LXR qemu/target/mips/fpu

   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
  11extern const FloatRoundMode ieee_rm[4];
  12
  13uint32_t float_class_s(uint32_t arg, float_status *fst);
  14uint64_t float_class_d(uint64_t arg, float_status *fst);
  15
  16static 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
  22static 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
  28static 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
  40static 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
  49enum CPUMIPSMSADataFormat {
  50    DF_BYTE = 0,
  51    DF_HALF,
  52    DF_WORD,
  53    DF_DOUBLE
  54};
  55
  56static 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}
  66