/*
 * Copyright (c) 2019 Western Digital Corporation or its affiliates.
 *
 * Authors:
 *   Anup Patel <anup.patel@wdc.com>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#ifndef __RISCV_FP_H__
#define __RISCV_FP_H__

#include <sbi/riscv_asm.h>
#include <sbi/riscv_encoding.h>
#include <sbi/sbi_types.h>

#define GET_PRECISION(insn) (((insn) >> 25) & 3)
#define GET_RM(insn) (((insn) >> 12) & 7)
#define PRECISION_S 0
#define PRECISION_D 1

#ifdef __riscv_flen

#define GET_F32_REG(insn, pos, regs) ({ \
  register s32 value asm("a0") = SHIFT_RIGHT(insn, (pos)-3) & 0xf8; \
  ulong tmp; \
  asm ("1: auipc %0, %%pcrel_hi(get_f32_reg); add %0, %0, %1; jalr t0, %0, %%pcrel_lo(1b)" : "=&r"(tmp), "+&r"(value) :: "t0"); \
  value; })
#define SET_F32_REG(insn, pos, regs, val) ({ \
  register u32 value asm("a0") = (val); \
  ulong offset = SHIFT_RIGHT(insn, (pos)-3) & 0xf8; \
  ulong tmp; \
  asm volatile ("1: auipc %0, %%pcrel_hi(put_f32_reg); add %0, %0, %2; jalr t0, %0, %%pcrel_lo(1b)" : "=&r"(tmp) : "r"(value), "r"(offset) : "t0"); })
#define init_fp_reg(i) SET_F32_REG((i) << 3, 3, 0, 0)
#define GET_F64_REG(insn, pos, regs) ({ \
  register ulong value asm("a0") = SHIFT_RIGHT(insn, (pos)-3) & 0xf8; \
  ulong tmp; \
  asm ("1: auipc %0, %%pcrel_hi(get_f64_reg); add %0, %0, %1; jalr t0, %0, %%pcrel_lo(1b)" : "=&r"(tmp), "+&r"(value) :: "t0"); \
  sizeof(ulong) == 4 ? *(int64_t*)value : (int64_t)value; })
#define SET_F64_REG(insn, pos, regs, val) ({ \
  uint64_t __val = (val); \
  register ulong value asm("a0") = sizeof(ulong) == 4 ? (ulong)&__val : (ulong)__val; \
  ulong offset = SHIFT_RIGHT(insn, (pos)-3) & 0xf8; \
  ulong tmp; \
  asm volatile ("1: auipc %0, %%pcrel_hi(put_f64_reg); add %0, %0, %2; jalr t0, %0, %%pcrel_lo(1b)" : "=&r"(tmp) : "r"(value), "r"(offset) : "t0"); })
#define GET_FCSR() csr_read(fcsr)
#define SET_FCSR(value) csr_write(fcsr, (value))
#define GET_FRM() csr_read(frm)
#define SET_FRM(value) csr_write(frm, (value))
#define GET_FFLAGS() csr_read(fflags)
#define SET_FFLAGS(value) csr_write(fflags, (value))

#define SET_FS_DIRTY() ((void) 0)

#else
#error "Floating point emulation not supported.\n"
#endif

#define GET_F32_RS1(insn, regs) (GET_F32_REG(insn, 15, regs))
#define GET_F32_RS2(insn, regs) (GET_F32_REG(insn, 20, regs))
#define GET_F32_RS3(insn, regs) (GET_F32_REG(insn, 27, regs))
#define GET_F64_RS1(insn, regs) (GET_F64_REG(insn, 15, regs))
#define GET_F64_RS2(insn, regs) (GET_F64_REG(insn, 20, regs))
#define GET_F64_RS3(insn, regs) (GET_F64_REG(insn, 27, regs))
#define SET_F32_RD(insn, regs, val) (SET_F32_REG(insn, 7, regs, val), SET_FS_DIRTY())
#define SET_F64_RD(insn, regs, val) (SET_F64_REG(insn, 7, regs, val), SET_FS_DIRTY())

#define GET_F32_RS2C(insn, regs) (GET_F32_REG(insn, 2, regs))
#define GET_F32_RS2S(insn, regs) (GET_F32_REG(RVC_RS2S(insn), 0, regs))
#define GET_F64_RS2C(insn, regs) (GET_F64_REG(insn, 2, regs))
#define GET_F64_RS2S(insn, regs) (GET_F64_REG(RVC_RS2S(insn), 0, regs))

#endif