+/*============================================================================
+
+This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
+Package, Release 3d, by John R. Hauser.
+
+Copyright 2011, 2012, 2013, 2014 The Regents of the University of California.
+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.
+
+ 3. Neither the name of the University nor the names of its contributors may
+ be used to endorse or promote products derived from this software without
+ specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 <stdbool.h>
#include <stdint.h>
#include "platform.h"
-#include "primitives.h"
#include "internals.h"
#include "specialize.h"
#include "softfloat.h"
bool signZ;
struct exp16_sig64 normExpSig;
int_fast16_t expZ;
+ uint32_t recip32, sig32Z, doubleTerm;
+ uint_fast64_t rem;
+ uint32_t q;
uint_fast64_t sigZ;
- struct uint128 term, rem;
uint_fast64_t uiZ;
union ui64_f64 uZ;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
uA.f = a;
uiA = uA.ui;
signA = signF64UI( uiA );
- expA = expF64UI( uiA );
- sigA = fracF64UI( uiA );
+ expA = expF64UI( uiA );
+ sigA = fracF64UI( uiA );
uB.f = b;
uiB = uB.ui;
signB = signF64UI( uiB );
- expB = expF64UI( uiB );
- sigB = fracF64UI( uiB );
+ expB = expF64UI( uiB );
+ sigB = fracF64UI( uiB );
signZ = signA ^ signB;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
if ( expA == 0x7FF ) {
if ( sigA ) goto propagateNaN;
if ( expB == 0x7FF ) {
if ( sigB ) goto propagateNaN;
goto zero;
}
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
if ( ! expB ) {
if ( ! sigB ) {
- if ( ! ( expA | sigA ) ) goto invalid;
- softfloat_raiseFlags( softfloat_flag_infinity );
+ if ( ! (expA | sigA) ) goto invalid;
+ softfloat_raiseFlags( softfloat_flag_infinite );
goto infinity;
}
normExpSig = softfloat_normSubnormalF64Sig( sigB );
expA = normExpSig.exp;
sigA = normExpSig.sig;
}
- expZ = expA - expB + 0x3FD;
- sigA = ( sigA | UINT64_C( 0x0010000000000000 ) )<<10;
- sigB = ( sigB | UINT64_C( 0x0010000000000000 ) )<<11;
- if ( sigB <= ( sigA + sigA ) ) {
- ++expZ;
- sigA >>= 1;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ expZ = expA - expB + 0x3FE;
+ sigA |= UINT64_C( 0x0010000000000000 );
+ sigB |= UINT64_C( 0x0010000000000000 );
+ if ( sigA < sigB ) {
+ --expZ;
+ sigA <<= 11;
+ } else {
+ sigA <<= 10;
}
- sigZ = softfloat_estimateDiv128To64( sigA, 0, sigB );
- if ( ( sigZ & 0x1FF ) <= 2 ) {
- term = softfloat_mul64To128( sigB, sigZ );
- rem = softfloat_sub128( sigA, 0, term.v64, term.v0 );
- while ( UINT64_C( 0x8000000000000000 ) <= rem.v64 ) {
- --sigZ;
- rem = softfloat_add128( rem.v64, rem.v0, 0, sigB );
+ sigB <<= 11;
+ recip32 = softfloat_approxRecip32_1( sigB>>32 ) - 2;
+ sig32Z = ((uint32_t) (sigA>>32) * (uint_fast64_t) recip32)>>32;
+ doubleTerm = sig32Z<<1;
+ rem =
+ ((sigA - (uint_fast64_t) doubleTerm * (uint32_t) (sigB>>32))<<28)
+ - (uint_fast64_t) doubleTerm * ((uint32_t) sigB>>4);
+ q = (((uint32_t) (rem>>32) * (uint_fast64_t) recip32)>>32) + 4;
+ sigZ = ((uint_fast64_t) sig32Z<<32) + ((uint_fast64_t) q<<4);
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ if ( (sigZ & 0x1FF) < 4<<4 ) {
+ q &= ~7;
+ sigZ &= ~(uint_fast64_t) 0x7F;
+ doubleTerm = q<<1;
+ rem =
+ ((rem - (uint_fast64_t) doubleTerm * (uint32_t) (sigB>>32))<<28)
+ - (uint_fast64_t) doubleTerm * ((uint32_t) sigB>>4);
+ if ( rem & UINT64_C( 0x8000000000000000 ) ) {
+ sigZ -= 1<<7;
+ } else {
+ if ( rem ) sigZ |= 1;
}
- sigZ |= ( rem.v0 != 0 );
}
return softfloat_roundPackToF64( signZ, expZ, sigZ );
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
propagateNaN:
uiZ = softfloat_propagateNaNF64UI( uiA, uiB );
goto uiZ;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
invalid:
softfloat_raiseFlags( softfloat_flag_invalid );
uiZ = defaultNaNF64UI;
goto uiZ;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
infinity:
uiZ = packToF64UI( signZ, 0x7FF, 0 );
goto uiZ;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
zero:
uiZ = packToF64UI( signZ, 0, 0 );
uiZ:
projects / riscv-isa-sim.git / blobdiff