diff options
Diffstat (limited to 'src/lib/softfloat/softfloat.h')
-rw-r--r-- | src/lib/softfloat/softfloat.h | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/src/lib/softfloat/softfloat.h b/src/lib/softfloat/softfloat.h index cb5ee9458ad..642daa901d6 100644 --- a/src/lib/softfloat/softfloat.h +++ b/src/lib/softfloat/softfloat.h @@ -58,6 +58,13 @@ typedef struct { #endif /*---------------------------------------------------------------------------- +| Primitive arithmetic functions, including multi-word arithmetic, and +| division and square root approximations. (Can be specialized to target if +| desired.) +*----------------------------------------------------------------------------*/ +#include "softfloat-macros" + +/*---------------------------------------------------------------------------- | Software IEC/IEEE floating-point underflow tininess-detection mode. *----------------------------------------------------------------------------*/ extern int8 float_detect_tininess; @@ -197,6 +204,21 @@ float128 floatx80_to_float128( floatx80 ); #endif /*---------------------------------------------------------------------------- +| Packs the sign `zSign', exponent `zExp', and significand `zSig' into an +| extended double-precision floating-point value, returning the result. +*----------------------------------------------------------------------------*/ + +INLINE floatx80 packFloatx80( flag zSign, int32 zExp, bits64 zSig ) +{ + floatx80 z; + + z.low = zSig; + z.high = ( ( (bits16) zSign )<<15 ) + zExp; + return z; + +} + +/*---------------------------------------------------------------------------- | Software IEC/IEEE extended double-precision rounding precision. Valid | values are 32, 64, and 80. *----------------------------------------------------------------------------*/ @@ -220,6 +242,10 @@ flag floatx80_le_quiet( floatx80, floatx80 ); flag floatx80_lt_quiet( floatx80, floatx80 ); flag floatx80_is_signaling_nan( floatx80 ); +int floatx80_fsin(floatx80 &a); +int floatx80_fcos(floatx80 &a); +int floatx80_ftan(floatx80 &a); + #endif #ifdef FLOAT128 @@ -255,5 +281,176 @@ flag float128_le_quiet( float128, float128 ); flag float128_lt_quiet( float128, float128 ); flag float128_is_signaling_nan( float128 ); +/*---------------------------------------------------------------------------- +| Packs the sign `zSign', the exponent `zExp', and the significand formed +| by the concatenation of `zSig0' and `zSig1' into a quadruple-precision +| floating-point value, returning the result. After being shifted into the +| proper positions, the three fields `zSign', `zExp', and `zSig0' are simply +| added together to form the most significant 32 bits of the result. This +| means that any integer portion of `zSig0' will be added into the exponent. +| Since a properly normalized significand will have an integer portion equal +| to 1, the `zExp' input should be 1 less than the desired result exponent +| whenever `zSig0' and `zSig1' concatenated form a complete, normalized +| significand. +*----------------------------------------------------------------------------*/ + +INLINE float128 + packFloat128( flag zSign, int32 zExp, bits64 zSig0, bits64 zSig1 ) +{ + float128 z; + + z.low = zSig1; + z.high = ( ( (bits64) zSign )<<63 ) + ( ( (bits64) zExp )<<48 ) + zSig0; + return z; + +} + +/*---------------------------------------------------------------------------- +| Takes an abstract floating-point value having sign `zSign', exponent `zExp', +| and extended significand formed by the concatenation of `zSig0', `zSig1', +| and `zSig2', and returns the proper quadruple-precision floating-point value +| corresponding to the abstract input. Ordinarily, the abstract value is +| simply rounded and packed into the quadruple-precision format, with the +| inexact exception raised if the abstract input cannot be represented +| exactly. However, if the abstract value is too large, the overflow and +| inexact exceptions are raised and an infinity or maximal finite value is +| returned. If the abstract value is too small, the input value is rounded to +| a subnormal number, and the underflow and inexact exceptions are raised if +| the abstract input cannot be represented exactly as a subnormal quadruple- +| precision floating-point number. +| The input significand must be normalized or smaller. If the input +| significand is not normalized, `zExp' must be 0; in that case, the result +| returned is a subnormal number, and it must not require rounding. In the +| usual case that the input significand is normalized, `zExp' must be 1 less +| than the ``true'' floating-point exponent. The handling of underflow and +| overflow follows the IEC/IEEE Standard for Binary Floating-Point Arithmetic. +*----------------------------------------------------------------------------*/ + +INLINE float128 + roundAndPackFloat128( + flag zSign, int32 zExp, bits64 zSig0, bits64 zSig1, bits64 zSig2 ) +{ + int8 roundingMode; + flag roundNearestEven, increment, isTiny; + + roundingMode = float_rounding_mode; + roundNearestEven = ( roundingMode == float_round_nearest_even ); + increment = ( (sbits64) zSig2 < 0 ); + if ( ! roundNearestEven ) { + if ( roundingMode == float_round_to_zero ) { + increment = 0; + } + else { + if ( zSign ) { + increment = ( roundingMode == float_round_down ) && zSig2; + } + else { + increment = ( roundingMode == float_round_up ) && zSig2; + } + } + } + if ( 0x7FFD <= (bits32) zExp ) { + if ( ( 0x7FFD < zExp ) + || ( ( zExp == 0x7FFD ) + && eq128( + LIT64( 0x0001FFFFFFFFFFFF ), + LIT64( 0xFFFFFFFFFFFFFFFF ), + zSig0, + zSig1 + ) + && increment + ) + ) { + float_raise( float_flag_overflow | float_flag_inexact ); + if ( ( roundingMode == float_round_to_zero ) + || ( zSign && ( roundingMode == float_round_up ) ) + || ( ! zSign && ( roundingMode == float_round_down ) ) + ) { + return + packFloat128( + zSign, + 0x7FFE, + LIT64( 0x0000FFFFFFFFFFFF ), + LIT64( 0xFFFFFFFFFFFFFFFF ) + ); + } + return packFloat128( zSign, 0x7FFF, 0, 0 ); + } + if ( zExp < 0 ) { + isTiny = + ( float_detect_tininess == float_tininess_before_rounding ) + || ( zExp < -1 ) + || ! increment + || lt128( + zSig0, + zSig1, + LIT64( 0x0001FFFFFFFFFFFF ), + LIT64( 0xFFFFFFFFFFFFFFFF ) + ); + shift128ExtraRightJamming( + zSig0, zSig1, zSig2, - zExp, &zSig0, &zSig1, &zSig2 ); + zExp = 0; + if ( isTiny && zSig2 ) float_raise( float_flag_underflow ); + if ( roundNearestEven ) { + increment = ( (sbits64) zSig2 < 0 ); + } + else { + if ( zSign ) { + increment = ( roundingMode == float_round_down ) && zSig2; + } + else { + increment = ( roundingMode == float_round_up ) && zSig2; + } + } + } + } + if ( zSig2 ) float_exception_flags |= float_flag_inexact; + if ( increment ) { + add128( zSig0, zSig1, 0, 1, &zSig0, &zSig1 ); + zSig1 &= ~ ( ( zSig2 + zSig2 == 0 ) & roundNearestEven ); + } + else { + if ( ( zSig0 | zSig1 ) == 0 ) zExp = 0; + } + return packFloat128( zSign, zExp, zSig0, zSig1 ); + +} + +/*---------------------------------------------------------------------------- +| Takes an abstract floating-point value having sign `zSign', exponent `zExp', +| and significand formed by the concatenation of `zSig0' and `zSig1', and +| returns the proper quadruple-precision floating-point value corresponding +| to the abstract input. This routine is just like `roundAndPackFloat128' +| except that the input significand has fewer bits and does not have to be +| normalized. In all cases, `zExp' must be 1 less than the ``true'' floating- +| point exponent. +*----------------------------------------------------------------------------*/ + +INLINE float128 + normalizeRoundAndPackFloat128( + flag zSign, int32 zExp, bits64 zSig0, bits64 zSig1 ) +{ + int8 shiftCount; + bits64 zSig2; + + if ( zSig0 == 0 ) { + zSig0 = zSig1; + zSig1 = 0; + zExp -= 64; + } + shiftCount = countLeadingZeros64( zSig0 ) - 15; + if ( 0 <= shiftCount ) { + zSig2 = 0; + shortShift128Left( zSig0, zSig1, shiftCount, &zSig0, &zSig1 ); + } + else { + shift128ExtraRightJamming( + zSig0, zSig1, 0, - shiftCount, &zSig0, &zSig1, &zSig2 ); + } + zExp -= shiftCount; + return roundAndPackFloat128( zSign, zExp, zSig0, zSig1, zSig2 ); + +} + #endif |