//! RISC-V RV64 specific intrinsics
use crate::arch::asm;

/// Loads virtual machine memory by unsigned word integer
///
/// This instruction performs an explicit memory access as though `V=1`;
/// i.e., with the address translation and protection, and the endianness, that apply to memory
/// accesses in either VS-mode or VU-mode.
///
/// This operation is not available under RV32 base instruction set.
///
/// This function is unsafe for it accesses the virtual supervisor or user via a `HLV.WU`
/// instruction which is effectively an unreference to any memory address.
#[inline]
pub unsafe fn hlv_wu(src: *const u32) -> u32 {
    let value: u32;
    asm!(".insn i 0x73, 0x4, {}, {}, 0x681", out(reg) value, in(reg) src, options(readonly, nostack));
    value
}

/// Loads virtual machine memory by unsigned double integer
///
/// This instruction performs an explicit memory access as though `V=1`;
/// i.e., with the address translation and protection, and the endianness, that apply to memory
/// accesses in either VS-mode or VU-mode.
///
/// This operation is not available under RV32 base instruction set.
///
/// This function is unsafe for it accesses the virtual supervisor or user via a `HLV.D`
/// instruction which is effectively an unreference to any memory address.
#[inline]
pub unsafe fn hlv_d(src: *const i64) -> i64 {
    let value: i64;
    asm!(".insn i 0x73, 0x4, {}, {}, 0x6C0", out(reg) value, in(reg) src, options(readonly, nostack));
    value
}

/// Stores virtual machine memory by double integer
///
/// This instruction performs an explicit memory access as though `V=1`;
/// i.e., with the address translation and protection, and the endianness, that apply to memory
/// accesses in either VS-mode or VU-mode.
///
/// This function is unsafe for it accesses the virtual supervisor or user via a `HSV.D`
/// instruction which is effectively an unreference to any memory address.
#[inline]
pub unsafe fn hsv_d(dst: *mut i64, src: i64) {
    asm!(".insn r 0x73, 0x4, 0x37, x0, {}, {}", in(reg) dst, in(reg) src, options(nostack));
}
