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Diffstat (limited to 'fpu/softfloat-specialize.h')
-rw-r--r-- | fpu/softfloat-specialize.h | 464 |
1 files changed, 464 insertions, 0 deletions
diff --git a/fpu/softfloat-specialize.h b/fpu/softfloat-specialize.h new file mode 100644 index 0000000000..d430f58a71 --- /dev/null +++ b/fpu/softfloat-specialize.h @@ -0,0 +1,464 @@ + +/*============================================================================ + +This C source fragment 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. + +=============================================================================*/ + +/*---------------------------------------------------------------------------- +| Underflow tininess-detection mode, statically initialized to default value. +| (The declaration in `softfloat.h' must match the `int8' type here.) +*----------------------------------------------------------------------------*/ +int8 float_detect_tininess = float_tininess_after_rounding; + +/*---------------------------------------------------------------------------- +| Raises the exceptions specified by `flags'. Floating-point traps can be +| defined here if desired. It is currently not possible for such a trap +| to substitute a result value. If traps are not implemented, this routine +| should be simply `float_exception_flags |= flags;'. +*----------------------------------------------------------------------------*/ + +void float_raise( int8 flags STATUS_PARAM ) +{ + + STATUS(float_exception_flags) |= flags; + +} + +/*---------------------------------------------------------------------------- +| Internal canonical NaN format. +*----------------------------------------------------------------------------*/ +typedef struct { + flag sign; + bits64 high, low; +} commonNaNT; + +/*---------------------------------------------------------------------------- +| The pattern for a default generated single-precision NaN. +*----------------------------------------------------------------------------*/ +#define float32_default_nan 0xFFC00000 + +/*---------------------------------------------------------------------------- +| Returns 1 if the single-precision floating-point value `a' is a NaN; +| otherwise returns 0. +*----------------------------------------------------------------------------*/ + +flag float32_is_nan( float32 a ) +{ + + return ( 0xFF000000 < (bits32) ( a<<1 ) ); + +} + +/*---------------------------------------------------------------------------- +| Returns 1 if the single-precision floating-point value `a' is a signaling +| NaN; otherwise returns 0. +*----------------------------------------------------------------------------*/ + +flag float32_is_signaling_nan( float32 a ) +{ + + return ( ( ( a>>22 ) & 0x1FF ) == 0x1FE ) && ( a & 0x003FFFFF ); + +} + +/*---------------------------------------------------------------------------- +| Returns the result of converting the single-precision floating-point NaN +| `a' to the canonical NaN format. If `a' is a signaling NaN, the invalid +| exception is raised. +*----------------------------------------------------------------------------*/ + +static commonNaNT float32ToCommonNaN( float32 a STATUS_PARAM ) +{ + commonNaNT z; + + if ( float32_is_signaling_nan( a ) ) float_raise( float_flag_invalid STATUS_VAR ); + z.sign = a>>31; + z.low = 0; + z.high = ( (bits64) a )<<41; + return z; + +} + +/*---------------------------------------------------------------------------- +| Returns the result of converting the canonical NaN `a' to the single- +| precision floating-point format. +*----------------------------------------------------------------------------*/ + +static float32 commonNaNToFloat32( commonNaNT a ) +{ + + return ( ( (bits32) a.sign )<<31 ) | 0x7FC00000 | ( a.high>>41 ); + +} + +/*---------------------------------------------------------------------------- +| Takes two single-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. +*----------------------------------------------------------------------------*/ + +static float32 propagateFloat32NaN( float32 a, float32 b STATUS_PARAM) +{ + flag aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN; + + aIsNaN = float32_is_nan( a ); + aIsSignalingNaN = float32_is_signaling_nan( a ); + bIsNaN = float32_is_nan( b ); + bIsSignalingNaN = float32_is_signaling_nan( b ); + a |= 0x00400000; + b |= 0x00400000; + if ( aIsSignalingNaN | bIsSignalingNaN ) float_raise( float_flag_invalid STATUS_VAR); + if ( aIsSignalingNaN ) { + if ( bIsSignalingNaN ) goto returnLargerSignificand; + return bIsNaN ? b : a; + } + else if ( aIsNaN ) { + if ( bIsSignalingNaN | ! bIsNaN ) return a; + returnLargerSignificand: + if ( (bits32) ( a<<1 ) < (bits32) ( b<<1 ) ) return b; + if ( (bits32) ( b<<1 ) < (bits32) ( a<<1 ) ) return a; + return ( a < b ) ? a : b; + } + else { + return b; + } + +} + +/*---------------------------------------------------------------------------- +| The pattern for a default generated double-precision NaN. +*----------------------------------------------------------------------------*/ +#define float64_default_nan LIT64( 0xFFF8000000000000 ) + +/*---------------------------------------------------------------------------- +| Returns 1 if the double-precision floating-point value `a' is a NaN; +| otherwise returns 0. +*----------------------------------------------------------------------------*/ + +flag float64_is_nan( float64 a ) +{ + + return ( LIT64( 0xFFE0000000000000 ) < (bits64) ( a<<1 ) ); + +} + +/*---------------------------------------------------------------------------- +| Returns 1 if the double-precision floating-point value `a' is a signaling +| NaN; otherwise returns 0. +*----------------------------------------------------------------------------*/ + +flag float64_is_signaling_nan( float64 a ) +{ + + return + ( ( ( a>>51 ) & 0xFFF ) == 0xFFE ) + && ( a & LIT64( 0x0007FFFFFFFFFFFF ) ); + +} + +/*---------------------------------------------------------------------------- +| Returns the result of converting the double-precision floating-point NaN +| `a' to the canonical NaN format. If `a' is a signaling NaN, the invalid +| exception is raised. +*----------------------------------------------------------------------------*/ + +static commonNaNT float64ToCommonNaN( float64 a STATUS_PARAM) +{ + commonNaNT z; + + if ( float64_is_signaling_nan( a ) ) float_raise( float_flag_invalid STATUS_VAR); + z.sign = a>>63; + z.low = 0; + z.high = a<<12; + return z; + +} + +/*---------------------------------------------------------------------------- +| Returns the result of converting the canonical NaN `a' to the double- +| precision floating-point format. +*----------------------------------------------------------------------------*/ + +static float64 commonNaNToFloat64( commonNaNT a ) +{ + + return + ( ( (bits64) a.sign )<<63 ) + | LIT64( 0x7FF8000000000000 ) + | ( a.high>>12 ); + +} + +/*---------------------------------------------------------------------------- +| Takes two 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. +*----------------------------------------------------------------------------*/ + +static float64 propagateFloat64NaN( float64 a, float64 b STATUS_PARAM) +{ + flag aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN; + + aIsNaN = float64_is_nan( a ); + aIsSignalingNaN = float64_is_signaling_nan( a ); + bIsNaN = float64_is_nan( b ); + bIsSignalingNaN = float64_is_signaling_nan( b ); + a |= LIT64( 0x0008000000000000 ); + b |= LIT64( 0x0008000000000000 ); + if ( aIsSignalingNaN | bIsSignalingNaN ) float_raise( float_flag_invalid STATUS_VAR); + if ( aIsSignalingNaN ) { + if ( bIsSignalingNaN ) goto returnLargerSignificand; + return bIsNaN ? b : a; + } + else if ( aIsNaN ) { + if ( bIsSignalingNaN | ! bIsNaN ) return a; + returnLargerSignificand: + if ( (bits64) ( a<<1 ) < (bits64) ( b<<1 ) ) return b; + if ( (bits64) ( b<<1 ) < (bits64) ( a<<1 ) ) return a; + return ( a < b ) ? a : b; + } + else { + return b; + } + +} + +#ifdef FLOATX80 + +/*---------------------------------------------------------------------------- +| The pattern for a default generated extended double-precision NaN. The +| `high' and `low' values hold the most- and least-significant bits, +| respectively. +*----------------------------------------------------------------------------*/ +#define floatx80_default_nan_high 0xFFFF +#define floatx80_default_nan_low LIT64( 0xC000000000000000 ) + +/*---------------------------------------------------------------------------- +| Returns 1 if the extended double-precision floating-point value `a' is a +| NaN; otherwise returns 0. +*----------------------------------------------------------------------------*/ + +flag floatx80_is_nan( floatx80 a ) +{ + + return ( ( a.high & 0x7FFF ) == 0x7FFF ) && (bits64) ( a.low<<1 ); + +} + +/*---------------------------------------------------------------------------- +| Returns 1 if the extended double-precision floating-point value `a' is a +| signaling NaN; otherwise returns 0. +*----------------------------------------------------------------------------*/ + +flag floatx80_is_signaling_nan( floatx80 a ) +{ + bits64 aLow; + + aLow = a.low & ~ LIT64( 0x4000000000000000 ); + return + ( ( a.high & 0x7FFF ) == 0x7FFF ) + && (bits64) ( aLow<<1 ) + && ( a.low == aLow ); + +} + +/*---------------------------------------------------------------------------- +| Returns the result of converting the extended double-precision floating- +| point NaN `a' to the canonical NaN format. If `a' is a signaling NaN, the +| invalid exception is raised. +*----------------------------------------------------------------------------*/ + +static commonNaNT floatx80ToCommonNaN( floatx80 a STATUS_PARAM) +{ + commonNaNT z; + + if ( floatx80_is_signaling_nan( a ) ) float_raise( float_flag_invalid STATUS_VAR); + z.sign = a.high>>15; + z.low = 0; + z.high = a.low<<1; + return z; + +} + +/*---------------------------------------------------------------------------- +| Returns the result of converting the canonical NaN `a' to the extended +| double-precision floating-point format. +*----------------------------------------------------------------------------*/ + +static floatx80 commonNaNToFloatx80( commonNaNT a ) +{ + floatx80 z; + + z.low = LIT64( 0xC000000000000000 ) | ( a.high>>1 ); + z.high = ( ( (bits16) a.sign )<<15 ) | 0x7FFF; + return z; + +} + +/*---------------------------------------------------------------------------- +| 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. +*----------------------------------------------------------------------------*/ + +static floatx80 propagateFloatx80NaN( floatx80 a, floatx80 b STATUS_PARAM) +{ + flag aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN; + + aIsNaN = floatx80_is_nan( a ); + aIsSignalingNaN = floatx80_is_signaling_nan( a ); + bIsNaN = floatx80_is_nan( b ); + bIsSignalingNaN = floatx80_is_signaling_nan( b ); + a.low |= LIT64( 0xC000000000000000 ); + b.low |= LIT64( 0xC000000000000000 ); + if ( aIsSignalingNaN | bIsSignalingNaN ) float_raise( float_flag_invalid STATUS_VAR); + if ( aIsSignalingNaN ) { + if ( bIsSignalingNaN ) goto returnLargerSignificand; + return bIsNaN ? b : a; + } + else if ( aIsNaN ) { + if ( bIsSignalingNaN | ! bIsNaN ) return a; + returnLargerSignificand: + if ( a.low < b.low ) return b; + if ( b.low < a.low ) return a; + return ( a.high < b.high ) ? a : b; + } + else { + return b; + } + +} + +#endif + +#ifdef FLOAT128 + +/*---------------------------------------------------------------------------- +| The pattern for a default generated quadruple-precision NaN. The `high' and +| `low' values hold the most- and least-significant bits, respectively. +*----------------------------------------------------------------------------*/ +#define float128_default_nan_high LIT64( 0xFFFF800000000000 ) +#define float128_default_nan_low LIT64( 0x0000000000000000 ) + +/*---------------------------------------------------------------------------- +| Returns 1 if the quadruple-precision floating-point value `a' is a NaN; +| otherwise returns 0. +*----------------------------------------------------------------------------*/ + +flag float128_is_nan( float128 a ) +{ + + return + ( LIT64( 0xFFFE000000000000 ) <= (bits64) ( a.high<<1 ) ) + && ( a.low || ( a.high & LIT64( 0x0000FFFFFFFFFFFF ) ) ); + +} + +/*---------------------------------------------------------------------------- +| Returns 1 if the quadruple-precision floating-point value `a' is a +| signaling NaN; otherwise returns 0. +*----------------------------------------------------------------------------*/ + +flag float128_is_signaling_nan( float128 a ) +{ + + return + ( ( ( a.high>>47 ) & 0xFFFF ) == 0xFFFE ) + && ( a.low || ( a.high & LIT64( 0x00007FFFFFFFFFFF ) ) ); + +} + +/*---------------------------------------------------------------------------- +| Returns the result of converting the quadruple-precision floating-point NaN +| `a' to the canonical NaN format. If `a' is a signaling NaN, the invalid +| exception is raised. +*----------------------------------------------------------------------------*/ + +static commonNaNT float128ToCommonNaN( float128 a STATUS_PARAM) +{ + commonNaNT z; + + if ( float128_is_signaling_nan( a ) ) float_raise( float_flag_invalid STATUS_VAR); + z.sign = a.high>>63; + shortShift128Left( a.high, a.low, 16, &z.high, &z.low ); + return z; + +} + +/*---------------------------------------------------------------------------- +| Returns the result of converting the canonical NaN `a' to the quadruple- +| precision floating-point format. +*----------------------------------------------------------------------------*/ + +static float128 commonNaNToFloat128( commonNaNT a ) +{ + float128 z; + + shift128Right( a.high, a.low, 16, &z.high, &z.low ); + z.high |= ( ( (bits64) a.sign )<<63 ) | LIT64( 0x7FFF800000000000 ); + return z; + +} + +/*---------------------------------------------------------------------------- +| Takes two quadruple-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. +*----------------------------------------------------------------------------*/ + +static float128 propagateFloat128NaN( float128 a, float128 b STATUS_PARAM) +{ + flag aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN; + + aIsNaN = float128_is_nan( a ); + aIsSignalingNaN = float128_is_signaling_nan( a ); + bIsNaN = float128_is_nan( b ); + bIsSignalingNaN = float128_is_signaling_nan( b ); + a.high |= LIT64( 0x0000800000000000 ); + b.high |= LIT64( 0x0000800000000000 ); + if ( aIsSignalingNaN | bIsSignalingNaN ) float_raise( float_flag_invalid STATUS_VAR); + if ( aIsSignalingNaN ) { + if ( bIsSignalingNaN ) goto returnLargerSignificand; + return bIsNaN ? b : a; + } + else if ( aIsNaN ) { + if ( bIsSignalingNaN | ! bIsNaN ) return a; + returnLargerSignificand: + if ( lt128( a.high<<1, a.low, b.high<<1, b.low ) ) return b; + if ( lt128( b.high<<1, b.low, a.high<<1, a.low ) ) return a; + return ( a.high < b.high ) ? a : b; + } + else { + return b; + } + +} + +#endif + |