root / fpu / softfloat-specialize.h @ 5a6932d5
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/*============================================================================
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This C source fragment is part of the SoftFloat IEC/IEEE Floating-point
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Arithmetic Package, Release 2b.
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Written by John R. Hauser. This work was made possible in part by the
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International Computer Science Institute, located at Suite 600, 1947 Center
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Street, Berkeley, California 94704. Funding was partially provided by the
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National Science Foundation under grant MIP-9311980. The original version
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of this code was written as part of a project to build a fixed-point vector
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processor in collaboration with the University of California at Berkeley,
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overseen by Profs. Nelson Morgan and John Wawrzynek. More information
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is available through the Web page `http://www.cs.berkeley.edu/~jhauser/
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arithmetic/SoftFloat.html'.
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THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE. Although reasonable effort has
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been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT TIMES
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RESULT IN INCORRECT BEHAVIOR. USE OF THIS SOFTWARE IS RESTRICTED TO PERSONS
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AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ALL LOSSES,
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COSTS, OR OTHER PROBLEMS THEY INCUR DUE TO THE SOFTWARE, AND WHO FURTHERMORE
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EFFECTIVELY INDEMNIFY JOHN HAUSER AND THE INTERNATIONAL COMPUTER SCIENCE
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INSTITUTE (possibly via similar legal warning) AGAINST ALL LOSSES, COSTS, OR
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OTHER PROBLEMS INCURRED BY THEIR CUSTOMERS AND CLIENTS DUE TO THE SOFTWARE.
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Derivative works are acceptable, even for commercial purposes, so long as
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(1) the source code for the derivative work includes prominent notice that
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the work is derivative, and (2) the source code includes prominent notice with
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these four paragraphs for those parts of this code that are retained.
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=============================================================================*/
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#if defined(TARGET_MIPS) || defined(TARGET_HPPA)
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#define SNAN_BIT_IS_ONE 1 |
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#else
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#define SNAN_BIT_IS_ONE 0 |
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#endif
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/*----------------------------------------------------------------------------
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| Underflow tininess-detection mode, statically initialized to default value.
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| (The declaration in `softfloat.h' must match the `int8' type here.)
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*----------------------------------------------------------------------------*/
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int8 float_detect_tininess = float_tininess_after_rounding; |
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/*----------------------------------------------------------------------------
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| Raises the exceptions specified by `flags'. Floating-point traps can be
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| defined here if desired. It is currently not possible for such a trap
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| to substitute a result value. If traps are not implemented, this routine
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| should be simply `float_exception_flags |= flags;'.
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*----------------------------------------------------------------------------*/
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void float_raise( int8 flags STATUS_PARAM )
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{ |
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STATUS(float_exception_flags) |= flags; |
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} |
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/*----------------------------------------------------------------------------
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| Internal canonical NaN format.
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*----------------------------------------------------------------------------*/
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typedef struct { |
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flag sign; |
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bits64 high, low; |
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} commonNaNT; |
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/*----------------------------------------------------------------------------
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| The pattern for a default generated single-precision NaN.
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*----------------------------------------------------------------------------*/
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#if SNAN_BIT_IS_ONE
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#define float32_default_nan 0x7FBFFFFF |
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#else
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#define float32_default_nan 0xFFC00000 |
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#endif
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/*----------------------------------------------------------------------------
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| Returns 1 if the single-precision floating-point value `a' is a quiet
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| NaN; otherwise returns 0.
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*----------------------------------------------------------------------------*/
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int float32_is_nan( float32 a )
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{ |
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#if SNAN_BIT_IS_ONE
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return ( ( ( a>>22 ) & 0x1FF ) == 0x1FE ) && ( a & 0x003FFFFF ); |
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#else
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return ( 0xFF800000 <= (bits32) ( a<<1 ) ); |
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#endif
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} |
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/*----------------------------------------------------------------------------
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| Returns 1 if the single-precision floating-point value `a' is a signaling
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| NaN; otherwise returns 0.
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*----------------------------------------------------------------------------*/
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int float32_is_signaling_nan( float32 a )
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{ |
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#if SNAN_BIT_IS_ONE
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return ( 0xFF800000 <= (bits32) ( a<<1 ) ); |
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#else
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return ( ( ( a>>22 ) & 0x1FF ) == 0x1FE ) && ( a & 0x003FFFFF ); |
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#endif
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} |
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/*----------------------------------------------------------------------------
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| Returns the result of converting the single-precision floating-point NaN
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| `a' to the canonical NaN format. If `a' is a signaling NaN, the invalid
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| exception is raised.
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*----------------------------------------------------------------------------*/
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static commonNaNT float32ToCommonNaN( float32 a STATUS_PARAM )
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{ |
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commonNaNT z; |
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if ( float32_is_signaling_nan( a ) ) float_raise( float_flag_invalid STATUS_VAR );
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z.sign = a>>31;
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z.low = 0;
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z.high = ( (bits64) a )<<41;
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return z;
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} |
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/*----------------------------------------------------------------------------
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| Returns the result of converting the canonical NaN `a' to the single-
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| precision floating-point format.
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*----------------------------------------------------------------------------*/
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static float32 commonNaNToFloat32( commonNaNT a )
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{ |
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return ( ( (bits32) a.sign )<<31 ) | 0x7FC00000 | ( a.high>>41 ); |
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} |
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/*----------------------------------------------------------------------------
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| Takes two single-precision floating-point values `a' and `b', one of which
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| is a NaN, and returns the appropriate NaN result. If either `a' or `b' is a
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| signaling NaN, the invalid exception is raised.
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*----------------------------------------------------------------------------*/
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static float32 propagateFloat32NaN( float32 a, float32 b STATUS_PARAM)
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{ |
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flag aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN; |
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aIsNaN = float32_is_nan( a ); |
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aIsSignalingNaN = float32_is_signaling_nan( a ); |
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bIsNaN = float32_is_nan( b ); |
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bIsSignalingNaN = float32_is_signaling_nan( b ); |
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#if SNAN_BIT_IS_ONE
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a &= ~0x00400000;
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b &= ~0x00400000;
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#else
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a |= 0x00400000;
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b |= 0x00400000;
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#endif
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if ( aIsSignalingNaN | bIsSignalingNaN ) float_raise( float_flag_invalid STATUS_VAR);
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if ( aIsSignalingNaN ) {
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if ( bIsSignalingNaN ) goto returnLargerSignificand; |
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return bIsNaN ? b : a;
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} |
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else if ( aIsNaN ) { |
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if ( bIsSignalingNaN | ! bIsNaN ) return a; |
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returnLargerSignificand:
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if ( (bits32) ( a<<1 ) < (bits32) ( b<<1 ) ) return b; |
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if ( (bits32) ( b<<1 ) < (bits32) ( a<<1 ) ) return a; |
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return ( a < b ) ? a : b;
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} |
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else {
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return b;
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} |
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} |
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/*----------------------------------------------------------------------------
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| The pattern for a default generated double-precision NaN.
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*----------------------------------------------------------------------------*/
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#if SNAN_BIT_IS_ONE
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#define float64_default_nan LIT64( 0x7FF7FFFFFFFFFFFF ) |
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#else
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#define float64_default_nan LIT64( 0xFFF8000000000000 ) |
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#endif
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/*----------------------------------------------------------------------------
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| Returns 1 if the double-precision floating-point value `a' is a quiet
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| NaN; otherwise returns 0.
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*----------------------------------------------------------------------------*/
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int float64_is_nan( float64 a )
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{ |
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#if SNAN_BIT_IS_ONE
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return
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( ( ( a>>51 ) & 0xFFF ) == 0xFFE ) |
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&& ( a & LIT64( 0x0007FFFFFFFFFFFF ) );
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#else
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return ( LIT64( 0xFFF0000000000000 ) <= (bits64) ( a<<1 ) ); |
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#endif
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} |
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/*----------------------------------------------------------------------------
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| Returns 1 if the double-precision floating-point value `a' is a signaling
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| NaN; otherwise returns 0.
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*----------------------------------------------------------------------------*/
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int float64_is_signaling_nan( float64 a )
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{ |
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#if SNAN_BIT_IS_ONE
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return ( LIT64( 0xFFF0000000000000 ) <= (bits64) ( a<<1 ) ); |
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#else
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return
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( ( ( a>>51 ) & 0xFFF ) == 0xFFE ) |
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&& ( a & LIT64( 0x0007FFFFFFFFFFFF ) );
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#endif
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} |
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/*----------------------------------------------------------------------------
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| Returns the result of converting the double-precision floating-point NaN
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| `a' to the canonical NaN format. If `a' is a signaling NaN, the invalid
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| exception is raised.
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*----------------------------------------------------------------------------*/
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static commonNaNT float64ToCommonNaN( float64 a STATUS_PARAM)
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{ |
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commonNaNT z; |
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if ( float64_is_signaling_nan( a ) ) float_raise( float_flag_invalid STATUS_VAR);
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z.sign = a>>63;
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z.low = 0;
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z.high = a<<12;
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return z;
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} |
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/*----------------------------------------------------------------------------
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| Returns the result of converting the canonical NaN `a' to the double-
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| precision floating-point format.
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*----------------------------------------------------------------------------*/
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static float64 commonNaNToFloat64( commonNaNT a )
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{ |
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return
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( ( (bits64) a.sign )<<63 )
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| LIT64( 0x7FF8000000000000 )
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| ( a.high>>12 );
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} |
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/*----------------------------------------------------------------------------
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| Takes two double-precision floating-point values `a' and `b', one of which
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| is a NaN, and returns the appropriate NaN result. If either `a' or `b' is a
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| signaling NaN, the invalid exception is raised.
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*----------------------------------------------------------------------------*/
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static float64 propagateFloat64NaN( float64 a, float64 b STATUS_PARAM)
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{ |
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flag aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN; |
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aIsNaN = float64_is_nan( a ); |
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aIsSignalingNaN = float64_is_signaling_nan( a ); |
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bIsNaN = float64_is_nan( b ); |
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bIsSignalingNaN = float64_is_signaling_nan( b ); |
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#if SNAN_BIT_IS_ONE
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a &= ~LIT64( 0x0008000000000000 );
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b &= ~LIT64( 0x0008000000000000 );
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#else
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a |= LIT64( 0x0008000000000000 );
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b |= LIT64( 0x0008000000000000 );
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#endif
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if ( aIsSignalingNaN | bIsSignalingNaN ) float_raise( float_flag_invalid STATUS_VAR);
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if ( aIsSignalingNaN ) {
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if ( bIsSignalingNaN ) goto returnLargerSignificand; |
262 |
return bIsNaN ? b : a;
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} |
264 |
else if ( aIsNaN ) { |
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if ( bIsSignalingNaN | ! bIsNaN ) return a; |
266 |
returnLargerSignificand:
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if ( (bits64) ( a<<1 ) < (bits64) ( b<<1 ) ) return b; |
268 |
if ( (bits64) ( b<<1 ) < (bits64) ( a<<1 ) ) return a; |
269 |
return ( a < b ) ? a : b;
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} |
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else {
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return b;
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} |
274 |
} |
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#ifdef FLOATX80
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/*----------------------------------------------------------------------------
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| The pattern for a default generated extended double-precision NaN. The
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| `high' and `low' values hold the most- and least-significant bits,
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| respectively.
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*----------------------------------------------------------------------------*/
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#if SNAN_BIT_IS_ONE
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#define floatx80_default_nan_high 0x7FFF |
285 |
#define floatx80_default_nan_low LIT64( 0xBFFFFFFFFFFFFFFF ) |
286 |
#else
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#define floatx80_default_nan_high 0xFFFF |
288 |
#define floatx80_default_nan_low LIT64( 0xC000000000000000 ) |
289 |
#endif
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|
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/*----------------------------------------------------------------------------
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| Returns 1 if the extended double-precision floating-point value `a' is a
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| quiet NaN; otherwise returns 0.
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*----------------------------------------------------------------------------*/
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|
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int floatx80_is_nan( floatx80 a )
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{ |
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#if SNAN_BIT_IS_ONE
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bits64 aLow; |
300 |
|
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aLow = a.low & ~ LIT64( 0x4000000000000000 );
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return
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( ( a.high & 0x7FFF ) == 0x7FFF ) |
304 |
&& (bits64) ( aLow<<1 )
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&& ( a.low == aLow ); |
306 |
#else
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return ( ( a.high & 0x7FFF ) == 0x7FFF ) && (bits64) ( a.low<<1 ); |
308 |
#endif
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} |
310 |
|
311 |
/*----------------------------------------------------------------------------
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312 |
| Returns 1 if the extended double-precision floating-point value `a' is a
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313 |
| signaling NaN; otherwise returns 0.
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314 |
*----------------------------------------------------------------------------*/
|
315 |
|
316 |
int floatx80_is_signaling_nan( floatx80 a )
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317 |
{ |
318 |
#if SNAN_BIT_IS_ONE
|
319 |
return ( ( a.high & 0x7FFF ) == 0x7FFF ) && (bits64) ( a.low<<1 ); |
320 |
#else
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321 |
bits64 aLow; |
322 |
|
323 |
aLow = a.low & ~ LIT64( 0x4000000000000000 );
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324 |
return
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325 |
( ( a.high & 0x7FFF ) == 0x7FFF ) |
326 |
&& (bits64) ( aLow<<1 )
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327 |
&& ( a.low == aLow ); |
328 |
#endif
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329 |
} |
330 |
|
331 |
/*----------------------------------------------------------------------------
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332 |
| Returns the result of converting the extended double-precision floating-
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333 |
| point NaN `a' to the canonical NaN format. If `a' is a signaling NaN, the
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334 |
| invalid exception is raised.
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335 |
*----------------------------------------------------------------------------*/
|
336 |
|
337 |
static commonNaNT floatx80ToCommonNaN( floatx80 a STATUS_PARAM)
|
338 |
{ |
339 |
commonNaNT z; |
340 |
|
341 |
if ( floatx80_is_signaling_nan( a ) ) float_raise( float_flag_invalid STATUS_VAR);
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342 |
z.sign = a.high>>15;
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343 |
z.low = 0;
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344 |
z.high = a.low<<1;
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345 |
return z;
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346 |
} |
347 |
|
348 |
/*----------------------------------------------------------------------------
|
349 |
| Returns the result of converting the canonical NaN `a' to the extended
|
350 |
| double-precision floating-point format.
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351 |
*----------------------------------------------------------------------------*/
|
352 |
|
353 |
static floatx80 commonNaNToFloatx80( commonNaNT a )
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354 |
{ |
355 |
floatx80 z; |
356 |
|
357 |
z.low = LIT64( 0xC000000000000000 ) | ( a.high>>1 ); |
358 |
z.high = ( ( (bits16) a.sign )<<15 ) | 0x7FFF; |
359 |
return z;
|
360 |
} |
361 |
|
362 |
/*----------------------------------------------------------------------------
|
363 |
| Takes two extended double-precision floating-point values `a' and `b', one
|
364 |
| of which is a NaN, and returns the appropriate NaN result. If either `a' or
|
365 |
| `b' is a signaling NaN, the invalid exception is raised.
|
366 |
*----------------------------------------------------------------------------*/
|
367 |
|
368 |
static floatx80 propagateFloatx80NaN( floatx80 a, floatx80 b STATUS_PARAM)
|
369 |
{ |
370 |
flag aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN; |
371 |
|
372 |
aIsNaN = floatx80_is_nan( a ); |
373 |
aIsSignalingNaN = floatx80_is_signaling_nan( a ); |
374 |
bIsNaN = floatx80_is_nan( b ); |
375 |
bIsSignalingNaN = floatx80_is_signaling_nan( b ); |
376 |
#if SNAN_BIT_IS_ONE
|
377 |
a.low &= ~LIT64( 0xC000000000000000 );
|
378 |
b.low &= ~LIT64( 0xC000000000000000 );
|
379 |
#else
|
380 |
a.low |= LIT64( 0xC000000000000000 );
|
381 |
b.low |= LIT64( 0xC000000000000000 );
|
382 |
#endif
|
383 |
if ( aIsSignalingNaN | bIsSignalingNaN ) float_raise( float_flag_invalid STATUS_VAR);
|
384 |
if ( aIsSignalingNaN ) {
|
385 |
if ( bIsSignalingNaN ) goto returnLargerSignificand; |
386 |
return bIsNaN ? b : a;
|
387 |
} |
388 |
else if ( aIsNaN ) { |
389 |
if ( bIsSignalingNaN | ! bIsNaN ) return a; |
390 |
returnLargerSignificand:
|
391 |
if ( a.low < b.low ) return b; |
392 |
if ( b.low < a.low ) return a; |
393 |
return ( a.high < b.high ) ? a : b;
|
394 |
} |
395 |
else {
|
396 |
return b;
|
397 |
} |
398 |
} |
399 |
|
400 |
#endif
|
401 |
|
402 |
#ifdef FLOAT128
|
403 |
|
404 |
/*----------------------------------------------------------------------------
|
405 |
| The pattern for a default generated quadruple-precision NaN. The `high' and
|
406 |
| `low' values hold the most- and least-significant bits, respectively.
|
407 |
*----------------------------------------------------------------------------*/
|
408 |
#if SNAN_BIT_IS_ONE
|
409 |
#define float128_default_nan_high LIT64( 0x7FFF7FFFFFFFFFFF ) |
410 |
#define float128_default_nan_low LIT64( 0xFFFFFFFFFFFFFFFF ) |
411 |
#else
|
412 |
#define float128_default_nan_high LIT64( 0xFFFF800000000000 ) |
413 |
#define float128_default_nan_low LIT64( 0x0000000000000000 ) |
414 |
#endif
|
415 |
|
416 |
/*----------------------------------------------------------------------------
|
417 |
| Returns 1 if the quadruple-precision floating-point value `a' is a quiet
|
418 |
| NaN; otherwise returns 0.
|
419 |
*----------------------------------------------------------------------------*/
|
420 |
|
421 |
int float128_is_nan( float128 a )
|
422 |
{ |
423 |
#if SNAN_BIT_IS_ONE
|
424 |
return
|
425 |
( ( ( a.high>>47 ) & 0xFFFF ) == 0xFFFE ) |
426 |
&& ( a.low || ( a.high & LIT64( 0x00007FFFFFFFFFFF ) ) );
|
427 |
#else
|
428 |
return
|
429 |
( LIT64( 0xFFFE000000000000 ) <= (bits64) ( a.high<<1 ) ) |
430 |
&& ( a.low || ( a.high & LIT64( 0x0000FFFFFFFFFFFF ) ) );
|
431 |
#endif
|
432 |
} |
433 |
|
434 |
/*----------------------------------------------------------------------------
|
435 |
| Returns 1 if the quadruple-precision floating-point value `a' is a
|
436 |
| signaling NaN; otherwise returns 0.
|
437 |
*----------------------------------------------------------------------------*/
|
438 |
|
439 |
int float128_is_signaling_nan( float128 a )
|
440 |
{ |
441 |
#if SNAN_BIT_IS_ONE
|
442 |
return
|
443 |
( LIT64( 0xFFFE000000000000 ) <= (bits64) ( a.high<<1 ) ) |
444 |
&& ( a.low || ( a.high & LIT64( 0x0000FFFFFFFFFFFF ) ) );
|
445 |
#else
|
446 |
return
|
447 |
( ( ( a.high>>47 ) & 0xFFFF ) == 0xFFFE ) |
448 |
&& ( a.low || ( a.high & LIT64( 0x00007FFFFFFFFFFF ) ) );
|
449 |
#endif
|
450 |
} |
451 |
|
452 |
/*----------------------------------------------------------------------------
|
453 |
| Returns the result of converting the quadruple-precision floating-point NaN
|
454 |
| `a' to the canonical NaN format. If `a' is a signaling NaN, the invalid
|
455 |
| exception is raised.
|
456 |
*----------------------------------------------------------------------------*/
|
457 |
|
458 |
static commonNaNT float128ToCommonNaN( float128 a STATUS_PARAM)
|
459 |
{ |
460 |
commonNaNT z; |
461 |
|
462 |
if ( float128_is_signaling_nan( a ) ) float_raise( float_flag_invalid STATUS_VAR);
|
463 |
z.sign = a.high>>63;
|
464 |
shortShift128Left( a.high, a.low, 16, &z.high, &z.low );
|
465 |
return z;
|
466 |
} |
467 |
|
468 |
/*----------------------------------------------------------------------------
|
469 |
| Returns the result of converting the canonical NaN `a' to the quadruple-
|
470 |
| precision floating-point format.
|
471 |
*----------------------------------------------------------------------------*/
|
472 |
|
473 |
static float128 commonNaNToFloat128( commonNaNT a )
|
474 |
{ |
475 |
float128 z; |
476 |
|
477 |
shift128Right( a.high, a.low, 16, &z.high, &z.low );
|
478 |
z.high |= ( ( (bits64) a.sign )<<63 ) | LIT64( 0x7FFF800000000000 ); |
479 |
return z;
|
480 |
} |
481 |
|
482 |
/*----------------------------------------------------------------------------
|
483 |
| Takes two quadruple-precision floating-point values `a' and `b', one of
|
484 |
| which is a NaN, and returns the appropriate NaN result. If either `a' or
|
485 |
| `b' is a signaling NaN, the invalid exception is raised.
|
486 |
*----------------------------------------------------------------------------*/
|
487 |
|
488 |
static float128 propagateFloat128NaN( float128 a, float128 b STATUS_PARAM)
|
489 |
{ |
490 |
flag aIsNaN, aIsSignalingNaN, bIsNaN, bIsSignalingNaN; |
491 |
|
492 |
aIsNaN = float128_is_nan( a ); |
493 |
aIsSignalingNaN = float128_is_signaling_nan( a ); |
494 |
bIsNaN = float128_is_nan( b ); |
495 |
bIsSignalingNaN = float128_is_signaling_nan( b ); |
496 |
#if SNAN_BIT_IS_ONE
|
497 |
a.high &= ~LIT64( 0x0000800000000000 );
|
498 |
b.high &= ~LIT64( 0x0000800000000000 );
|
499 |
#else
|
500 |
a.high |= LIT64( 0x0000800000000000 );
|
501 |
b.high |= LIT64( 0x0000800000000000 );
|
502 |
#endif
|
503 |
if ( aIsSignalingNaN | bIsSignalingNaN ) float_raise( float_flag_invalid STATUS_VAR);
|
504 |
if ( aIsSignalingNaN ) {
|
505 |
if ( bIsSignalingNaN ) goto returnLargerSignificand; |
506 |
return bIsNaN ? b : a;
|
507 |
} |
508 |
else if ( aIsNaN ) { |
509 |
if ( bIsSignalingNaN | ! bIsNaN ) return a; |
510 |
returnLargerSignificand:
|
511 |
if ( lt128( a.high<<1, a.low, b.high<<1, b.low ) ) return b; |
512 |
if ( lt128( b.high<<1, b.low, a.high<<1, a.low ) ) return a; |
513 |
return ( a.high < b.high ) ? a : b;
|
514 |
} |
515 |
else {
|
516 |
return b;
|
517 |
} |
518 |
} |
519 |
|
520 |
#endif
|