From 8046f4241d07d399c28e63613e5b9ff1a554f8f4 Mon Sep 17 00:00:00 2001 From: iximeow Date: Sat, 5 Dec 2020 18:36:40 -0800 Subject: use bitvec in thumb decoder --- src/armv7/thumb.rs | 463 +++++++++++++++++++++++++++-------------------------- 1 file changed, 240 insertions(+), 223 deletions(-) (limited to 'src/armv7') 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>(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::(); // `A6.1 Thumb instruction set encoding` if opword >= 0b11101 { @@ -116,23 +121,25 @@ pub fn decode_into>(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::(); // 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::() << 2) | instr2[4..6].load::(); + let imm8 = lower2[..8].load::(); + let rd = lower2[8..12].load::(); + let rt = lower2[12..16].load::(); // all only-wide, no w suffix inst.set_w(false); @@ -191,8 +198,8 @@ pub fn decode_into>(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>(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>(decoder: &InstDecoder, inst: &mut I 0b0100 => { // `STREX_` // v7 - let op3 = (lower >> 4) & 0b1111; + let op3 = lower2[4..8].load::(); let rt2 = rd; let rd = (imm8 & 0b1111) as u8; match op3 { @@ -323,7 +330,7 @@ pub fn decode_into>(decoder: &InstDecoder, inst: &mut I } 0b0101 => { // `TBB`/`TBH`/`LDREX_` - let op3 = (lower >> 4) & 0b1111; + let op3 = lower2[4..8].load::(); let rt2 = rd; let rd = (imm8 & 0b1111) as u8; match op3 { @@ -430,8 +437,8 @@ pub fn decode_into>(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>(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>(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::() { 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), // # ? what's the syntax here? #? + Operand::Imm12(lower2[0..4].load::()), // # ? what's the syntax here? #? Operand::Nothing, Operand::Nothing, ]; @@ -602,7 +609,7 @@ pub fn decode_into>(decoder: &InstDecoder, inst: &mut I } } else { // `L == 1` - match (instr >> 7) & 0b11 { + match instr2[7..9].load::() { 0b00 => { // `RFE` (`B9-1986`) // v6T2 @@ -691,19 +698,19 @@ pub fn decode_into>(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::(); + let s = instr2[4]; + let rn = instr2[0..4].load::(); + let rd = lower2[8..12].load::(); - 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::(); + let imm2 = lower2[6..8].load::(); + let tp = lower2[4..6].load::(); + let rm = lower2[0..4].load::(); 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>(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::(); + let i = lower2[10..11].load::(); + let s = lower2[4]; + let rn = lower2[0..4].load::(); + let imm3 = lower2[12..15].load::(); + let rd = lower2[8..12].load::(); + let imm8 = lower2[0..8].load::(); let imm = (i << 11) | (imm3 << 8) | imm8; inst.s = s; @@ -1169,14 +1176,14 @@ pub fn decode_into>(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::(); + let i = instr2[10..11].load::(); + 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::(); + let imm3 = lower2[12..15].load::(); + let rd = lower2[8..12].load::(); + let imm8 = lower2[0..8].load::(); let imm = (i << 11) | (imm3 << 8) | imm8; match op { @@ -1266,7 +1273,7 @@ pub fn decode_into>(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::() << 1, imm3_2 as u8); // `SSAT` // v6T2 inst.opcode = Opcode::SSAT; @@ -1395,11 +1402,15 @@ pub fn decode_into>(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::(); + let op2 = lower2[8..11].load::(); + let op1 = instr2[12..15].load::(); + let op = instr2[4..11].load::(); 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>(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::(); 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>(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::(); + 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>(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::(); + 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>(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::(); + let op2 = lower2[0..8].load::(); if op1 != 0b000 { // `CPS (Thumb)` (`B9-1964`) // v6T2 @@ -1512,7 +1523,7 @@ pub fn decode_into>(decoder: &InstDecoder, inst: &mut I } else { if op2 >= 0b11110000 { // `DBG` (`A8-378`) - let option = lower & 0b1111; + let option = lower2[0..4].load::(); inst.opcode = Opcode::DBG; inst.operands = [ Operand::Imm12(option), @@ -1675,7 +1686,7 @@ pub fn decode_into>(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::(); inst.opcode = Opcode::BXJ; inst.operands = [ Operand::Reg(Reg::from_u8(rm)), @@ -1689,7 +1700,7 @@ pub fn decode_into>(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::(); if imm8 == 0 { // `ERET` (`B9-1968`) // v6T2 @@ -1709,7 +1720,7 @@ pub fn decode_into>(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>(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::(); + let imm6 = instr2[0..6].load::(); + let j1 = lower2[13..14].load::(); + let j2 = lower2[11..12].load::(); + let s = instr2[10..11].load::(); let imm = (imm11 as u32) | ((imm6 as u32) << 11) | @@ -1830,11 +1841,11 @@ pub fn decode_into>(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::(); + let imm10 = instr2[0..10].load::(); + let j1 = lower2[13..14].load::(); + let j2 = lower2[11..12].load::(); + let s = instr2[10..11].load::(); let imm = (imm11 as u32) | ((imm10 as u32) << 11) | @@ -1852,11 +1863,11 @@ pub fn decode_into>(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::(); + let imm10 = instr2[0..10].load::(); + let j1 = lower2[13..14].load::(); + let j2 = lower2[11..12].load::(); + let s = instr2[10..11].load::(); let imm = (imm11 as u32) | ((imm10 as u32) << 11) | @@ -1874,17 +1885,21 @@ pub fn decode_into>(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::(); + let op1 = instr2[5..8].load::(); 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>(decoder: &InstDecoder, inst: &mut I } } else { // load {byte, halfword, word} - let size_bits = (op2 >> 1) & 0b11; + let size_bits = (op2[1..].load::()); if size_bits == 0b00 { // `Load byte, memory hints` (`A6-239`) } else if size_bits == 0b01 { @@ -2173,14 +2188,14 @@ pub fn decode_into>(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::(); + 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>(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::()]; + let rd = lower2[8..12].load::(); + let rm = lower2[0..4].load::(); inst.opcode = op; inst.operands = [ Operand::Reg(Reg::from_u8(rd)), @@ -2199,6 +2214,7 @@ pub fn decode_into>(decoder: &InstDecoder, inst: &mut I Operand::Nothing, ]; } else { + let op1 = op1[0..3].load::(); // `SXTAH` and friends if op1 > 0b101 { return Err(DecodeError::Undefined); @@ -2212,11 +2228,11 @@ pub fn decode_into>(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::(); + let rotate = lower2[1..3].load::() << 2;; + let rd = lower2[8..12].load::(); inst.opcode = op; inst.operands = [ @@ -2233,11 +2249,11 @@ pub fn decode_into>(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::(); + let rotate = lower2[1..3].load::() << 2;; + let rd = lower2[8..12].load::(); inst.opcode = op; inst.operands = [ @@ -2249,6 +2265,7 @@ pub fn decode_into>(decoder: &InstDecoder, inst: &mut I }; } } else { + let op2 = op2.load::(); if op2 < 0b0100 { // `Parallel addition and subtraction, signed` return Err(DecodeError::Incomplete); @@ -2263,7 +2280,7 @@ pub fn decode_into>(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>(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::(); + let rm = instr2[3..6].load::(); + let imm5 = instr2[6..11].load::(); inst.opcode = Opcode::LSL; inst.operands = [ Operand::Reg(Reg::from_u8(rd)), @@ -2304,9 +2321,9 @@ pub fn decode_into>(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::(); + let rm = instr2[3..6].load::(); + let imm5 = instr2[6..11].load::(); let imm = if imm5 == 0 { 0x20 } else { @@ -2322,9 +2339,9 @@ pub fn decode_into>(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::(); + let rm = instr2[3..6].load::(); + let imm5 = instr2[6..11].load::(); let imm = if imm5 == 0 { 0x20 } else { @@ -2340,10 +2357,10 @@ pub fn decode_into>(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::(); + let rm = instr2[6..9].load::(); + let rd = instr2[0..3].load::(); + let rn = instr2[3..6].load::(); match oplower { 0b00 => { @@ -2390,8 +2407,8 @@ pub fn decode_into>(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::(); + let rd = instr2[8..11].load::(); inst.opcode = Opcode::MOV; inst.operands = [ Operand::Reg(Reg::from_u8(rd)), @@ -2403,8 +2420,8 @@ pub fn decode_into>(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::(); + let rd = instr2[8..11].load::(); inst.opcode = Opcode::CMP; inst.operands = [ Operand::Reg(Reg::from_u8(rd)), @@ -2415,8 +2432,8 @@ pub fn decode_into>(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::(); + let rdn = instr2[8..11].load::(); inst.opcode = Opcode::ADD; inst.operands = [ Operand::Reg(Reg::from_u8(rdn)), @@ -2427,8 +2444,8 @@ pub fn decode_into>(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::(); + let rdn = instr2[8..11].load::(); inst.opcode = Opcode::SUB; inst.operands = [ Operand::Reg(Reg::from_u8(rdn)), @@ -2442,7 +2459,7 @@ pub fn decode_into>(decoder: &InstDecoder, inst: &mut I } } } else if opword < 0b01001 { - let opcode_bits = (instr >> 6) & 0b1111; + let opcode_bits = instr2[6..10].load::(); // `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>(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::(); + let rm = instr2[3..6].load::(); if opcode_bits == 0b1101 { inst.opcode = Opcode::MUL; inst.operands = [ @@ -2504,8 +2521,8 @@ pub fn decode_into>(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::() | (instr2[7..8].load::() << 3); + let rm = instr2[3..7].load::(); inst.opcode = Opcode::ADD; inst.operands = [ Operand::Reg(Reg::from_u8(rdn)), @@ -2519,8 +2536,8 @@ pub fn decode_into>(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::() | (instr2[7..8].load::() << 3); + let rm = instr2[3..7].load::(); inst.opcode = Opcode::ADD; inst.operands = [ Operand::Reg(Reg::from_u8(rdn)), @@ -2535,8 +2552,8 @@ pub fn decode_into>(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::() | (instr2[7..8].load::() << 3); + let rm = instr2[3..7].load::(); inst.opcode = Opcode::CMP; inst.operands = [ Operand::Reg(Reg::from_u8(rn)), @@ -2549,8 +2566,8 @@ pub fn decode_into>(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::() | (instr2[7..8].load::() << 3); + let rm = instr2[3..7].load::(); inst.opcode = Opcode::MOV; inst.operands = [ Operand::Reg(Reg::from_u8(rd)), @@ -2564,8 +2581,8 @@ pub fn decode_into>(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::() | (instr2[7..8].load::() << 3); + let rm = instr2[3..7].load::(); inst.opcode = Opcode::MOV; inst.operands = [ Operand::Reg(Reg::from_u8(rd)), @@ -2578,7 +2595,7 @@ pub fn decode_into>(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::(); inst.opcode = Opcode::BX; inst.operands = [ Operand::Reg(Reg::from_u8(rm)), @@ -2591,7 +2608,7 @@ pub fn decode_into>(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::(); inst.opcode = Opcode::BLX; inst.operands = [ Operand::Reg(Reg::from_u8(rm)), @@ -2607,8 +2624,8 @@ pub fn decode_into>(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::(); + let rt = instr2[8..11].load::(); inst.opcode = Opcode::LDR; inst.operands = [ Operand::Reg(Reg::from_u8(rt)), @@ -2622,14 +2639,14 @@ pub fn decode_into>(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::(); + let op_a = instr2[12..].load::(); // `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::(); + let rn = instr2[3..6].load::(); + let rm = instr2[6..9].load::(); + let imm5 = instr2[6..11].load::(); if op_a == 0b0101 { let op = [ Opcode::STR, @@ -2640,7 +2657,7 @@ pub fn decode_into>(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>(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>(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::(); + let imm8 = instr2[..8].load::(); inst.operands = [ Operand::Reg(Reg::from_u8(rt)), Operand::RegDerefPreindexOffset( @@ -2706,8 +2723,8 @@ pub fn decode_into>(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::(); + let imm8 = instr2[..8].load::(); inst.opcode = Opcode::ADR; inst.operands = [ Operand::Reg(Reg::from_u8(rd)), @@ -2717,8 +2734,8 @@ pub fn decode_into>(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::(); + let imm8 = instr2[..8].load::(); inst.opcode = Opcode::ADD; inst.operands = [ Operand::Reg(Reg::from_u8(rd)), @@ -2728,38 +2745,38 @@ pub fn decode_into>(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::(); if opcode_bits < 0b0000100 { // `Add Immediate to SP` (`A8-314`) // v4T // encoding T2 - let imm7 = instr & 0b111_1111; + let imm7 = instr2[..7].load::(); 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::(); 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::(); + let imm5 = instr2[3..8].load::(); let imm = (((instr >> 9) & 1) << 5) | imm5; inst.opcode = if op { Opcode::CBNZ @@ -2775,8 +2792,8 @@ pub fn decode_into>(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::(); + let rm = instr2[3..6].load::(); inst.opcode = Opcode::SXTH; inst.operands = [ Operand::Reg(Reg::from_u8(rd)), @@ -2787,8 +2804,8 @@ pub fn decode_into>(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::(); + let rm = instr2[3..6].load::(); inst.opcode = Opcode::SXTB; inst.operands = [ Operand::Reg(Reg::from_u8(rd)), @@ -2799,8 +2816,8 @@ pub fn decode_into>(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::(); + let rm = instr2[3..6].load::(); inst.opcode = Opcode::UXTH; inst.operands = [ Operand::Reg(Reg::from_u8(rd)), @@ -2811,8 +2828,8 @@ pub fn decode_into>(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::(); + let rm = instr2[3..6].load::(); inst.opcode = Opcode::UXTB; inst.operands = [ Operand::Reg(Reg::from_u8(rd)), @@ -2823,9 +2840,9 @@ pub fn decode_into>(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::(); + let imm5 = instr2[3..8].load::(); let imm = (((instr >> 9) & 1) << 5) | imm5; inst.opcode = if op { Opcode::CBNZ @@ -2841,8 +2858,8 @@ pub fn decode_into>(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::(); + let reglist = instr2[0..8].load::() | (m << (6 + 8)); inst.opcode = Opcode::PUSH; inst.operands = [ Operand::RegList(reglist), @@ -2857,7 +2874,7 @@ pub fn decode_into>(decoder: &InstDecoder, inst: &mut I // opword == 0b0110010 // `Set Endianness` (`A8-605`) // v6 - let e = (instr >> 3) & 1; + let e = instr2[3..4].load::(); inst.opcode = Opcode::SETEND; inst.operands = [ Operand::Imm12(e), @@ -2869,9 +2886,9 @@ pub fn decode_into>(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::(); + let im = instr2[4]; + inst.opcode = Opcode::CPS(im); inst.operands = [ Operand::Imm12(aif), Operand::Nothing, @@ -2884,9 +2901,9 @@ pub fn decode_into>(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::(); + let imm5 = instr2[3..8].load::(); let imm = (((instr >> 9) & 1) << 5) | imm5; inst.opcode = if op { Opcode::CBNZ @@ -2902,8 +2919,8 @@ pub fn decode_into>(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::(); + let rm = instr2[3..6].load::(); inst.opcode = Opcode::REV; inst.operands = [ Operand::Reg(Reg::from_u8(rd)), @@ -2914,8 +2931,8 @@ pub fn decode_into>(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::(); + let rm = instr2[3..6].load::(); inst.opcode = Opcode::REV16; inst.operands = [ Operand::Reg(Reg::from_u8(rd)), @@ -2929,8 +2946,8 @@ pub fn decode_into>(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::(); + let rm = instr2[3..6].load::(); inst.opcode = Opcode::REVSH; inst.operands = [ Operand::Reg(Reg::from_u8(rd)), @@ -2941,9 +2958,9 @@ pub fn decode_into>(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::(); + let imm5 = instr2[3..8].load::(); let imm = (((instr >> 9) & 1) << 5) | imm5; inst.opcode = if op { Opcode::CBNZ @@ -2959,8 +2976,8 @@ pub fn decode_into>(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::(); + let reglist = instr2[0..8].load::() | (p << (7 + 8)); inst.opcode = Opcode::POP; inst.operands = [ Operand::RegList(reglist), @@ -2971,18 +2988,18 @@ pub fn decode_into>(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::(); 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::(); + let opa = instr2[4..8].load::(); if opb != 0 { // `IT` (`A8-391`) @@ -2994,8 +3011,8 @@ pub fn decode_into>(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>(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>(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::(); + let reglist = instr2[0..8].load::(); 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>(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::(); + let reglist = instr2[0..8].load::(); 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>(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::(); 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::() 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>(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::()), Operand::Nothing, Operand::Nothing, Operand::Nothing, @@ -3126,7 +3141,7 @@ pub fn decode_into>(decoder: &InstDecoder, inst: &mut I // v4T inst.opcode = Opcode::SVC; inst.operands = [ - Operand::Imm32((instr & 0xff) as u32), + Operand::Imm32(instr2[..8].load::()), Operand::Nothing, Operand::Nothing, Operand::Nothing, @@ -3134,11 +3149,13 @@ pub fn decode_into>(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::(); + let imm = ((imm as i32) << 20) >> 20; inst.operands = [ - Operand::Imm32(imm as u32), + Operand::BranchThumbOffset(imm), Operand::Nothing, Operand::Nothing, Operand::Nothing, -- cgit v1.1