--- /dev/null
+
+/*============================================================================
+
+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"
+
+extern const uint16_t softfloat_approxRecip_1k0s[];
+extern const uint16_t softfloat_approxRecip_1k1s[];
+
+float16_t f16_div( float16_t a, float16_t b )
+{
+ union ui16_f16 uA;
+ uint_fast16_t uiA;
+ bool signA;
+ int_fast8_t expA;
+ uint_fast16_t sigA;
+ union ui16_f16 uB;
+ uint_fast16_t uiB;
+ bool signB;
+ int_fast8_t expB;
+ uint_fast16_t sigB;
+ bool signZ;
+ struct exp8_sig16 normExpSig;
+ int_fast8_t expZ;
+#ifdef SOFTFLOAT_FAST_DIV32TO16
+ uint_fast32_t sig32A;
+ uint_fast16_t sigZ;
+#else
+ int index;
+ uint16_t r0;
+ uint_fast16_t sigZ, rem;
+#endif
+ uint_fast16_t uiZ;
+ union ui16_f16 uZ;
+
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ uA.f = a;
+ uiA = uA.ui;
+ signA = signF16UI( uiA );
+ expA = expF16UI( uiA );
+ sigA = fracF16UI( uiA );
+ uB.f = b;
+ uiB = uB.ui;
+ signB = signF16UI( uiB );
+ expB = expF16UI( uiB );
+ sigB = fracF16UI( uiB );
+ signZ = signA ^ signB;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ if ( expA == 0x1F ) {
+ if ( sigA ) goto propagateNaN;
+ if ( expB == 0x1F ) {
+ if ( sigB ) goto propagateNaN;
+ goto invalid;
+ }
+ goto infinity;
+ }
+ if ( expB == 0x1F ) {
+ if ( sigB ) goto propagateNaN;
+ goto zero;
+ }
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ if ( ! expB ) {
+ if ( ! sigB ) {
+ if ( ! (expA | sigA) ) goto invalid;
+ softfloat_raiseFlags( softfloat_flag_infinite );
+ goto infinity;
+ }
+ normExpSig = softfloat_normSubnormalF16Sig( sigB );
+ expB = normExpSig.exp;
+ sigB = normExpSig.sig;
+ }
+ if ( ! expA ) {
+ if ( ! sigA ) goto zero;
+ normExpSig = softfloat_normSubnormalF16Sig( sigA );
+ expA = normExpSig.exp;
+ sigA = normExpSig.sig;
+ }
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ expZ = expA - expB + 0xE;
+ sigA |= 0x0400;
+ sigB |= 0x0400;
+#ifdef SOFTFLOAT_FAST_DIV32TO16
+ if ( sigA < sigB ) {
+ --expZ;
+ sig32A = (uint_fast32_t) sigA<<15;
+ } else {
+ sig32A = (uint_fast32_t) sigA<<14;
+ }
+ sigZ = sig32A / sigB;
+ if ( ! (sigZ & 7) ) sigZ |= ((uint_fast32_t) sigB * sigZ != sig32A);
+#else
+ if ( sigA < sigB ) {
+ --expZ;
+ sigA <<= 5;
+ } else {
+ sigA <<= 4;
+ }
+ index = sigB>>6 & 0xF;
+ r0 = softfloat_approxRecip_1k0s[index]
+ - (((uint_fast32_t) softfloat_approxRecip_1k1s[index]
+ * (sigB & 0x3F))
+ >>10);
+ sigZ = ((uint_fast32_t) sigA * r0)>>16;
+ rem = (sigA<<10) - sigZ * sigB;
+ sigZ += (rem * (uint_fast32_t) r0)>>26;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ ++sigZ;
+ if ( ! (sigZ & 7) ) {
+ sigZ &= ~1;
+ rem = (sigA<<10) - sigZ * sigB;
+ if ( rem & 0x8000 ) {
+ sigZ -= 2;
+ } else {
+ if ( rem ) sigZ |= 1;
+ }
+ }
+#endif
+ return softfloat_roundPackToF16( signZ, expZ, sigZ );
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ propagateNaN:
+ uiZ = softfloat_propagateNaNF16UI( uiA, uiB );
+ goto uiZ;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ invalid:
+ softfloat_raiseFlags( softfloat_flag_invalid );
+ uiZ = defaultNaNF16UI;
+ goto uiZ;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ infinity:
+ uiZ = packToF16UI( signZ, 0x1F, 0 );
+ goto uiZ;
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ zero:
+ uiZ = packToF16UI( signZ, 0, 0 );
+ uiZ:
+ uZ.ui = uiZ;
+ return uZ.f;
+
+}
+
projects / riscv-isa-sim.git / blobdiff