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Diffstat (limited to 'libgcc/config/arm/fp16.c')
-rw-r--r--libgcc/config/arm/fp16.c145
1 files changed, 145 insertions, 0 deletions
diff --git a/libgcc/config/arm/fp16.c b/libgcc/config/arm/fp16.c
new file mode 100644
index 00000000000..936caeb78d0
--- /dev/null
+++ b/libgcc/config/arm/fp16.c
@@ -0,0 +1,145 @@
+/* Half-float conversion routines.
+
+ Copyright (C) 2008, 2009 Free Software Foundation, Inc.
+ Contributed by CodeSourcery.
+
+ This file is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by the
+ Free Software Foundation; either version 3, or (at your option) any
+ later version.
+
+ This file is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ Under Section 7 of GPL version 3, you are granted additional
+ permissions described in the GCC Runtime Library Exception, version
+ 3.1, as published by the Free Software Foundation.
+
+ You should have received a copy of the GNU General Public License and
+ a copy of the GCC Runtime Library Exception along with this program;
+ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+ <http://www.gnu.org/licenses/>. */
+
+static inline unsigned short
+__gnu_f2h_internal(unsigned int a, int ieee)
+{
+ unsigned short sign = (a >> 16) & 0x8000;
+ int aexp = (a >> 23) & 0xff;
+ unsigned int mantissa = a & 0x007fffff;
+ unsigned int mask;
+ unsigned int increment;
+
+ if (aexp == 0xff)
+ {
+ if (!ieee)
+ return sign;
+ return sign | 0x7e00 | (mantissa >> 13);
+ }
+
+ if (aexp == 0 && mantissa == 0)
+ return sign;
+
+ aexp -= 127;
+
+ /* Decimal point between bits 22 and 23. */
+ mantissa |= 0x00800000;
+ if (aexp < -14)
+ {
+ mask = 0x007fffff;
+ if (aexp < -25)
+ aexp = -26;
+ else if (aexp != -25)
+ mask >>= 24 + aexp;
+ }
+ else
+ mask = 0x00001fff;
+
+ /* Round. */
+ if (mantissa & mask)
+ {
+ increment = (mask + 1) >> 1;
+ if ((mantissa & mask) == increment)
+ increment = mantissa & (increment << 1);
+ mantissa += increment;
+ if (mantissa >= 0x01000000)
+ {
+ mantissa >>= 1;
+ aexp++;
+ }
+ }
+
+ if (ieee)
+ {
+ if (aexp > 15)
+ return sign | 0x7c00;
+ }
+ else
+ {
+ if (aexp > 16)
+ return sign | 0x7fff;
+ }
+
+ if (aexp < -24)
+ return sign;
+
+ if (aexp < -14)
+ {
+ mantissa >>= -14 - aexp;
+ aexp = -14;
+ }
+
+ /* We leave the leading 1 in the mantissa, and subtract one
+ from the exponent bias to compensate. */
+ return sign | (((aexp + 14) << 10) + (mantissa >> 13));
+}
+
+unsigned int
+__gnu_h2f_internal(unsigned short a, int ieee)
+{
+ unsigned int sign = (unsigned int)(a & 0x8000) << 16;
+ int aexp = (a >> 10) & 0x1f;
+ unsigned int mantissa = a & 0x3ff;
+
+ if (aexp == 0x1f && ieee)
+ return sign | 0x7f800000 | (mantissa << 13);
+
+ if (aexp == 0)
+ {
+ int shift;
+
+ if (mantissa == 0)
+ return sign;
+
+ shift = __builtin_clz(mantissa) - 21;
+ mantissa <<= shift;
+ aexp = -shift;
+ }
+
+ return sign | (((aexp + 0x70) << 23) + (mantissa << 13));
+}
+
+unsigned short
+__gnu_f2h_ieee(unsigned int a)
+{
+ return __gnu_f2h_internal(a, 1);
+}
+
+unsigned int
+__gnu_h2f_ieee(unsigned short a)
+{
+ return __gnu_h2f_internal(a, 1);
+}
+
+unsigned short
+__gnu_f2h_alternative(unsigned int x)
+{
+ return __gnu_f2h_internal(x, 0);
+}
+
+unsigned int
+__gnu_h2f_alternative(unsigned short a)
+{
+ return __gnu_h2f_internal(a, 0);
+}