softfloat-macros.h

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/*	$NetBSD: softfloat-macros.h,v 1.4 1998/04/24 18:46:53 cgd Exp $	*/

/*
===============================================================================

This C source fragment is part of the SoftFloat IEC/IEEE Floating-point
Arithmetic Package, Release 1a.

Written by John R. Hauser.  This work was made possible by the International
Computer Science Institute, located at Suite 600, 1947 Center Street,
Berkeley, California 94704.  Funding was provided in part 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/
softfloat.html'.

THIS PACKAGE IS DISTRIBUTED AS IS, FOR FREE.  Although reasonable effort has
been made to avoid it, THIS PACKAGE MAY CONTAIN FAULTS THAT WILL AT TIMES
RESULT IN INCORRECT BEHAVIOR.  USE OF THIS PACKAGE 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 three paragraphs for those parts of
this code that are retained.

===============================================================================
*/

INLINE void shiftDown32Jamming( bits32 a, uint16 count, bits32 *zPtr );

INLINE void shiftDown64ExtraJamming(
     bits32 a0,
     bits32 a1,
     bits32 a2,
     uint16 count,
     bits32 *z0Ptr,
     bits32 *z1Ptr,
     bits32 *z2Ptr
 );

INLINE void shiftDown64Jamming(
     bits32 a0, bits32 a1, uint16 count, bits32 *z0Ptr, bits32 *z1Ptr );

INLINE void shiftDown64(
     bits32 a0, bits32 a1, uint16 count, bits32 *z0Ptr, bits32 *z1Ptr );

INLINE void shortShiftUp64(
     bits32 a0, bits32 a1, uint16 count, bits32 *z0Ptr, bits32 *z1Ptr );

INLINE void shortShiftUp96(
     bits32 a0,
     bits32 a1,
     bits32 a2,
     uint16 count,
     bits32 *z0Ptr,
     bits32 *z1Ptr,
     bits32 *z2Ptr
 );

INLINE void add64(
     bits32 a0, bits32 a1, bits32 b0, bits32 b1, bits32 *z0Ptr, bits32 *z1Ptr );

INLINE void add96(
     bits32 a0,
     bits32 a1,
     bits32 a2,
     bits32 b0,
     bits32 b1,
     bits32 b2,
     bits32 *z0Ptr,
     bits32 *z1Ptr,
     bits32 *z2Ptr
 );

INLINE void sub64(
     bits32 a0, bits32 a1, bits32 b0, bits32 b1, bits32 *z0Ptr, bits32 *z1Ptr );

INLINE void sub96(
     bits32 a0,
     bits32 a1,
     bits32 a2,
     bits32 b0,
     bits32 b1,
     bits32 b2,
     bits32 *z0Ptr,
     bits32 *z1Ptr,
     bits32 *z2Ptr
 );

INLINE void mul32To64( bits32 a, bits32 b, bits32 *z0Ptr, bits32 *z1Ptr );

INLINE void mul64By32To96(
     bits32 a0,
     bits32 a1,
     bits32 b,
     bits32 *z0Ptr,
     bits32 *z1Ptr,
     bits32 *z2Ptr
 );

INLINE void mul64To128(
     bits32 a0,
     bits32 a1,
     bits32 b0,
     bits32 b1,
     bits32 *z0Ptr,
     bits32 *z1Ptr,
     bits32 *z2Ptr,
     bits32 *z3Ptr
 );

static bits32 estimateDiv64To32( bits32 a0, bits32 a1, bits32 b );

static bits32 estimateSqrt32( int16 aExp, bits32 a );

static int8 countLeadingZeros( bits32 a );

INLINE flag eq64( bits32 a0, bits32 a1, bits32 b0, bits32 b1 );

INLINE flag le64( bits32 a0, bits32 a1, bits32 b0, bits32 b1 );

INLINE flag lt64( bits32 a0, bits32 a1, bits32 b0, bits32 b1 );

#if 0 /* XXX not used */
INLINE flag ne64( bits32 a0, bits32 a1, bits32 b0, bits32 b1 );
#endif


/*
-------------------------------------------------------------------------------
Shifts `a' down by the number of bits given in `count'.  If any nonzero bits
are shifted off, they are ``jammed'' into the least significant bit of the
result by setting the least significant bit to 1.  The value of `count' can
be arbitrarily large; in particular, if `count' is greater than 32, the
result will be either 0 or 1, depending on whether `a' is zero or nonzero.
The result is stored in the location pointed to by `zPtr'.
-------------------------------------------------------------------------------
*/
INLINE void shiftDown32Jamming( bits32 a, uint16 count, bits32 *zPtr )
{
    bits32 z;

    if ( count == 0 ) {
        z = a;
    }
    else if ( count < 32 ) {
        z = ( a>>count ) | ( 0 < ( a<<( ( - count ) & 31 ) ) );
    }
    else {
        z = ( 0 < a );
    }
    *zPtr = z;

}

/*
-------------------------------------------------------------------------------
Shifts the 96-bit value formed by concatenating `a0', `a1', and `a2' down by
32 _plus_ the number of bits given in `count'.  The shifted-down result is
at most 64 nonzero bits; these are broken into two 32-bit pieces which are
stored at the locations pointed to by `z0Ptr' and `z1Ptr'.  The bits shifted
off form a third 32-bit result as follows:  The _last_ bit shifted off is
the most-significant bit of the extra result, and the other 31 bits of the
extra result are all zero if and only if _all_but_the_last_ bits shifted off
were all zero.  This extra result is stored in the location pointed to by
`z2Ptr'.  The value of `count' can be arbitrarily large.
    (This routine makes more sense if `a0', `a1', and `a2' are considered
to form a fixed-point value with binary point between `a1' and `a2'.  This
fixed-point value is shifted down by the number of bits given in `count',
and the integer part of the result is returned at the locations pointed to
by `z0Ptr' and `z1Ptr'.  The fractional part of the result may be slightly
corrupted as described above, and is returned at the location pointed to by
`z2Ptr'.)
-------------------------------------------------------------------------------
*/
INLINE void
 shiftDown64ExtraJamming(
     bits32 a0,
     bits32 a1,
     bits32 a2,
     uint16 count,
     bits32 *z0Ptr,
     bits32 *z1Ptr,
     bits32 *z2Ptr
 )
{
    bits32 z0, z1, z2;
    int8 negCount = ( - count ) & 31;

    if ( count == 0 ) {
        z2 = a2;
        z1 = a1;
        z0 = a0;
    }
    else {
        if ( count < 32 ) {
            z2 = a1<<negCount;
            z1 = ( a0<<negCount ) | ( a1>>count );
            z0 = a0>>count;
        }
        else {
            if ( count == 32 ) {
                z2 = a1;
                z1 = a0;
            }
            else {
                a2 |= a1;
                if ( count < 64 ) {
                    z2 = a0<<negCount;
                    z1 = a0>>( count & 31 );
                }
                else {
                    z2 = ( count == 64 ) ? a0 : ( 0 < a0 );
                    z1 = 0;
                }
            }
            z0 = 0;
        }
        z2 |= ( 0 < a2 );
    }
    *z2Ptr = z2;
    *z1Ptr = z1;
    *z0Ptr = z0;

}

/*
-------------------------------------------------------------------------------
Shifts the 64-bit value formed by concatenating `a0' and `a1' down by the
number of bits given in `count'.  If any nonzero bits are shifted off, they
are ``jammed'' into the least significant bit of the result by setting the
least significant bit to 1.  The value of `count' can be arbitrarily large;
in particular, if `count' is greater than 64, the result will be either 0
or 1, depending on whether the concatenation of `a0' and `a1' is zero or
nonzero.  The result is broken into two 32-bit pieces which are stored at
the locations pointed to by `z0Ptr' and `z1Ptr'.
-------------------------------------------------------------------------------
*/
INLINE void
 shiftDown64Jamming(
     bits32 a0, bits32 a1, uint16 count, bits32 *z0Ptr, bits32 *z1Ptr )
{
    bits32 z0, z1;
    int8 negCount = ( - count ) & 31;

    if ( count == 0 ) {
        z1 = a1;
        z0 = a0;
    }
    else if ( count < 32 ) {
        z1 = ( a0<<negCount ) | ( a1>>count ) | ( 0 < ( a1<<negCount ) );
        z0 = a0>>count;
    }
    else {
        if ( count == 32 ) {
            z1 = a0 | ( 0 < a1 );
        }
        else if ( count < 64 ) {
            z1 = ( a0>>( count & 31 ) ) | ( 0 < ( ( a0<<negCount ) | a1 ) );
        }
        else {
            z1 = ( 0 < ( a0 | a1 ) );
        }
        z0 = 0;
    }
    *z1Ptr = z1;
    *z0Ptr = z0;

}

/*
-------------------------------------------------------------------------------
Shifts the 64-bit value formed by concatenating `a0' and `a1' down by the
number of bits given in `count'.  Any bits shifted off are lost.  The value
of `count' can be arbitrarily large; in particular, if `count' is greater
than 64, the result will be 0.  The result is broken into two 32-bit pieces
which are stored at the locations pointed to by `z0Ptr' and `z1Ptr'.
-------------------------------------------------------------------------------
*/
INLINE void
 shiftDown64(
     bits32 a0, bits32 a1, uint16 count, bits32 *z0Ptr, bits32 *z1Ptr )
{
    bits32 z0, z1;
    int8 negCount = ( - count ) & 31;

    if ( count == 0 ) {
        z1 = a1;
        z0 = a0;
    }
    else if ( count < 32 ) {
        z1 = ( a0<<negCount ) | ( a1>>count );
        z0 = a0>>count;
    }
    else {
        z1 = ( count < 64 ) ? ( a0>>( count & 31 ) ) : 0;
        z0 = 0;
    }
    *z1Ptr = z1;
    *z0Ptr = z0;

}

/*
-------------------------------------------------------------------------------
Shifts the 64-bit value formed by concatenating `a0' and `a1' up by the
number of bits given in `count'.  Any bits shifted off are lost.  The value
of `count' must be less than 32.  The result is broken into two 32-bit
pieces which are stored at the locations pointed to by `z0Ptr' and `z1Ptr'.
-------------------------------------------------------------------------------
*/
INLINE void
 shortShiftUp64(
     bits32 a0, bits32 a1, uint16 count, bits32 *z0Ptr, bits32 *z1Ptr )
{

    *z1Ptr = a1<<count;
    *z0Ptr =
        ( count == 0 ) ? a0 : ( a0<<count ) | ( a1>>( ( - count ) & 31 ) );

}

/*
-------------------------------------------------------------------------------
Shifts the 96-bit value formed by concatenating `a0', `a1', and `a2' up by
the number of bits given in `count'.  Any bits shifted off are lost.  The
value of `count' must be less than 32.  The result is broken into three
32-bit pieces which are stored at the locations pointed to by `z0Ptr',
`z1Ptr', and `z2Ptr'.
-------------------------------------------------------------------------------
*/
INLINE void
 shortShiftUp96(
     bits32 a0,
     bits32 a1,
     bits32 a2,
     uint16 count,
     bits32 *z0Ptr,
     bits32 *z1Ptr,
     bits32 *z2Ptr
 )
{
    bits32 z0, z1, z2;
    int8 negCount;

    z2 = a2<<count;
    z1 = a1<<count;
    z0 = a0<<count;
    if ( 0 < count ) {
        negCount = ( ( - count ) & 31 );
        z1 |= a2>>negCount;
        z0 |= a1>>negCount;
    }
    *z2Ptr = z2;
    *z1Ptr = z1;
    *z0Ptr = z0;

}

/*
-------------------------------------------------------------------------------
Adds the 64-bit value formed by concatenating `a0' and `a1' to the 64-bit
value formed by concatenating `b0' and `b1'.  Addition is modulo 2^64, so
any carry out is lost.  The result is broken into two 32-bit pieces which
are stored at the locations pointed to by `z0Ptr' and `z1Ptr'.
-------------------------------------------------------------------------------
*/
INLINE void
 add64(
     bits32 a0, bits32 a1, bits32 b0, bits32 b1, bits32 *z0Ptr, bits32 *z1Ptr )
{
    bits32 z1;