From e70be7245eac6acd6dde565c69b55bf8f55653e9 Mon Sep 17 00:00:00 2001 From: iximeow Date: Tue, 31 Dec 2019 18:02:43 -0800 Subject: add the mips decoder --- src/display.rs | 260 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 260 insertions(+) create mode 100644 src/display.rs (limited to 'src/display.rs') diff --git a/src/display.rs b/src/display.rs new file mode 100644 index 0000000..036fb28 --- /dev/null +++ b/src/display.rs @@ -0,0 +1,260 @@ +use std::fmt; + +use crate::{Instruction, Opcode, Operand}; + +impl fmt::Display for Instruction { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + if self.opcode == Opcode::OR { + match (self.operand(&self.operands[0]), self.operand(&self.operands[1]), self.operand(&self.operands[2])) { + (Some(a), Some(b), Some(Operand::Reg(0))) => { + return write!(f, "move {}, {}", a, b); + } + _ => {} + } + } else if self.opcode == Opcode::BEQ { + match (self.operand(&self.operands[0]), self.operand(&self.operands[1]), self.operand(&self.operands[2])) { + (Some(Operand::Reg(a)), Some(Operand::Reg(b)), Some(Operand::Imm(offs))) => { + if a == b { + if offs < 0 { + return write!(f, "b $-{:#x}", -offs); + } else { + return write!(f, "b $+{:#x}", offs); + } + } + } + _ => {} + } + } else if self.opcode == Opcode::SLL { + match (self.operand(&self.operands[0]), self.operand(&self.operands[1]), self.operand(&self.operands[2])) { + (Some(Operand::Reg(dest)), Some(Operand::Reg(src)), Some(Operand::Shift(0))) => { + // TODO: should this also test for dest == `zero`? + if dest == src { + return write!(f, "nop"); + } + } + _ => { } + } + } + + fn display_operand(f: &mut fmt::Formatter, opcode: &Opcode, op: &Operand) -> fmt::Result { + if *opcode == Opcode::LUI { + // we show the immediate of LUI as an unsigned integer, becaue the docs say so. + if let Operand::Imm(imm) = op { + return write!(f, "{:#x}", *imm as u16); + } + } else if let Operand::Imm(imm) = op { + if *imm < 0 { + return write!(f, "-{:#x}", -imm); + } else { + return write!(f, "{:#x}", imm); + } + } + + write!(f, "{}", op) + } + write!(f, "{}", self.opcode)?; + + let mut wrote_operand = false; + for op in self.operands.iter() { + match self.operand(op) { + Some(op) => { + if wrote_operand { + write!(f, ", ")?; + } else { + write!(f, " ")?; + wrote_operand = true; + } + display_operand(f, &self.opcode, &op)?; + } + _ => { + return Ok(()); + } + } + } + + Ok(()) + } +} + +impl fmt::Display for Operand { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + match self { + Operand::Reg(reg) => { + let name = [ + "zero", "at", + "v0", "v1", + "a0", "a1", "a2", "a3", + "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", + "s0", "s1", "s2", "s3", "s4", "s5", "s6", "s7", + "t8", "t9", + "k0", "k1", + "gp", "sp", "fp", "ra" + ][*reg as usize]; + write!(f, "{}", name) + } + Operand::Imm(imm) => { + write!(f, "{:#x}", imm) + } + Operand::BaseOffset(reg, offs) => { + let name = [ + "zero", "at", + "v0", "v1", + "a0", "a1", "a2", "a3", + "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", + "s0", "s1", "s2", "s3", "s4", "s5", "s6", "s7", + "t8", "t9", + "k0", "k1", + "gp", "sp", "fp", "ra" + ][*reg as usize]; + if *offs == 0 { + write!(f, "({})", name) + } else { + if *offs < 0 { + write!(f, "-{:#x}({})", -offs, name) + } else { + write!(f, "{:#x}({})", offs, name) + } + } + } + Operand::Shift(sa) => { + write!(f, "{:#x}", sa) + } + Operand::LongImm(imm) => { + write!(f, "{:#x}", imm) + } + Operand::JOffset(offs) => { + write!(f, "$+{:#x}", offs) + } + } + } +} + +impl fmt::Display for Opcode { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + match self { + Opcode::J => write!(f, "j"), + Opcode::JAL => write!(f, "jal"), + Opcode::BEQ => write!(f, "beq"), + Opcode::BNE => write!(f, "bne"), + Opcode::BLEZ => write!(f, "blez"), + Opcode::BGTZ => write!(f, "bgtz"), + Opcode::ADDI => write!(f, "addi"), + Opcode::ADDIU => write!(f, "addiu"), + Opcode::SLTI => write!(f, "slti"), + Opcode::SLTIU => write!(f, "sltiu"), + Opcode::ANDI => write!(f, "andi"), + Opcode::ORI => write!(f, "ori"), + Opcode::XORI => write!(f, "xori"), + Opcode::LUI => write!(f, "lui"), + Opcode::COP1 => write!(f, "cop1"), + Opcode::COP2 => write!(f, "cop2"), + Opcode::COP3 => write!(f, "cop3"), + Opcode::COP4 => write!(f, "cop4"), + Opcode::BEQL => write!(f, "beql"), + Opcode::BNEL => write!(f, "bnel"), + Opcode::BLEZL => write!(f, "blezl"), + Opcode::BGTZL => write!(f, "bgtzl"), + Opcode::DADDI => write!(f, "daddi"), + Opcode::DADDIU => write!(f, "daddiu"), + Opcode::LDL => write!(f, "ldl"), + Opcode::LDR => write!(f, "ldr"), + Opcode::LB => write!(f, "lb"), + Opcode::LH => write!(f, "lh"), + Opcode::LWL => write!(f, "lwl"), + Opcode::LW => write!(f, "lw"), + Opcode::LBU => write!(f, "lbu"), + Opcode::LHU => write!(f, "lhu"), + Opcode::LWR => write!(f, "lwr"), + Opcode::LWU => write!(f, "lwu"), + Opcode::SB => write!(f, "sb"), + Opcode::SH => write!(f, "sh"), + Opcode::SWL => write!(f, "swl"), + Opcode::SW => write!(f, "sw"), + Opcode::SDL => write!(f, "sdl"), + Opcode::SDR => write!(f, "sdr"), + Opcode::SWR => write!(f, "swr"), + Opcode::LL => write!(f, "ll"), + Opcode::LWC1 => write!(f, "lwc1"), + Opcode::LWC2 => write!(f, "lwc2"), + Opcode::PREF => write!(f, "pref"), + Opcode::LLD => write!(f, "lld"), + Opcode::LDC1 => write!(f, "ldc1"), + Opcode::LDC2 => write!(f, "ldc2"), + Opcode::LD => write!(f, "ld"), + Opcode::SC => write!(f, "sc"), + Opcode::SWC1 => write!(f, "swc1"), + Opcode::SWC2 => write!(f, "swc2"), + Opcode::SCD => write!(f, "scd"), + Opcode::SDC1 => write!(f, "sdc1"), + Opcode::SDC2 => write!(f, "sdc2"), + Opcode::SD => write!(f, "sd"), + Opcode::SLL => write!(f, "sll"), + Opcode::SRL => write!(f, "srl"), + Opcode::SRA => write!(f, "sra"), + Opcode::SLLV => write!(f, "sllv"), + Opcode::SRLV => write!(f, "srlv"), + Opcode::SRAV => write!(f, "srav"), + Opcode::JR => write!(f, "jr"), + Opcode::JALR => write!(f, "jalr"), + Opcode::MOVZ => write!(f, "movz"), + Opcode::MOVN => write!(f, "movn"), + Opcode::SYSCALL => write!(f, "syscall"), + Opcode::BREAK => write!(f, "break"), + Opcode::SYNC => write!(f, "sync"), + Opcode::MFHI => write!(f, "mfhi"), + Opcode::MTHI => write!(f, "mthi"), + Opcode::MFLO => write!(f, "mflo"), + Opcode::MTLO => write!(f, "mtlo"), + Opcode::DSLLV => write!(f, "dsllv"), + Opcode::DSRLV => write!(f, "dsrlv"), + Opcode::DSRAV => write!(f, "dsrav"), + Opcode::MULT => write!(f, "mult"), + Opcode::MULTU => write!(f, "multu"), + Opcode::DIV => write!(f, "div"), + Opcode::DIVU => write!(f, "divu"), + Opcode::DMULT => write!(f, "dmult"), + Opcode::DMULTU => write!(f, "dmultu"), + Opcode::DDIV => write!(f, "ddiv"), + Opcode::DDIVU => write!(f, "ddivu"), + Opcode::ADD => write!(f, "add"), + Opcode::ADDU => write!(f, "addu"), + Opcode::SUB => write!(f, "sub"), + Opcode::SUBU => write!(f, "subu"), + Opcode::AND => write!(f, "and"), + Opcode::OR => write!(f, "or"), + Opcode::XOR => write!(f, "xor"), + Opcode::NOR => write!(f, "nor"), + Opcode::SLT => write!(f, "slt"), + Opcode::DADD => write!(f, "dadd"), + Opcode::DADDU => write!(f, "daddu"), + Opcode::DSUB => write!(f, "dsub"), + Opcode::DSUBU => write!(f, "dsubu"), + Opcode::TGE => write!(f, "tge"), + Opcode::TGEU => write!(f, "tgeu"), + Opcode::TLT => write!(f, "tlt"), + Opcode::TLTU => write!(f, "tltu"), + Opcode::TEQ => write!(f, "teq"), + Opcode::TNE => write!(f, "tne"), + Opcode::DSLL => write!(f, "dsll"), + Opcode::DSRL => write!(f, "dsrl"), + Opcode::DSRA => write!(f, "dsra"), + Opcode::DSLL32 => write!(f, "dsll32"), + Opcode::DSRL32 => write!(f, "dsrl32"), + Opcode::DSRA32 => write!(f, "dsra32"), + Opcode::BLTZ => write!(f, "bltz"), + Opcode::BGEZ => write!(f, "bgez"), + Opcode::BLTZL => write!(f, "bltzl"), + Opcode::BGEZL => write!(f, "bgezl"), + Opcode::TGEI => write!(f, "tgei"), + Opcode::TGEIU => write!(f, "tgeiu"), + Opcode::TLTI => write!(f, "tlti"), + Opcode::TLTIU => write!(f, "tltiu"), + Opcode::TEQI => write!(f, "teqi"), + Opcode::TNEI => write!(f, "tnei"), + Opcode::BLTZAL => write!(f, "bltzal"), + Opcode::BGEZAL => write!(f, "bgezal"), + Opcode::BLTZALL => write!(f, "bltzall"), + Opcode::BGEZALL => write!(f, "bgezall"), + } + } +} -- cgit v1.1