From 8f59d925353145a65c09301dea6c47da1f1311b1 Mon Sep 17 00:00:00 2001
From: John Hauser <jhauser@eecs.berkeley.edu>
Date: Fri, 28 Nov 2014 19:49:28 -0800
Subject: First draft of RC for Release 3, to start review process.
---
source/extF80_rem.c | 224 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 224 insertions(+)
create mode 100644 source/extF80_rem.c
(limited to 'source/extF80_rem.c')
diff --git a/source/extF80_rem.c b/source/extF80_rem.c
new file mode 100644
index 0000000..d9ccb1e
--- /dev/null
+++ b/source/extF80_rem.c
@@ -0,0 +1,224 @@
+
+/*============================================================================
+
+This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
+Package, Release 3, by John R. Hauser.
+
+Copyright 2011, 2012, 2013, 2014 The Regents of the University of California
+(Regents). All Rights Reserved. Redistribution and use in source and binary
+forms, with or without modification, are permitted provided that the following
+conditions are met:
+
+Redistributions of source code must retain the above copyright notice,
+this list of conditions, and the following two paragraphs of disclaimer.
+Redistributions in binary form must reproduce the above copyright notice,
+this list of conditions, and the following two paragraphs of disclaimer in the
+documentation and/or other materials provided with the distribution. Neither
+the name of the Regents nor the names of its contributors may be used to
+endorse or promote products derived from this software without specific prior
+written permission.
+
+IN NO EVENT SHALL REGENTS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
+SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING
+OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF REGENTS HAS
+BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+REGENTS SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED
+TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+PURPOSE. THE SOFTWARE AND ACCOMPANYING DOCUMENTATION, IF ANY, PROVIDED
+HEREUNDER IS PROVIDED "AS IS". REGENTS HAS NO OBLIGATION TO PROVIDE
+MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+
+=============================================================================*/
+
+#include <stdbool.h>
+#include <stdint.h>
+#include "platform.h"
+#include "internals.h"
+#include "specialize.h"
+#include "softfloat.h"
+
+extFloat80_t extF80_rem( extFloat80_t a, extFloat80_t b )
+{
+ union { struct extFloat80M s; extFloat80_t f; } uA;
+ uint_fast16_t uiA64;
+ uint_fast64_t uiA0;
+ bool signA;
+ int_fast32_t expA;
+ uint_fast64_t sigA;
+ union { struct extFloat80M s; extFloat80_t f; } uB;
+ uint_fast16_t uiB64;
+ uint_fast64_t uiB0;
+ bool signB;
+ int_fast32_t expB;
+ uint_fast64_t sigB;
+ struct exp32_sig64 normExpSig;
+ int_fast32_t expDiff;
+ struct uint128 rem, shiftedSigB;
+ uint_fast32_t q, recip32;
+ uint_fast64_t q64;
+ struct uint128 term, altRem, meanRem;
+ bool signRem;
+ struct uint128 uiZ;
+ uint_fast16_t uiZ64;
+ uint_fast64_t uiZ0;
+ union { struct extFloat80M s; extFloat80_t f; } uZ;
+
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ uA.f = a;
+ uiA64 = uA.s.signExp;
+ uiA0 = uA.s.signif;
+ signA = signExtF80UI64( uiA64 );
+ expA = expExtF80UI64( uiA64 );
+ sigA = uiA0;
+ uB.f = b;
+ uiB64 = uB.s.signExp;
+ uiB0 = uB.s.signif;
+ signB = signExtF80UI64( uiB64 );
+ expB = expExtF80UI64( uiB64 );
+ sigB = uiB0;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ if ( expA == 0x7FFF ) {
+ if (
+ (sigA & UINT64_C( 0x7FFFFFFFFFFFFFFF ))
+ || ((expB == 0x7FFF) && (sigB & UINT64_C( 0x7FFFFFFFFFFFFFFF )))
+ ) {
+ goto propagateNaN;
+ }
+ goto invalid;
+ }
+ if ( expB == 0x7FFF ) {
+ if ( sigB & UINT64_C( 0x7FFFFFFFFFFFFFFF ) ) goto propagateNaN;
+ /*--------------------------------------------------------------------
+ | Argument b is an infinity. Doubling `expB' is an easy way to ensure
+ | that `expDiff' later is less than -1, which will result in returning
+ | a canonicalized version of argument a.
+ *--------------------------------------------------------------------*/
+ expB += expB;
+ }
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ if ( ! expB ) expB = 1;
+ if ( ! (sigB & UINT64_C( 0x8000000000000000 )) ) {
+ if ( ! sigB ) goto invalid;
+ normExpSig = softfloat_normSubnormalExtF80Sig( sigB );
+ expB += normExpSig.exp;
+ sigB = normExpSig.sig;
+ }
+ if ( ! expA ) expA = 1;
+ if ( ! (sigA & UINT64_C( 0x8000000000000000 )) ) {
+ if ( ! sigA ) {
+ expA = 0;
+ goto copyA;
+ }
+ normExpSig = softfloat_normSubnormalExtF80Sig( sigA );
+ expA += normExpSig.exp;
+ sigA = normExpSig.sig;
+ }
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ expDiff = expA - expB;
+ if ( expDiff < -1 ) goto copyA;
+ rem = softfloat_shortShiftLeft128( 0, sigA, 32 );
+ shiftedSigB = softfloat_shortShiftLeft128( 0, sigB, 32 );
+ if ( expDiff < 1 ) {
+ if ( expDiff ) {
+ --expB;
+ shiftedSigB = softfloat_shortShiftLeft128( 0, sigB, 33 );
+ q = 0;
+ } else {
+ q = (sigB <= sigA);
+ if ( q ) {
+ rem =
+ softfloat_sub128(
+ rem.v64, rem.v0, shiftedSigB.v64, shiftedSigB.v0 );
+ }
+ }
+ } else {
+ recip32 = softfloat_approxRecip32_1( sigB>>32 );
+ expDiff -= 30;
+ for (;;) {
+ q64 = (uint_fast64_t) (uint32_t) (rem.v64>>2) * recip32;
+ if ( expDiff < 0 ) break;
+ q = (q64 + 0x80000000)>>32;
+ rem = softfloat_shortShiftLeft128( rem.v64, rem.v0, 29 );
+ term = softfloat_mul64ByShifted32To128( sigB, 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, shiftedSigB.v64, shiftedSigB.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_mul64ByShifted32To128( sigB, 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, shiftedSigB.v64, shiftedSigB.v0 );
+ goto selectRem;
+ }
+ }
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ do {
+ altRem = rem;
+ ++q;
+ rem =
+ softfloat_sub128(
+ rem.v64, rem.v0, shiftedSigB.v64, shiftedSigB.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_normRoundPackToExtF80(
+ signRem, expB + 32, rem.v64, rem.v0, 80 );
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ propagateNaN:
+ uiZ = softfloat_propagateNaNExtF80UI( uiA64, uiA0, uiB64, uiB0 );
+ uiZ64 = uiZ.v64;
+ uiZ0 = uiZ.v0;
+ goto uiZ;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ invalid:
+ softfloat_raiseFlags( softfloat_flag_invalid );
+ uiZ64 = defaultNaNExtF80UI64;
+ uiZ0 = defaultNaNExtF80UI0;
+ goto uiZ;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ copyA:
+ if ( expA < 1 ) {
+ sigA >>= 1 - expA;
+ expA = 0;
+ }
+ uiZ64 = packToExtF80UI64( signA, expA );
+ uiZ0 = sigA;
+ uiZ:
+ uZ.s.signExp = uiZ64;
+ uZ.s.signif = uiZ0;
+ return uZ.f;
+
+}
+
--
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