Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / mips / math-emu / dp_tint.c

diff --git a/kernel/arch/mips/math-emu/dp_tint.c b/kernel/arch/mips/math-emu/dp_tint.c
new file mode 100644 (file)
index 0000000..6ffc336
--- /dev/null
+++ b/kernel/arch/mips/math-emu/dp_tint.c
@@ -0,0 +1,105 @@
+/* IEEE754 floating point arithmetic
+ * double precision: common utilities
+ */
+/*
+ * MIPS floating point support
+ * Copyright (C) 1994-2000 Algorithmics Ltd.
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope 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.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA.
+ */
+
+#include "ieee754dp.h"
+
+int ieee754dp_tint(union ieee754dp x)
+{
+       u64 residue;
+       int round;
+       int sticky;
+       int odd;
+
+       COMPXDP;
+
+       ieee754_clearcx();
+
+       EXPLODEXDP;
+       FLUSHXDP;
+
+       switch (xc) {
+       case IEEE754_CLASS_SNAN:
+       case IEEE754_CLASS_QNAN:
+       case IEEE754_CLASS_INF:
+               ieee754_setcx(IEEE754_INVALID_OPERATION);
+               return ieee754si_indef();
+
+       case IEEE754_CLASS_ZERO:
+               return 0;
+
+       case IEEE754_CLASS_DNORM:
+       case IEEE754_CLASS_NORM:
+               break;
+       }
+       if (xe > 31) {
+               /* Set invalid. We will only use overflow for floating
+                  point overflow */
+               ieee754_setcx(IEEE754_INVALID_OPERATION);
+               return ieee754si_indef();
+       }
+       /* oh gawd */
+       if (xe > DP_FBITS) {
+               xm <<= xe - DP_FBITS;
+       } else if (xe < DP_FBITS) {
+               if (xe < -1) {
+                       residue = xm;
+                       round = 0;
+                       sticky = residue != 0;
+                       xm = 0;
+               } else {
+                       residue = xm << (64 - DP_FBITS + xe);
+                       round = (residue >> 63) != 0;
+                       sticky = (residue << 1) != 0;
+                       xm >>= DP_FBITS - xe;
+               }
+               /* Note: At this point upper 32 bits of xm are guaranteed
+                  to be zero */
+               odd = (xm & 0x1) != 0x0;
+               switch (ieee754_csr.rm) {
+               case FPU_CSR_RN:
+                       if (round && (sticky || odd))
+                               xm++;
+                       break;
+               case FPU_CSR_RZ:
+                       break;
+               case FPU_CSR_RU:        /* toward +Infinity */
+                       if ((round || sticky) && !xs)
+                               xm++;
+                       break;
+               case FPU_CSR_RD:        /* toward -Infinity */
+                       if ((round || sticky) && xs)
+                               xm++;
+                       break;
+               }
+               /* look for valid corner case 0x80000000 */
+               if ((xm >> 31) != 0 && (xs == 0 || xm != 0x80000000)) {
+                       /* This can happen after rounding */
+                       ieee754_setcx(IEEE754_INVALID_OPERATION);
+                       return ieee754si_indef();
+               }
+               if (round || sticky)
+                       ieee754_setcx(IEEE754_INEXACT);
+       }
+       if (xs)
+               return -xm;
+       else
+               return xm;
+}