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authoriximeow <me@iximeow.net>2021-10-24 19:29:48 -0700
committeriximeow <me@iximeow.net>2021-10-24 19:29:54 -0700
commitb55e519458d8f01be0dbe205de4f7f9aeb8a3ca2 (patch)
tree77fc01c08ff256d4dece8767bd828ba0e29a5a7d /src/armv8
parentbd0be59eb6ed363faba14adf9ab04efe8a714316 (diff)
constify more of ld/st code, fix incorrect shift size
extended register forms of ld*/st* instructions do not shift by 0 or 1, they are an instruction/operand-size-dependent shift amount.
Diffstat (limited to 'src/armv8')
-rw-r--r--src/armv8/a64.rs441
1 files changed, 132 insertions, 309 deletions
diff --git a/src/armv8/a64.rs b/src/armv8/a64.rs
index 6bce61e..5dd3d1c 100644
--- a/src/armv8/a64.rs
+++ b/src/armv8/a64.rs
@@ -2454,196 +2454,107 @@ impl Decoder<ARMv8> for InstDecoder {
let category = (word >> 10) & 0x03;
// println!("load/store: size_opc: {:#b}, category: {:#b}", size_opc, category);
if word & 0x200000 != 0 {
- if category != 0b10 {
- inst.opcode = Opcode::Invalid;
- return Err(DecodeError::InvalidOpcode);
- } else {
- // Load/store register (register offset)
- // C3.3.10
- let size = match size_opc {
- 0b0000 => {
- inst.opcode = Opcode::STRB;
- SizeCode::W
- },
- 0b0001 => {
- inst.opcode = Opcode::LDRB;
- SizeCode::W
- },
- 0b0010 => {
- inst.opcode = Opcode::LDRSB;
- SizeCode::X
- },
- 0b0011 => {
- inst.opcode = Opcode::LDRSB;
- SizeCode::W
- },
- 0b0100 => {
- inst.opcode = Opcode::STRH;
- SizeCode::W
- },
- 0b0101 => {
- inst.opcode = Opcode::LDRH;
- SizeCode::W
- },
- 0b0110 => {
- inst.opcode = Opcode::LDRSH;
- SizeCode::X
- },
- 0b0111 => {
- inst.opcode = Opcode::LDRSH;
- SizeCode::W
- },
- 0b1000 => {
- inst.opcode = Opcode::STR;
- SizeCode::W
- },
- 0b1001 => {
- inst.opcode = Opcode::LDR;
- SizeCode::W
- },
- 0b1010 => {
- inst.opcode = Opcode::LDRSW;
- SizeCode::X
- },
- 0b1011 => {
- inst.opcode = Opcode::Invalid;
- SizeCode::X
- },
- 0b1100 => {
- inst.opcode = Opcode::STR;
- SizeCode::X
- },
- 0b1101 => {
- inst.opcode = Opcode::LDR;
- SizeCode::X
- },
- 0b1110 => {
- // eprintln!("PRFM is not supported yet");
- return Err(DecodeError::IncompleteDecoder);
-// inst.opcode = Opcode::PRFM;
-// SizeCode::X
- },
- 0b1111 => {
- inst.opcode = Opcode::Invalid;
- SizeCode::X
- },
- _ => { unreachable!("size and opc are four bits"); }
- };
+ match category {
+ 0b00 => {
+ // Atomic memory operations
+ // V==1
+ return Err(DecodeError::IncompleteDecoder);
+ }
+ 0b01 |
+ 0b11 => {
+ // Load/store register (pac)
+ // V==1
+ return Err(DecodeError::IncompleteDecoder);
+ }
+ 0b10 => {
+ // Load/store register (register offset)
+ // C3.3.10
+ const OPCODES: &[Result<(Opcode, SizeCode, u8), DecodeError>] = &[
+ Ok((Opcode::STRB, SizeCode::W, 1)),
+ Ok((Opcode::LDRB, SizeCode::W, 1)),
+ Ok((Opcode::LDRSB, SizeCode::X, 1)),
+ Ok((Opcode::LDRSB, SizeCode::W, 1)),
+ Ok((Opcode::STRH, SizeCode::W, 1)),
+ Ok((Opcode::LDRH, SizeCode::W, 1)),
+ Ok((Opcode::LDRSH, SizeCode::X, 1)),
+ Ok((Opcode::LDRSH, SizeCode::W, 1)),
+ Ok((Opcode::STR, SizeCode::W, 2)),
+ Ok((Opcode::LDR, SizeCode::W, 2)),
+ Ok((Opcode::LDRSW, SizeCode::X, 2)),
+ Err(DecodeError::InvalidOpcode),
+ Ok((Opcode::STR, SizeCode::X, 3)),
+ Ok((Opcode::LDR, SizeCode::X, 3)),
+ Err(DecodeError::IncompleteDecoder), // PRFM is not supported yet
+ Err(DecodeError::InvalidOpcode),
+ ];
- let S = ((word >> 12) & 0x1) as u8;
- let option = ((word >> 13) & 0x07) as u8;
- let Rm = ((word >> 16) & 0x1f) as u16;
+ let (opcode, size, shamt) = OPCODES[size_opc as usize]?;
+ inst.opcode = opcode;
- let index_size = match option & 0x3 {
- 0b00 |
- 0b01 => {
- inst.opcode = Opcode::Invalid;
- return Err(DecodeError::InvalidOpcode);
- },
- 0b10 => { SizeCode::W }
- 0b11 => { SizeCode::X }
- _ => { unreachable!("option is two bits"); }
- };
+ let S = ((word >> 12) & 0x1) as u8;
+ let option = ((word >> 13) & 0x07) as u8;
+ let Rm = ((word >> 16) & 0x1f) as u16;
- let shift_style = match option {
- 0b000 |
- 0b001 => {
- inst.opcode = Opcode::Invalid;
- return Err(DecodeError::InvalidOpcode);
- },
- 0b010 => { ShiftStyle::UXTW },
- 0b011 => { ShiftStyle::LSL },
- 0b100 |
- 0b101 => {
- inst.opcode = Opcode::Invalid;
- return Err(DecodeError::InvalidOpcode);
- },
- 0b110 => { ShiftStyle::SXTW },
- 0b111 => { ShiftStyle::SXTX },
- _ => { unreachable!("option is three bits"); }
- };
+ let index_size = match option & 0x3 {
+ 0b00 |
+ 0b01 => {
+ inst.opcode = Opcode::Invalid;
+ return Err(DecodeError::InvalidOpcode);
+ },
+ 0b10 => { SizeCode::W }
+ 0b11 => { SizeCode::X }
+ _ => { unreachable!("option is two bits"); }
+ };
- inst.operands = [
- Operand::Register(size, Rt),
- Operand::RegRegOffset(Rn, index_size, Rm, shift_style, S),
- Operand::Nothing,
- Operand::Nothing,
- ];
+ const SHIFT_STYLES: &[Result<ShiftStyle, DecodeError>] = &[
+ Err(DecodeError::InvalidOperand),
+ Err(DecodeError::InvalidOperand),
+ Ok(ShiftStyle::UXTW),
+ Ok(ShiftStyle::LSL),
+ Err(DecodeError::InvalidOperand),
+ Err(DecodeError::InvalidOperand),
+ Ok(ShiftStyle::SXTW),
+ Ok(ShiftStyle::SXTX),
+ ];
+ let shift_style = SHIFT_STYLES[option as usize]?;
+
+ inst.operands = [
+ Operand::Register(size, Rt),
+ Operand::RegRegOffset(Rn, index_size, Rm, shift_style, S * shamt),
+ Operand::Nothing,
+ Operand::Nothing,
+ ];
+ }
+ _ => {
+ unreachable!("category is two bits");
+ }
}
} else {
let imm9 = ((((word >> 12) & 0x1ff) as i16) << 7) >> 7;
match category {
0b00 => {
// Load/store register (unscaled immediate)
- let size = match size_opc {
- 0b0000 => {
- inst.opcode = Opcode::STURB;
- SizeCode::W
- }
- 0b0001 => {
- inst.opcode = Opcode::LDURB;
- SizeCode::W
- }
- 0b0010 => {
- inst.opcode = Opcode::LDURSB;
- SizeCode::X
- }
- 0b0011 => {
- inst.opcode = Opcode::LDURSB;
- SizeCode::W
- }
- 0b0100 => {
- inst.opcode = Opcode::STURH;
- SizeCode::W
- }
- 0b0101 => {
- inst.opcode = Opcode::LDURH;
- SizeCode::W
- }
- 0b0110 => {
- inst.opcode = Opcode::LDURSH;
- SizeCode::X
- }
- 0b0111 => {
- inst.opcode = Opcode::LDURSH;
- SizeCode::W
- }
- 0b1000 => {
- inst.opcode = Opcode::STUR;
- SizeCode::W
- }
- 0b1001 => {
- inst.opcode = Opcode::LDUR;
- SizeCode::W
- }
- 0b1010 => {
- inst.opcode = Opcode::LDURSW;
- SizeCode::X
- }
- 0b1011 => {
- inst.opcode = Opcode::Invalid;
- SizeCode::W
- }
- 0b1100 => {
- inst.opcode = Opcode::STUR;
- SizeCode::X
- }
- 0b1101 => {
- inst.opcode = Opcode::LDUR;
- SizeCode::X
- }
- 0b1110 => {
- // eprintln!("PRFUM not handled yet");
- return Err(DecodeError::IncompleteDecoder);
- },
- 0b1111 => {
- inst.opcode = Opcode::Invalid;
- SizeCode::W
- }
- _ => {
- unreachable!("size and opc are four bits");
- }
- };
+ const OPCODES: &[Result<(Opcode, SizeCode), DecodeError>] = &[
+ Ok((Opcode::STURB, SizeCode::W)),
+ Ok((Opcode::LDURB, SizeCode::W)),
+ Ok((Opcode::LDURSB, SizeCode::X)),
+ Ok((Opcode::LDURSB, SizeCode::W)),
+ Ok((Opcode::STURH, SizeCode::W)),
+ Ok((Opcode::LDURH, SizeCode::W)),
+ Ok((Opcode::LDURSH, SizeCode::X)),
+ Ok((Opcode::LDURSH, SizeCode::W)),
+ Ok((Opcode::STUR, SizeCode::W)),
+ Ok((Opcode::LDUR, SizeCode::W)),
+ Ok((Opcode::LDURSW, SizeCode::X)),
+ Err(DecodeError::InvalidOpcode),
+ Ok((Opcode::STUR, SizeCode::X)),
+ Ok((Opcode::LDUR, SizeCode::X)),
+ Err(DecodeError::IncompleteDecoder), // PRFM is not supported yet
+ Err(DecodeError::InvalidOpcode),
+ ];
+
+ let (opcode, size) = OPCODES[size_opc as usize]?;
+ inst.opcode = opcode;
inst.operands = [
Operand::Register(size, Rt),
@@ -2654,73 +2565,27 @@ impl Decoder<ARMv8> for InstDecoder {
}
0b10 => {
// Load/store register (unprivileged)
+ const OPCODES: &[Result<(Opcode, SizeCode), DecodeError>] = &[
+ Ok((Opcode::STTRB, SizeCode::W)),
+ Ok((Opcode::LDTRB, SizeCode::W)),
+ Ok((Opcode::LDTRSB, SizeCode::X)),
+ Ok((Opcode::LDTRSB, SizeCode::W)),
+ Ok((Opcode::STTRH, SizeCode::W)),
+ Ok((Opcode::LDTRH, SizeCode::W)),
+ Ok((Opcode::LDTRSH, SizeCode::X)),
+ Ok((Opcode::LDTRSH, SizeCode::W)),
+ Ok((Opcode::STTR, SizeCode::W)),
+ Ok((Opcode::LDTR, SizeCode::W)),
+ Ok((Opcode::LDTRSW, SizeCode::X)),
+ Err(DecodeError::InvalidOpcode),
+ Ok((Opcode::STUR, SizeCode::X)),
+ Ok((Opcode::LDTR, SizeCode::X)),
+ Err(DecodeError::InvalidOpcode),
+ Err(DecodeError::InvalidOpcode),
+ ];
- let size = match size_opc {
- 0b0000 => {
- inst.opcode = Opcode::STTRB;
- SizeCode::W
- }
- 0b0001 => {
- inst.opcode = Opcode::LDTRB;
- SizeCode::W
- }
- 0b0010 => {
- inst.opcode = Opcode::LDTRSB;
- SizeCode::X
- }
- 0b0011 => {
- inst.opcode = Opcode::LDTRSB;
- SizeCode::W
- }
- 0b0100 => {
- inst.opcode = Opcode::STTRH;
- SizeCode::W
- }
- 0b0101 => {
- inst.opcode = Opcode::LDTRH;
- SizeCode::W
- }
- 0b0110 => {
- inst.opcode = Opcode::LDTRSH;
- SizeCode::X
- }
- 0b0111 => {
- inst.opcode = Opcode::LDTRSH;
- SizeCode::W
- }
- 0b1000 => {
- inst.opcode = Opcode::STTR;
- SizeCode::W
- }
- 0b1001 => {
- inst.opcode = Opcode::LDTR;
- SizeCode::W
- }
- 0b1010 => {
- inst.opcode = Opcode::LDTRSW;
- SizeCode::X
- }
- 0b1011 => {
- inst.opcode = Opcode::Invalid;
- SizeCode::W
- }
- 0b1100 => {
- inst.opcode = Opcode::STTR;
- SizeCode::X
- }
- 0b1101 => {
- inst.opcode = Opcode::LDTR;
- SizeCode::X
- }
- 0b1110 |
- 0b1111 => {
- inst.opcode = Opcode::Invalid;
- SizeCode::W
- }
- _ => {
- unreachable!("size and opc are four bits");
- }
- };
+ let (opcode, size) = OPCODES[size_opc as usize]?;
+ inst.opcode = opcode;
inst.operands = [
Operand::Register(size, Rt),
@@ -2731,69 +2596,27 @@ impl Decoder<ARMv8> for InstDecoder {
}
0b01 |
0b11 => {
- let size = match size_opc {
- 0b0000 => {
- inst.opcode = Opcode::STRB;
- SizeCode::W
- },
- 0b0001 => {
- inst.opcode = Opcode::LDRB;
- SizeCode::W
- }
- 0b0010 => {
- inst.opcode = Opcode::LDRSB;
- SizeCode::X
- }
- 0b0011 => {
- inst.opcode = Opcode::LDRSB;
- SizeCode::W
- }
- 0b0100 => {
- inst.opcode = Opcode::STRH;
- SizeCode::W
- }
- 0b0101 => {
- inst.opcode = Opcode::LDRH;
- SizeCode::W
- }
- 0b0110 => {
- inst.opcode = Opcode::LDRSH;
- SizeCode::X
- }
- 0b0111 => {
- inst.opcode = Opcode::LDRSH;
- SizeCode::W
- }
- 0b1000 => {
- inst.opcode = Opcode::STR;
- SizeCode::W
- }
- 0b1001 => {
- inst.opcode = Opcode::LDR;
- SizeCode::W
- }
- 0b1010 |
- 0b1011 => {
- inst.opcode = Opcode::Invalid;
- SizeCode::W
- }
- 0b1100 => {
- inst.opcode = Opcode::STR;
- SizeCode::X
- }
- 0b1101 => {
- inst.opcode = Opcode::LDR;
- SizeCode::X
- }
- 0b1110 |
- 0b1111 => {
- inst.opcode = Opcode::Invalid;
- SizeCode::X
- }
- _ => {
- unreachable!("size and opc are four bits");
- }
- };
+ const OPCODES: &[Result<(Opcode, SizeCode), DecodeError>] = &[
+ Ok((Opcode::STRB, SizeCode::W)),
+ Ok((Opcode::LDRB, SizeCode::W)),
+ Ok((Opcode::LDRSB, SizeCode::X)),
+ Ok((Opcode::LDRSB, SizeCode::W)),
+ Ok((Opcode::STRH, SizeCode::W)),
+ Ok((Opcode::LDRH, SizeCode::W)),
+ Ok((Opcode::LDRSH, SizeCode::X)),
+ Ok((Opcode::LDRSH, SizeCode::W)),
+ Ok((Opcode::STR, SizeCode::W)),
+ Ok((Opcode::LDR, SizeCode::W)),
+ Err(DecodeError::InvalidOpcode),
+ Err(DecodeError::InvalidOpcode),
+ Ok((Opcode::STR, SizeCode::X)),
+ Ok((Opcode::LDR, SizeCode::X)),
+ Err(DecodeError::InvalidOpcode),
+ Err(DecodeError::InvalidOpcode),
+ ];
+
+ let (opcode, size) = OPCODES[size_opc as usize]?;
+ inst.opcode = opcode;
inst.operands = [
Operand::Register(size, Rt),