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Diffstat (limited to 'benchmarks/CHStone/dfadd/softfloat.c')
| -rwxr-xr-x | benchmarks/CHStone/dfadd/softfloat.c | 417 |
1 files changed, 417 insertions, 0 deletions
diff --git a/benchmarks/CHStone/dfadd/softfloat.c b/benchmarks/CHStone/dfadd/softfloat.c new file mode 100755 index 0000000..baeedab --- /dev/null +++ b/benchmarks/CHStone/dfadd/softfloat.c @@ -0,0 +1,417 @@ +/* ++--------------------------------------------------------------------------+ +| CHStone : a suite of benchmark programs for C-based High-Level Synthesis | +| ======================================================================== | +| | +| * Collected and Modified : Y. Hara, H. Tomiyama, S. Honda, | +| H. Takada and K. Ishii | +| Nagoya University, Japan | +| | +| * Remark : | +| 1. This source code is modified to unify the formats of the benchmark | +| programs in CHStone. | +| 2. Test vectors are added for CHStone. | +| 3. If "main_result" is 0 at the end of the program, the program is | +| correctly executed. | +| 4. Please follow the copyright of each benchmark program. | ++--------------------------------------------------------------------------+ +*/ +/*============================================================================ + +This C source file is part of the SoftFloat IEC/IEEE Floating-point Arithmetic +Package, Release 2b. + +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://www.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 ALL LOSSES, +COSTS, OR OTHER PROBLEMS THEY INCUR DUE TO THE SOFTWARE, AND WHO FURTHERMORE +EFFECTIVELY INDEMNIFY JOHN HAUSER AND THE INTERNATIONAL COMPUTER SCIENCE +INSTITUTE (possibly via similar legal warning) AGAINST ALL LOSSES, COSTS, OR +OTHER PROBLEMS INCURRED BY THEIR CUSTOMERS AND CLIENTS DUE TO THE SOFTWARE. + +Derivative works are acceptable, even for commercial purposes, so long as +(1) the source code for the derivative work includes prominent notice that +the work is derivative, and (2) the source code includes prominent notice with +these four paragraphs for those parts of this code that are retained. + +=============================================================================*/ + +#include "milieu.h" +#include "softfloat.h" + +/*---------------------------------------------------------------------------- +| Floating-point rounding mode, extended double-precision rounding precision, +| and exception flags. +*----------------------------------------------------------------------------*/ +int8 float_rounding_mode = float_round_nearest_even; +int8 float_exception_flags = 0; + +/*---------------------------------------------------------------------------- +| Primitive arithmetic functions, including multi-word arithmetic, and +| division and square root approximations. (Can be specialized to target if +| desired.) +*----------------------------------------------------------------------------*/ +#include "softfloat-macros" + +/*---------------------------------------------------------------------------- +| Functions and definitions to determine: (1) whether tininess for underflow +| is detected before or after rounding by default, (2) what (if anything) +| happens when exceptions are raised, (3) how signaling NaNs are distinguished +| from quiet NaNs, (4) the default generated quiet NaNs, and (5) how NaNs +| are propagated from function inputs to output. These details are target- +| specific. +*----------------------------------------------------------------------------*/ +#include "softfloat-specialize" + +/*---------------------------------------------------------------------------- +| Returns the fraction bits of the double-precision floating-point value `a'. +*----------------------------------------------------------------------------*/ + +INLINE bits64 +extractFloat64Frac (float64 a) +{ + + return a & LIT64 (0x000FFFFFFFFFFFFF); + +} + +/*---------------------------------------------------------------------------- +| Returns the exponent bits of the double-precision floating-point value `a'. +*----------------------------------------------------------------------------*/ + +INLINE int16 +extractFloat64Exp (float64 a) +{ + + return (a >> 52) & 0x7FF; + +} + +/*---------------------------------------------------------------------------- +| Returns the sign bit of the double-precision floating-point value `a'. +*----------------------------------------------------------------------------*/ + +INLINE flag +extractFloat64Sign (float64 a) +{ + + return a >> 63; + +} + +/*---------------------------------------------------------------------------- +| Packs the sign `zSign', exponent `zExp', and significand `zSig' into a +| double-precision floating-point value, returning the result. After being +| shifted into the proper positions, the three fields are simply added +| together to form the result. This means that any integer portion of `zSig' +| will be added into the exponent. Since a properly normalized significand +| will have an integer portion equal to 1, the `zExp' input should be 1 less +| than the desired result exponent whenever `zSig' is a complete, normalized +| significand. +*----------------------------------------------------------------------------*/ + +INLINE float64 +packFloat64 (flag zSign, int16 zExp, bits64 zSig) +{ + + return (((bits64) zSign) << 63) + (((bits64) zExp) << 52) + zSig; + +} + +/*---------------------------------------------------------------------------- +| Takes an abstract floating-point value having sign `zSign', exponent `zExp', +| and significand `zSig', and returns the proper double-precision floating- +| point value corresponding to the abstract input. Ordinarily, the abstract +| value is simply rounded and packed into the double-precision format, with +| the inexact exception raised if the abstract input cannot be represented +| exactly. However, if the abstract value is too large, the overflow and +| inexact exceptions are raised and an infinity or maximal finite value is +| returned. If the abstract value is too small, the input value is rounded +| to a subnormal number, and the underflow and inexact exceptions are raised +| if the abstract input cannot be represented exactly as a subnormal double- +| precision floating-point number. +| The input significand `zSig' has its binary point between bits 62 +| and 61, which is 10 bits to the left of the usual location. This shifted +| significand must be normalized or smaller. If `zSig' is not normalized, +| `zExp' must be 0; in that case, the result returned is a subnormal number, +| and it must not require rounding. In the usual case that `zSig' is +| normalized, `zExp' must be 1 less than the ``true'' floating-point exponent. +| The handling of underflow and overflow follows the IEC/IEEE Standard for +| Binary Floating-Point Arithmetic. +*----------------------------------------------------------------------------*/ + +static float64 +roundAndPackFloat64 (flag zSign, int16 zExp, bits64 zSig) +{ + int8 roundingMode; + flag roundNearestEven, isTiny; + int16 roundIncrement, roundBits; + + roundingMode = float_rounding_mode; + roundNearestEven = (roundingMode == float_round_nearest_even); + roundIncrement = 0x200; + if (!roundNearestEven) + { + if (roundingMode == float_round_to_zero) + { + roundIncrement = 0; + } + else + { + roundIncrement = 0x3FF; + if (zSign) + { + if (roundingMode == float_round_up) + roundIncrement = 0; + } + else + { + if (roundingMode == float_round_down) + roundIncrement = 0; + } + } + } + roundBits = zSig & 0x3FF; + if (0x7FD <= (bits16) zExp) + { + if ((0x7FD < zExp) + || ((zExp == 0x7FD) && ((sbits64) (zSig + roundIncrement) < 0))) + { + float_raise (float_flag_overflow | float_flag_inexact); + return packFloat64 (zSign, 0x7FF, 0) - (roundIncrement == 0); + } + if (zExp < 0) + { + isTiny = (float_detect_tininess == float_tininess_before_rounding) + || (zExp < -1) + || (zSig + roundIncrement < LIT64 (0x8000000000000000)); + shift64RightJamming (zSig, -zExp, &zSig); + zExp = 0; + roundBits = zSig & 0x3FF; + if (isTiny && roundBits) + float_raise (float_flag_underflow); + } + } + if (roundBits) + float_exception_flags |= float_flag_inexact; + zSig = (zSig + roundIncrement) >> 10; + zSig &= ~(((roundBits ^ 0x200) == 0) & roundNearestEven); + if (zSig == 0) + zExp = 0; + return packFloat64 (zSign, zExp, zSig); + +} + +/*---------------------------------------------------------------------------- +| Takes an abstract floating-point value having sign `zSign', exponent `zExp', +| and significand `zSig', and returns the proper double-precision floating- +| point value corresponding to the abstract input. This routine is just like +| `roundAndPackFloat64' except that `zSig' does not have to be normalized. +| Bit 63 of `zSig' must be zero, and `zExp' must be 1 less than the ``true'' +| floating-point exponent. +*----------------------------------------------------------------------------*/ + +static float64 +normalizeRoundAndPackFloat64 (flag zSign, int16 zExp, bits64 zSig) +{ + int8 shiftCount; + + shiftCount = countLeadingZeros64 (zSig) - 1; + return roundAndPackFloat64 (zSign, zExp - shiftCount, zSig << shiftCount); + +} + +/*---------------------------------------------------------------------------- +| Returns the result of adding the absolute values of the double-precision +| floating-point values `a' and `b'. If `zSign' is 1, the sum is negated +| before being returned. `zSign' is ignored if the result is a NaN. +| The addition is performed according to the IEC/IEEE Standard for Binary +| Floating-Point Arithmetic. +*----------------------------------------------------------------------------*/ + +static float64 +addFloat64Sigs (float64 a, float64 b, flag zSign) +{ + int16 aExp, bExp, zExp; + bits64 aSig, bSig, zSig; + int16 expDiff; + + aSig = extractFloat64Frac (a); + aExp = extractFloat64Exp (a); + bSig = extractFloat64Frac (b); + bExp = extractFloat64Exp (b); + expDiff = aExp - bExp; + aSig <<= 9; + bSig <<= 9; + if (0 < expDiff) + { + if (aExp == 0x7FF) + { + if (aSig) + return propagateFloat64NaN (a, b); + return a; + } + if (bExp == 0) + --expDiff; + else + bSig |= LIT64 (0x2000000000000000); + shift64RightJamming (bSig, expDiff, &bSig); + zExp = aExp; + } + else if (expDiff < 0) + { + if (bExp == 0x7FF) + { + if (bSig) + return propagateFloat64NaN (a, b); + return packFloat64 (zSign, 0x7FF, 0); + } + if (aExp == 0) + ++expDiff; + else + { + aSig |= LIT64 (0x2000000000000000); + } + shift64RightJamming (aSig, -expDiff, &aSig); + zExp = bExp; + } + else + { + if (aExp == 0x7FF) + { + if (aSig | bSig) + return propagateFloat64NaN (a, b); + return a; + } + if (aExp == 0) + return packFloat64 (zSign, 0, (aSig + bSig) >> 9); + zSig = LIT64 (0x4000000000000000) + aSig + bSig; + zExp = aExp; + goto roundAndPack; + } + aSig |= LIT64 (0x2000000000000000); + zSig = (aSig + bSig) << 1; + --zExp; + if ((sbits64) zSig < 0) + { + zSig = aSig + bSig; + ++zExp; + } +roundAndPack: + return roundAndPackFloat64 (zSign, zExp, zSig); + +} + +/*---------------------------------------------------------------------------- +| Returns the result of subtracting the absolute values of the double- +| precision floating-point values `a' and `b'. If `zSign' is 1, the +| difference is negated before being returned. `zSign' is ignored if the +| result is a NaN. The subtraction is performed according to the IEC/IEEE +| Standard for Binary Floating-Point Arithmetic. +*----------------------------------------------------------------------------*/ + +static float64 +subFloat64Sigs (float64 a, float64 b, flag zSign) +{ + int16 aExp, bExp, zExp; + bits64 aSig, bSig, zSig; + int16 expDiff; + + aSig = extractFloat64Frac (a); + aExp = extractFloat64Exp (a); + bSig = extractFloat64Frac (b); + bExp = extractFloat64Exp (b); + expDiff = aExp - bExp; + aSig <<= 10; + bSig <<= 10; + if (0 < expDiff) + goto aExpBigger; + if (expDiff < 0) + goto bExpBigger; + if (aExp == 0x7FF) + { + if (aSig | bSig) + return propagateFloat64NaN (a, b); + float_raise (float_flag_invalid); + return float64_default_nan; + } + if (aExp == 0) + { + aExp = 1; + bExp = 1; + } + if (bSig < aSig) + goto aBigger; + if (aSig < bSig) + goto bBigger; + return packFloat64 (float_rounding_mode == float_round_down, 0, 0); +bExpBigger: + if (bExp == 0x7FF) + { + if (bSig) + return propagateFloat64NaN (a, b); + return packFloat64 (zSign ^ 1, 0x7FF, 0); + } + if (aExp == 0) + ++expDiff; + else + aSig |= LIT64 (0x4000000000000000); + shift64RightJamming (aSig, -expDiff, &aSig); + bSig |= LIT64 (0x4000000000000000); +bBigger: + zSig = bSig - aSig; + zExp = bExp; + zSign ^= 1; + goto normalizeRoundAndPack; +aExpBigger: + if (aExp == 0x7FF) + { + if (aSig) + return propagateFloat64NaN (a, b); + return a; + } + if (bExp == 0) + --expDiff; + else + bSig |= LIT64 (0x4000000000000000); + shift64RightJamming (bSig, expDiff, &bSig); + aSig |= LIT64 (0x4000000000000000); +aBigger: + zSig = aSig - bSig; + zExp = aExp; +normalizeRoundAndPack: + --zExp; + return normalizeRoundAndPackFloat64 (zSign, zExp, zSig); + +} + +/*---------------------------------------------------------------------------- +| Returns the result of adding the double-precision floating-point values `a' +| and `b'. The operation is performed according to the IEC/IEEE Standard for +| Binary Floating-Point Arithmetic. +*----------------------------------------------------------------------------*/ + +float64 +float64_add (float64 a, float64 b) +{ + flag aSign, bSign; + + aSign = extractFloat64Sign (a); + bSign = extractFloat64Sign (b); + if (aSign == bSign) + return addFloat64Sigs (a, b, aSign); + else + return subFloat64Sigs (a, b, aSign); + +} |