8 bit floating point

softfloat/f16_to_f8.c

@@ -0,0 +1,104 @@
+
+/*============================================================================
+
+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 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"
+
+float8_t f16_to_f8( float16_t a )
+{
+  union ui16_f16 uA;
+  uint_fast16_t uiA;
+  bool sign;
+  int_fast8_t exp;
+  uint_fast16_t frac;
+  struct commonNaN commonNaN;
+  uint_fast8_t uiZ;
+  uint_fast16_t frac8;
+  union ui8_f8 uZ;
+
+  /*------------------------------------------------------------------------
+   *------------------------------------------------------------------------*/
+  uA.f = a;
+  uiA = uA.ui;
+  sign = signF16UI( uiA );
+  exp  = expF16UI( uiA );
+  frac = fracF16UI( uiA );
+  /*------------------------------------------------------------------------
+   *------------------------------------------------------------------------*/
+  if ( exp == 0xFF ) {
+    if ( frac ) {
+      softfloat_f16UIToCommonNaN( uiA, &commonNaN );
+      switch ( softfloat_fp8Mode ) {
+          case softfloat_fp8_e4m3:
+              uiZ = softfloat_commonNaNToE4M3F8UI( &commonNaN );
+          case softfloat_fp8_e5m2:
+              uiZ = softfloat_commonNaNToE5M2F8UI( &commonNaN );
+          default:
+              uiZ = softfloat_commonNaNToF8UI( &commonNaN );
+      }
+    } else {
+        switch ( softfloat_fp8Mode ) {
+          case softfloat_fp8_e4m3:
+              // Assuming overflow mode (Inf --> NaN)
+              uiZ = softfloat_commonNaNToE4M3F8UI( &commonNaN );
+          case softfloat_fp8_e5m2:
+              uiZ = signInfE5M2F8UI( sign );
+          default:
+              uiZ = signInfF8UI( sign );
+        }
+    }
+    goto uiZ;
+  }
+  /*------------------------------------------------------------------------
+   *------------------------------------------------------------------------*/
+  frac8 = frac>>2 | ((frac & 0x3) != 0); // Round and preserve sticky bit
+  if ( ! (exp | frac8) ) {
+    uiZ = packToF8UI( 0, 0, 0 ); // zero
+    goto uiZ;
+  }
+  /*------------------------------------------------------------------------
+   *------------------------------------------------------------------------*/
+  return softfloat_roundPackToF8( sign, exp - 0xC, frac8 | 0x100 );
+ uiZ:
+  uZ.ui = uiZ;
+  return uZ.f;
+
+}
+

softfloat/f8_add.c

@@ -0,0 +1,46 @@
+/*============================================================================
+
+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"
+
+float8_t f8_add( float8_t a, float8_t b )
+{
+  return f8_emulation_2_operands(a, b, f16_add);
+}

softfloat/f8_classify.c

@@ -0,0 +1,34 @@
+#include <stdbool.h>
+#include <stdint.h>
+#include "platform.h"
+#include "internals.h"
+#include "specialize.h"
+#include "softfloat.h"
+
+uint_fast16_t f8_classify( float8_t a )
+{
+    union ui8_f8 uA;
+    uint_fast16_t uiA;
+
+    uA.f = a;
+    uiA = uA.ui;
+
+    uint_fast16_t infOrNaN = isInfF8UI(uiA) || isNaNF8UI(uiA);
+    uint_fast16_t subnormalOrZero = expF8UI( uiA ) == 0;
+    bool sign = signF8UI( uiA );
+    bool fracZero = fracF8UI( uiA ) == 0;
+    bool isNaN = isNaNF8UI( uiA );
+    bool isSNaN = false;
+
+    return
+        (  sign && infOrNaN && fracZero )          << 0 |
+        (  sign && !infOrNaN && !subnormalOrZero ) << 1 |
+        (  sign && subnormalOrZero && !fracZero )  << 2 |
+        (  sign && subnormalOrZero && fracZero )   << 3 |
+        ( !sign && infOrNaN && fracZero )          << 7 |
+        ( !sign && !infOrNaN && !subnormalOrZero ) << 6 |
+        ( !sign && subnormalOrZero && !fracZero )  << 5 |
+        ( !sign && subnormalOrZero && fracZero )   << 4 |
+        ( isNaN &&  isSNaN )                       << 8 |
+        ( isNaN && !isSNaN )                       << 9;
+}

softfloat/f8_div.c

@@ -0,0 +1,46 @@
+/*============================================================================
+
+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"
+
+float8_t f8_div( float8_t a, float8_t b )
+{
+  return f8_emulation_2_operands(a, b, f16_div);
+}

softfloat/f8_emulation.c

@@ -0,0 +1,74 @@
+/*============================================================================
+
+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"
+
+float8_t f8_emulation_3_operands(float8_t a8, float8_t b8, float8_t c8, float16_t (*operation)(float16_t, float16_t, float16_t)) {
+  uint_fast8_t roundingMode = softfloat_roundingMode;
+  softfloat_roundingMode = softfloat_round_odd;
+  float16_t a16 = f8_to_f16(a8);
+  float16_t b16 = f8_to_f16(b8);
+  float16_t c16 = f8_to_f16(c8);
+  float16_t z16 = operation(a16, b16, c16);
+  softfloat_roundingMode = roundingMode;
+  float8_t z = f16_to_f8(z16);
+  return z;
+}
+
+float8_t f8_emulation_2_operands(float8_t a8, float8_t b8, float16_t (*operation)(float16_t, float16_t)) {
+  uint_fast8_t roundingMode = softfloat_roundingMode;
+  softfloat_roundingMode = softfloat_round_odd;
+  float16_t a16 = f8_to_f16(a8);
+  float16_t b16 = f8_to_f16(b8);
+  float16_t z16 = operation(a16, b16);
+  softfloat_roundingMode = roundingMode;
+  float8_t z = f16_to_f8(z16);
+  return z;
+}
+
+float8_t f8_emulation_1_operand(float8_t a8, float16_t (*operation)(float16_t)) {
+  uint_fast8_t roundingMode = softfloat_roundingMode;
+  softfloat_roundingMode = softfloat_round_odd;
+  float16_t a16 = f8_to_f16(a8);
+  float16_t z16 = operation(a16);
+  softfloat_roundingMode = roundingMode;
+  float8_t z = f16_to_f8(z16);
+  return z;
+}

softfloat/f8_eq.c

@@ -0,0 +1,59 @@
+/*============================================================================
+
+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 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"
+#include "specialize.h"
+
+bool f8_eq( float8_t a, float8_t b )
+{
+  union ui8_f8 uA;
+  uint_fast8_t uiA;
+  union ui8_f8 uB;
+  uint_fast8_t uiB;
+
+  uA.f = a;
+  uiA = uA.ui;
+  uB.f = b;
+  uiB = uB.ui;
+  if ( isNaNF8UI( uiA ) || isNaNF8UI( uiB ) ) {
+    softfloat_raiseFlags( softfloat_flag_invalid );
+    return false;
+  }
+  return (uiA == uiB);
+}