This repository has been archived on 2024-06-01. You can view files and clone it, but cannot push or open issues or pull requests.
rustboyadvance-ng/build.rs
Michel Heily a18ea022cd arm7tdmi: Small optimizations
Former-commit-id: 3348eae804c85f49231aa95e6436655c1a7c692f
2020-04-10 00:36:10 +03:00

310 lines
12 KiB
Rust

use std::env;
use std::fs;
use std::io::Write;
use std::path::Path;
extern crate bit;
use bit::BitIndex;
// copied and slightly adjusted from src/core/arm7tdmi/thumb/mod.rs
fn thumb_decode(i: u16) -> &'static str {
if i & 0xf800 == 0x1800 {
"AddSub"
} else if i & 0xe000 == 0x0000 {
"MoveShiftedReg"
} else if i & 0xe000 == 0x2000 {
"DataProcessImm"
} else if i & 0xfc00 == 0x4000 {
"AluOps"
} else if i & 0xfc00 == 0x4400 {
"HiRegOpOrBranchExchange"
} else if i & 0xf800 == 0x4800 {
"LdrPc"
} else if i & 0xf200 == 0x5000 {
"LdrStrRegOffset"
} else if i & 0xf200 == 0x5200 {
"LdrStrSHB"
} else if i & 0xe000 == 0x6000 {
"LdrStrImmOffset"
} else if i & 0xf000 == 0x8000 {
"LdrStrHalfWord"
} else if i & 0xf000 == 0x9000 {
"LdrStrSp"
} else if i & 0xf000 == 0xa000 {
"LoadAddress"
} else if i & 0xff00 == 0xb000 {
"AddSp"
} else if i & 0xf600 == 0xb400 {
"PushPop"
} else if i & 0xf000 == 0xc000 {
"LdmStm"
} else if i & 0xff00 == 0xdf00 {
"Swi"
} else if i & 0xf000 == 0xd000 {
"BranchConditional"
} else if i & 0xf800 == 0xe000 {
"Branch"
} else if i & 0xf000 == 0xf000 {
"BranchLongWithLink"
} else {
"Undefined"
}
}
trait BitAsInt<T: From<bool>>: BitIndex {
fn ibit(&self, i: usize) -> T {
self.bit(i).into()
}
}
impl BitAsInt<u32> for u32 {}
/// Returns a string representation of rustboyadvance_ng::core::arm7tdmi::arm::ArmFormat enum member
/// # Arguments
/// * `i` - A 32bit ARM instruction
///
/// Decoding is according to this table from http://problemkaputt.de/gbatek.htm#ARMBinaryOpcodeFormat
/// ```
/// |..3 ..................2 ..................1 ..................0|
/// |1_0_9_8_7_6_5_4_3_2_1_0_9_8_7_6_5_4_3_2_1_0_9_8_7_6_5_4_3_2_1_0|
/// |_Cond__|0_0_0|___Op__|S|__Rn___|__Rd___|__Shift__|Typ|0|__Rm___| DataProc
/// |_Cond__|0_0_0|___Op__|S|__Rn___|__Rd___|__Rs___|0|Typ|1|__Rm___| DataProc
/// |_Cond__|0_0_1|___Op__|S|__Rn___|__Rd___|_Shift_|___Immediate___| DataProc
/// |_Cond__|0_0_1_1_0_0_1_0_0_0_0_0_1_1_1_1_0_0_0_0|_____Hint______| ARM11:Hint
/// |_Cond__|0_0_1_1_0|P|1|0|_Field_|__Rd___|_Shift_|___Immediate___| PSR Imm
/// |_Cond__|0_0_0_1_0|P|L|0|_Field_|__Rd___|0_0_0_0|0_0_0_0|__Rm___| PSR Reg
/// |_Cond__|0_0_0_1_0_0_1_0_1_1_1_1_1_1_1_1_1_1_1_1|0_0|L|1|__Rn___| BX,BLX
/// |1_1_1_0|0_0_0_1_0_0_1_0|_____immediate_________|0_1_1_1|_immed_| ARM9:BKPT
/// |_Cond__|0_0_0_1_0_1_1_0_1_1_1_1|__Rd___|1_1_1_1|0_0_0_1|__Rm___| ARM9:CLZ
/// |_Cond__|0_0_0_1_0|Op_|0|__Rn___|__Rd___|0_0_0_0|0_1_0_1|__Rm___| ARM9:QALU
/// |_Cond__|0_0_0_0_0_0|A|S|__Rd___|__Rn___|__Rs___|1_0_0_1|__Rm___| Multiply
/// |_Cond__|0_0_0_0_0_1_0_0|_RdHi__|_RdLo__|__Rs___|1_0_0_1|__Rm___| ARM11:UMAAL
/// |_Cond__|0_0_0_0_1|U|A|S|_RdHi__|_RdLo__|__Rs___|1_0_0_1|__Rm___| MulLong
/// |_Cond__|0_0_0_1_0|Op_|0|Rd/RdHi|Rn/RdLo|__Rs___|1|y|x|0|__Rm___| MulHalfARM9
/// |_Cond__|0_0_0_1_0|B|0_0|__Rn___|__Rd___|0_0_0_0|1_0_0_1|__Rm___| TransSwp12
/// |_Cond__|0_0_0_1_1|_Op__|__Rn___|__Rd___|1_1_1_1|1_0_0_1|__Rm___| ARM11:LDREX
/// |_Cond__|0_0_0|P|U|0|W|L|__Rn___|__Rd___|0_0_0_0|1|S|H|1|__Rm___| TransReg10
/// |_Cond__|0_0_0|P|U|1|W|L|__Rn___|__Rd___|OffsetH|1|S|H|1|OffsetL| TransImm10
/// |_Cond__|0_1_0|P|U|B|W|L|__Rn___|__Rd___|_________Offset________| TransImm9
/// |_Cond__|0_1_1|P|U|B|W|L|__Rn___|__Rd___|__Shift__|Typ|0|__Rm___| TransReg9
/// |_Cond__|0_1_1|________________xxx____________________|1|__xxx__| Undefined
/// |_Cond__|0_1_1|Op_|x_x_x_x_x_x_x_x_x_x_x_x_x_x_x_x_x_x|1|x_x_x_x| ARM11:Media
/// |1_1_1_1_0_1_0_1_0_1_1_1_1_1_1_1_1_1_1_1_0_0_0_0_0_0_0_1_1_1_1_1| ARM11:CLREX
/// |_Cond__|1_0_0|P|U|S|W|L|__Rn___|__________Register_List________| BlockTrans
/// |_Cond__|1_0_1|L|___________________Offset______________________| B,BL,BLX
/// |_Cond__|1_1_0|P|U|N|W|L|__Rn___|__CRd__|__CP#__|____Offset_____| CoDataTrans
/// |_Cond__|1_1_0_0_0_1_0|L|__Rn___|__Rd___|__CP#__|_CPopc_|__CRm__| CoRR ARM9
/// |_Cond__|1_1_1_0|_CPopc_|__CRn__|__CRd__|__CP#__|_CP__|0|__CRm__| CoDataOp
/// |_Cond__|1_1_1_0|CPopc|L|__CRn__|__Rd___|__CP#__|_CP__|1|__CRm__| CoRegTrans
/// |_Cond__|1_1_1_1|_____________Ignored_by_Processor______________| SWI
/// ```
fn arm_decode(i: u32) -> &'static str {
const T: bool = true;
const F: bool = false;
// First, decode the the top-most non-condition bits
match i.bit_range(26..28) {
0b00 => {
/* DataProcessing and friends */
let result: Option<&str> = match (i.bit_range(23..26), i.bit_range(4..8)) {
(0b000, 0b1001) => {
if 0b0 == i.ibit(22) {
Some("Multiply")
} else {
None
}
}
(0b001, 0b1001) => Some("MultiplyLong"),
(0b010, 0b1001) => {
if 0b00 == i.bit_range(20..22) {
Some("SingleDataSwap")
} else {
None
}
}
(0b010, 0b0001) => {
if 0b010 == i.bit_range(20..23) {
Some("BranchExchange")
} else {
None
}
}
_ => None,
};
result.unwrap_or_else(|| {
match (i.ibit(25), i.ibit(22), i.ibit(7), i.ibit(4)) {
(0, 0, 1, 1) => "HalfwordDataTransferRegOffset",
(0, 1, 1, 1) => "HalfwordDataTransferImmediateOffset",
_ => {
let set_cond_flags = i.bit(20);
// PSR Transfers are encoded as a subset of Data Processing,
// with S bit OFF and the encode opcode is one of TEQ,CMN,TST,CMN
let is_op_not_touching_rd = i.bit_range(21..25) & 0b1100 == 0b1000;
if !set_cond_flags && is_op_not_touching_rd {
if i.bit(21) {
// Since bit-16 is ignored and we can't know statically if this is a MoveToStatus or MoveToFlags
"MoveToStatus"
} else {
"MoveFromStatus"
}
} else {
"DataProcessing"
}
}
}
})
}
0b01 => {
match (i.bit(25), i.bit(4)) {
(_, F) | (F, T) => "SingleDataTransfer",
(T, T) => "Undefined", /* Possible ARM11 but we don't implement these */
}
}
0b10 => match i.bit(25) {
F => "BlockDataTransfer",
T => "BranchLink",
},
0b11 => {
match (i.ibit(25), i.ibit(24), i.ibit(4)) {
(0b0, _, _) => "Undefined", /* CoprocessorDataTransfer not implemented */
(0b1, 0b0, 0b0) => "Undefined", /* CoprocessorDataOperation not implemented */
(0b1, 0b0, 0b1) => "Undefined", /* CoprocessorRegisterTransfer not implemented */
(0b1, 0b1, _) => "SoftwareInterrupt",
_ => "Undefined",
}
}
_ => unreachable!(),
}
}
fn thumb_format_to_handler(thumb_fmt: &str) -> &'static str {
match thumb_fmt {
"MoveShiftedReg" => "exec_thumb_move_shifted_reg",
"AddSub" => "exec_thumb_add_sub",
"DataProcessImm" => "exec_thumb_data_process_imm",
"AluOps" => "exec_thumb_alu_ops",
"HiRegOpOrBranchExchange" => "exec_thumb_hi_reg_op_or_bx",
"LdrPc" => "exec_thumb_ldr_pc",
"LdrStrRegOffset" => "exec_thumb_ldr_str_reg_offset",
"LdrStrSHB" => "exec_thumb_ldr_str_shb",
"LdrStrImmOffset" => "exec_thumb_ldr_str_imm_offset",
"LdrStrHalfWord" => "exec_thumb_ldr_str_halfword",
"LdrStrSp" => "exec_thumb_ldr_str_sp",
"LoadAddress" => "exec_thumb_load_address",
"AddSp" => "exec_thumb_add_sp",
"PushPop" => "exec_thumb_push_pop",
"LdmStm" => "exec_thumb_ldm_stm",
"BranchConditional" => "exec_thumb_branch_with_cond",
"Swi" => "exec_thumb_swi",
"Branch" => "exec_thumb_branch",
"BranchLongWithLink" => "exec_thumb_branch_long_with_link",
"Undefined" => "thumb_undefined",
_ => unreachable!(),
}
}
fn arm_format_to_handler(arm_fmt: &str) -> &'static str {
match arm_fmt {
"BranchExchange" => "exec_arm_bx",
"BranchLink" => "exec_arm_b_bl",
"DataProcessing" => "exec_arm_data_processing",
"SoftwareInterrupt" => "exec_arm_swi",
"SingleDataTransfer" => "exec_arm_ldr_str",
"HalfwordDataTransferImmediateOffset" => "exec_arm_ldr_str_hs_imm",
"HalfwordDataTransferRegOffset" => "exec_arm_ldr_str_hs_reg",
"BlockDataTransfer" => "exec_arm_ldm_stm",
"MoveFromStatus" => "exec_arm_mrs",
"MoveToStatus" => "exec_arm_transfer_to_status",
"MoveToFlags" => "exec_arm_transfer_to_status",
"Multiply" => "exec_arm_mul_mla",
"MultiplyLong" => "exec_arm_mull_mlal",
"SingleDataSwap" => "exec_arm_swp",
"Undefined" => "arm_undefined",
_ => unreachable!(),
}
}
fn generate_thumb_lut(file: &mut fs::File) -> Result<(), std::io::Error> {
writeln!(
file,
"use super::thumb::ThumbFormat;
pub type ThumbInstructionHandler = fn(&mut Core, &mut SysBus, &ThumbInstruction) -> CpuAction;
pub struct ThumbInstructionInfo {{
pub fmt: ThumbFormat,
pub handler_fn: ThumbInstructionHandler
}}
"
)?;
writeln!(
file,
"pub const THUMB_LUT: [ThumbInstructionInfo; 1024] = ["
)?;
for i in 0..1024 {
let thumb_fmt = thumb_decode(i << 6);
let handler_name = thumb_format_to_handler(thumb_fmt);
writeln!(
file,
" /* {:#x} */ ThumbInstructionInfo {{ fmt: ThumbFormat::{}, handler_fn: Core::{} }},",
i, thumb_fmt, handler_name
)?;
}
writeln!(file, "];")?;
Ok(())
}
fn generate_arm_lut(file: &mut fs::File) -> Result<(), std::io::Error> {
writeln!(
file,
"use super::arm::ArmFormat;
pub type ArmInstructionHandler = fn(&mut Core, &mut SysBus, &ArmInstruction) -> CpuAction;
pub struct ArmInstructionInfo {{
pub fmt: ArmFormat,
pub handler_fn: ArmInstructionHandler
}}
"
)?;
writeln!(file, "pub const ARM_LUT: [ArmInstructionInfo; 4096] = [")?;
for i in 0..4096 {
let arm_fmt = arm_decode(((i & 0xff0) << 16) | ((i & 0x00f) << 4));
let handler_name = arm_format_to_handler(arm_fmt);
writeln!(
file,
" /* {:#x} */ ArmInstructionInfo {{ fmt: ArmFormat::{}, handler_fn: Core::{} }},",
i, arm_fmt, handler_name
)?;
}
writeln!(file, "];")?;
Ok(())
}
fn main() {
let arm7tdmi_dispatch_table_enabled =
env::var_os("CARGO_FEATURE_ARM7TDMI_DISPATCH_TABLE").is_some();
if arm7tdmi_dispatch_table_enabled {
// TODO - don't do this in the build script and use `const fn` instead when it becomes stable
let out_dir = env::var_os("OUT_DIR").unwrap();
let thumb_lut_path = Path::new(&out_dir).join("thumb_lut.rs");
let mut thumb_lut_file = fs::File::create(&thumb_lut_path).expect("failed to create file");
generate_thumb_lut(&mut thumb_lut_file).expect("failed to generate thumb table");
let arm_lut_path = Path::new(&out_dir).join("arm_lut.rs");
let mut arm_lut_file = fs::File::create(&arm_lut_path).expect("failed to create file");
generate_arm_lut(&mut arm_lut_file).expect("failed to generate arm table");
println!("cargo:rerun-if-changed=build.rs");
}
}