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//! # BC.cond
//!
//! This instruction branches conditionally to a label at a PC-relative offset, with a hint that this branch is very unlikely to change direction. This instruction provides a hint that this is not a subroutine call or return.
#![allow(non_snake_case)]
#![allow(unused)]
use crate::error::Result;
use crate::utils::*;
use super::super::formatter::*;
use super::super::instruction::*;
use super::super::operand::*;
use super::super::consts::*;
use super::super::config::*;
use super::super::decoder::*;
// ---------------------------------------------------------------------------
// Iclass IclassBcOnlyCondbranch
// ---------------------------------------------------------------------------
/// Type that represents the IclassBcOnlyCondbranch instruction class.
pub(crate) struct IclassBcOnlyCondbranch;
impl IclassBcOnlyCondbranch {
/// Tries to decode the instruction in `data`.
pub(crate) fn decode(data: u32, decoder: &mut Decoder) -> Result<Instruction> {
let field_28 = (data >> 26) & 7;
let field_28_post = field_28;
let field_31 = (data >> 29) & 7;
let field_31_post = field_31;
let o0 = (data >> 4) & 1;
let o0_post = o0;
let cond = (data >> 0) & 15;
let cond_post = cond;
let field_25 = (data >> 24) & 3;
let field_25_post = field_25;
let imm19 = (data >> 5) & 524287;
let imm19_post = imm19;
return BcOnlyCondbranch::decode(data as u32, decoder);
unreachable!()
}
}
/// None-bit encoding.
///
/// # Encoding
///
/// <table style="font-family: courier, monospace">
/// <tr>
/// <td style="border: none">31</td>
/// <td style="border: none">30</td>
/// <td style="border: none">29</td>
/// <td style="border: none">28</td>
/// <td style="border: none">27</td>
/// <td style="border: none">26</td>
/// <td style="border: none">25</td>
/// <td style="border: none">24</td>
/// <td style="border: none">23</td>
/// <td style="border: none">22</td>
/// <td style="border: none">21</td>
/// <td style="border: none">20</td>
/// <td style="border: none">19</td>
/// <td style="border: none">18</td>
/// <td style="border: none">17</td>
/// <td style="border: none">16</td>
/// <td style="border: none">15</td>
/// <td style="border: none">14</td>
/// <td style="border: none">13</td>
/// <td style="border: none">12</td>
/// <td style="border: none">11</td>
/// <td style="border: none">10</td>
/// <td style="border: none">9</td>
/// <td style="border: none">8</td>
/// <td style="border: none">7</td>
/// <td style="border: none">6</td>
/// <td style="border: none">5</td>
/// <td style="border: none">4</td>
/// <td style="border: none">3</td>
/// <td style="border: none">2</td>
/// <td style="border: none">1</td>
/// <td style="border: none">0</td>
/// </tr>
/// <tr>
/// <td style="text-align: center; border-right: none" colspan="1">0</td>
/// <td style="text-align: center; border-left: none; border-right: none" colspan="1">1</td>
/// <td style="text-align: center; border-left: none" colspan="1">0</td>
/// <td style="text-align: center; border-right: none" colspan="1">1</td>
/// <td style="text-align: center; border-left: none; border-right: none" colspan="1">0</td>
/// <td style="text-align: center; border-left: none" colspan="1">1</td>
/// <td style="text-align: center; border-right: none" colspan="1">0</td>
/// <td style="text-align: center; border-left: none" colspan="1">0</td>
/// <td style="text-align: center" colspan="19">imm19</td>
/// <td style="text-align: center; border-right: none" colspan="1">1</td>
/// <td style="text-align: center" colspan="4">cond</td>
/// </tr>
/// <tr>
/// <td style="text-align: center; border: none" colspan="3"></td>
/// <td style="text-align: center; border: none" colspan="3"></td>
/// <td style="text-align: center; border: none" colspan="2"></td>
/// <td style="text-align: center; border: none" colspan="19"></td>
/// <td style="text-align: center; border: none" colspan="1">o0</td>
/// <td style="text-align: center; border: none" colspan="4"></td>
/// </tr>
/// </table>
pub struct BcOnlyCondbranch;
impl BcOnlyCondbranch {
/// Returns the instruction mnemonic.
pub fn mnemonic(_instr: &Instruction) -> Mnemonic {
Mnemonic::BC
}
/// Returns the instruction size.
pub fn size(_instr: &Instruction) -> usize {
4
}
/// Decodes the instruction in `data`.
pub fn decode(data: u32, decoder: &mut Decoder) -> Result<Instruction> {
// Fields are extracted from the input value.
let imm19 = (data >> 5) & 524287;
let imm19_post = imm19;
let cond = (data >> 0) & 15;
let cond_post = cond;
// Operand values are computed from the base fields.
let op_0 = match cond {
0 => Condition::Eq,
1 => Condition::Ne,
2 => Condition::Cs,
3 => Condition::Cc,
4 => Condition::Mi,
5 => Condition::Pl,
6 => Condition::Vs,
7 => Condition::Vc,
8 => Condition::Hi,
9 => Condition::Ls,
10 => Condition::Ge,
11 => Condition::Lt,
12 => Condition::Gt,
13 => Condition::Le,
14 => Condition::Al,
15 => Condition::Nv,
_ => todo!(),
};
let imm19_post = ((((imm19) as i64) * 4) << 43) >> 43;
let op_1 = Label::decode(imm19_post.into());
// Instruction creation from the operands.
let mut instr = Instruction::builder(Code::BC_only_condbranch)
.operand(0, op_0)?
.operand(1, op_1)?
.build();
// For encodings using labels, we check if we are decoding instruction blocks,
// which requires labels to be tracked.
if decoder.block_decoding {
// TODO: handle addition
// The label target is computed from the value stored in the corresponding operand.
let pc = match instr.op1().as_label()? {
Label::Label(imm) => (decoder.pc as i128 + imm as i128) as u64,
_ => unreachable!(),
};
// The label target is added to the decoder hashset and will be used
// to see if labels should be added in the resulting decoded instructions block.
decoder.labels.insert(pc);
// The operand is also replaced by a named label that references the label
// that was added to the hashset.
instr.set_op(1, Label::LabelName(pc as u64))?;
}
Ok(instr)
}
/// Encodes the instruction into `buf`.
pub fn encode(instr: &Instruction, buf: &mut Vec<u8>) -> Result<usize> {
// Retrieve all operand values.
let cond_pre = match instr.op0().as_condition()? {
Condition::Eq => 0,
Condition::Ne => 1,
Condition::Cs => 2,
Condition::Cc => 3,
Condition::Mi => 4,
Condition::Pl => 5,
Condition::Vs => 6,
Condition::Vc => 7,
Condition::Hi => 8,
Condition::Ls => 9,
Condition::Ge => 10,
Condition::Lt => 11,
Condition::Gt => 12,
Condition::Le => 13,
Condition::Al => 14,
Condition::Nv => 15,
_ => todo!(),
};
let imm19_pre = instr.op1().as_label()?.encode()?;
// Compute all instruction fields from the operand values.
let cond = (cond_pre & 15);
let imm19_pre = ((imm19_pre) / 4) as u32;
let imm19 = (imm19_pre & 524287);
// Add all fields to the base instruction encoding.
let mut instr: u32 = 0b01010100000000000000000000010000;
instr |= (cond & 15) << 0;
instr |= (imm19 & 524287) << 5;
let bytes = instr.to_le_bytes();
let len = bytes.len();
buf.extend(bytes);
Ok(len)
}
/// Encode an instruction part of an instruction block into `buf`.
pub fn encode_block(instr: &mut Instruction, buf: &mut Vec<u8>, labels: &std::collections::HashMap<u64, u64>) -> Result<usize> {
if let Label::LabelName(label_name) = instr.op1().as_label()? {
if let Some(label_pc) = labels.get(&label_name) {
// TODO: handle addition
let pc = *label_pc as i128 - instr.pc as i128;
instr.set_op(1, Label::decode(pc as i64))?;
} else {
// TODO: handle addition
let pc = label_name as i128 - instr.pc as i128;
instr.set_op(1, Label::decode(pc as i64))?;
}
}
Self::encode(instr, buf)
}
/// Verifies that operand #0 is valid.
pub fn check_op0(instr: &Instruction, op: &Operand) -> Result<()> {
if let Operand::Condition(c) = op {
return Ok(())
}
todo!()
}
/// Verifies that operand #1 is valid.
pub fn check_op1(instr: &Instruction, op: &Operand) -> Result<()> {
if let Operand::Label(Label::LabelName(_)) = op {
return Ok(())
}
if let Operand::Label(Label::Label(i)) = op {
if !(-1048576..=1048576).contains(i) {
todo!()
}
return Ok(())
}
todo!()
}
/// Verifies that operand #2 is valid.
pub fn check_op2(instr: &Instruction, op: &Operand) -> Result<()> {
todo!()
}
/// Verifies that operand #3 is valid.
pub fn check_op3(instr: &Instruction, op: &Operand) -> Result<()> {
todo!()
}
/// Verifies that operand #4 is valid.
pub fn check_op4(instr: &Instruction, op: &Operand) -> Result<()> {
todo!()
}
/// Verifies that operand #5 is valid.
pub fn check_op5(instr: &Instruction, op: &Operand) -> Result<()> {
todo!()
}
/// Verifies that operand #6 is valid.
pub fn check_op6(instr: &Instruction, op: &Operand) -> Result<()> {
todo!()
}
/// Formats the instruction.
pub fn format(instr: &Instruction, fmt: &mut impl Formatter, output: &mut impl FormatterOutput, config: &Config) -> Result<()> {
fmt.format_mnemonic(output, &config.global, &config.instructions.bc_only_condbranch, instr)?;
fmt.format_punctuation(output, &config.global, &config.instructions.bc_only_condbranch, instr, FormatterTextKind::Dot)?;
fmt.format_operand(output, &config.global, &config.instructions.bc_only_condbranch, instr, 0)?;
fmt.format_punctuation(output, &config.global, &config.instructions.bc_only_condbranch, instr, FormatterTextKind::Space)?;
fmt.format_operand(output, &config.global, &config.instructions.bc_only_condbranch, instr, 1)?;
Ok(())
}
}
/// Type that represents alias identifiers for [`BcOnlyCondbranch`].
#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Debug, Hash)]
pub enum BcOnlyCondbranchAliases {
None,
}