From 0e581ea4608c9510c1c2eb18e943212df5c037da Mon Sep 17 00:00:00 2001 From: iximeow Date: Sat, 5 Jan 2019 15:42:30 -0800 Subject: read_E cleanup --- src/lib.rs | 130 ++++++++++++++++++------------------------------------------- 1 file changed, 37 insertions(+), 93 deletions(-) (limited to 'src') 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, instruction: &mut Instructio fn read_E(bytes_iter: &mut Iterator, 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, 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, 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( -- cgit v1.1