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-rw-r--r--src/armv7/thumb.rs463
1 files changed, 240 insertions, 223 deletions
diff --git a/src/armv7/thumb.rs b/src/armv7/thumb.rs
index 93290a1..8e6c009 100644
--- a/src/armv7/thumb.rs
+++ b/src/armv7/thumb.rs
@@ -12,6 +12,8 @@ use armv7::Instruction;
use armv7::InstDecoder;
use armv7::StatusRegMask;
+use bitvec::prelude::*;
+
#[allow(non_snake_case)]
fn ROR_C(x: u32, shift: u16) -> (u32, bool) {
// let m = shift % 32; // `shift` is known to be 31 or lower
@@ -103,7 +105,10 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
((iter.next().ok_or(DecodeError::ExhaustedInput)? as u16) ) |
((iter.next().ok_or(DecodeError::ExhaustedInput)? as u16) << 8 );
- let opword = instr >> 11;
+ let mut instr2 = bitarr![Lsb0, u16; 0u16; 16];
+ instr2[0..16].store(instr);
+
+ let opword = instr2[11..].load::<u16>();
// `A6.1 Thumb instruction set encoding`
if opword >= 0b11101 {
@@ -116,23 +121,25 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
((iter.next().ok_or(DecodeError::ExhaustedInput)? as u16) ) |
((iter.next().ok_or(DecodeError::ExhaustedInput)? as u16) << 8 );
- let op2 = (instr >> 5) & 0b1111111;
+ let mut lower2 = bitarr![Lsb0, u16; 0u16; 16];
+ lower2[0..16].store(lower);
+
+ let op2 = &instr2[4..11];
if opword < 0b11110 {
// op1 == 0b01
- if op2 < 0b1000000 {
+ if !op2[6] {
// `op2` is `0b00.. ` or `0b01..`
- if op2 < 0b0100000 {
+ if !op2[5] {
// `Load/store`, either `multiple` or `dual`
- let rn = (instr & 0b1111) as u8;
+ let rn = instr2[..4].load::<u8>();
// TODO: double check
- if op2 & 0b0000100 != 0 {
+ if op2[2] {
// `Load/store dual, load/store exclusive, table branch` (`A6-236`)
- let op1op2 = ((instr >> 7) & 0b11) | ((instr >> 4) & 0b11);
- let rn = (instr & 0b1111) as u8;
- let imm8 = lower & 0b11111111;
- let rd = ((lower >> 8) & 0b1111) as u8;
- let rt = ((lower >> 12) & 0b1111) as u8;
+ let op1op2 = (instr2[5..7].load::<u8>() << 2) | instr2[4..6].load::<u8>();
+ let imm8 = lower2[..8].load::<u16>();
+ let rd = lower2[8..12].load::<u8>();
+ let rt = lower2[12..16].load::<u8>();
// all only-wide, no w suffix
inst.set_w(false);
@@ -191,8 +198,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
// v6T2
// bit 5 (w) == 0
let w = false;
- let u = (instr >> 7) & 1 != 0;
- let p = (instr >> 8) & 1 != 0;
+ let u = instr2[7];
+ let p = instr2[8];
// `if P == '0' && W == '0' then SEE "Related encodings"` -> this
// would imply tbb/tbh, should be unreachable
if rn == 15 || rt == 13 || rt == 15 || rd == 13 || rd == 15 {
@@ -216,8 +223,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
// `LDRD (immediate)`/`(literal)` (`A8-687`)
// bit 5 (w) == 0
let w = false;
- let u = (instr >> 7) & 1 != 0;
- let p = (instr >> 8) & 1 != 0;
+ let u = instr2[7];
+ let p = instr2[8];
// `if P == '0' && W == '0' then SEE "Related encodings"` -> this
// would imply tbb/tbh, should be unreachable
if rt == 13 || rt == 15 || rd == 13 || rd == 15 || rd == rt {
@@ -260,7 +267,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
0b0100 => {
// `STREX_`
// v7
- let op3 = (lower >> 4) & 0b1111;
+ let op3 = lower2[4..8].load::<u8>();
let rt2 = rd;
let rd = (imm8 & 0b1111) as u8;
match op3 {
@@ -323,7 +330,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
}
0b0101 => {
// `TBB`/`TBH`/`LDREX_`
- let op3 = (lower >> 4) & 0b1111;
+ let op3 = lower2[4..8].load::<u8>();
let rt2 = rd;
let rd = (imm8 & 0b1111) as u8;
match op3 {
@@ -430,8 +437,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
// v6T2
// bit 5 (w) == 1
let w = true;
- let u = (instr >> 7) & 1 != 0;
- let p = (instr >> 8) & 1 != 0;
+ let u = instr2[7];
+ let p = instr2[8];
// `if P == '0' && W == '0' then SEE "Related encodings"` -> this
// would imply tbb/tbh, should be unreachable
if rn == 15 || rt == 13 || rt == 15 || rd == 13 || rd == 15 {
@@ -458,8 +465,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
// v6T2
// bit 5 (w) == 1
let w = true;
- let u = (instr >> 7) & 1 != 0;
- let p = (instr >> 8) & 1 != 0;
+ let u = instr2[7];
+ let p = instr2[8];
// `if P == '0' && W == '0' then SEE "Related encodings"` -> this
// would imply tbb/tbh, should be unreachable
if rt == 13 || rt == 15 || rd == 13 || rd == 15 || rd == rt {
@@ -504,18 +511,18 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
}
}
} else {
- let w = instr & 0b100000 != 0;
+ let w = instr2[5];
// `Load/store multiple` (`A6-235`)
- if instr & 0b10000 == 0 {
+ if !instr2[4] {
// `L == 0`
- match (instr >> 7) & 0b11 {
+ match instr2[7..9].load::<u8>() {
0b00 => {
// `SRS (Thumb)` (`B9-1990`)
// v6T2
inst.opcode = Opcode::SRS(false, true); // `srsdb`
inst.operands = [
Operand::RegWBack(Reg::from_u8(13), w),
- Operand::Imm12(lower & 0b1111), // #<mode> ? what's the syntax here? #<the literal>?
+ Operand::Imm12(lower2[0..4].load::<u16>()), // #<mode> ? what's the syntax here? #<the literal>?
Operand::Nothing,
Operand::Nothing,
];
@@ -602,7 +609,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
}
} else {
// `L == 1`
- match (instr >> 7) & 0b11 {
+ match instr2[7..9].load::<u8>() {
0b00 => {
// `RFE` (`B9-1986`)
// v6T2
@@ -691,19 +698,19 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
} else {
// `Data-processing (shfited register)` (`A6-241`)
// v6T2
- let op = op2 & 0b1111;
- let s = instr & 0b10000 != 0;
- let rn = (instr & 0b1111) as u8;
- let rd = ((lower >> 8) & 0b1111) as u8;
+ let op = op2[0..4].load::<u8>();
+ let s = instr2[4];
+ let rn = instr2[0..4].load::<u8>();
+ let rd = lower2[8..12].load::<u8>();
- let imm3 = (lower >> 12) & 0b111;
- let imm2 = (lower >> 6) & 0b11;
- let tp = (lower >> 4) & 0b11;
- let rm = (lower & 0b1111) as u8;
+ let imm3 = lower2[12..15].load::<u16>();
+ let imm2 = lower2[6..8].load::<u16>();
+ let tp = lower2[4..6].load::<u16>();
+ let rm = lower2[0..4].load::<u16>();
let shift = RegShift::from_raw(
0b1000 | // reg-imm shift. TODO: probably need to change the const
- rm as u16 |
+ rm as u16 |
(imm2 << 7) | (imm3 << 9) |
tp << 5
);
@@ -956,18 +963,18 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
// op1 == 0b10
if lower & 0x80 == 0 {
// op == 0
- if op2 & 0b0100000 == 0 {
+ if !op2[4] {
// `A6.3.1` `Data-processing (modified immediate)` (`A6-229`)
// see `A6.3.2` for `Modified immediate constants in Thumb instructions` on how
// to decode immediates
// v6T2
- let op = op2 & 0b1111;
- let i = instr >> 10 & 1;
- let s = instr & 0b10000 != 0;
- let rn = (instr & 0b1111) as u8;
- let imm3 = (lower >> 12) & 0b111;
- let rd = ((lower >> 8) & 0b1111) as u8;
- let imm8 = lower & 0b11111111;
+ let op = op2[..4].load::<u8>();
+ let i = lower2[10..11].load::<u16>();
+ let s = lower2[4];
+ let rn = lower2[0..4].load::<u8>();
+ let imm3 = lower2[12..15].load::<u16>();
+ let rd = lower2[8..12].load::<u8>();
+ let imm8 = lower2[0..8].load::<u16>();
let imm = (i << 11) | (imm3 << 8) | imm8;
inst.s = s;
@@ -1169,14 +1176,14 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
} else {
// `Data-processing (plain binary immediate)` (`A6-232`)
// v6T2
- let op = (instr >> 4) & 0b11111;
- let i = instr >> 10 & 1;
- let s = instr & 0b10000 != 0;
+ let op = instr2[4..9].load::<u8>();
+ let i = instr2[10..11].load::<u16>();
+ let s = instr2[4];
inst.s = s;
- let rn = (instr & 0b1111) as u8;
- let imm3 = (lower >> 12) & 0b111;
- let rd = ((lower >> 8) & 0b1111) as u8;
- let imm8 = lower & 0b11111111;
+ let rn = instr2[0..4].load::<u8>();
+ let imm3 = lower2[12..15].load::<u16>();
+ let rd = lower2[8..12].load::<u8>();
+ let imm8 = lower2[0..8].load::<u16>();
let imm = (i << 11) | (imm3 << 8) | imm8;
match op {
@@ -1266,7 +1273,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
0b10010 => {
let imm3_2 = ((lower >> 10) & 0b11100) | ((lower >> 6) & 0b11);
if imm3_2 != 0 {
- let shift = DecodeImmShift(rn, ((instr >> 4) & 0b10) as u8, imm3_2 as u8);
+ let shift = DecodeImmShift(rn, instr2[5..6].load::<u8>() << 1, imm3_2 as u8);
// `SSAT`
// v6T2
inst.opcode = Opcode::SSAT;
@@ -1395,11 +1402,15 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
} else {
// op == 1
// `Branches and miscellaneous control` (`A6-233`)
- let imm8 = lower & 0b11111111;
- let op2 = (lower >> 8) & 0b0111;
- let op1 = (lower >> 12) & 0b111;
- let op = (instr >> 4) & 0b1111111;
+ let imm8 = lower2[0..8].load::<u16>();
+ let op2 = lower2[8..11].load::<u8>();
+ let op1 = instr2[12..15].load::<u8>();
+ let op = instr2[4..11].load::<u8>();
if op1 & 0b101 == 0b000 {
+ // TODO: This entire section appears wrong? what encoding is the conditional
+ // branch, none of those line up with the above components, or provided
+ // operands.
+ //
// the high bit of op is a sign bit, if a conditional branch. otherwise, it is
// 0 for valid instructiosn other than `udf`, `hvc`, and `smc`. `Branch` is
// ruled out as `op1` is `0x1`, so see if this is any of the misc
@@ -1421,16 +1432,16 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
// misc instruction
if op < 0b0111010 {
// `MSR` in some form, slightly more work to figure this out
- let rn = (instr & 0b1111) as u8;
+ let rn = instr2[0..4].load::<u8>();
if imm8 & 0b00100000 != 0 {
// `MSR` (`B9-1980`)
// v7VE
let sysm = (((lower >> 4) & 1) << 4) | ((lower >> 8) & 0b1111);
- let r = (instr >> 4) & 1;
+ let R = instr2[4];
inst.opcode = Opcode::MSR;
inst.operands = [
// TODO: is this the appropriate banked reg?
- Reg::from_sysm(r != 0, sysm as u8).expect("from_sysm works"),
+ Reg::from_sysm(R, sysm as u8).expect("from_sysm works"),
Operand::Reg(Reg::from_u8(rn)),
Operand::Nothing,
Operand::Nothing,
@@ -1469,12 +1480,12 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
];
} else {
// `Move to Special register, System level` (`B9-1984`)
- let mask = ((lower >> 8) & 0b1111) as u8;
- let r = (instr >> 4) & 1;
+ let mask = lower2[8..12].load::<u8>();
+ let R = instr2[4];
inst.opcode = Opcode::MSR;
inst.operands = [
// TODO: is this the appropriate?
- Reg::from_sysm(r != 0, mask).expect("from_sysm works"),
+ Reg::from_sysm(R, mask).expect("from_sysm works"),
Operand::Reg(Reg::from_u8(rn)),
Operand::Nothing,
Operand::Nothing,
@@ -1482,12 +1493,12 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
}
} else {
// `Move to Special register, System level` (`B9-1984`)
- let mask = ((lower >> 8) & 0b1111) as u8;
- let r = (instr >> 4) & 1;
+ let mask = lower2[8..12].load::<u8>();
+ let R = instr2[4];
inst.opcode = Opcode::MSR;
inst.operands = [
// TODO: is this the appropriate?
- Reg::from_sysm(r != 0, mask).expect("from_sysm works"),
+ Reg::from_sysm(R, mask).expect("from_sysm works"),
Operand::Reg(Reg::from_u8(rn)),
Operand::Nothing,
Operand::Nothing,
@@ -1496,8 +1507,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
}
} else if op < 0b0111011 {
// `Change Processor State, and hints` (`A6-234`)
- let op1 = (lower >> 8) & 0b111;
- let op2 = lower & 0b11111111;
+ let op1 = lower2[8..11].load::<u8>();
+ let op2 = lower2[0..8].load::<u8>();
if op1 != 0b000 {
// `CPS (Thumb)` (`B9-1964`)
// v6T2
@@ -1512,7 +1523,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
} else {
if op2 >= 0b11110000 {
// `DBG` (`A8-378`)
- let option = lower & 0b1111;
+ let option = lower2[0..4].load::<u16>();
inst.opcode = Opcode::DBG;
inst.operands = [
Operand::Imm12(option),
@@ -1675,7 +1686,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
} else if op < 0b0111101 {
// `BXJ` (`A8-352`)
// v6T2
- let rm = (instr & 0b1111) as u8;
+ let rm = instr2[0..4].load::<u8>();
inst.opcode = Opcode::BXJ;
inst.operands = [
Operand::Reg(Reg::from_u8(rm)),
@@ -1689,7 +1700,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
// `v7VE` defines `ERET` here, identical to `subs pc, lr` with
// `imm8 == 0`. `v7VE` does not change the behavior of this
// instruction at `PL1`.
- let imm8 = lower & 0b11111111;
+ let imm8 = lower2[0..8].load::<u16>();
if imm8 == 0 {
// `ERET` (`B9-1968`)
// v6T2
@@ -1709,7 +1720,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
inst.operands = [
Operand::Reg(Reg::from_u8(15)), // pc
Operand::Reg(Reg::from_u8(14)), // lr
- Operand::Imm12(lower & 0b11111111),
+ Operand::Imm12(imm8),
Operand::Nothing,
];
}
@@ -1806,12 +1817,12 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
} else if op1 & 0b101 == 0b001 {
// `Branch` (`A8-332`)
// v6T2
- //
- let imm11 = lower & 0b111_1111_1111;
- let imm6 = instr & 0b11_1111;
- let j1 = (lower >> 13) & 1;
- let j2 = (lower >> 11) & 1;
- let s = (instr >> 10) & 1;
+ // TODO: encoding T3? unclear
+ let imm11 = lower2[0..11].load::<u32>();
+ let imm6 = instr2[0..6].load::<u32>();
+ let j1 = lower2[13..14].load::<u32>();
+ let j2 = lower2[11..12].load::<u32>();
+ let s = instr2[10..11].load::<u32>();
let imm =
(imm11 as u32) |
((imm6 as u32) << 11) |
@@ -1830,11 +1841,11 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
// `Branch with Link and Exchange` (`A8-346`)
// `UNDEFINED` in v4T
// v5T
- let imm11 = lower & 0b111_1111_1111;
- let imm10 = instr & 0b11_1111_1111;
- let j1 = (lower >> 13) & 1;
- let j2 = (lower >> 11) & 1;
- let s = (instr >> 10) & 1;
+ let imm11 = lower2[0..11].load::<u32>();
+ let imm10 = instr2[0..10].load::<u32>();
+ let j1 = lower2[13..14].load::<u32>();
+ let j2 = lower2[11..12].load::<u32>();
+ let s = instr2[10..11].load::<u32>();
let imm =
(imm11 as u32) |
((imm10 as u32) << 11) |
@@ -1852,11 +1863,11 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
} else {
// `Brach with Link` (`A8-346`)
// v4T
- let imm11 = lower & 0b111_1111_1111;
- let imm10 = instr & 0b11_1111_1111;
- let j1 = (lower >> 13) & 1;
- let j2 = (lower >> 11) & 1;
- let s = (instr >> 10) & 1;
+ let imm11 = lower2[0..11].load::<u32>();
+ let imm10 = instr2[0..10].load::<u32>();
+ let j1 = lower2[13..14].load::<u32>();
+ let j2 = lower2[11..12].load::<u32>();
+ let s = instr2[10..11].load::<u32>();
let imm =
(imm11 as u32) |
((imm10 as u32) << 11) |
@@ -1874,17 +1885,21 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
}
}
} else {
+ // working through table `A6-9 32-bit Thumb instruction encoding`
+
// op1 == 0b11
- if op2 & 0b1000000 == 0 {
- if op2 & 0b0100000 == 0 {
+ if !op2[6] {
+ // not coprocessor, advanced simd, or floating point instructions
+ if !op2[5] {
// loads, stores
- if op2 & 0b0000001 == 0 {
+ if !op2[0] {
// store single item, or advanced simd load/store
- if op2 & 0b00100000 == 0 {
+ if !op2[4] {
// `Store single data item` (`A6-240`)
- let rn = (instr & 0b1111) as u8;
- let op1 = (instr >> 5) & 0b111;
+ let rn = instr2[0..4].load::<u8>();
+ let op1 = instr2[5..8].load::<u8>();
let size_bits = op1 & 0b011;
+ let has_imm12 = op1 & 0b100 != 0;
let op2 = (lower >> 6) & 0b111111;
match size_bits {
0b00 => {
@@ -2160,7 +2175,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
}
} else {
// load {byte, halfword, word}
- let size_bits = (op2 >> 1) & 0b11;
+ let size_bits = (op2[1..].load::<u8>());
if size_bits == 0b00 {
// `Load byte, memory hints` (`A6-239`)
} else if size_bits == 0b01 {
@@ -2173,14 +2188,14 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
}
}
} else {
- if op2 & 0b0010000 == 0 {
+ if !op2[4] {
// `Data-processing (register)` (`A6-243`)
- let op1 = (instr >> 4) & 0b1111;
- let op2 = (lower >> 4) & 0b1111;
- let rn = (instr & 0b1111) as u8;
- if op1 < 0b1000 {
+ let op1 = &instr2[4..8];
+ let op2 = &lower2[4..8];
+ let rn = instr2[0..4].load::<u8>();
+ if !op1[3] {
// `LSL`, `LSR`, `ASR`, `ROR`, `SXTAH`, .... out of table `A6-24`
- if op2 < 0b1000 {
+ if !op2[3] {
// `LSL`, `LSR`, `ASR`, `ROR`
// v6T2
let op = [
@@ -2188,9 +2203,9 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
Opcode::LSR,
Opcode::ASR,
Opcode::ROR,
- ][((op2 >> 1) & 0b11) as usize];
- let rd = ((lower >> 8) & 0b1111) as u8;
- let rm = (lower & 0b1111) as u8;
+ ][op2[1..3].load::<usize>()];
+ let rd = lower2[8..12].load::<u8>();
+ let rm = lower2[0..4].load::<u8>();
inst.opcode = op;
inst.operands = [
Operand::Reg(Reg::from_u8(rd)),
@@ -2199,6 +2214,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
Operand::Nothing,
];
} else {
+ let op1 = op1[0..3].load::<usize>();
// `SXTAH` and friends
if op1 > 0b101 {
return Err(DecodeError::Undefined);
@@ -2212,11 +2228,11 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
Opcode::UXTB16,
Opcode::SXTB,
Opcode::UXTB,
- ][(op1 & 0b111) as usize];
+ ][op1];
- let rm = (lower & 0b1111) as u8;
- let rotate = (lower >> 1) & 0b11000;
- let rd = ((lower >> 8) & 0b1111) as u8;
+ let rm = lower2[..4].load::<u8>();
+ let rotate = lower2[1..3].load::<u8>() << 2;;
+ let rd = lower2[8..12].load::<u8>();
inst.opcode = op;
inst.operands = [
@@ -2233,11 +2249,11 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
Opcode::UXTAB16,
Opcode::SXTAH,
Opcode::UXTAB,
- ][(op1 & 0b111) as usize];
+ ][op1];
- let rm = (lower & 0b1111) as u8;
- let rotate = (lower >> 1) & 0b11000;
- let rd = ((lower >> 8) & 0b1111) as u8;
+ let rm = lower2[..4].load::<u8>();
+ let rotate = lower2[1..3].load::<u8>() << 2;;
+ let rd = lower2[8..12].load::<u8>();
inst.opcode = op;
inst.operands = [
@@ -2249,6 +2265,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
};
}
} else {
+ let op2 = op2.load::<u8>();
if op2 < 0b0100 {
// `Parallel addition and subtraction, signed`
return Err(DecodeError::Incomplete);
@@ -2263,7 +2280,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
}
}
} else {
- if op2 & 0b0001000 != 0 {
+ if op2[3] {
// `Long multiply, long multiply accumulate, and divide` (`A6-248`)
return Err(DecodeError::Incomplete);
} else {
@@ -2291,9 +2308,9 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
0b000 => {
// LSL (immediate)
// footnote: when opcode is 0, bits 8:6 are 0, encoding is `MOV`. see `A8-487`.
- let rd = (instr & 0b111) as u8;
- let rm = ((instr >> 3) & 0b111) as u8;
- let imm5 = (instr >> 6) & 0b11111;
+ let rd = instr2[0..3].load::<u8>();
+ let rm = instr2[3..6].load::<u8>();
+ let imm5 = instr2[6..11].load::<u16>();
inst.opcode = Opcode::LSL;
inst.operands = [
Operand::Reg(Reg::from_u8(rd)),
@@ -2304,9 +2321,9 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
}
0b001 => {
/* LSR on page A8-473 */
- let rd = (instr & 0b111) as u8;
- let rm = ((instr >> 3) & 0b111) as u8;
- let imm5 = (instr >> 6) & 0b11111;
+ let rd = instr2[0..3].load::<u8>();
+ let rm = instr2[3..6].load::<u8>();
+ let imm5 = instr2[6..11].load::<u16>();
let imm = if imm5 == 0 {
0x20
} else {
@@ -2322,9 +2339,9 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
}
0b010 => {
/* ASR on page A8-328 */
- let rd = (instr & 0b111) as u8;
- let rm = ((instr >> 3) & 0b111) as u8;
- let imm5 = (instr >> 6) & 0b11111;
+ let rd = instr2[0..3].load::<u8>();
+ let rm = instr2[3..6].load::<u8>();
+ let imm5 = instr2[6..11].load::<u16>();
let imm = if imm5 == 0 {
0x20
} else {
@@ -2340,10 +2357,10 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
}
0b011 => {
/* ADD, SUB (register/immediate) */
- let oplower = (instr >> 9) & 0b11;
- let rd = (instr & 0b111) as u8;
- let rn = ((instr >> 3) & 0b111) as u8;
- let rm = ((instr >> 6) & 0b111) as u8;
+ let oplower = instr2[9..11].load::<u32>();
+ let rm = instr2[6..9].load::<u8>();
+ let rd = instr2[0..3].load::<u8>();
+ let rn = instr2[3..6].load::<u8>();
match oplower {
0b00 => {
@@ -2390,8 +2407,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
0b100 => {
/* MOV on page A8-485 */
- let imm8 = instr & 0b1111_1111;
- let rd = ((instr >> 8) & 0b111) as u8;
+ let imm8 = instr2[0..8].load::<u32>();
+ let rd = instr2[8..11].load::<u8>();
inst.opcode = Opcode::MOV;
inst.operands = [
Operand::Reg(Reg::from_u8(rd)),
@@ -2403,8 +2420,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
0b101 => {
/* CMP on page A8-368 */
inst.s = false;
- let imm8 = instr & 0b1111_1111;
- let rd = ((instr >> 8) & 0b111) as u8;
+ let imm8 = instr2[0..8].load::<u32>();
+ let rd = instr2[8..11].load::<u8>();
inst.opcode = Opcode::CMP;
inst.operands = [
Operand::Reg(Reg::from_u8(rd)),
@@ -2415,8 +2432,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
}
0b110 => {
/* ADD (immediate, Thumb) on page A8-304 */
- let imm8 = instr & 0b1111_1111;
- let rdn = ((instr >> 8) & 0b111) as u8;
+ let imm8 = instr2[0..8].load::<u32>();
+ let rdn = instr2[8..11].load::<u8>();
inst.opcode = Opcode::ADD;
inst.operands = [
Operand::Reg(Reg::from_u8(rdn)),
@@ -2427,8 +2444,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
}
0b111 => {
/* SUB (immediate, Thumb) on page A8-709 */
- let imm8 = instr & 0b1111_1111;
- let rdn = ((instr >> 8) & 0b111) as u8;
+ let imm8 = instr2[0..8].load::<u32>();
+ let rdn = instr2[8..11].load::<u8>();
inst.opcode = Opcode::SUB;
inst.operands = [
Operand::Reg(Reg::from_u8(rdn)),
@@ -2442,7 +2459,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
}
}
} else if opword < 0b01001 {
- let opcode_bits = (instr >> 6) & 0b1111;
+ let opcode_bits = instr2[6..10].load::<u8>();
// `Data-processing` on page `A6-223` or `Special data instructions and branch and
// exchange` on page `A6-224`
if (instr >> 10) < 0b010001 {
@@ -2450,8 +2467,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
// v4T
// TODO: condition inside IT block, no S
inst.s = true;
- let rdn = (instr & 0b111) as u8;
- let rm = ((instr >> 3) & 0b111) as u8;
+ let rdn = instr2[0..3].load::<u8>();
+ let rm = instr2[3..6].load::<u8>();
if opcode_bits == 0b1101 {
inst.opcode = Opcode::MUL;
inst.operands = [
@@ -2504,8 +2521,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
0b0000 => {
// `Add Low Registers` (`A8-308`)
// v6T2, `UNPREDICTABLE` in earlier versions
- let rdn = ((instr & 0b111) | ((instr >> 4) & 0b1000)) as u8;
- let rm = ((instr >> 3) & 0b1111) as u8;
+ let rdn = instr2[0..3].load::<u8>() | (instr2[7..8].load::<u8>() << 3);
+ let rm = instr2[3..7].load::<u8>();
inst.opcode = Opcode::ADD;
inst.operands = [
Operand::Reg(Reg::from_u8(rdn)),
@@ -2519,8 +2536,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
0b0011 => {
// `Add High Registers` (`A8-308`)
// v4T
- let rdn = ((instr & 0b111) | ((instr >> 4) & 0b1000)) as u8;
- let rm = ((instr >> 3) & 0b1111) as u8;
+ let rdn = instr2[0..3].load::<u8>() | (instr2[7..8].load::<u8>() << 3);
+ let rm = instr2[3..7].load::<u8>();
inst.opcode = Opcode::ADD;
inst.operands = [
Operand::Reg(Reg::from_u8(rdn)),
@@ -2535,8 +2552,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
0b0111 => {
// `Compare High Registers` (`A8-307`)
// v4T
- let rn = ((instr & 0b111) | ((instr >> 4) & 0b1000)) as u8;
- let rm = ((instr >> 3) & 0b1111) as u8;
+ let rn = instr2[0..3].load::<u8>() | (instr2[7..8].load::<u8>() << 3);
+ let rm = instr2[3..7].load::<u8>();
inst.opcode = Opcode::CMP;
inst.operands = [
Operand::Reg(Reg::from_u8(rn)),
@@ -2549,8 +2566,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
// `Move Low Registers` (`A8-487`)
// v6, `UNPREDICTABLE` in earlier versions
// (encoding T1)
- let rd = ((instr & 0b111) | ((instr >> 4) & 0b1000)) as u8;
- let rm = ((instr >> 3) & 0b1111) as u8;
+ let rd = instr2[0..3].load::<u8>() | (instr2[7..8].load::<u8>() << 3);
+ let rm = instr2[3..7].load::<u8>();
inst.opcode = Opcode::MOV;
inst.operands = [
Operand::Reg(Reg::from_u8(rd)),
@@ -2564,8 +2581,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
0b1011 => {
// `Move High Registers` (`A8-487`)
// v4T
- let rd = ((instr & 0b111) | ((instr >> 4) & 0b1000)) as u8;
- let rm = ((instr >> 3) & 0b1111) as u8;
+ let rd = instr2[0..3].load::<u8>() | (instr2[7..8].load::<u8>() << 3);
+ let rm = instr2[3..7].load::<u8>();
inst.opcode = Opcode::MOV;
inst.operands = [
Operand::Reg(Reg::from_u8(rd)),
@@ -2578,7 +2595,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
0b1101 => {
// `Branch and Exchange` (`A8-350`)
// v4T
- let rm = ((instr >> 3) & 0b1111) as u8;
+ let rm = instr2[3..7].load::<u8>();
inst.opcode = Opcode::BX;
inst.operands = [
Operand::Reg(Reg::from_u8(rm)),
@@ -2591,7 +2608,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
0b1111 => {
// `Branch and Link with Exchange` (`A8-348`)
// v5T, `UNPREDICTABLE` in earlier versions
- let rm = ((instr >> 3) & 0b1111) as u8;
+ let rm = instr2[3..7].load::<u8>();
inst.opcode = Opcode::BLX;
inst.operands = [
Operand::Reg(Reg::from_u8(rm)),
@@ -2607,8 +2624,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
}
} else if opword < 0b01010 {
// `LDR (literal)` on page `A8-411` -- v4T
- let imm8 = instr & 0b1111_1111;
- let rt = ((instr >> 8) & 0b111) as u8;
+ let imm8 = instr2[0..8].load::<u16>();
+ let rt = instr2[8..11].load::<u8>();
inst.opcode = Opcode::LDR;
inst.operands = [
Operand::Reg(Reg::from_u8(rt)),
@@ -2622,14 +2639,14 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
Operand::Nothing,
];
} else if opword < 0b10100 {
- let op_b = (instr >> 9) & 0b111;
- let op_a = instr >> 12;
+ let op_b = instr2[9..12].load::<usize>();
+ let op_a = instr2[12..].load::<usize>();
// `Load/store single data item` on page `A6-225`
// v4T
- let rt = (instr & 0b111) as u8;
- let rn = ((instr >> 3) & 0b111) as u8;
- let rm = ((instr >> 6) & 0b111) as u8;
- let imm5 = (instr >> 6) & 0b11111;
+ let rt = instr2[0..3].load::<u8>();
+ let rn = instr2[3..6].load::<u8>();
+ let rm = instr2[6..9].load::<u8>();
+ let imm5 = instr2[6..11].load::<u16>();
if op_a == 0b0101 {
let op = [
Opcode::STR,
@@ -2640,7 +2657,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
Opcode::LDRH,
Opcode::LDRB,
Opcode::LDRSH,
- ][op_b as usize];
+ ][op_b];
inst.opcode = op;
inst.operands = [
Operand::Reg(Reg::from_u8(rt)),
@@ -2668,7 +2685,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
Opcode::LDRH,
Opcode::STR,
Opcode::LDR,
- ][idx as usize];
+ ][idx];
inst.opcode = op;
if idx < 6 {
let shift = match idx >> 1 {
@@ -2689,8 +2706,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
Operand::Nothing,
];
} else {
- let rt = ((instr >> 8) & 0b111) as u8;
- let imm8 = instr & 0b1111_1111;
+ let rt = instr2[8..11].load::<u8>();
+ let imm8 = instr2[..8].load::<u16>();
inst.operands = [
Operand::Reg(Reg::from_u8(rt)),
Operand::RegDerefPreindexOffset(
@@ -2706,8 +2723,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
}
} else if opword < 0b10101 {
// `ADR` on page `A8-320` -- v4T
- let rd = ((instr >> 8) & 0b111) as u8;
- let imm8 = instr & 0b1111_1111;
+ let rd = instr2[8..11].load::<u8>();
+ let imm8 = instr2[..8].load::<u16>();
inst.opcode = Opcode::ADR;
inst.operands = [
Operand::Reg(Reg::from_u8(rd)),
@@ -2717,8 +2734,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
];
} else if opword < 0b10110 {
// `ADD (SP plus immediate)` on `A8-314` -- v4T
- let rd = ((instr >> 8) & 0b111) as u8;
- let imm8 = instr & 0b1111_1111;
+ let rd = instr2[8..11].load::<u8>();
+ let imm8 = instr2[..8].load::<u16>();
inst.opcode = Opcode::ADD;
inst.operands = [
Operand::Reg(Reg::from_u8(rd)),
@@ -2728,38 +2745,38 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
];
} else if opword < 0b11000 {
// `Miscellaneous 16-bit instructions` on page `A6-226`
- let opcode_bits = (instr >> 5) & 0b1111111;
+ let opcode_bits = instr2[5..12].load::<u16>();
if opcode_bits < 0b0000100 {
// `Add Immediate to SP` (`A8-314`)
// v4T
// encoding T2
- let imm7 = instr & 0b111_1111;
+ let imm7 = instr2[..7].load::<u32>();
inst.s = false;
inst.opcode = Opcode::ADD;
inst.operands = [
Operand::Reg(Reg::from_u8(13)),
Operand::Reg(Reg::from_u8(13)),
- Operand::Imm32((imm7 << 2) as u32),
+ Operand::Imm32(imm7 << 2),
Operand::Nothing,
];
} else if opcode_bits < 0b0001000 {
// `Subtract Immediate to SP` (`A8-717`)
// v4T
- let imm7 = instr & 0b111_1111;
+ let imm7 = instr2[..7].load::<u32>();
inst.s = false;
inst.opcode = Opcode::SUB;
inst.operands = [
Operand::Reg(Reg::from_u8(13)),
Operand::Reg(Reg::from_u8(13)),
- Operand::Imm32((imm7 << 2) as u32),
+ Operand::Imm32(imm7 << 2),
Operand::Nothing,
];
} else if opcode_bits < 0b0010000 {
// `Compare and Branch on Zero` (`A8-354`)
// v6T2
- let op = (instr >> 11) & 1 != 0;
- let rn = (instr & 0b111) as u8;
- let imm5 = (instr >> 3) & 0b11111;
+ let op = instr2[11];
+ let rn = instr2[..3].load::<u8>();
+ let imm5 = instr2[3..8].load::<u16>();
let imm = (((instr >> 9) & 1) << 5) | imm5;
inst.opcode = if op {
Opcode::CBNZ
@@ -2775,8 +2792,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
} else if opcode_bits < 0b0010010 {
// `Signed Extend Halfword` (`A8-735`)
// v6
- let rd = (instr & 0b111) as u8;
- let rm = ((instr >> 3) & 0b111) as u8;
+ let rd = instr2[..3].load::<u8>();
+ let rm = instr2[3..6].load::<u8>();
inst.opcode = Opcode::SXTH;
inst.operands = [
Operand::Reg(Reg::from_u8(rd)),
@@ -2787,8 +2804,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
} else if opcode_bits < 0b0010100 {
// `Signed Extend Byte` (`A8-731`)
// v6
- let rd = (instr & 0b111) as u8;
- let rm = ((instr >> 3) & 0b111) as u8;
+ let rd = instr2[..3].load::<u8>();
+ let rm = instr2[3..6].load::<u8>();
inst.opcode = Opcode::SXTB;
inst.operands = [
Operand::Reg(Reg::from_u8(rd)),
@@ -2799,8 +2816,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
} else if opcode_bits < 0b0010110 {
// `Unsigned Extend Halfword` (`A8-817`)
// v6
- let rd = (instr & 0b111) as u8;
- let rm = ((instr >> 3) & 0b111) as u8;
+ let rd = instr2[..3].load::<u8>();
+ let rm = instr2[3..6].load::<u8>();
inst.opcode = Opcode::UXTH;
inst.operands = [
Operand::Reg(Reg::from_u8(rd)),
@@ -2811,8 +2828,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
} else if opcode_bits < 0b0011000 {
// `Unsigned Extend Byte` (`A8-813`)
// v6
- let rd = (instr & 0b111) as u8;
- let rm = ((instr >> 3) & 0b111) as u8;
+ let rd = instr2[..3].load::<u8>();
+ let rm = instr2[3..6].load::<u8>();
inst.opcode = Opcode::UXTB;
inst.operands = [
Operand::Reg(Reg::from_u8(rd)),
@@ -2823,9 +2840,9 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
} else if opcode_bits < 0b0100000 {
// `Compare and Branch on Zero` (`A8-354`)
// v6T2
- let op = (instr >> 11) & 1 != 0;
- let rn = (instr & 0b111) as u8;
- let imm5 = (instr >> 3) & 0b11111;
+ let op = instr2[11];
+ let rn = instr2[..3].load::<u8>();
+ let imm5 = instr2[3..8].load::<u16>();
let imm = (((instr >> 9) & 1) << 5) | imm5;
inst.opcode = if op {
Opcode::CBNZ
@@ -2841,8 +2858,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
} else if opcode_bits < 0b0110000 {
// `Push multiple registers` (`A8-539`)
// v4T
- let m = (instr >> 8) & 1;
- let reglist = (instr & 0b1111_1111) | (m << (6 + 8));
+ let m = instr2[8..9].load::<u16>();
+ let reglist = instr2[0..8].load::<u16>() | (m << (6 + 8));
inst.opcode = Opcode::PUSH;
inst.operands = [
Operand::RegList(reglist),
@@ -2857,7 +2874,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
// opword == 0b0110010
// `Set Endianness` (`A8-605`)
// v6
- let e = (instr >> 3) & 1;
+ let e = instr2[3..4].load::<u16>();
inst.opcode = Opcode::SETEND;
inst.operands = [
Operand::Imm12(e),
@@ -2869,9 +2886,9 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
// opword == 0b0110011
// `Change Processor State` (`B9-1964`)
// v6
- let aif = instr & 0b111;
- let im = (instr >> 4) & 1;
- inst.opcode = Opcode::CPS(im != 0);
+ let aif = instr2[0..3].load::<u16>();
+ let im = instr2[4];
+ inst.opcode = Opcode::CPS(im);
inst.operands = [
Operand::Imm12(aif),
Operand::Nothing,
@@ -2884,9 +2901,9 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
} else if opcode_bits < 0b1010000 {
// `Compare and Branch on Nonzero` (`A8-354`)
// v6T2
- let op = (instr >> 11) & 1 != 0;
- let rn = (instr & 0b111) as u8;
- let imm5 = (instr >> 3) & 0b11111;
+ let op = instr2[11];
+ let rn = instr2[0..3].load::<u8>();
+ let imm5 = instr2[3..8].load::<u16>();
let imm = (((instr >> 9) & 1) << 5) | imm5;
inst.opcode = if op {
Opcode::CBNZ
@@ -2902,8 +2919,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
} else if opcode_bits < 0b1010010 {
// `Byte-Reverse Word` (`A8-563`)
// v6
- let rd = (instr & 0b111) as u8;
- let rm = ((instr >> 3) & 0b111) as u8;
+ let rd = instr2[0..3].load::<u8>();
+ let rm = instr2[3..6].load::<u8>();
inst.opcode = Opcode::REV;
inst.operands = [
Operand::Reg(Reg::from_u8(rd)),
@@ -2914,8 +2931,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
} else if opcode_bits < 0b1010100 {
// `Byte-Reverse Packed Halfword` (`A8-565`)
// v6
- let rd = (instr & 0b111) as u8;
- let rm = ((instr >> 3) & 0b111) as u8;
+ let rd = instr2[0..3].load::<u8>();
+ let rm = instr2[3..6].load::<u8>();
inst.opcode = Opcode::REV16;
inst.operands = [
Operand::Reg(Reg::from_u8(rd)),
@@ -2929,8 +2946,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
} else if opcode_bits < 0b1011000 {
// `Byte-Reverse Signed Halfword` (`A8-567`)
// v6
- let rd = (instr & 0b111) as u8;
- let rm = ((instr >> 3) & 0b111) as u8;
+ let rd = instr2[0..3].load::<u8>();
+ let rm = instr2[3..6].load::<u8>();
inst.opcode = Opcode::REVSH;
inst.operands = [
Operand::Reg(Reg::from_u8(rd)),
@@ -2941,9 +2958,9 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
} else if opcode_bits < 0b1100000 {
// `Compare and Branch on Nonzero` (`A8-354`)
// v6T2
- let op = (instr >> 11) & 1 != 0;
- let rn = (instr & 0b111) as u8;
- let imm5 = (instr >> 3) & 0b11111;
+ let op = instr2[11];
+ let rn = instr2[0..3].load::<u8>();
+ let imm5 = instr2[3..8].load::<u16>();
let imm = (((instr >> 9) & 1) << 5) | imm5;
inst.opcode = if op {
Opcode::CBNZ
@@ -2959,8 +2976,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
} else if opcode_bits < 0b1110000 {
// `Pop Multiple Registers` (`A8-535`)
// v4T
- let p = (instr >> 8) & 1;
- let reglist = (instr & 0b1111_1111) | (p << (7 + 8));
+ let p = instr2[8..9].load::<u16>();
+ let reglist = instr2[0..8].load::<u16>() | (p << (7 + 8));
inst.opcode = Opcode::POP;
inst.operands = [
Operand::RegList(reglist),
@@ -2971,18 +2988,18 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
} else if opcode_bits < 0b1111000 {
// `Breakpoint` (`A8-344`)
// v5
- let imm8 = instr & 0b1111_1111;
+ let imm8 = instr2[0..8].load::<u32>();
inst.opcode = Opcode::BKPT;
inst.operands = [
- Operand::Imm32(imm8 as u32),
+ Operand::Imm32(imm8),
Operand::Nothing,
Operand::Nothing,
Operand::Nothing,
];
} else {
// `If-Then, and hints` (`A6-227`)
- let opb = instr & 0b1111;
- let opa = (instr >> 4) & 0b1111;
+ let opb = instr2[0..4].load::<u32>();
+ let opa = instr2[4..8].load::<u32>();
if opb != 0 {
// `IT` (`A8-391`)
@@ -2994,8 +3011,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
return Err(DecodeError::InvalidOperand);
}
inst.operands = [
- Operand::Imm32(firstcond as u32),
- Operand::Imm32(mask as u32),
+ Operand::Imm32(firstcond),
+ Operand::Imm32(mask),
Operand::Nothing,
Operand::Nothing,
];
@@ -3061,7 +3078,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
// as NOPs, but software must not use them.`
inst.opcode = Opcode::HINT;
inst.operands = [
- Operand::Imm12(hint),
+ Operand::Imm32(hint),
Operand::Nothing,
Operand::Nothing,
Operand::Nothing,
@@ -3072,8 +3089,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
}
} else if opword < 0b11001 {
// `STM (STMIA, STMEA)` on page `A8-665` -- v4T
- let rn = ((instr >> 8) & 0b111) as u8;
- let reglist = instr & 0b1111_1111;
+ let rn = instr2[8..11].load::<u8>();
+ let reglist = instr2[0..8].load::<u16>();
inst.opcode = Opcode::STM(true, true, false, true); // stmia, no wback, yes usermode
inst.operands = [
Operand::RegWBack(Reg::from_u8(rn), true), // always wback
@@ -3083,8 +3100,8 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
];
} else if opword < 0b11010 {
// `LDM/LDMIA/LDMFD (Thumb)` on page `A8-397` -- v4T
- let rn = ((instr >> 8) & 0b111) as u8;
- let reglist = instr & 0b1111_1111;
+ let rn = instr2[8..11].load::<u8>();
+ let reglist = instr2[0..8].load::<u16>();
let w = (reglist & (1 << rn)) == 0;
inst.opcode = Opcode::LDM(true, false, false, true); // ldmia, no wback, yes usermode
inst.operands = [
@@ -3095,15 +3112,13 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
];
} else if opword < 0b11100 {
// `Conditional branch, and Supervisor Call` on page `A6-227`
- let opcode = (instr >> 8) & 0b1111;
+ let opcode = instr2[8..12].load::<u8>();
if opcode < 0b1110 {
// `B` (`A8-332`)
// v4T
inst.opcode = Opcode::B;
- let imm = instr & 0b1111_1111;
- let imm = imm as i8 as i32;
- let cond = (instr >> 8) & 0b1111;
- inst.condition = ConditionCode::build(cond as u8);
+ let imm = instr2[0..8].load::<u8>() as i8 as i32;
+ inst.condition = ConditionCode::build(opcode);
inst.operands = [
Operand::BranchThumbOffset(imm + 1),
Operand::Nothing,
@@ -3116,7 +3131,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
// first described in revision `C.a`
inst.opcode = Opcode::UDF;
inst.operands = [
- Operand::Imm32((instr & 0xff) as u32),
+ Operand::Imm32(instr2[..8].load::<u32>()),
Operand::Nothing,
Operand::Nothing,
Operand::Nothing,
@@ -3126,7 +3141,7 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
// v4T
inst.opcode = Opcode::SVC;
inst.operands = [
- Operand::Imm32((instr & 0xff) as u32),
+ Operand::Imm32(instr2[..8].load::<u32>()),
Operand::Nothing,
Operand::Nothing,
Operand::Nothing,
@@ -3134,11 +3149,13 @@ pub fn decode_into<T: IntoIterator<Item=u8>>(decoder: &InstDecoder, inst: &mut I
}
} else {
// `B` on page `A8-332` -- v4T
+ // encoding T2
+ // v4T
inst.opcode = Opcode::B;
- let imm = instr & 0b111_1111_1111;
- let imm = ((imm as i32) << 21) >> 20;
+ let imm = instr2[0..11].load::<u32>();
+ let imm = ((imm as i32) << 20) >> 20;
inst.operands = [
- Operand::Imm32(imm as u32),
+ Operand::BranchThumbOffset(imm),
Operand::Nothing,
Operand::Nothing,
Operand::Nothing,
generated by cgit v1.1 at 2024-11-15 01:32:10 +0000