target/mips/msa.c

   1 /*
   2  * MIPS SIMD Architecture Module Instruction emulation helpers for QEMU.
   3  *
   4  * Copyright (c) 2014 Imagination Technologies
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "qemu/osdep.h"
  21 #include "cpu.h"
  22 #include "internal.h"
  23 #include "fpu/softfloat.h"
  24 #include "fpu_helper.h"
  25
  26 void msa_reset(CPUMIPSState *env)
  27 {
  28     if (!ase_msa_available(env)) {
  29         return;
  30     }
  31
  32 #ifdef CONFIG_USER_ONLY
  33     /* MSA access enabled */
  34     env->CP0_Config5 |= 1 << CP0C5_MSAEn;
  35     env->CP0_Status |= (1 << CP0St_CU1) | (1 << CP0St_FR);
  36 #endif
  37
  38     /*
  39      * MSA CSR:
  40      * - non-signaling floating point exception mode off (NX bit is 0)
  41      * - Cause, Enables, and Flags are all 0
  42      * - round to nearest / ties to even (RM bits are 0)
  43      */
  44     env->active_tc.msacsr = 0;
  45
  46     restore_msa_fp_status(env);
  47
  48     /* tininess detected after rounding.*/
  49     set_float_detect_tininess(float_tininess_after_rounding,
  50                               &env->active_tc.msa_fp_status);
  51
  52     /* clear float_status exception flags */
  53     set_float_exception_flags(0, &env->active_tc.msa_fp_status);
  54
  55     /* clear float_status nan mode */
  56     set_default_nan_mode(0, &env->active_tc.msa_fp_status);
  57
  58     /* set proper signanling bit meaning ("1" means "quiet") */
  59     set_snan_bit_is_one(0, &env->active_tc.msa_fp_status);
  60 }