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-rw-r--r--src/lib.rs130
1 files changed, 37 insertions, 93 deletions
diff --git a/src/lib.rs b/src/lib.rs
index 179b9d0..3ebac76 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1277,26 +1277,16 @@ fn read_opcode(bytes_iter: &mut Iterator<Item=&u8>, instruction: &mut Instructio
fn read_E(bytes_iter: &mut Iterator<Item=&u8>, prefixes: &Prefixes, m: u8, modbits: u8, width: u8, result: &mut Operand) -> Result<(), String> {
let addr_width = if prefixes.address_size() { 4 } else { 8 };
if modbits == 0b11 {
- if prefixes.rex().b() {
- *result = Operand::Register(RegSpec {
- num: m + 0b1000,
- bank: width_to_gp_reg_bank(width)
- });
- return Ok(());
- } else {
- *result = Operand::Register(RegSpec {
- num: m,
- bank: width_to_gp_reg_bank(width)
- });
- return Ok(());
- }
+ *result = Operand::Register(RegSpec {
+ num: m + if prefixes.rex().b() { 0b1000 } else { 0 },
+ bank: width_to_gp_reg_bank(width)
+ });
} else if m == 5 && modbits == 0b00 {
let disp = read_num(bytes_iter, 4);
*result = Operand::RegDisp(RegSpec {
num: 0,
bank: if addr_width == 8 { RegisterBank::RIP } else { RegisterBank::EIP }
}, disp as i32);
- Ok(())
} else if m == 4 {
let sibbyte = *bytes_iter.next().unwrap();
let (ss, index, base) = octets_of(sibbyte);
@@ -1315,99 +1305,60 @@ fn read_E(bytes_iter: &mut Iterator<Item=&u8>, prefixes: &Prefixes, m: u8, modbi
if index == 0b100 {
if modbits == 0b00 && !prefixes.rex().x() {
*result = Operand::DisplacementU32(disp as i32);
- Ok(())
} else {
- let indexnum = if prefixes.rex().x() {
- 0b1000 + 0b100
- } else {
- 0b100
+ let reg = RegSpec {
+ num: 0b100 + if prefixes.rex().x() { 0b1000 } else { 0 },
+ bank: width_to_gp_reg_bank(addr_width)
};
if disp == 0 {
- *result = Operand::RegDeref(RegSpec {
- num: indexnum,
- bank: width_to_gp_reg_bank(addr_width)
- });
- Ok(())
+ *result = Operand::RegDeref(reg);
} else {
- *result = Operand::RegDisp(RegSpec {
- num: indexnum,
- bank: width_to_gp_reg_bank(addr_width)
- }, disp as i32);
- Ok(())
+ *result = Operand::RegDisp(reg, disp as i32);
}
}
} else {
- let base_reg = if prefixes.rex().b() {
- RegSpec {
- num: 5 + 0b1000,
- bank: width_to_gp_reg_bank(addr_width)
- }
- } else {
- RegSpec {
- num: 5,
- bank: width_to_gp_reg_bank(addr_width)
- }
+ let base_reg = RegSpec {
+ num: 5 + if prefixes.rex().b() { 0b1000 } else { 0 },
+ bank: width_to_gp_reg_bank(addr_width)
};
- let index_reg = if prefixes.rex().x() {
- RegSpec {
- num: index + 0b1000,
- bank: width_to_gp_reg_bank(addr_width)
- }
- } else {
- RegSpec {
- num: index,
- bank: width_to_gp_reg_bank(addr_width)
- }
+ let index_reg = RegSpec {
+ num: index + if prefixes.rex().x() { 0b1000 } else { 0 },
+ bank: width_to_gp_reg_bank(addr_width)
};
- match (ss, modbits, disp) {
+ *result = match (ss, modbits, disp) {
(0, 0b00, 0) => {
- *result = Operand::RegDeref(index_reg);
- Ok(())
+ Operand::RegDeref(index_reg)
},
(0, 0b00, _) => {
- *result = Operand::RegDisp(index_reg, disp as i32);
- Ok(())
+ Operand::RegDisp(index_reg, disp as i32)
},
(0, _, 0) => {
- *result = Operand::RegIndexBase(base_reg, index_reg);
- Ok(())
+ Operand::RegIndexBase(base_reg, index_reg)
},
(0, _, _) => {
- *result = Operand::RegIndexBaseDisp(base_reg, index_reg, disp as i32);
- Ok(())
+ Operand::RegIndexBaseDisp(base_reg, index_reg, disp as i32)
},
(_, 0b00, 0) => {
- *result = Operand::RegScale(index_reg, 1u8 << ss);
- Ok(())
+ Operand::RegScale(index_reg, 1u8 << ss)
},
(_, 0b00, _) => {
- *result = Operand::RegScaleDisp(index_reg, 1u8 << ss, disp as i32);
- Ok(())
+ Operand::RegScaleDisp(index_reg, 1u8 << ss, disp as i32)
},
(_, _, 0) => {
- *result = Operand::RegIndexBaseScale(base_reg, index_reg, 1u8 << ss);
- Ok(())
+ Operand::RegIndexBaseScale(base_reg, index_reg, 1u8 << ss)
},
(_, _, _) => {
- *result = Operand::RegIndexBaseScaleDisp(base_reg, index_reg, 1u8 << ss, disp as i32);
- Ok(())
+ Operand::RegIndexBaseScaleDisp(base_reg, index_reg, 1u8 << ss, disp as i32)
}
- }
+ };
}
} else {
- let base_reg = if prefixes.rex().b() {
- RegSpec {
- num: base + 0b1000,
- bank: width_to_gp_reg_bank(addr_width)
- }
- } else {
- RegSpec {
- num: base,
- bank: width_to_gp_reg_bank(addr_width)
- }
+ let base_reg = RegSpec {
+ num: base + if prefixes.rex().b() { 0b1000 } else { 0 },
+ bank: width_to_gp_reg_bank(addr_width)
};
let disp = if modbits == 0b00 {
@@ -1421,43 +1372,36 @@ fn read_E(bytes_iter: &mut Iterator<Item=&u8>, prefixes: &Prefixes, m: u8, modbi
if index == 0b100 {
if disp == 0 {
*result = Operand::RegDeref(base_reg);
- Ok(())
} else {
*result = Operand::RegDisp(base_reg, disp as i32);
- Ok(())
}
} else {
let index_reg = RegSpec {
- num: index,
+ num: index + if prefixes.rex().x() { 0b1000 } else { 0 },
bank: width_to_gp_reg_bank(addr_width)
};
if disp == 0 {
*result = Operand::RegIndexBaseScale(base_reg, index_reg, 1u8 << ss);
- Ok(())
} else {
*result = Operand::RegIndexBaseScaleDisp(base_reg, index_reg, 1u8 << ss, disp as i32);
- Ok(())
}
}
}
} else {
- let regidx = m + if prefixes.rex().b() { 0b1000 } else { 0 };
+ let reg = RegSpec {
+ num: m + if prefixes.rex().b() { 0b1000 } else { 0 },
+ bank: width_to_gp_reg_bank(addr_width)
+ };
+
if modbits == 0b00 {
- *result = Operand::RegDeref(RegSpec {
- num: regidx,
- bank: width_to_gp_reg_bank(addr_width)
- });
- Ok(())
+ *result = Operand::RegDeref(reg);
} else {
let disp_width = if modbits == 0b01 { 1 } else { 4 };
let disp = read_num(bytes_iter, disp_width) as i32;
- *result = Operand::RegDisp(RegSpec {
- num: regidx,
- bank: width_to_gp_reg_bank(addr_width)
- }, disp);
- Ok(())
+ *result = Operand::RegDisp(reg, disp);
}
}
+ Ok(())
}
fn read_operands(
generated by cgit v1.1 at 2024-11-11 03:27:21 +0000