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authorAndrew Waterman <andrew@sifive.com>2018-07-11 01:16:28 -0700
committerAndrew Waterman <andrew@sifive.com>2018-07-11 01:16:28 -0700
commit5cd8d2b93fad2011fdf8f49a263d77697af35b32 (patch)
treef6fb9cb6d3bef2aa5c9903511b92e5a6e99e9519 /softfloat/s_roundPackToF128.c
parent8e69141749065ff957383d2112768f95a33429b6 (diff)
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Upgrade to SoftFloat 3e
Diffstat (limited to 'softfloat/s_roundPackToF128.c')
-rw-r--r--softfloat/s_roundPackToF128.c171
1 files changed, 171 insertions, 0 deletions
diff --git a/softfloat/s_roundPackToF128.c b/softfloat/s_roundPackToF128.c
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+
+/*============================================================================
+
+This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
+Package, Release 3e, by John R. Hauser.
+
+Copyright 2011, 2012, 2013, 2014, 2015, 2017 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 "softfloat.h"
+
+float128_t
+ softfloat_roundPackToF128(
+ bool sign,
+ int_fast32_t exp,
+ uint_fast64_t sig64,
+ uint_fast64_t sig0,
+ uint_fast64_t sigExtra
+ )
+{
+ uint_fast8_t roundingMode;
+ bool roundNearEven, doIncrement, isTiny;
+ struct uint128_extra sig128Extra;
+ uint_fast64_t uiZ64, uiZ0;
+ struct uint128 sig128;
+ union ui128_f128 uZ;
+
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ roundingMode = softfloat_roundingMode;
+ roundNearEven = (roundingMode == softfloat_round_near_even);
+ doIncrement = (UINT64_C( 0x8000000000000000 ) <= sigExtra);
+ if ( ! roundNearEven && (roundingMode != softfloat_round_near_maxMag) ) {
+ doIncrement =
+ (roundingMode
+ == (sign ? softfloat_round_min : softfloat_round_max))
+ && sigExtra;
+ }
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ if ( 0x7FFD <= (uint32_t) exp ) {
+ if ( exp < 0 ) {
+ /*----------------------------------------------------------------
+ *----------------------------------------------------------------*/
+ isTiny =
+ (softfloat_detectTininess
+ == softfloat_tininess_beforeRounding)
+ || (exp < -1)
+ || ! doIncrement
+ || softfloat_lt128(
+ sig64,
+ sig0,
+ UINT64_C( 0x0001FFFFFFFFFFFF ),
+ UINT64_C( 0xFFFFFFFFFFFFFFFF )
+ );
+ sig128Extra =
+ softfloat_shiftRightJam128Extra( sig64, sig0, sigExtra, -exp );
+ sig64 = sig128Extra.v.v64;
+ sig0 = sig128Extra.v.v0;
+ sigExtra = sig128Extra.extra;
+ exp = 0;
+ if ( isTiny && sigExtra ) {
+ softfloat_raiseFlags( softfloat_flag_underflow );
+ }
+ doIncrement = (UINT64_C( 0x8000000000000000 ) <= sigExtra);
+ if (
+ ! roundNearEven
+ && (roundingMode != softfloat_round_near_maxMag)
+ ) {
+ doIncrement =
+ (roundingMode
+ == (sign ? softfloat_round_min : softfloat_round_max))
+ && sigExtra;
+ }
+ } else if (
+ (0x7FFD < exp)
+ || ((exp == 0x7FFD)
+ && softfloat_eq128(
+ sig64,
+ sig0,
+ UINT64_C( 0x0001FFFFFFFFFFFF ),
+ UINT64_C( 0xFFFFFFFFFFFFFFFF )
+ )
+ && doIncrement)
+ ) {
+ /*----------------------------------------------------------------
+ *----------------------------------------------------------------*/
+ softfloat_raiseFlags(
+ softfloat_flag_overflow | softfloat_flag_inexact );
+ if (
+ roundNearEven
+ || (roundingMode == softfloat_round_near_maxMag)
+ || (roundingMode
+ == (sign ? softfloat_round_min : softfloat_round_max))
+ ) {
+ uiZ64 = packToF128UI64( sign, 0x7FFF, 0 );
+ uiZ0 = 0;
+ } else {
+ uiZ64 =
+ packToF128UI64(
+ sign, 0x7FFE, UINT64_C( 0x0000FFFFFFFFFFFF ) );
+ uiZ0 = UINT64_C( 0xFFFFFFFFFFFFFFFF );
+ }
+ goto uiZ;
+ }
+ }
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ if ( sigExtra ) {
+ softfloat_raiseFlags( softfloat_flag_inexact );
+#ifdef SOFTFLOAT_ROUND_ODD
+ if ( roundingMode == softfloat_round_odd ) {
+ sig0 |= 1;
+ goto packReturn;
+ }
+#endif
+ }
+ if ( doIncrement ) {
+ sig128 = softfloat_add128( sig64, sig0, 0, 1 );
+ sig64 = sig128.v64;
+ sig0 =
+ sig128.v0
+ & ~(uint64_t)
+ (! (sigExtra & UINT64_C( 0x7FFFFFFFFFFFFFFF ))
+ & roundNearEven);
+ } else {
+ if ( ! (sig64 | sig0) ) exp = 0;
+ }
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ packReturn:
+ uiZ64 = packToF128UI64( sign, exp, sig64 );
+ uiZ0 = sig0;
+ uiZ:
+ uZ.ui.v64 = uiZ64;
+ uZ.ui.v0 = uiZ0;
+ return uZ.f;
+
+}
+