aboutsummaryrefslogtreecommitdiff
path: root/softfloat/f64_to_f16.c
diff options
context:
space:
mode:
authorAndrew Waterman <andrew@sifive.com>2017-09-24 20:25:34 -0700
committerAndrew Waterman <andrew@sifive.com>2017-09-24 20:25:34 -0700
commitbd85811c35ea38180d27440507fc222d585ef780 (patch)
tree214c6b615d7775f73da5ff9a94bd4a0a2772f9cf /softfloat/f64_to_f16.c
parentb86f2a51f522f020ad0d90f598f4c501f41da232 (diff)
downloadriscv-isa-sim-bd85811c35ea38180d27440507fc222d585ef780.zip
riscv-isa-sim-bd85811c35ea38180d27440507fc222d585ef780.tar.gz
riscv-isa-sim-bd85811c35ea38180d27440507fc222d585ef780.tar.bz2
Update SoftFloat
Diffstat (limited to 'softfloat/f64_to_f16.c')
-rw-r--r--softfloat/f64_to_f16.c88
1 files changed, 88 insertions, 0 deletions
diff --git a/softfloat/f64_to_f16.c b/softfloat/f64_to_f16.c
new file mode 100644
index 0000000..325788c
--- /dev/null
+++ b/softfloat/f64_to_f16.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"
+
+float16_t f64_to_f16( 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_commonNaNToF16UI( &commonNaN );
+ } else {
+ uiZ = packToF16UI( sign, 0x1F, 0 );
+ }
+ goto uiZ;
+ }
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ frac16 = softfloat_shortShiftRightJam64( frac, 38 );
+ if ( ! (exp | frac16) ) {
+ uiZ = packToF16UI( sign, 0, 0 );
+ goto uiZ;
+ }
+ /*------------------------------------------------------------------------
+ *------------------------------------------------------------------------*/
+ return softfloat_roundPackToF16( sign, exp - 0x3F1, frac16 | 0x4000 );
+ uiZ:
+ uZ.ui = uiZ;
+ return uZ.f;
+
+}
+