#[cfg(test)]
use stdarch_test::assert_instr;

extern "unadjusted" {
    #[link_name = "llvm.riscv.sm4ed"]
    fn _sm4ed(rs1: i32, rs2: i32, bs: i32) -> i32;

    #[link_name = "llvm.riscv.sm4ks"]
    fn _sm4ks(rs1: i32, rs2: i32, bs: i32) -> i32;

    #[link_name = "llvm.riscv.sm3p0"]
    fn _sm3p0(rs1: i32) -> i32;

    #[link_name = "llvm.riscv.sm3p1"]
    fn _sm3p1(rs1: i32) -> i32;

    #[link_name = "llvm.riscv.sha256sig0"]
    fn _sha256sig0(rs1: i32) -> i32;

    #[link_name = "llvm.riscv.sha256sig1"]
    fn _sha256sig1(rs1: i32) -> i32;

    #[link_name = "llvm.riscv.sha256sum0"]
    fn _sha256sum0(rs1: i32) -> i32;

    #[link_name = "llvm.riscv.sha256sum1"]
    fn _sha256sum1(rs1: i32) -> i32;
}

#[cfg(target_arch = "riscv32")]
extern "unadjusted" {
    #[link_name = "llvm.riscv.xperm8.i32"]
    fn _xperm8_32(rs1: i32, rs2: i32) -> i32;

    #[link_name = "llvm.riscv.xperm4.i32"]
    fn _xperm4_32(rs1: i32, rs2: i32) -> i32;
}

#[cfg(target_arch = "riscv64")]
extern "unadjusted" {
    #[link_name = "llvm.riscv.xperm8.i64"]
    fn _xperm8_64(rs1: i64, rs2: i64) -> i64;

    #[link_name = "llvm.riscv.xperm4.i64"]
    fn _xperm4_64(rs1: i64, rs2: i64) -> i64;
}

/// Byte-wise lookup of indicies into a vector in registers.
///
/// The xperm8 instruction operates on bytes. The rs1 register contains a vector of XLEN/8
/// 8-bit elements. The rs2 register contains a vector of XLEN/8 8-bit indexes. The result is
/// each element in rs2 replaced by the indexed element in rs1, or zero if the index into rs2
/// is out of bounds.
///
/// Source: RISC-V Cryptography Extensions Volume I: Scalar & Entropy Source Instructions
///
/// Version: v1.0.1
///
/// Section: 3.47
///
/// # Safety
///
/// This function is safe to use if the `zbkx` target feature is present.
#[target_feature(enable = "zbkx")]
#[cfg_attr(test, assert_instr(xperm8))]
#[inline]
pub unsafe fn xperm8(rs1: usize, rs2: usize) -> usize {
    #[cfg(target_arch = "riscv32")]
    {
        _xperm8_32(rs1 as i32, rs2 as i32) as usize
    }

    #[cfg(target_arch = "riscv64")]
    {
        _xperm8_64(rs1 as i64, rs2 as i64) as usize
    }
}

/// Nibble-wise lookup of indicies into a vector.
///
/// The xperm4 instruction operates on nibbles. The rs1 register contains a vector of XLEN/4
/// 4-bit elements. The rs2 register contains a vector of XLEN/4 4-bit indexes. The result is
/// each element in rs2 replaced by the indexed element in rs1, or zero if the index into rs2
/// is out of bounds.
///
/// Source: RISC-V Cryptography Extensions Volume I: Scalar & Entropy Source Instructions
///
/// Version: v1.0.1
///
/// Section: 3.48
///
/// # Safety
///
/// This function is safe to use if the `zbkx` target feature is present.
#[target_feature(enable = "zbkx")]
#[cfg_attr(test, assert_instr(xperm4))]
#[inline]
pub unsafe fn xperm4(rs1: usize, rs2: usize) -> usize {
    #[cfg(target_arch = "riscv32")]
    {
        _xperm4_32(rs1 as i32, rs2 as i32) as usize
    }

    #[cfg(target_arch = "riscv64")]
    {
        _xperm4_64(rs1 as i64, rs2 as i64) as usize
    }
}

/// Implements the Sigma0 transformation function as used in the SHA2-256 hash function \[49\]
/// (Section 4.1.2).
///
/// This instruction is supported for both RV32 and RV64 base architectures. For RV32, the
/// entire XLEN source register is operated on. For RV64, the low 32 bits of the source
/// register are operated on, and the result sign extended to XLEN bits. Though named for
/// SHA2-256, the instruction works for both the SHA2-224 and SHA2-256 parameterisations as
/// described in \[49\]. This instruction must always be implemented such that its execution
/// latency does not depend on the data being operated on.
///
/// Source: RISC-V Cryptography Extensions Volume I: Scalar & Entropy Source Instructions
///
/// Version: v1.0.1
///
/// Section: 3.27
///
/// # Safety
///
/// This function is safe to use if the `zknh` target feature is present.
#[target_feature(enable = "zknh")]
#[cfg_attr(test, assert_instr(sha256sig0))]
#[inline]
pub unsafe fn sha256sig0(rs1: u32) -> u32 {
    _sha256sig0(rs1 as i32) as u32
}

/// Implements the Sigma1 transformation function as used in the SHA2-256 hash function \[49\]
/// (Section 4.1.2).
///
/// This instruction is supported for both RV32 and RV64 base architectures. For RV32, the
/// entire XLEN source register is operated on. For RV64, the low 32 bits of the source
/// register are operated on, and the result sign extended to XLEN bits. Though named for
/// SHA2-256, the instruction works for both the SHA2-224 and SHA2-256 parameterisations as
/// described in \[49\]. This instruction must always be implemented such that its execution
/// latency does not depend on the data being operated on.
///
/// Source: RISC-V Cryptography Extensions Volume I: Scalar & Entropy Source Instructions
///
/// Version: v1.0.1
///
/// Section: 3.28
///
/// # Safety
///
/// This function is safe to use if the `zknh` target feature is present.
#[target_feature(enable = "zknh")]
#[cfg_attr(test, assert_instr(sha256sig1))]
#[inline]
pub unsafe fn sha256sig1(rs1: u32) -> u32 {
    _sha256sig1(rs1 as i32) as u32
}

/// Implements the Sum0 transformation function as used in the SHA2-256 hash function \[49\]
/// (Section 4.1.2).
///
/// This instruction is supported for both RV32 and RV64 base architectures. For RV32, the
/// entire XLEN source register is operated on. For RV64, the low 32 bits of the source
/// register are operated on, and the result sign extended to XLEN bits. Though named for
/// SHA2-256, the instruction works for both the SHA2-224 and SHA2-256 parameterisations as
/// described in \[49\]. This instruction must always be implemented such that its execution
/// latency does not depend on the data being operated on.
///
/// Source: RISC-V Cryptography Extensions Volume I: Scalar & Entropy Source Instructions
///
/// Version: v1.0.1
///
/// Section: 3.29
///
/// # Safety
///
/// This function is safe to use if the `zknh` target feature is present.
#[target_feature(enable = "zknh")]
#[cfg_attr(test, assert_instr(sha256sum0))]
#[inline]
pub unsafe fn sha256sum0(rs1: u32) -> u32 {
    _sha256sum0(rs1 as i32) as u32
}

/// Implements the Sum1 transformation function as used in the SHA2-256 hash function \[49\]
/// (Section 4.1.2).
///
/// This instruction is supported for both RV32 and RV64 base architectures. For RV32, the
/// entire XLEN source register is operated on. For RV64, the low 32 bits of the source
/// register are operated on, and the result sign extended to XLEN bits. Though named for
/// SHA2-256, the instruction works for both the SHA2-224 and SHA2-256 parameterisations as
/// described in \[49\]. This instruction must always be implemented such that its execution
/// latency does not depend on the data being operated on.
///
/// Source: RISC-V Cryptography Extensions Volume I: Scalar & Entropy Source Instructions
///
/// Version: v1.0.1
///
/// Section: 3.30
///
/// # Safety
///
/// This function is safe to use if the `zknh` target feature is present.
#[target_feature(enable = "zknh")]
#[cfg_attr(test, assert_instr(sha256sum1))]
#[inline]
pub unsafe fn sha256sum1(rs1: u32) -> u32 {
    _sha256sum1(rs1 as i32) as u32
}

/// Accelerates the block encrypt/decrypt operation of the SM4 block cipher \[5, 31\].
///
/// Implements a T-tables in hardware style approach to accelerating the SM4 round function. A
/// byte is extracted from rs2 based on bs, to which the SBox and linear layer transforms are
/// applied, before the result is XOR’d with rs1 and written back to rd. This instruction
/// exists on RV32 and RV64 base architectures. On RV64, the 32-bit result is sign extended to
/// XLEN bits. This instruction must always be implemented such that its execution latency does
/// not depend on the data being operated on.
///
/// Source: RISC-V Cryptography Extensions Volume I: Scalar & Entropy Source Instructions
///
/// Version: v1.0.1
///
/// Section: 3.43
///
/// # Note
///
/// The `BS` parameter is expected to be a constant value and only the bottom 2 bits of `bs` are
/// used.
///
/// # Safety
///
/// This function is safe to use if the `zksed` target feature is present.
///
/// # Details
///
/// Accelerates the round function `F` in the SM4 block cipher algorithm
///
/// This instruction is included in extension `Zksed`. It's defined as:
///
/// ```text
/// SM4ED(x, a, BS) = x ⊕ T(ai)
/// ... where
/// ai = a.bytes[BS]
/// T(ai) = L(τ(ai))
/// bi = τ(ai) = SM4-S-Box(ai)
/// ci = L(bi) = bi ⊕ (bi ≪ 2) ⊕ (bi ≪ 10) ⊕ (bi ≪ 18) ⊕ (bi ≪ 24)
/// SM4ED = (ci ≪ (BS * 8)) ⊕ x
/// ```
///
/// where `⊕` represents 32-bit xor, and `≪ k` represents rotate left by `k` bits.
/// As is defined above, `T` is a combined transformation of non linear S-Box transform `τ`
/// and linear layer transform `L`.
///
/// In the SM4 algorithm, the round function `F` is defined as:
///
/// ```text
/// F(x0, x1, x2, x3, rk) = x0 ⊕ T(x1 ⊕ x2 ⊕ x3 ⊕ rk)
/// ... where
/// T(A) = L(τ(A))
/// B = τ(A) = (SM4-S-Box(a0), SM4-S-Box(a1), SM4-S-Box(a2), SM4-S-Box(a3))
/// C = L(B) = B ⊕ (B ≪ 2) ⊕ (B ≪ 10) ⊕ (B ≪ 18) ⊕ (B ≪ 24)
/// ```
///
/// It can be implemented by `sm4ed` instruction like:
///
/// ```no_run
/// # #[cfg(any(target_arch = "riscv32", target_arch = "riscv64"))]
/// # fn round_function(x0: u32, x1: u32, x2: u32, x3: u32, rk: u32) -> u32 {
/// # #[cfg(target_arch = "riscv32")] use core::arch::riscv32::sm4ed;
/// # #[cfg(target_arch = "riscv64")] use core::arch::riscv64::sm4ed;
/// let a = x1 ^ x2 ^ x3 ^ rk;
/// let c0 = sm4ed(x0, a, 0);
/// let c1 = sm4ed(c0, a, 1); // c1 represents c[0..=1], etc.
/// let c2 = sm4ed(c1, a, 2);
/// let c3 = sm4ed(c2, a, 3);
/// return c3; // c3 represents c[0..=3]
/// # }
/// ```
#[target_feature(enable = "zksed")]
#[rustc_legacy_const_generics(2)]
#[cfg_attr(test, assert_instr(sm4ed, BS = 0))]
#[inline]
pub unsafe fn sm4ed<const BS: u8>(rs1: u32, rs2: u32) -> u32 {
    static_assert!(BS < 4);

    _sm4ed(rs1 as i32, rs2 as i32, BS as i32) as u32
}

/// Accelerates the Key Schedule operation of the SM4 block cipher \[5, 31\] with `bs=0`.
///
/// Implements a T-tables in hardware style approach to accelerating the SM4 Key Schedule. A
/// byte is extracted from rs2 based on bs, to which the SBox and linear layer transforms are
/// applied, before the result is XOR’d with rs1 and written back to rd. This instruction
/// exists on RV32 and RV64 base architectures. On RV64, the 32-bit result is sign extended to
/// XLEN bits. This instruction must always be implemented such that its execution latency does
/// not depend on the data being operated on.
///
/// Source: RISC-V Cryptography Extensions Volume I: Scalar & Entropy Source Instructions
///
/// Version: v1.0.1
///
/// Section: 3.44
///
/// # Note
///
/// The `BS` parameter is expected to be a constant value and only the bottom 2 bits of `bs` are
/// used.
///
/// # Safety
///
/// This function is safe to use if the `zksed` target feature is present.
///
/// # Details
///
/// Accelerates the round function `F` in the SM4 block cipher algorithm
///
/// This instruction is included in extension `Zksed`. It's defined as:
///
/// ```text
/// SM4ED(x, a, BS) = x ⊕ T(ai)
/// ... where
/// ai = a.bytes[BS]
/// T(ai) = L(τ(ai))
/// bi = τ(ai) = SM4-S-Box(ai)
/// ci = L(bi) = bi ⊕ (bi ≪ 2) ⊕ (bi ≪ 10) ⊕ (bi ≪ 18) ⊕ (bi ≪ 24)
/// SM4ED = (ci ≪ (BS * 8)) ⊕ x
/// ```
///
/// where `⊕` represents 32-bit xor, and `≪ k` represents rotate left by `k` bits.
/// As is defined above, `T` is a combined transformation of non linear S-Box transform `τ`
/// and linear layer transform `L`.
///
/// In the SM4 algorithm, the round function `F` is defined as:
///
/// ```text
/// F(x0, x1, x2, x3, rk) = x0 ⊕ T(x1 ⊕ x2 ⊕ x3 ⊕ rk)
/// ... where
/// T(A) = L(τ(A))
/// B = τ(A) = (SM4-S-Box(a0), SM4-S-Box(a1), SM4-S-Box(a2), SM4-S-Box(a3))
/// C = L(B) = B ⊕ (B ≪ 2) ⊕ (B ≪ 10) ⊕ (B ≪ 18) ⊕ (B ≪ 24)
/// ```
///
/// It can be implemented by `sm4ed` instruction like:
///
/// ```no_run
/// # #[cfg(any(target_arch = "riscv32", target_arch = "riscv64"))]
/// # fn round_function(x0: u32, x1: u32, x2: u32, x3: u32, rk: u32) -> u32 {
/// # #[cfg(target_arch = "riscv32")] use core::arch::riscv32::sm4ed;
/// # #[cfg(target_arch = "riscv64")] use core::arch::riscv64::sm4ed;
/// let a = x1 ^ x2 ^ x3 ^ rk;
/// let c0 = sm4ed(x0, a, 0);
/// let c1 = sm4ed(c0, a, 1); // c1 represents c[0..=1], etc.
/// let c2 = sm4ed(c1, a, 2);
/// let c3 = sm4ed(c2, a, 3);
/// return c3; // c3 represents c[0..=3]
/// # }
/// ```
#[target_feature(enable = "zksed")]
#[rustc_legacy_const_generics(2)]
#[cfg_attr(test, assert_instr(sm4ks, BS = 0))]
#[inline]
pub unsafe fn sm4ks<const BS: u8>(rs1: u32, rs2: u32) -> u32 {
    static_assert!(BS < 4);

    _sm4ks(rs1 as i32, rs2 as i32, BS as i32) as u32
}

/// Implements the P0 transformation function as used in the SM3 hash function [4, 30].
///
/// This instruction is supported for the RV32 and RV64 base architectures. It implements the
/// P0 transform of the SM3 hash function [4, 30]. This instruction must always be implemented
/// such that its execution latency does not depend on the data being operated on.
///
/// Source: RISC-V Cryptography Extensions Volume I: Scalar & Entropy Source Instructions
///
/// Version: v1.0.1
///
/// Section: 3.41
///
/// # Safety
///
/// This function is safe to use if the `zksh` target feature is present.
///
/// # Details
///
/// `P0` transformation function as is used in the SM3 hash algorithm
///
/// This function is included in `Zksh` extension. It's defined as:
///
/// ```text
/// P0(X) = X ⊕ (X ≪ 9) ⊕ (X ≪ 17)
/// ```
///
/// where `⊕` represents 32-bit xor, and `≪ k` represents rotate left by `k` bits.
///
/// In the SM3 algorithm, the `P0` transformation is used as `E ← P0(TT2)` when the
/// compression function `CF` uses the intermediate value `TT2` to calculate
/// the variable `E` in one iteration for subsequent processes.
#[target_feature(enable = "zksh")]
#[cfg_attr(test, assert_instr(sm3p0))]
#[inline]
pub unsafe fn sm3p0(rs1: u32) -> u32 {
    _sm3p0(rs1 as i32) as u32
}

/// Implements the P1 transformation function as used in the SM3 hash function [4, 30].
///
/// This instruction is supported for the RV32 and RV64 base architectures. It implements the
/// P1 transform of the SM3 hash function [4, 30]. This instruction must always be implemented
/// such that its execution latency does not depend on the data being operated on.
///
/// Source: RISC-V Cryptography Extensions Volume I: Scalar & Entropy Source Instructions
///
/// Version: v1.0.1
///
/// Section: 3.42
///
/// # Safety
///
/// This function is safe to use if the `zksh` target feature is present.
///
/// # Details
///
/// `P1` transformation function as is used in the SM3 hash algorithm
///
/// This function is included in `Zksh` extension. It's defined as:
///
/// ```text
/// P1(X) = X ⊕ (X ≪ 15) ⊕ (X ≪ 23)
/// ```
///
/// where `⊕` represents 32-bit xor, and `≪ k` represents rotate left by `k` bits.
///
/// In the SM3 algorithm, the `P1` transformation is used to expand message,
/// where expanded word `Wj` can be generated from the previous words.
/// The whole process can be described as the following pseudocode:
///
/// ```text
/// FOR j=16 TO 67
///     Wj ← P1(Wj−16 ⊕ Wj−9 ⊕ (Wj−3 ≪ 15)) ⊕ (Wj−13 ≪ 7) ⊕ Wj−6
/// ENDFOR
/// ```
#[target_feature(enable = "zksh")]
#[cfg_attr(test, assert_instr(sm3p1))]
#[inline]
pub unsafe fn sm3p1(rs1: u32) -> u32 {
    _sm3p1(rs1 as i32) as u32
}