a.high & 0x0000FFFFFFFFFFFFULL)); |
| } else { |
| return (((a.high >> 47) & 0xFFFF) == 0xFFFE) |
| && (a.low || (a.high & UINT64_C(0x00007FFFFFFFFFFF))); |
| } |
| } |
| } |
