Add f64_to_bf16; fix f32_to_bf16

softfloat/f32_to_bf16.c

@@ -43,45 +43,6 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 bfloat16_t f32_to_bf16( float32_t a )
 {
-    union ui32_f32 uA;
-    uint_fast32_t uiA;
-    bool sign;
-    int_fast16_t exp;
-    uint_fast32_t frac;
-    struct commonNaN commonNaN;
-    uint_fast16_t uiZ, frac16;
-    union ui16_f16 uZ;
-    /*------------------------------------------------------------------------
-    *------------------------------------------------------------------------*/
-    uA.f = a;
-    uiA = uA.ui;
-    sign = signF32UI( uiA );
-    exp  = expF32UI( uiA );
-    frac = fracF32UI( uiA );
-    /*------------------------------------------------------------------------
-    *------------------------------------------------------------------------*/
-    if ( exp == 0xFF ) {
-        if ( frac ) {
-            softfloat_f32UIToCommonNaN( uiA, &commonNaN );
-            uiZ = softfloat_commonNaNToBF16UI( &commonNaN );
-        } else {
-            uiZ = packToBF16UI( sign, 0xFF, 0 );
-        }
-        goto uiZ;
-    }
-    /*------------------------------------------------------------------------
-    *------------------------------------------------------------------------*/
-    frac16 = frac>>9 | ((frac & 0x1FF) != 0);
-    if ( ! (exp | frac16) ) {
-        uiZ = packToBF16UI( sign, 0, 0 );
-        goto uiZ;
-    }
-    /*------------------------------------------------------------------------
-    *------------------------------------------------------------------------*/
-    return softfloat_roundPackToBF16( sign, exp - 1, frac16 | 0x4000 );
- uiZ:
-    uZ.ui = uiZ;
-    return uZ.f;
-
+    return f64_to_bf16( f32_to_f64( a ) );
 }
 

softfloat/f64_to_bf16.c

@@ -0,0 +1,88 @@
+
+/*============================================================================
+
+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"
+
+bfloat16_t f64_to_bf16( float64_t a )
+{
+    union ui64_f64 uA;
+    uint_fast64_t uiA;
+    bool sign;
+    int_fast16_t exp;
+    uint_fast64_t frac;
+    struct commonNaN commonNaN;
+    uint_fast16_t uiZ, frac16;
+    union ui16_f16 uZ;
+
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    uA.f = a;
+    uiA = uA.ui;
+    sign = signF64UI( uiA );
+    exp  = expF64UI( uiA );
+    frac = fracF64UI( uiA );
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    if ( exp == 0x7FF ) {
+        if ( frac ) {
+            softfloat_f64UIToCommonNaN( uiA, &commonNaN );
+            uiZ = softfloat_commonNaNToBF16UI( &commonNaN );
+        } else {
+            uiZ = packToBF16UI( sign, 0xFF, 0 );
+        }
+        goto uiZ;
+    }
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    frac16 = softfloat_shortShiftRightJam64( frac, 38 );
+    if ( ! (exp | frac16) ) {
+        uiZ = packToBF16UI( sign, 0, 0 );
+        goto uiZ;
+    }
+    /*------------------------------------------------------------------------
+    *------------------------------------------------------------------------*/
+    return softfloat_roundPackToBF16( sign, exp - 0x381, frac16 | 0x4000 );
+ uiZ:
+    uZ.ui = uiZ;
+    return uZ.f;
+
+}
+

softfloat/softfloat.h

@@ -238,6 +238,7 @@ uint_fast64_t f64_to_ui64_r_minMag( float64_t, bool );
 int_fast32_t f64_to_i32_r_minMag( float64_t, bool );
 int_fast64_t f64_to_i64_r_minMag( float64_t, bool );
 float16_t f64_to_f16( float64_t );
+bfloat16_t f64_to_bf16( float64_t );
 float32_t f64_to_f32( float64_t );
 #ifdef SOFTFLOAT_FAST_INT64
 extFloat80_t f64_to_extF80( float64_t );

softfloat/softfloat.mk.in

@@ -107,6 +107,7 @@ softfloat_c_srcs = \
 	f64_sqrt.c \
 	f64_sub.c \
 	f64_to_f128.c \
+	f64_to_bf16.c \
 	f64_to_f16.c \
 	f64_to_f32.c \
 	f64_to_i32.c \