target/mips/fpu_helper.h

   1 /*
   2  * Helpers for emulation of FPU-related MIPS instructions.
   3  *
   4  *  Copyright (C) 2004-2005  Jocelyn Mayer
   5  *
   6  * SPDX-License-Identifier: LGPL-2.1-or-later
   7  */
   8 #include "fpu/softfloat-helpers.h"
   9 #include "cpu.h"
  10
  11 extern const FloatRoundMode ieee_rm[4];
  12
  13 uint32_t float_class_s(uint32_t arg, float_status *fst);
  14 uint64_t float_class_d(uint64_t arg, float_status *fst);
  15
  16 static inline void restore_rounding_mode(CPUMIPSState *env)
  17 {
  18     set_float_rounding_mode(ieee_rm[env->active_fpu.fcr31 & 3],
  19                             &env->active_fpu.fp_status);
  20 }
  21
  22 static inline void restore_flush_mode(CPUMIPSState *env)
  23 {
  24     set_flush_to_zero((env->active_fpu.fcr31 & (1 << FCR31_FS)) != 0,
  25                       &env->active_fpu.fp_status);
  26 }
  27
  28 static inline void restore_snan_bit_mode(CPUMIPSState *env)
  29 {
  30     bool nan2008 = env->active_fpu.fcr31 & (1 << FCR31_NAN2008);
  31
  32     /*
  33      * With nan2008, SNaNs are silenced in the usual way.
  34      * Before that, SNaNs are not silenced; default nans are produced.
  35      */
  36     set_snan_bit_is_one(!nan2008, &env->active_fpu.fp_status);
  37     set_default_nan_mode(!nan2008, &env->active_fpu.fp_status);
  38 }
  39
  40 static inline void restore_fp_status(CPUMIPSState *env)
  41 {
  42     restore_rounding_mode(env);
  43     restore_flush_mode(env);
  44     restore_snan_bit_mode(env);
  45 }
  46
  47 /* MSA */
  48
  49 enum CPUMIPSMSADataFormat {
  50     DF_BYTE = 0,
  51     DF_HALF,
  52     DF_WORD,
  53     DF_DOUBLE
  54 };
  55
  56 static inline void restore_msa_fp_status(CPUMIPSState *env)
  57 {
  58     float_status *status = &env->active_tc.msa_fp_status;
  59     int rounding_mode = (env->active_tc.msacsr & MSACSR_RM_MASK) >> MSACSR_RM;
  60     bool flush_to_zero = (env->active_tc.msacsr & MSACSR_FS_MASK) != 0;
  61
  62     set_float_rounding_mode(ieee_rm[rounding_mode], status);
  63     set_flush_to_zero(flush_to_zero, status);
  64     set_flush_inputs_to_zero(flush_to_zero, status);
  65 }