/* $NetBSD: softfloat-macros.h,v 1.5 1999/05/06 13:56:28 kleink 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 ); #if 0 /* unused */ static bits32 estimateSqrt32( int16 aExp, bits32 a ); #endif 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<>count ); z0 = a0>>count; } else { if ( count == 32 ) { z2 = a1; z1 = a0; } else { a2 |= a1; if ( count < 64 ) { z2 = 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<>count ) | ( 0 < ( a1<>count; } else { if ( count == 32 ) { z1 = a0 | ( 0 < a1 ); } else if ( count < 64 ) { z1 = ( a0>>( count & 31 ) ) | ( 0 < ( ( a0<>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 ) & 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<>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; z1 = a1 + b1; *z1Ptr = z1; *z0Ptr = a0 + b0 + ( z1 < a1 ); } /* ------------------------------------------------------------------------------- Adds the 96-bit value formed by concatenating `a0', `a1', and `a2' to the 96-bit value formed by concatenating `b0', `b1', and `b2'. Addition is modulo 2^96, so any carry out is lost. The result is broken into three 32-bit pieces which are stored at the locations pointed to by `z0Ptr', `z1Ptr', and `z2Ptr'. ------------------------------------------------------------------------------- */ INLINE void add96( bits32 a0, bits32 a1, bits32 a2, bits32 b0, bits32 b1, bits32 b2, bits32 *z0Ptr, bits32 *z1Ptr, bits32 *z2Ptr ) { bits32 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 64-bit value formed by concatenating `b0' and `b1' from the 64-bit value formed by concatenating `a0' and `a1'. Subtraction is modulo 2^64, so any borrow out (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 sub64( bits32 a0, bits32 a1, bits32 b0, bits32 b1, bits32 *z0Ptr, bits32 *z1Ptr ) { *z1Ptr = a1 - b1; *z0Ptr = a0 - b0 - ( a1 < b1 ); } /* ------------------------------------------------------------------------------- Subtracts the 96-bit value formed by concatenating `b0', `b1', and `b2' from the 96-bit value formed by concatenating `a0', `a1', and `a2'. Subtraction is modulo 2^96, so any borrow out (carry out) is lost. The result is broken into three 32-bit pieces which are stored at the locations pointed to by `z0Ptr', `z1Ptr', and `z2Ptr'. ------------------------------------------------------------------------------- */ INLINE void sub96( bits32 a0, bits32 a1, bits32 a2, bits32 b0, bits32 b1, bits32 b2, bits32 *z0Ptr, bits32 *z1Ptr, bits32 *z2Ptr ) { bits32 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 64-bit product. The product is broken into two 32-bit pieces which are stored at the locations pointed to by `z0Ptr' and `z1Ptr'. ------------------------------------------------------------------------------- */ INLINE void mul32To64( bits32 a, bits32 b, bits32 *z0Ptr, bits32 *z1Ptr ) { bits16 aHigh, aLow, bHigh, bLow; bits32 z0, zMiddle, zMiddleOther, z1; aLow = ( a & 0xFFFF ); aHigh = a>>16; bLow = ( b & 0xFFFF ); bHigh = b>>16; z1 = aLow * bLow; zMiddle = aLow * bHigh; zMiddleOther = aHigh * bLow; z0 = aHigh * bHigh; zMiddle += zMiddleOther; z0 += ( ( zMiddle < zMiddleOther )<<16 ) + ( zMiddle>>16 ); zMiddle = zMiddle<<16; z1 += zMiddle; z0 += ( z1 < zMiddle ); *z1Ptr = z1; *z0Ptr = z0; } /* ------------------------------------------------------------------------------- Multiplies the 64-bit value formed by concatenating `a0' and `a1' by `b' to obtain a 96-bit product. The product is broken into three 32-bit pieces which are stored at the locations pointed to by `z0Ptr', `z1Ptr', and `z2Ptr'. ------------------------------------------------------------------------------- */ INLINE void mul64By32To96( bits32 a0, bits32 a1, bits32 b, bits32 *z0Ptr, bits32 *z1Ptr, bits32 *z2Ptr ) { bits32 z0, z1, z2, more1; mul32To64( a1, b, &z1, &z2 ); mul32To64( a0, b, &z0, &more1 ); add64( z0, more1, 0, z1, &z0, &z1 ); *z2Ptr = z2; *z1Ptr = z1; *z0Ptr = z0; } /* ------------------------------------------------------------------------------- Multiplies the 64-bit value formed by concatenating `a0' and `a1' to the 64-bit value formed by concatenating `b0' and `b1' to obtain a 128-bit product. The product is broken into four 32-bit pieces which are stored at the locations pointed to by `z0Ptr', `z1Ptr', `z2Ptr', and `z3Ptr'. ------------------------------------------------------------------------------- */ INLINE void mul64To128( bits32 a0, bits32 a1, bits32 b0, bits32 b1, bits32 *z0Ptr, bits32 *z1Ptr, bits32 *z2Ptr, bits32 *z3Ptr ) { bits32 z0, z1, z2, z3; bits32 more1, more2; mul32To64( a1, b1, &z2, &z3 ); mul32To64( a1, b0, &z1, &more2 ); add64( z1, more2, 0, z2, &z1, &z2 ); mul32To64( a0, b0, &z0, &more1 ); add64( z0, more1, 0, z1, &z0, &z1 ); mul32To64( a0, b1, &more1, &more2 ); add64( more1, more2, 0, z2, &more1, &z2 ); add64( z0, z1, 0, more1, &z0, &z1 ); *z3Ptr = z3; *z2Ptr = z2; *z1Ptr = z1; *z0Ptr = z0; } /* ------------------------------------------------------------------------------- Returns an approximation to the 32-bit integer quotient obtained by dividing the 64-bit value formed by concatenating `a0' and `a1' by `b'. The divisor `b' must be at least 2^31. 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 32 bits, the maximum positive 32-bit unsigned integer is returned. ------------------------------------------------------------------------------- */ static bits32 estimateDiv64To32( bits32 a0, bits32 a1, bits32 b ) { bits32 z; bits32 rem0, rem1; bits32 term0, term1; bits32 b0, b1; if ( b <= a0 ) return 0xFFFFFFFF; b0 = b>>16; z = ( b0<<16 <= a0 ) ? 0xFFFF0000 : ( a0 / b0 )<<16; mul32To64( b, z, &term0, &term1 ); sub64( a0, a1, term0, term1, &rem0, &rem1 ); while ( ( (sbits32) rem0 ) < 0 ) { z -= 0x10000; b1 = b<<16; add64( rem0, rem1, b0, b1, &rem0, &rem1 ); } rem0 = ( rem0<<16 ) | ( rem1>>16 ); z |= ( b0<<16 <= rem0 ) ? 0xFFFF : rem0 / b0; return z; } #if 0 /* unused */ /* ------------------------------------------------------------------------------- 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 = 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 ( ( estimateDiv64To32( a, 0, z ) )>>1 ) + ( z>>1 ); } #endif /* unused */ /* ------------------------------------------------------------------------------- Returns the number of leading 0 bits before the most-significant 1 bit of `a'. If `a' is zero, 32 is returned. ------------------------------------------------------------------------------- */ static int8 countLeadingZeros( 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 = a<<16; } if ( a < 0x1000000 ) { shiftCount += 8; a = a<<8; } shiftCount += countLeadingZerosHigh[ a>>24 ]; return shiftCount; } /* ------------------------------------------------------------------------------- Returns 1 if the 64-bit value formed by concatenating `a0' and `a1' is equal to the 64-bit value formed by concatenating `b0' and `b1'. Otherwise, returns 0. ------------------------------------------------------------------------------- */ INLINE flag eq64( bits32 a0, bits32 a1, bits32 b0, bits32 b1 ) { return ( a0 == b0 ) && ( a1 == b1 ); } /* ------------------------------------------------------------------------------- Returns 1 if the 64-bit value formed by concatenating `a0' and `a1' is less than or equal to the 64-bit value formed by concatenating `b0' and `b1'. Otherwise, returns 0. ------------------------------------------------------------------------------- */ INLINE flag le64( bits32 a0, bits32 a1, bits32 b0, bits32 b1 ) { return ( a0 < b0 ) || ( ( a0 == b0 ) && ( a1 <= b1 ) ); } /* ------------------------------------------------------------------------------- Returns 1 if the 64-bit value formed by concatenating `a0' and `a1' is less than the 64-bit value formed by concatenating `b0' and `b1'. Otherwise, returns 0. ------------------------------------------------------------------------------- */ INLINE flag lt64( bits32 a0, bits32 a1, bits32 b0, bits32 b1 ) { return ( a0 < b0 ) || ( ( a0 == b0 ) && ( a1 < b1 ) ); } /* ------------------------------------------------------------------------------- Returns 1 if the 64-bit value formed by concatenating `a0' and `a1' is not equal to the 64-bit value formed by concatenating `b0' and `b1'. Otherwise, returns 0. ------------------------------------------------------------------------------- */ #if 0 /* XXX not used */ INLINE flag ne64( bits32 a0, bits32 a1, bits32 b0, bits32 b1 ) { return ( a0 != b0 ) || ( a1 != b1 ); } #endif