100 lines
2.6 KiB
Rust
100 lines
2.6 KiB
Rust
// Copyright (c) 2025 taitep
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// SPDX-License-Identifier: MIT
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//
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// This file is part of TRVE (https://gitea.taitep.se/taitep/trve)
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// See LICENSE file in the project root for full license text.
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use crate::consts::{DWord, RegId, Word};
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const MASK_REGISTER: Word = 0x1f;
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#[derive(Debug, Clone, Copy)]
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pub struct Instruction(pub Word);
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#[allow(dead_code)]
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impl Instruction {
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#[inline]
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pub fn opcode(self) -> u8 {
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(self.0 & 0x7f) as u8
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}
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/// Returns the opcode of the instruction, with the last 2 bits stripped away, as they are always 0b11 in a non-compressed instruction
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#[inline]
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pub fn opcode_noncompressed(self) -> u8 {
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debug_assert_eq!(self.0 & 0b11, 0b11, "Compressed (or invalid) opcode");
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(self.0 >> 2 & 0x1f) as u8
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}
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#[inline]
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pub fn rd(self) -> RegId {
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(self.0 >> 7 & MASK_REGISTER) as RegId
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}
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#[inline]
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pub fn funct3(self) -> u8 {
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(self.0 >> 12 & 0x7) as u8
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}
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#[inline]
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pub fn rs1(self) -> RegId {
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(self.0 >> 15 & MASK_REGISTER) as RegId
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}
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#[inline]
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pub fn rs2(self) -> RegId {
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(self.0 >> 20 & MASK_REGISTER) as RegId
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}
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#[inline]
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pub fn funct7(self) -> u8 {
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(self.0 >> 25 & 0x7f) as u8
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}
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#[inline]
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pub fn imm_i(self) -> DWord {
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(self.0 as i32 as i64 >> 20) as DWord
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}
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#[inline]
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pub fn imm_s(self) -> DWord {
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(self.0 as i32 as i64 >> (25 - 5) & (0x7f << 5)) as DWord | (self.0 >> 7 & 0b11111) as DWord
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}
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#[inline]
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pub fn imm_b(self) -> DWord {
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let imm_12 = ((self.0 & 0x8000_0000) as i32 as i64 >> (31 - 12)) as DWord;
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let imm_10_5 = ((self.0 >> 25 & 0x3f) << 5) as DWord;
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let imm_4_1 = ((self.0 >> 8 & 0xf) << 1) as DWord;
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let imm_11 = ((self.0 >> 7 & 1) << 11) as DWord;
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imm_12 | imm_10_5 | imm_4_1 | imm_11
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}
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#[inline]
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pub fn imm_u(self) -> DWord {
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(self.0 & 0xffff_f000) as i32 as i64 as DWord
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}
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#[inline]
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pub fn imm_j(self) -> DWord {
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let imm_20 = ((self.0 & 0x8000_0000) as i32 as i64 >> (31 - 20)) as DWord;
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let imm_10_1 = ((self.0 >> 21 & 0x3ff) << 1) as DWord;
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let imm_11 = ((self.0 >> 20 & 1) << 11) as DWord;
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let imm_19_12 = ((self.0 >> 12 & 0xff) << 12) as DWord;
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imm_20 | imm_10_1 | imm_11 | imm_19_12
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}
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// The following are AFAIK only used for shift by immediate operations
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#[inline]
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pub fn funct6(self) -> u8 {
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(self.0 >> 26 & 0x3f) as u8
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}
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#[inline]
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pub fn imm_shamt(self) -> usize {
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(self.0 >> 20 & 0x3f) as usize
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}
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}
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