gem5 / arm / linux-arm-legacy / 69ac35cf7a312006b4b0d7db8077aed0dbfbac32 / . / arch / arm / nwfpe / softfloat-macros

/* | |

=============================================================================== | |

This C source fragment is part of the SoftFloat IEC/IEEE Floating-point | |

Arithmetic Package, Release 2. | |

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.jhauser.us/arithmetic/SoftFloat-2b/SoftFloat-source.txt | |

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 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. | |

=============================================================================== | |

*/ | |

/* | |

------------------------------------------------------------------------------- | |

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; | |

__asm__("@shift64RightJamming -- start"); | |

if ( count == 0 ) { | |

z = a; | |

} | |

else if ( count < 64 ) { | |

z = ( a>>count ) | ( ( a<<( ( - count ) & 63 ) ) != 0 ); | |

} | |

else { | |

z = ( a != 0 ); | |

} | |

__asm__("@shift64RightJamming -- end"); | |

*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; /* hence b0 is 32 bits wide now */ | |

if ( b0<<32 <= a0 ) { | |

z = LIT64( 0xFFFFFFFF00000000 ); | |

} else { | |

z = a0; | |

do_div( z, b0 ); | |

z <<= 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 ); | |

if ( b0<<32 <= rem0 ) { | |

z |= 0xFFFFFFFF; | |

} else { | |

do_div( rem0, b0 ); | |

z |= rem0; | |

} | |

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; | |

bits64 A; | |

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 ); | |

} | |

A = ( (bits64) a )<<31; | |

do_div( A, z ); | |

return ( (bits32) A ) + ( 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 ); | |

} | |