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66 lines
2.0 KiB
66 lines
2.0 KiB
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#include <stdbool.h>
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#include <stdint.h>
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#include "platform.h"
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#include "primitives.h"
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#include "internals.h"
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#include "softfloat.h"
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float64_t
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softfloat_roundPackToF64( bool sign, int_fast16_t exp, uint_fast64_t sig )
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{
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int roundingMode;
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bool roundNearestEven;
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int roundIncrement, roundBits;
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bool isTiny;
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uint_fast64_t uiZ;
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union ui64_f64 uZ;
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roundingMode = softfloat_roundingMode;
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roundNearestEven = ( roundingMode == softfloat_round_nearest_even );
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roundIncrement = 0x200;
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if (
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! roundNearestEven
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&& ( roundingMode != softfloat_round_nearest_maxMag )
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) {
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roundIncrement =
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( roundingMode == softfloat_round_minMag )
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|| ( roundingMode
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== ( sign ? softfloat_round_max : softfloat_round_min ) )
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? 0
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: 0x3FF;
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}
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roundBits = sig & 0x3FF;
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if ( 0x7FD <= (uint16_t) exp ) {
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if ( exp < 0 ) {
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isTiny =
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( softfloat_detectTininess
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== softfloat_tininess_beforeRounding )
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|| ( exp < -1 )
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|| ( sig + roundIncrement < UINT64_C( 0x8000000000000000 ) );
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sig = softfloat_shift64RightJam( sig, - exp );
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exp = 0;
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roundBits = sig & 0x3FF;
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if ( isTiny && roundBits ) {
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softfloat_raiseFlags( softfloat_flag_underflow );
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}
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} else if (
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( 0x7FD < exp )
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|| ( UINT64_C( 0x8000000000000000 ) <= sig + roundIncrement )
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) {
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softfloat_raiseFlags(
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softfloat_flag_overflow | softfloat_flag_inexact );
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uiZ = packToF64UI( sign, 0x7FF, 0 ) - ! roundIncrement;
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goto uiZ;
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}
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}
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if ( roundBits ) softfloat_raiseFlags( softfloat_flag_inexact );
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sig = ( sig + roundIncrement )>>10;
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sig &= ~ ( ! ( roundBits ^ 0x200 ) & roundNearestEven );
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uiZ = packToF64UI( sign, sig ? exp : 0, sig );
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uiZ:
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uZ.ui = uiZ;
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return uZ.f;
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}
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