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authorAndrew Waterman <andrew@sifive.com>2017-09-24 20:25:34 -0700
committerAndrew Waterman <andrew@sifive.com>2017-09-24 20:25:34 -0700
commitbd85811c35ea38180d27440507fc222d585ef780 (patch)
tree214c6b615d7775f73da5ff9a94bd4a0a2772f9cf /softfloat/f128_rem.c
parentb86f2a51f522f020ad0d90f598f4c501f41da232 (diff)
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Update SoftFloat
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-rw-r--r--softfloat/f128_rem.c190
1 files changed, 190 insertions, 0 deletions
diff --git a/softfloat/f128_rem.c b/softfloat/f128_rem.c
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+
+/*============================================================================
+
+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, 2015, 2016 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 "internals.h"
+#include "specialize.h"
+#include "softfloat.h"
+
+float128_t f128_rem( float128_t a, float128_t b )
+{
+ union ui128_f128 uA;
+ uint_fast64_t uiA64, uiA0;
+ bool signA;
+ int_fast32_t expA;
+ struct uint128 sigA;
+ union ui128_f128 uB;
+ uint_fast64_t uiB64, uiB0;
+ int_fast32_t expB;
+ struct uint128 sigB;
+ struct exp32_sig128 normExpSig;
+ struct uint128 rem;
+ int_fast32_t expDiff;
+ uint_fast32_t q, recip32;
+ uint_fast64_t q64;
+ struct uint128 term, altRem, meanRem;
+ bool signRem;
+ struct uint128 uiZ;
+ union ui128_f128 uZ;
+
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ uA.f = a;
+ uiA64 = uA.ui.v64;
+ uiA0 = uA.ui.v0;
+ signA = signF128UI64( uiA64 );
+ expA = expF128UI64( uiA64 );
+ sigA.v64 = fracF128UI64( uiA64 );
+ sigA.v0 = uiA0;
+ uB.f = b;
+ uiB64 = uB.ui.v64;
+ uiB0 = uB.ui.v0;
+ expB = expF128UI64( uiB64 );
+ sigB.v64 = fracF128UI64( uiB64 );
+ sigB.v0 = uiB0;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ if ( expA == 0x7FFF ) {
+ if (
+ (sigA.v64 | sigA.v0) || ((expB == 0x7FFF) && (sigB.v64 | sigB.v0))
+ ) {
+ goto propagateNaN;
+ }
+ goto invalid;
+ }
+ if ( expB == 0x7FFF ) {
+ if ( sigB.v64 | sigB.v0 ) goto propagateNaN;
+ return a;
+ }
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ if ( ! expB ) {
+ if ( ! (sigB.v64 | sigB.v0) ) goto invalid;
+ normExpSig = softfloat_normSubnormalF128Sig( sigB.v64, sigB.v0 );
+ expB = normExpSig.exp;
+ sigB = normExpSig.sig;
+ }
+ if ( ! expA ) {
+ if ( ! (sigA.v64 | sigA.v0) ) return a;
+ normExpSig = softfloat_normSubnormalF128Sig( sigA.v64, sigA.v0 );
+ expA = normExpSig.exp;
+ sigA = normExpSig.sig;
+ }
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ sigA.v64 |= UINT64_C( 0x0001000000000000 );
+ sigB.v64 |= UINT64_C( 0x0001000000000000 );
+ rem = sigA;
+ expDiff = expA - expB;
+ if ( expDiff < 1 ) {
+ if ( expDiff < -1 ) return a;
+ if ( expDiff ) {
+ --expB;
+ sigB = softfloat_add128( sigB.v64, sigB.v0, sigB.v64, sigB.v0 );
+ q = 0;
+ } else {
+ q = softfloat_le128( sigB.v64, sigB.v0, rem.v64, rem.v0 );
+ if ( q ) {
+ rem = softfloat_sub128( rem.v64, rem.v0, sigB.v64, sigB.v0 );
+ }
+ }
+ } else {
+ recip32 = softfloat_approxRecip32_1( sigB.v64>>17 );
+ expDiff -= 30;
+ for (;;) {
+ q64 = (uint_fast64_t) (uint32_t) (rem.v64>>19) * recip32;
+ if ( expDiff < 0 ) break;
+ q = (q64 + 0x80000000)>>32;
+ rem = softfloat_shortShiftLeft128( rem.v64, rem.v0, 29 );
+ term = softfloat_mul128By32( sigB.v64, sigB.v0, q );
+ rem = softfloat_sub128( rem.v64, rem.v0, term.v64, term.v0 );
+ if ( rem.v64 & UINT64_C( 0x8000000000000000 ) ) {
+ rem = softfloat_add128( rem.v64, rem.v0, sigB.v64, sigB.v0 );
+ }
+ expDiff -= 29;
+ }
+ /*--------------------------------------------------------------------
+ | (`expDiff' cannot be less than -29 here.)
+ *--------------------------------------------------------------------*/
+ q = (uint32_t) (q64>>32)>>(~expDiff & 31);
+ rem = softfloat_shortShiftLeft128( rem.v64, rem.v0, expDiff + 30 );
+ term = softfloat_mul128By32( sigB.v64, sigB.v0, q );
+ rem = softfloat_sub128( rem.v64, rem.v0, term.v64, term.v0 );
+ if ( rem.v64 & UINT64_C( 0x8000000000000000 ) ) {
+ altRem = softfloat_add128( rem.v64, rem.v0, sigB.v64, sigB.v0 );
+ goto selectRem;
+ }
+ }
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ do {
+ altRem = rem;
+ ++q;
+ rem = softfloat_sub128( rem.v64, rem.v0, sigB.v64, sigB.v0 );
+ } while ( ! (rem.v64 & UINT64_C( 0x8000000000000000 )) );
+ selectRem:
+ meanRem = softfloat_add128( rem.v64, rem.v0, altRem.v64, altRem.v0 );
+ if (
+ (meanRem.v64 & UINT64_C( 0x8000000000000000 ))
+ || (! (meanRem.v64 | meanRem.v0) && (q & 1))
+ ) {
+ rem = altRem;
+ }
+ signRem = signA;
+ if ( rem.v64 & UINT64_C( 0x8000000000000000 ) ) {
+ signRem = ! signRem;
+ rem = softfloat_sub128( 0, 0, rem.v64, rem.v0 );
+ }
+ return softfloat_normRoundPackToF128( signRem, expB - 1, rem.v64, rem.v0 );
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ propagateNaN:
+ uiZ = softfloat_propagateNaNF128UI( uiA64, uiA0, uiB64, uiB0 );
+ goto uiZ;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ invalid:
+ softfloat_raiseFlags( softfloat_flag_invalid );
+ uiZ.v64 = defaultNaNF128UI64;
+ uiZ.v0 = defaultNaNF128UI0;
+ uiZ:
+ uZ.ui = uiZ;
+ return uZ.f;
+
+}
+