Working on a total FPU rewrite based on softfloat

5 instructions down, a million more to go
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pruten 2014-09-27 13:46:57 -04:00
parent a0810f55b9
commit bb2ec0a27d
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core/SoftFloat/386-GCC.h Normal file
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/*----------------------------------------------------------------------------
| One of the macros `BIGENDIAN' or `LITTLEENDIAN' must be defined.
*----------------------------------------------------------------------------*/
#define LITTLEENDIAN
/*----------------------------------------------------------------------------
| The macro `BITS64' can be defined to indicate that 64-bit integer types are
| supported by the compiler.
*----------------------------------------------------------------------------*/
#define BITS64
/*----------------------------------------------------------------------------
| Each of the following `typedef's defines the most convenient type that holds
| integers of at least as many bits as specified. For example, `uint8' should
| be the most convenient type that can hold unsigned integers of as many as
| 8 bits. The `flag' type must be able to hold either a 0 or 1. For most
| implementations of C, `flag', `uint8', and `int8' should all be `typedef'ed
| to the same as `int'.
*----------------------------------------------------------------------------*/
typedef char flag;
typedef unsigned char uint8;
typedef signed char int8;
typedef int uint16;
typedef int int16;
typedef unsigned int uint32;
typedef signed int int32;
#ifdef BITS64
typedef unsigned long long int uint64;
typedef signed long long int int64;
#endif
/*----------------------------------------------------------------------------
| Each of the following `typedef's defines a type that holds integers
| of _exactly_ the number of bits specified. For instance, for most
| implementation of C, `bits16' and `sbits16' should be `typedef'ed to
| `unsigned short int' and `signed short int' (or `short int'), respectively.
*----------------------------------------------------------------------------*/
typedef unsigned char bits8;
typedef signed char sbits8;
typedef unsigned short int bits16;
typedef signed short int sbits16;
typedef unsigned int bits32;
typedef signed int sbits32;
#ifdef BITS64
typedef unsigned long long int bits64;
typedef signed long long int sbits64;
#endif
#ifdef BITS64
/*----------------------------------------------------------------------------
| The `LIT64' macro takes as its argument a textual integer literal and
| if necessary ``marks'' the literal as having a 64-bit integer type.
| For example, the GNU C Compiler (`gcc') requires that 64-bit literals be
| appended with the letters `LL' standing for `long long', which is `gcc's
| name for the 64-bit integer type. Some compilers may allow `LIT64' to be
| defined as the identity macro: `#define LIT64( a ) a'.
*----------------------------------------------------------------------------*/
#define LIT64( a ) a##LL
#endif
/*----------------------------------------------------------------------------
| The macro `INLINE' can be used before functions that should be inlined. If
| a compiler does not support explicit inlining, this macro should be defined
| to be `static'.
*----------------------------------------------------------------------------*/
#define INLINE static

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/*============================================================================
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 notice) 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.
=============================================================================*/
/*----------------------------------------------------------------------------
| Shifts `a' right 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 shift32RightJamming( bits32 a, int16 count, bits32 *zPtr )
{
bits32 z;
if ( count == 0 ) {
z = a;
}
else if ( count < 32 ) {
z = ( a>>count ) | ( ( a<<( ( - count ) & 31 ) ) != 0 );
}
else {
z = ( a != 0 );
}
*zPtr = z;
}
/*----------------------------------------------------------------------------
| Shifts `a' right 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 `a' is zero or nonzero.
| The result is stored in the location pointed to by `zPtr'.
*----------------------------------------------------------------------------*/
INLINE void shift64RightJamming( bits64 a, int16 count, bits64 *zPtr )
{
bits64 z;
if ( count == 0 ) {
z = a;
}
else if ( count < 64 ) {
z = ( a>>count ) | ( ( a<<( ( - count ) & 63 ) ) != 0 );
}
else {
z = ( a != 0 );
}
*zPtr = z;
}
/*----------------------------------------------------------------------------
| Shifts the 128-bit value formed by concatenating `a0' and `a1' right by 64
| _plus_ the number of bits given in `count'. The shifted result is at most
| 64 nonzero bits; this is stored at the location pointed to by `z0Ptr'. The
| bits shifted off form a second 64-bit result as follows: The _last_ bit
| shifted off is the most-significant bit of the extra result, and the other
| 63 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 `z1Ptr'. The value of `count' can be arbitrarily large.
| (This routine makes more sense if `a0' and `a1' are considered to form
| a fixed-point value with binary point between `a0' and `a1'. This fixed-
| point value is shifted right by the number of bits given in `count', and
| the integer part of the result is returned at the location pointed to by
| `z0Ptr'. The fractional part of the result may be slightly corrupted as
| described above, and is returned at the location pointed to by `z1Ptr'.)
*----------------------------------------------------------------------------*/
INLINE void
shift64ExtraRightJamming(
bits64 a0, bits64 a1, int16 count, bits64 *z0Ptr, bits64 *z1Ptr )
{
bits64 z0, z1;
int8 negCount = ( - count ) & 63;
if ( count == 0 ) {
z1 = a1;
z0 = a0;
}
else if ( count < 64 ) {
z1 = ( a0<<negCount ) | ( a1 != 0 );
z0 = a0>>count;
}
else {
if ( count == 64 ) {
z1 = a0 | ( a1 != 0 );
}
else {
z1 = ( ( a0 | a1 ) != 0 );
}
z0 = 0;
}
*z1Ptr = z1;
*z0Ptr = z0;
}
/*----------------------------------------------------------------------------
| Shifts the 128-bit value formed by concatenating `a0' and `a1' right 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 128, the result will be 0. The result is broken into two 64-bit pieces
| which are stored at the locations pointed to by `z0Ptr' and `z1Ptr'.
*----------------------------------------------------------------------------*/
INLINE void
shift128Right(
bits64 a0, bits64 a1, int16 count, bits64 *z0Ptr, bits64 *z1Ptr )
{
bits64 z0, z1;
int8 negCount = ( - count ) & 63;
if ( count == 0 ) {
z1 = a1;
z0 = a0;
}
else if ( count < 64 ) {
z1 = ( a0<<negCount ) | ( a1>>count );
z0 = a0>>count;
}
else {
z1 = ( count < 64 ) ? ( a0>>( count & 63 ) ) : 0;
z0 = 0;
}
*z1Ptr = z1;
*z0Ptr = z0;
}
/*----------------------------------------------------------------------------
| Shifts the 128-bit value formed by concatenating `a0' and `a1' right 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 128, 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 64-bit pieces which are stored at
| the locations pointed to by `z0Ptr' and `z1Ptr'.
*----------------------------------------------------------------------------*/
INLINE void
shift128RightJamming(
bits64 a0, bits64 a1, int16 count, bits64 *z0Ptr, bits64 *z1Ptr )
{
bits64 z0, z1;
int8 negCount = ( - count ) & 63;
if ( count == 0 ) {
z1 = a1;
z0 = a0;
}
else if ( count < 64 ) {
z1 = ( a0<<negCount ) | ( a1>>count ) | ( ( a1<<negCount ) != 0 );
z0 = a0>>count;
}
else {
if ( count == 64 ) {
z1 = a0 | ( a1 != 0 );
}
else if ( count < 128 ) {
z1 = ( a0>>( count & 63 ) ) | ( ( ( a0<<negCount ) | a1 ) != 0 );
}
else {
z1 = ( ( a0 | a1 ) != 0 );
}
z0 = 0;
}
*z1Ptr = z1;
*z0Ptr = z0;
}
/*----------------------------------------------------------------------------
| Shifts the 192-bit value formed by concatenating `a0', `a1', and `a2' right
| by 64 _plus_ the number of bits given in `count'. The shifted result is
| at most 128 nonzero bits; these are broken into two 64-bit pieces which are
| stored at the locations pointed to by `z0Ptr' and `z1Ptr'. The bits shifted
| off form a third 64-bit result as follows: The _last_ bit shifted off is
| the most-significant bit of the extra result, and the other 63 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 right 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
shift128ExtraRightJamming(
bits64 a0,
bits64 a1,
bits64 a2,
int16 count,
bits64 *z0Ptr,
bits64 *z1Ptr,
bits64 *z2Ptr
)
{
bits64 z0, z1, z2;
int8 negCount = ( - count ) & 63;
if ( count == 0 ) {
z2 = a2;
z1 = a1;
z0 = a0;
}
else {
if ( count < 64 ) {
z2 = a1<<negCount;
z1 = ( a0<<negCount ) | ( a1>>count );
z0 = a0>>count;
}
else {
if ( count == 64 ) {
z2 = a1;
z1 = a0;
}
else {
a2 |= a1;
if ( count < 128 ) {
z2 = a0<<negCount;
z1 = a0>>( count & 63 );
}
else {
z2 = ( count == 128 ) ? a0 : ( a0 != 0 );
z1 = 0;
}
}
z0 = 0;
}
z2 |= ( a2 != 0 );
}
*z2Ptr = z2;
*z1Ptr = z1;
*z0Ptr = z0;
}
/*----------------------------------------------------------------------------
| Shifts the 128-bit value formed by concatenating `a0' and `a1' left by the
| number of bits given in `count'. Any bits shifted off are lost. The value
| of `count' must be less than 64. The result is broken into two 64-bit
| pieces which are stored at the locations pointed to by `z0Ptr' and `z1Ptr'.
*----------------------------------------------------------------------------*/
INLINE void
shortShift128Left(
bits64 a0, bits64 a1, int16 count, bits64 *z0Ptr, bits64 *z1Ptr )
{
*z1Ptr = a1<<count;
*z0Ptr =
( count == 0 ) ? a0 : ( a0<<count ) | ( a1>>( ( - count ) & 63 ) );
}
/*----------------------------------------------------------------------------
| Shifts the 192-bit value formed by concatenating `a0', `a1', and `a2' left
| by the number of bits given in `count'. Any bits shifted off are lost.
| The value of `count' must be less than 64. The result is broken into three
| 64-bit pieces which are stored at the locations pointed to by `z0Ptr',
| `z1Ptr', and `z2Ptr'.
*----------------------------------------------------------------------------*/
INLINE void
shortShift192Left(
bits64 a0,
bits64 a1,
bits64 a2,
int16 count,
bits64 *z0Ptr,
bits64 *z1Ptr,
bits64 *z2Ptr
)
{
bits64 z0, z1, z2;
int8 negCount;
z2 = a2<<count;
z1 = a1<<count;
z0 = a0<<count;
if ( 0 < count ) {
negCount = ( ( - count ) & 63 );
z1 |= a2>>negCount;
z0 |= a1>>negCount;
}
*z2Ptr = z2;
*z1Ptr = z1;
*z0Ptr = z0;
}
/*----------------------------------------------------------------------------
| Adds the 128-bit value formed by concatenating `a0' and `a1' to the 128-bit
| value formed by concatenating `b0' and `b1'. Addition is modulo 2^128, so
| any carry out is lost. The result is broken into two 64-bit pieces which
| are stored at the locations pointed to by `z0Ptr' and `z1Ptr'.
*----------------------------------------------------------------------------*/
INLINE void
add128(
bits64 a0, bits64 a1, bits64 b0, bits64 b1, bits64 *z0Ptr, bits64 *z1Ptr )
{
bits64 z1;
z1 = a1 + b1;
*z1Ptr = z1;
*z0Ptr = a0 + b0 + ( z1 < a1 );
}
/*----------------------------------------------------------------------------
| Adds the 192-bit value formed by concatenating `a0', `a1', and `a2' to the
| 192-bit value formed by concatenating `b0', `b1', and `b2'. Addition is
| modulo 2^192, so any carry out is lost. The result is broken into three
| 64-bit pieces which are stored at the locations pointed to by `z0Ptr',
| `z1Ptr', and `z2Ptr'.
*----------------------------------------------------------------------------*/
INLINE void
add192(
bits64 a0,
bits64 a1,
bits64 a2,
bits64 b0,
bits64 b1,
bits64 b2,
bits64 *z0Ptr,
bits64 *z1Ptr,
bits64 *z2Ptr
)
{
bits64 z0, z1, z2;
int8 carry0, carry1;
z2 = a2 + b2;
carry1 = ( z2 < a2 );
z1 = a1 + b1;
carry0 = ( z1 < a1 );
z0 = a0 + b0;
z1 += carry1;
z0 += ( z1 < carry1 );
z0 += carry0;
*z2Ptr = z2;
*z1Ptr = z1;
*z0Ptr = z0;
}
/*----------------------------------------------------------------------------
| Subtracts the 128-bit value formed by concatenating `b0' and `b1' from the
| 128-bit value formed by concatenating `a0' and `a1'. Subtraction is modulo
| 2^128, so any borrow out (carry out) is lost. The result is broken into two
| 64-bit pieces which are stored at the locations pointed to by `z0Ptr' and
| `z1Ptr'.
*----------------------------------------------------------------------------*/
INLINE void
sub128(
bits64 a0, bits64 a1, bits64 b0, bits64 b1, bits64 *z0Ptr, bits64 *z1Ptr )
{
*z1Ptr = a1 - b1;
*z0Ptr = a0 - b0 - ( a1 < b1 );
}
/*----------------------------------------------------------------------------
| Subtracts the 192-bit value formed by concatenating `b0', `b1', and `b2'
| from the 192-bit value formed by concatenating `a0', `a1', and `a2'.
| Subtraction is modulo 2^192, so any borrow out (carry out) is lost. The
| result is broken into three 64-bit pieces which are stored at the locations
| pointed to by `z0Ptr', `z1Ptr', and `z2Ptr'.
*----------------------------------------------------------------------------*/
INLINE void
sub192(
bits64 a0,
bits64 a1,
bits64 a2,
bits64 b0,
bits64 b1,
bits64 b2,
bits64 *z0Ptr,
bits64 *z1Ptr,
bits64 *z2Ptr
)
{
bits64 z0, z1, z2;
int8 borrow0, borrow1;
z2 = a2 - b2;
borrow1 = ( a2 < b2 );
z1 = a1 - b1;
borrow0 = ( a1 < b1 );
z0 = a0 - b0;
z0 -= ( z1 < borrow1 );
z1 -= borrow1;
z0 -= borrow0;
*z2Ptr = z2;
*z1Ptr = z1;
*z0Ptr = z0;
}
/*----------------------------------------------------------------------------
| Multiplies `a' by `b' to obtain a 128-bit product. The product is broken
| into two 64-bit pieces which are stored at the locations pointed to by
| `z0Ptr' and `z1Ptr'.
*----------------------------------------------------------------------------*/
INLINE void mul64To128( bits64 a, bits64 b, bits64 *z0Ptr, bits64 *z1Ptr )
{
bits32 aHigh, aLow, bHigh, bLow;
bits64 z0, zMiddleA, zMiddleB, z1;
aLow = a;
aHigh = a>>32;
bLow = b;
bHigh = b>>32;
z1 = ( (bits64) aLow ) * bLow;
zMiddleA = ( (bits64) aLow ) * bHigh;
zMiddleB = ( (bits64) aHigh ) * bLow;
z0 = ( (bits64) aHigh ) * bHigh;
zMiddleA += zMiddleB;
z0 += ( ( (bits64) ( zMiddleA < zMiddleB ) )<<32 ) + ( zMiddleA>>32 );
zMiddleA <<= 32;
z1 += zMiddleA;
z0 += ( z1 < zMiddleA );
*z1Ptr = z1;
*z0Ptr = z0;
}
/*----------------------------------------------------------------------------
| Multiplies the 128-bit value formed by concatenating `a0' and `a1' by
| `b' to obtain a 192-bit product. The product is broken into three 64-bit
| pieces which are stored at the locations pointed to by `z0Ptr', `z1Ptr', and
| `z2Ptr'.
*----------------------------------------------------------------------------*/
INLINE void
mul128By64To192(
bits64 a0,
bits64 a1,
bits64 b,
bits64 *z0Ptr,
bits64 *z1Ptr,
bits64 *z2Ptr
)
{
bits64 z0, z1, z2, more1;
mul64To128( a1, b, &z1, &z2 );
mul64To128( a0, b, &z0, &more1 );
add128( z0, more1, 0, z1, &z0, &z1 );
*z2Ptr = z2;
*z1Ptr = z1;
*z0Ptr = z0;
}
/*----------------------------------------------------------------------------
| Multiplies the 128-bit value formed by concatenating `a0' and `a1' to the
| 128-bit value formed by concatenating `b0' and `b1' to obtain a 256-bit
| product. The product is broken into four 64-bit pieces which are stored at
| the locations pointed to by `z0Ptr', `z1Ptr', `z2Ptr', and `z3Ptr'.
*----------------------------------------------------------------------------*/
INLINE void
mul128To256(
bits64 a0,
bits64 a1,
bits64 b0,
bits64 b1,
bits64 *z0Ptr,
bits64 *z1Ptr,
bits64 *z2Ptr,
bits64 *z3Ptr
)
{
bits64 z0, z1, z2, z3;
bits64 more1, more2;
mul64To128( a1, b1, &z2, &z3 );
mul64To128( a1, b0, &z1, &more2 );
add128( z1, more2, 0, z2, &z1, &z2 );
mul64To128( a0, b0, &z0, &more1 );
add128( z0, more1, 0, z1, &z0, &z1 );
mul64To128( a0, b1, &more1, &more2 );
add128( more1, more2, 0, z2, &more1, &z2 );
add128( z0, z1, 0, more1, &z0, &z1 );
*z3Ptr = z3;
*z2Ptr = z2;
*z1Ptr = z1;
*z0Ptr = z0;
}
/*----------------------------------------------------------------------------
| Returns an approximation to the 64-bit integer quotient obtained by dividing
| `b' into the 128-bit value formed by concatenating `a0' and `a1'. The
| divisor `b' must be at least 2^63. If q is the exact quotient truncated
| toward zero, the approximation returned lies between q and q + 2 inclusive.
| If the exact quotient q is larger than 64 bits, the maximum positive 64-bit
| unsigned integer is returned.
*----------------------------------------------------------------------------*/
static bits64 estimateDiv128To64( bits64 a0, bits64 a1, bits64 b )
{
bits64 b0, b1;
bits64 rem0, rem1, term0, term1;
bits64 z;
if ( b <= a0 ) return LIT64( 0xFFFFFFFFFFFFFFFF );
b0 = b>>32;
z = ( b0<<32 <= a0 ) ? LIT64( 0xFFFFFFFF00000000 ) : ( a0 / b0 )<<32;
mul64To128( b, z, &term0, &term1 );
sub128( a0, a1, term0, term1, &rem0, &rem1 );
while ( ( (sbits64) rem0 ) < 0 ) {
z -= LIT64( 0x100000000 );
b1 = b<<32;
add128( rem0, rem1, b0, b1, &rem0, &rem1 );
}
rem0 = ( rem0<<32 ) | ( rem1>>32 );
z |= ( b0<<32 <= rem0 ) ? 0xFFFFFFFF : rem0 / b0;
return z;
}
/*----------------------------------------------------------------------------
| Returns an approximation to the square root of the 32-bit significand given
| by `a'. Considered as an integer, `a' must be at least 2^31. If bit 0 of
| `aExp' (the least significant bit) is 1, the integer returned approximates
| 2^31*sqrt(`a'/2^31), where `a' is considered an integer. If bit 0 of `aExp'
| is 0, the integer returned approximates 2^31*sqrt(`a'/2^30). In either
| case, the approximation returned lies strictly within +/-2 of the exact
| value.
*----------------------------------------------------------------------------*/
static bits32 estimateSqrt32( int16 aExp, bits32 a )
{
static const bits16 sqrtOddAdjustments[] = {
0x0004, 0x0022, 0x005D, 0x00B1, 0x011D, 0x019F, 0x0236, 0x02E0,
0x039C, 0x0468, 0x0545, 0x0631, 0x072B, 0x0832, 0x0946, 0x0A67
};
static const bits16 sqrtEvenAdjustments[] = {
0x0A2D, 0x08AF, 0x075A, 0x0629, 0x051A, 0x0429, 0x0356, 0x029E,
0x0200, 0x0179, 0x0109, 0x00AF, 0x0068, 0x0034, 0x0012, 0x0002
};
int8 index;
bits32 z;
index = ( a>>27 ) & 15;
if ( aExp & 1 ) {
z = 0x4000 + ( a>>17 ) - sqrtOddAdjustments[ index ];
z = ( ( a / z )<<14 ) + ( z<<15 );
a >>= 1;
}
else {
z = 0x8000 + ( a>>17 ) - sqrtEvenAdjustments[ index ];
z = a / z + z;
z = ( 0x20000 <= z ) ? 0xFFFF8000 : ( z<<15 );
if ( z <= a ) return (bits32) ( ( (sbits32) a )>>1 );
}
return ( (bits32) ( ( ( (bits64) a )<<31 ) / z ) ) + ( z>>1 );
}
/*----------------------------------------------------------------------------
| Returns the number of leading 0 bits before the most-significant 1 bit of
| `a'. If `a' is zero, 32 is returned.
*----------------------------------------------------------------------------*/
static int8 countLeadingZeros32( bits32 a )
{
static const int8 countLeadingZerosHigh[] = {
8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
int8 shiftCount;
shiftCount = 0;
if ( a < 0x10000 ) {
shiftCount += 16;
a <<= 16;
}
if ( a < 0x1000000 ) {
shiftCount += 8;
a <<= 8;
}
shiftCount += countLeadingZerosHigh[ a>>24 ];
return shiftCount;
}
/*----------------------------------------------------------------------------
| Returns the number of leading 0 bits before the most-significant 1 bit of
| `a'. If `a' is zero, 64 is returned.
*----------------------------------------------------------------------------*/
static int8 countLeadingZeros64( bits64 a )
{
int8 shiftCount;
shiftCount = 0;
if ( a < ( (bits64) 1 )<<32 ) {
shiftCount += 32;
}
else {
a >>= 32;
}
shiftCount += countLeadingZeros32( a );
return shiftCount;
}
/*----------------------------------------------------------------------------
| Returns 1 if the 128-bit value formed by concatenating `a0' and `a1'
| is equal to the 128-bit value formed by concatenating `b0' and `b1'.
| Otherwise, returns 0.
*----------------------------------------------------------------------------*/
INLINE flag eq128( bits64 a0, bits64 a1, bits64 b0, bits64 b1 )
{
return ( a0 == b0 ) && ( a1 == b1 );
}
/*----------------------------------------------------------------------------
| Returns 1 if the 128-bit value formed by concatenating `a0' and `a1' is less
| than or equal to the 128-bit value formed by concatenating `b0' and `b1'.
| Otherwise, returns 0.
*----------------------------------------------------------------------------*/
INLINE flag le128( bits64 a0, bits64 a1, bits64 b0, bits64 b1 )
{
return ( a0 < b0 ) || ( ( a0 == b0 ) && ( a1 <= b1 ) );
}
/*----------------------------------------------------------------------------
| Returns 1 if the 128-bit value formed by concatenating `a0' and `a1' is less
| than the 128-bit value formed by concatenating `b0' and `b1'. Otherwise,
| returns 0.
*----------------------------------------------------------------------------*/
INLINE flag lt128( bits64 a0, bits64 a1, bits64 b0, bits64 b1 )
{
return ( a0 < b0 ) || ( ( a0 == b0 ) && ( a1 < b1 ) );
}
/*----------------------------------------------------------------------------
| Returns 1 if the 128-bit value formed by concatenating `a0' and `a1' is
| not equal to the 128-bit value formed by concatenating `b0' and `b1'.
| Otherwise, returns 0.
*----------------------------------------------------------------------------*/
INLINE flag ne128( bits64 a0, bits64 a1, bits64 b0, bits64 b1 )
{
return ( a0 != b0 ) || ( a1 != b1 );
}

View File

@ -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 )
{
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 )
{
commonNaNT z;
if ( float32_is_signaling_nan( a ) ) float_raise( float_flag_invalid );
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 )
{
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 );
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 )
{
commonNaNT z;
if ( float64_is_signaling_nan( a ) ) float_raise( float_flag_invalid );
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 )
{
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 );
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 )
{
commonNaNT z;
if ( floatx80_is_signaling_nan( a ) ) float_raise( float_flag_invalid );
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 )
{
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 );
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 )
{
commonNaNT z;
if ( float128_is_signaling_nan( a ) ) float_raise( float_flag_invalid );
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 )
{
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 );
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

5201
core/SoftFloat/softfloat.c Normal file

File diff suppressed because it is too large Load Diff

259
core/SoftFloat/softfloat.h Normal file
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@ -0,0 +1,259 @@
/*============================================================================
This C header 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.
=============================================================================*/
/*----------------------------------------------------------------------------
| The macro `FLOATX80' must be defined to enable the extended double-precision
| floating-point format `floatx80'. If this macro is not defined, the
| `floatx80' type will not be defined, and none of the functions that either
| input or output the `floatx80' type will be defined. The same applies to
| the `FLOAT128' macro and the quadruple-precision format `float128'.
*----------------------------------------------------------------------------*/
#define FLOATX80
#define FLOAT128
/*----------------------------------------------------------------------------
| Software IEC/IEEE floating-point types.
*----------------------------------------------------------------------------*/
typedef unsigned int float32;
typedef unsigned long long float64;
#ifdef FLOATX80
typedef struct {
unsigned long long low;
unsigned short high;
} floatx80;
#endif
#ifdef FLOAT128
typedef struct {
unsigned long long low, high;
} float128;
#endif
/*----------------------------------------------------------------------------
| Software IEC/IEEE floating-point underflow tininess-detection mode.
*----------------------------------------------------------------------------*/
extern signed char float_detect_tininess;
enum {
float_tininess_after_rounding = 0,
float_tininess_before_rounding = 1
};
/*----------------------------------------------------------------------------
| Software IEC/IEEE floating-point rounding mode.
*----------------------------------------------------------------------------*/
extern signed char float_rounding_mode;
enum {
float_round_nearest_even = 0,
float_round_down = 1,
float_round_up = 2,
float_round_to_zero = 3
};
/*----------------------------------------------------------------------------
| Software IEC/IEEE floating-point exception flags.
*----------------------------------------------------------------------------*/
extern signed char float_exception_flags;
enum {
float_flag_invalid = 1,
float_flag_divbyzero = 4,
float_flag_overflow = 8,
float_flag_underflow = 16,
float_flag_inexact = 32
};
/*----------------------------------------------------------------------------
| Routine to raise any or all of the software IEC/IEEE floating-point
| exception flags.
*----------------------------------------------------------------------------*/
void float_raise( signed char );
/*----------------------------------------------------------------------------
| Software IEC/IEEE integer-to-floating-point conversion routines.
*----------------------------------------------------------------------------*/
float32 int32_to_float32( int );
float64 int32_to_float64( int );
#ifdef FLOATX80
floatx80 int32_to_floatx80( int );
#endif
#ifdef FLOAT128
float128 int32_to_float128( int );
#endif
float32 int64_to_float32( long long );
float64 int64_to_float64( long long );
#ifdef FLOATX80
floatx80 int64_to_floatx80( long long );
#endif
#ifdef FLOAT128
float128 int64_to_float128( long long );
#endif
/*----------------------------------------------------------------------------
| Software IEC/IEEE single-precision conversion routines.
*----------------------------------------------------------------------------*/
int float32_to_int32( float32 );
int float32_to_int32_round_to_zero( float32 );
long long float32_to_int64( float32 );
long long float32_to_int64_round_to_zero( float32 );
float64 float32_to_float64( float32 );
#ifdef FLOATX80
floatx80 float32_to_floatx80( float32 );
#endif
#ifdef FLOAT128
float128 float32_to_float128( float32 );
#endif
/*----------------------------------------------------------------------------
| Software IEC/IEEE single-precision operations.
*----------------------------------------------------------------------------*/
float32 float32_round_to_int( float32 );
float32 float32_add( float32, float32 );
float32 float32_sub( float32, float32 );
float32 float32_mul( float32, float32 );
float32 float32_div( float32, float32 );
float32 float32_rem( float32, float32 );
float32 float32_sqrt( float32 );
char float32_eq( float32, float32 );
char float32_le( float32, float32 );
char float32_lt( float32, float32 );
char float32_eq_signaling( float32, float32 );
char float32_le_quiet( float32, float32 );
char float32_lt_quiet( float32, float32 );
char float32_is_signaling_nan( float32 );
/*----------------------------------------------------------------------------
| Software IEC/IEEE double-precision conversion routines.
*----------------------------------------------------------------------------*/
int float64_to_int32( float64 );
int float64_to_int32_round_to_zero( float64 );
long long float64_to_int64( float64 );
long long float64_to_int64_round_to_zero( float64 );
float32 float64_to_float32( float64 );
#ifdef FLOATX80
floatx80 float64_to_floatx80( float64 );
#endif
#ifdef FLOAT128
float128 float64_to_float128( float64 );
#endif
/*----------------------------------------------------------------------------
| Software IEC/IEEE double-precision operations.
*----------------------------------------------------------------------------*/
float64 float64_round_to_int( float64 );
float64 float64_add( float64, float64 );
float64 float64_sub( float64, float64 );
float64 float64_mul( float64, float64 );
float64 float64_div( float64, float64 );
float64 float64_rem( float64, float64 );
float64 float64_sqrt( float64 );
char float64_eq( float64, float64 );
char float64_le( float64, float64 );
char float64_lt( float64, float64 );
char float64_eq_signaling( float64, float64 );
char float64_le_quiet( float64, float64 );
char float64_lt_quiet( float64, float64 );
char float64_is_signaling_nan( float64 );
#ifdef FLOATX80
/*----------------------------------------------------------------------------
| Software IEC/IEEE extended double-precision conversion routines.
*----------------------------------------------------------------------------*/
int floatx80_to_int32( floatx80 );
int floatx80_to_int32_round_to_zero( floatx80 );
long long floatx80_to_int64( floatx80 );
long long floatx80_to_int64_round_to_zero( floatx80 );
float32 floatx80_to_float32( floatx80 );
float64 floatx80_to_float64( floatx80 );
#ifdef FLOAT128
float128 floatx80_to_float128( floatx80 );
#endif
/*----------------------------------------------------------------------------
| Software IEC/IEEE extended double-precision rounding precision. Valid
| values are 32, 64, and 80.
*----------------------------------------------------------------------------*/
extern signed char floatx80_rounding_precision;
/*----------------------------------------------------------------------------
| Software IEC/IEEE extended double-precision operations.
*----------------------------------------------------------------------------*/
floatx80 floatx80_round_to_int( floatx80 );
floatx80 floatx80_add( floatx80, floatx80 );
floatx80 floatx80_sub( floatx80, floatx80 );
floatx80 floatx80_mul( floatx80, floatx80 );
floatx80 floatx80_div( floatx80, floatx80 );
floatx80 floatx80_rem( floatx80, floatx80 );
floatx80 floatx80_sqrt( floatx80 );
char floatx80_eq( floatx80, floatx80 );
char floatx80_le( floatx80, floatx80 );
char floatx80_lt( floatx80, floatx80 );
char floatx80_eq_signaling( floatx80, floatx80 );
char floatx80_le_quiet( floatx80, floatx80 );
char floatx80_lt_quiet( floatx80, floatx80 );
char floatx80_is_signaling_nan( floatx80 );
#endif
#ifdef FLOAT128
/*----------------------------------------------------------------------------
| Software IEC/IEEE quadruple-precision conversion routines.
*----------------------------------------------------------------------------*/
int float128_to_int32( float128 );
int float128_to_int32_round_to_zero( float128 );
long long float128_to_int64( float128 );
long long float128_to_int64_round_to_zero( float128 );
float32 float128_to_float32( float128 );
float64 float128_to_float64( float128 );
#ifdef FLOATX80
floatx80 float128_to_floatx80( float128 );
#endif
/*----------------------------------------------------------------------------
| Software IEC/IEEE quadruple-precision operations.
*----------------------------------------------------------------------------*/
float128 float128_round_to_int( float128 );
float128 float128_add( float128, float128 );
float128 float128_sub( float128, float128 );
float128 float128_mul( float128, float128 );
float128 float128_div( float128, float128 );
float128 float128_rem( float128, float128 );
float128 float128_sqrt( float128 );
char float128_eq( float128, float128 );
char float128_le( float128, float128 );
char float128_lt( float128, float128 );
char float128_eq_signaling( float128, float128 );
char float128_le_quiet( float128, float128 );
char float128_lt_quiet( float128, float128 );
char float128_is_signaling_nan( float128 );
#endif

23
core/SoftFloat/test.c Normal file
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#include <stdio.h>
#include <stdint.h>
#include <math.h>
#include "softfloat.h"
floatx80 f[8];
int main (void)
{
float128 a = int64_to_float128(123);
float128 b = int64_to_float128(123);
float128 c = float128_mul(a, b);
int32_t c_int = float128_to_int32(c);
printf("123 * 123 = %d (expected %d)\n", c_int, 123 * 123);
printf("%f\n", a);
return 0;
}

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/*
* Copyright (c) 2013-2014, Peter Rutenbar <pruten@gmail.com>
* 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.
*
* 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 OWNER 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.
*/
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include "../core/shoebill.h"
#include "../core/SoftFloat/softfloat.h"
#pragma mark Structures and macros
// Mode control byte
#define mc_rnd (fpu->fpcr.b._mc_rnd)
#define mc_prec (fpu->fpcr.b._mc_prec)
// Exception enable byte
#define ee_inex1 (fpu->fpcr.b._ee_inex1)
#define ee_inex2 (fpu->fpcr.b._ee_inex2)
#define ee_dz (fpu->fpcr.b._ee_dz)
#define ee_unfl (fpu->fpcr.b._ee_unfl)
#define ee_ovfl (fpu->fpcr.b._ee_ovfl)
#define ee_operr (fpu->fpcr.b._ee_operr)
#define ee_snan (fpu->fpcr.b._ee_snan)
#define ee_bsun (fpu->fpcr.b._ee_bsun)
// Accrued exception byte
#define ae_inex (fpu->fpsr.b._ae_inex)
#define ae_dz (fpu->fpsr.b._ae_dz)
#define ae_unfl (fpu->fpsr.b._ae_unfl)
#define ae_ovfl (fpu->fpsr.b._ae_ovfl)
#define ae_iop (fpu->fpsr.b._ae_iop)
// Exception status byte
#define es_inex1 (fpu->fpsr.b._es_inex1)
#define es_inex2 (fpu->fpsr.b._es_inex2)
#define es_dz (fpu->fpsr.b._es_dz)
#define es_unfl (fpu->fpsr.b._es_unfl)
#define es_ovfl (fpu->fpsr.b._es_ovfl)
#define es_operr (fpu->fpsr.b._es_operr)
#define es_snan (fpu->fpsr.b._es_snan)
#define es_bsun (fpu->fpsr.b._es_bsun)
// Quotient byte
#define qu_quotient (fpu->fpsr.b._qu_quotient)
#define qu_s (fpu->fpsr.b._qu_s) /* quotient sign */
// Condition codes
#define cc_nan (fpu->fpsr.b._cc_nan)
#define cc_i (fpu->fpsr.b._cc_i)
#define cc_z (fpu->fpsr.b._cc_z)
#define cc_n (fpu->fpsr.b._cc_n)
typedef struct {
uint32_t fpiar; // FPU iaddr
union { // fpcr, fpu control register
struct {
// Mode control byte
uint16_t _mc_zero : 4; // zero/dummy
uint16_t _mc_rnd : 2; // rounding mode
uint16_t _mc_prec : 2; // rounding precision
// Exception enable byte
uint16_t _ee_inex1 : 1; // inexact decimal input
uint16_t _ee_inex2 : 1; // inxact operation
uint16_t _ee_dz : 1; // divide by zero
uint16_t _ee_unfl : 1; // underflow
uint16_t _ee_ovfl : 1; // overflow
uint16_t _ee_operr : 1; // operand error
uint16_t _ee_snan : 1; // signalling not a number
uint16_t _ee_bsun : 1; // branch/set on unordered
} b;
uint16_t raw;
} fpcr;
union { // fpsr, fpu status register
struct {
// Accrued exception byte
uint32_t _dummy1 : 3; // dummy/zero
uint32_t _ae_inex : 1; // inexact
uint32_t _ae_dz : 1; // divide by zero
uint32_t _ae_unfl : 1; // underflow
uint32_t _ae_ovfl : 1; // overflow
uint32_t _ae_iop : 1; // invalid operation
// Exception status byte
uint32_t _es_inex1 : 1; // inexact decimal input
uint32_t _es_inex2 : 1; // inxact operation
uint32_t _es_dz : 1; // divide by zero
uint32_t _es_unfl : 1; // underflow
uint32_t _es_ovfl : 1; // overflow
uint32_t _es_operr : 1; // operand error
uint32_t _es_snan : 1; // signalling not a number
uint32_t _es_bsun : 1; // branch/set on unordered
// Quotient byte
uint32_t _qu_quotient : 7;
uint32_t _qu_s : 1;
// Condition code byte
uint32_t _cc_nan : 1; // not a number
uint32_t _cc_i : 1; // infinity
uint32_t _cc_z : 1; // zero
uint32_t _cc_n : 1; // negative
uint32_t _dummy2 : 4; // dummy/zero
} b;
uint32_t raw;
} fpsr;
floatx80 fp[8]; // 80 bit floating point general registers
} fpu_state_t;
#define fpu_get_state_ptr() fpu_state_t *fpu = (fpu_state_t*)shoe.fpu_state
#define nextword() ({const uint16_t w=lget(shoe.pc,2); if (shoe.abort) {return;}; shoe.pc+=2; w;})
#define nextlong() ({const uint32_t L=lget(shoe.pc,4); if (shoe.abort) {return;}; shoe.pc+=4; L;})
#define verify_supervisor() {if (!sr_s()) {throw_privilege_violation(); return;}}
#pragma mark FPU exception throwers
enum fpu_vector_t {
fpu_vector_ftrapcc = 7,
fpu_vector_fline = 11,
fpu_vector_coprocessor_protocol_violation = 13, // won't be using this one
fpu_vector_bsun = 48,
fpu_vector_inexact = 49,
fpu_vector_divide_by_zero = 50,
fpu_vector_underflow = 51,
fpu_vector_operr = 52,
fpu_vector_overflow = 53,
fpu_vector_snan = 54
};
#define expush(_dat, _sz) {\
const uint32_t sz = (_sz); \
lset(shoe.a[7] - sz, sz, (_dat)); \
if (shoe.abort) assert(!"fpu: expush: double fault during lset!"); \
shoe.a[7] -= sz; \
}
static void throw_fpu_pre_instruction_exception(enum fpu_vector_t vector)
{
throw_frame_zero(shoe.orig_sr, shoe.orig_pc, vector);
}
// Note: I may be able to get away without implementing the
// mid-instruction exception.
/*
* _bsun_test() is called by every inst_f*cc instruction
* to test whether the bsun exception is enabled, throw an
* exception if so, and otherwise just set the appropriate
* bit in fpsr, and update the accrued exception byte.
*/
static _Bool _bsun_test()
{
fpu_get_state_ptr();
// BSUN counts against the IOP accrued exception bit
ae_iop = 1;
// Set the BSUN exception status bit
es_bsun = 1;
// If the BSUN exception isn't enabled, then we can just return
if (!ee_bsun)
return 0; // 0 -> elected not to throw an exception
throw_fpu_pre_instruction_exception(fpu_vector_bsun);
return 1;
}
#pragma mark Second-hop instructions
static void inst_fmath (const uint16_t ext)
{
~decompose(shoe.op, 1111 001 000 MMMMMM);
~decompose(ext, 0 a 0 sss ddd eeeeeee);
const uint8_t src_in_ea = a;
const uint8_t source_specifier = s;
const uint8_t dest_register = d;
const uint8_t extension = e;
_Bool do_write_back_result = 1;
float128 source, result;
if (src_in_ea) {
source = _fpu_read_ea(M, source_specifier);
if (shoe.abort)
return ;
}
else
source = floatx80_to_float128(fpu->fp[source_specifier]);
float128 dest = floatx80_to_float128(fpu->fp[dest_register]);
assert(!"fmath");
}
static void inst_fmove (const uint16_t ext)
{
assert(!"fmove");
}
static void inst_fmovem_control (const uint16_t ext)
{
assert(!"fmovem_control");
}
static void inst_fmovem (const uint16_t ext)
{
assert(!"fmovem");
}
#pragma mark First-hop decoder table inst implementations
/*
* The table generated by decoder_gen.c will refer directly
* to these instructions. inst_fpu_other() will handle all
* other FPU instructions.
*/
static _Bool fpu_test_cc(uint8_t cc)
{
fpu_get_state_ptr();
const _Bool z = cc_z;
const _Bool n = cc_n;
const _Bool nan = cc_nan;
switch (cc & 0x0f) {
case 0: // false
return 0;
case 1: // equal
return z;
case 2: // greater than
return !(nan | z | n);
case 3: // greater than or equal
return z | !(nan | n);
case 4: // less than
return n & !(nan | z);
case 5: // less than or equal
return z | (n & !nan);
case 6: // greater or less than
return !(nan | z);
case 7: // ordered
return !nan;
case 8: // unordered
return nan;
case 9: // not (greater or less than)
return nan | z;
case 10: // not (less than or equal)
return nan | !(n | z);
case 11: // not (less than)
return nan | (z | !n);
case 12: // not (greater than or equal)
return nan | (n & !z);
case 13: // not (greater than)
return nan | z | n;
case 14: // not equal
return !z;
case 15: // true
return 1;
}
assert(0);
return 0;
}
void inst_fscc () {
fpu_get_state_ptr();
// fscc can throw an exception
fpu->fpiar = shoe.orig_pc;
const uint16_t ext = nextword();
~decompose(shoe.op, 1111 001 001 MMMMMM);
~decompose(ext, 0000 0000 000 b cccc);
/*
* inst_f*cc instructions throw a pre-instruction exception
* if b && cc_nan
*/
if (b && _bsun_test())
return ;
shoe.dat = fpu_test_cc(c) ? 0xff : 0;
call_ea_write(M, 1);
}
void inst_fbcc () {
fpu_get_state_ptr();
// fbcc can throw an exception
fpu->fpiar = shoe.orig_pc;
~decompose(shoe.op, 1111 001 01 s 0bcccc); // b => raise BSUN if NaN
const uint8_t sz = 2 << s;
/*
* inst_f*cc instructions throw a pre-instruction exception
* if b && cc_nan
*/
if (b && _bsun_test())
return ;
if (fpu_test_cc(c)) {
const uint16_t ext = nextword();
uint32_t displacement;
if (s) {
const uint16_t ext2 = nextword();
displacement = (ext << 16) | ext2;
}
else
displacement = (int16_t)ext;
shoe.pc = shoe.orig_pc + 2 + displacement;
}
else
shoe.pc += sz;
}
void inst_fsave () {
fpu_get_state_ptr();
verify_supervisor();
// Don't modify fpiar for fsave
~decompose(shoe.op, 1111 001 100 MMMMMM);
~decompose(shoe.op, 1111 001 100 mmmrrr);
const uint32_t size = 0x1c; // IDLE frame
const uint16_t frame_header = 0xfd18;
uint32_t addr;
if (m == 4)
addr = shoe.a[r] - size;
else {
call_ea_addr(M);
addr = shoe.dat;
}
lset(addr, 2, frame_header);
if (shoe.abort)
return ;
if (m == 4)
shoe.a[r] = addr;
}
void inst_frestore () {
fpu_get_state_ptr();
verify_supervisor();
// Don't modify fpiar for frestore
~decompose(shoe.op, 1111 001 101 MMMMMM);
~decompose(shoe.op, 1111 001 101 mmmrrr);
uint32_t addr, size;
if (m == 3)
addr = shoe.a[r];
else {
call_ea_addr(M);
addr = shoe.dat;
}
const uint16_t word = lget(addr, 2);
if (shoe.abort) return ;
// XXX: These frame sizes are different on 68881/68882/68040
if ((word & 0xff00) == 0x0000)
size = 4; // NULL state frame
else if ((word & 0xff) == 0x0018)
size = 0x1c; // IDLE state frame
else if ((word & 0xff) == 0x00b4)
size = 0xb8; // BUSY state frame
else {
slog("Frestore encountered an unknown state frame 0x%04x\n", word);
assert("inst_frestore: bad state frame");
return ;
}
if (m==3) {
shoe.a[r] += size;
slog("frestore: changing shoe.a[%u] += %u\n", r, size);
}
}
void inst_fdbcc () {
fpu_get_state_ptr();
~decompose(shoe.op, 1111 001 001 001 rrr);
// fdbcc can throw an exception
fpu->fpiar = shoe.orig_pc;
const uint16_t ext = nextword();
~decompose(ext, 0000 0000 000 b cccc);
/*
* inst_f*cc instructions throw a pre-instruction exception
* if b && cc_nan
*/
if (b && _bsun_test())
return ;
if (fpu_test_cc(c)) {
shoe.pc += 2;
}
else {
const int16_t disp = nextword();
const uint16_t newd = get_d(r, 2) - 1;
set_d(r, newd, 2);
if (newd != 0xffff)
shoe.pc = shoe.orig_pc + 2 + disp;
}
}
void inst_ftrapcc () {
fpu_get_state_ptr();
~decompose(shoe.op, 1111 001 001 111 xyz);
// ftrapcc can throw an exception
fpu->fpiar = shoe.orig_pc;
// (xyz) == (100) -> sz=0
// (xyz) == (010) -> sz=2
// (xyz) == (011) -> sz=4
const uint32_t sz = y << (z+1);
const uint32_t next_pc = shoe.orig_pc + 2 + sz;
const uint16_t ext = nextword();
~decompose(ext, 0000 0000 000 b cccc);
/*
* inst_f*cc instructions throw a pre-instruction exception
* if b && cc_nan
*/
if (b && _bsun_test())
return ;
if (fpu_test_cc(c))
throw_frame_two(shoe.sr, next_pc, 7, shoe.orig_pc);
else
shoe.pc = next_pc;
}
void inst_fnop() {
// This is technically fbcc, so we should set fpiar too
fpu->fpiar = shoe.orig_pc;
}
void inst_fpu_other () {
fpu_get_state_ptr();
~decompose(shoe.op, 1111 001 000 MMMMMM);
const uint16_t ext = nextword();
~decompose(ext, ccc xxx yyy eeeeeee);
switch (c) {
case 0: // Reg to reg
fpu->fpiar = shoe.orig_pc; // fmath() can throw an exception
inst_fmath(ext);
return;
case 1: // unused
throw_illegal_instruction();
return;
case 2: // Memory->reg & movec
fpu->fpiar = shoe.orig_pc; // fmath() can throw an exception
inst_fmath(ext);
return;
case 3: // reg->mem
fpu->fpiar = shoe.orig_pc; // fmove() can throw an exception
inst_fmove(ext);
return;
case 4: // mem -> sys ctl registers
case 5: // sys ctl registers -> mem
// fmovem_control() cannot throw an FPU exception (don't modify fpiar)
inst_fmovem_control(ext);
return;
case 6: // movem to fp registers
case 7: // movem to memory
// fmovem() cannot throw an FPU exception (don't modify fpiar)
inst_fmovem(ext);
return;
}
assert(0); // never get here
return;
}
#pragma mark FPU-state initialization and reset
void fpu_initialize()
{
fpu_state_t *fpu = (fpu_state_t*)p_alloc(shoe.pool, sizeof(fpu_state_t));
memset(fpu, sizeof(fpu_state_t), 0);
shoe.fpu_state = fpu;
}
void fpu_reset()
{
p_free(shoe.fpu_state);
fpu_initialize();
}