Release 3b. See "doc/SoftFloat-history.html".

1 files changed, 111 insertions, 0 deletions

diff --git a/source/f16_roundToInt.c b/source/f16_roundToInt.c
new file mode 100644
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--- /dev/null
+++ b/source/f16_roundToInt.c
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+
+/*============================================================================
+
+This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
+Package, Release 3b, by John R. Hauser.
+
+Copyright 2011, 2012, 2013, 2014, 2015 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"
+
+float16_t f16_roundToInt( float16_t a, uint_fast8_t roundingMode, bool exact )
+{
+    union ui16_f16 uA;
+    uint_fast16_t uiA;
+    int_fast8_t exp;
+    uint_fast16_t uiZ, lastBitMask, roundBitsMask;
+    union ui16_f16 uZ;
+
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    uA.f = a;
+    uiA = uA.ui;
+    exp = expF16UI( uiA );
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    if ( exp <= 0xE ) {
+        if ( ! (uint16_t) (uiA<<1) ) return a;
+        if ( exact ) softfloat_exceptionFlags |= softfloat_flag_inexact;
+        uiZ = uiA & packToF16UI( 1, 0, 0 );
+        switch ( roundingMode ) {
+         case softfloat_round_near_even:
+            if ( ! fracF16UI( uiA ) ) break;
+         case softfloat_round_near_maxMag:
+            if ( exp == 0xE ) uiZ |= packToF16UI( 0, 0xF, 0 );
+            break;
+         case softfloat_round_min:
+            if ( uiZ ) uiZ = packToF16UI( 1, 0xF, 0 );
+            break;
+         case softfloat_round_max:
+            if ( ! uiZ ) uiZ = packToF16UI( 0, 0xF, 0 );
+            break;
+        }
+        goto uiZ;
+    }
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    if ( 0x19 <= exp ) {
+        if ( (exp == 0x1F) && fracF16UI( uiA ) ) {
+            uiZ = softfloat_propagateNaNF16UI( uiA, 0 );
+            goto uiZ;
+        }
+        return a;
+    }
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    uiZ = uiA;
+    lastBitMask = (uint_fast16_t) 1<<(0x19 - exp);
+    roundBitsMask = lastBitMask - 1;
+    if ( roundingMode == softfloat_round_near_maxMag ) {
+        uiZ += lastBitMask>>1;
+    } else if ( roundingMode == softfloat_round_near_even ) {
+        uiZ += lastBitMask>>1;
+        if ( ! (uiZ & roundBitsMask) ) uiZ &= ~lastBitMask;
+    } else if ( roundingMode != softfloat_round_minMag ) {
+        if ( signF16UI( uiZ ) ^ (roundingMode == softfloat_round_max) ) {
+            uiZ += roundBitsMask;
+        }
+    }
+    uiZ &= ~roundBitsMask;
+    if ( exact && (uiZ != uiA) ) {
+        softfloat_exceptionFlags |= softfloat_flag_inexact;
+    }
+ uiZ:
+    uZ.ui = uiZ;
+    return uZ.f;
+
+}
+