MIPS Instructions for the Tiger Compiler
Here is a collection of MIPS Instructions that should suffice
for implementing the Tiger intermediate codes. Most of these instructions
are pseudo-ops that are expanded by the MIPS assembler (and SPIM) into
appropriate machine instructions.
If you are interested in some fancier instructions, or want to optimize your
code at a more detailed level, please refer to the MIPS instruction
reference in the SPIM manual (Section 2).
Notation:
Source registers or values are designated by the prefix Src,
while destination registers are designated by the prefix Dest.
The modifiers are
| Gpr | General purpose register
|
| Imm | Immediate value or constant, 32 bit signed
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| Imm2 | Immediate value or constant, power of 2
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| Imm16 | Immediate value or constant, 16 bit signed
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| Label | Label in code (.text) or data (.data) section
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Thus "Src{Gpr | Imm}" indicates a source value that can be the
contents of a general purpose register ("Gpr") or a constant
"Imm". In our case, the destination (e.g. of a load, move,
or arithmetic operation) is always going to be a register. Sources
of the form "Imm(Gpr)" designate an address offset by Imm from the
contents of Gpr (i.e. Gpr + Imm).
1. Arithmetic Instructions
ADD -- Addition
| Syntax: | add DestGpr, Src1Gpr, Src2{Gpr | Imm}
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| Description: | Dest = Src1 + Src2
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SUB -- Substract
| Syntax: | sub DestGpr, Src1Gpr, Src2{Gpr | Imm}
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| Description: | Dest = Src1 - Src2
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MULT -- Multiplication
| Syntax: | mult DestGpr, Src1Gpr, Src2{Gpr | Imm}
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| Description: | Dest = Src1 * Src2
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DIV -- Division
| Syntax: | div DestGpr, Src1Gpr, Src2{Gpr | Imm}
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| Description: | Dest = Src1 / Src2
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2. Logical Instructions
AND-- Logical AND
| Syntax: | and DestGpr, Src1Gpr, Src2{Gpr | Imm}
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| Description: | Dest = Src1 AND Src2
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OR -- Logical OR
| Syntax: | or DestGpr, Src1Gpr, Src2{Gpr | Imm}
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| Description: | Dest = Src1 OR Src2
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XOR -- Bitwise Exclusive OR
| Syntax: | xor DestGpr, Src1Gpr, Src2{Gpr | Imm}
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| Description: | Dest = Src1 XOR Src2
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3. Shift Instructions
SLL -- Shift Left Logical
| Syntax: | sll DestGpr, Src1Gpr, Src2{Gpr | Imm}
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| Description: | Dest = Src1 << Scr2
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SRL -- Shift Right Logical
| Syntax: | srl DestGpr, Src1Gpr, Src2{Gpr | Imm}
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| Description: | Dest = Src1 >> Src2 (zero fill)
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SRA -- Shift Right Arithmetic
| Syntax: | sra DestGpr, Src1Gpr, Src2{Gpr | Imm}
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| Description: | Dest = Src1 >> Src2 (sign bit fill)
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4. Branch Instructions
BEQ -- Branch on Equal
| Syntax: | beq Src1Gpr, Src2{Gpr | Imm}, Label
|
| Description: | Branch if Src1 = Src2
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BNE -- Branch on Not equal
| Syntax: | bne Src1Gpr, Src2{Gpr | Imm}, Label
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| Description: | Branches if Src1 != Src2
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BGT -- Branch on Greater Than
| Syntax: | bgt Src1Gpr, Src2{Gpr | Imm}, Label
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| Description: | Branches if Src1 > Src2
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BGTU -- Branch on Greater Than (Unsigned)
| Syntax: | bgtu Src1Gpr, Src2{Gpr | Imm}, Label
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| Description: | Branches if Src1 > Src2 (unsigned)
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BGE -- Branch on Greater Than or Equal
| Syntax: | bge Src1Gpr, Src2{Gpr | Imm}, Label
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| Description: | Branches if Src1 >= Src2
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BGEU -- Branch on Greater Than or Equal (Unsigned)
| Syntax: | bgeu Src1Gpr, Src2{Gpr | Imm}, Label
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| Description: | Branches if Src1 >= Src2 (unsigned)
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BLT -- Branch on Less Than
| Syntax: | blt Src1Gpr, Src2{Gpr | Imm}, Label
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| Description: | Branches if Src1 < Src2
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BLTU -- Branch on Less Than (Unsigned)
| Syntax: | bltu Src1Gpr, Src2{Gpr | Imm}, Label
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| Description: | Branches if Src1 < Src2 (unsigned)
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BLE -- Branch on Less Than or Equal
| Syntax: | ble Src1Gpr, Src2{Gpr | Imm}, Label
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| Description: | Branches if Src1 <= Src2
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BLEU -- Branch on Less Than or Equal (Unsigned)
| Syntax: | bleu Src1Gpr, Src2{Gpr | Imm}, Label
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| Description: | Branches if Src1 <= Src2 (unsigned)
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5. Jump Instructions
J -- Jump
| Syntax: | j Src{Gpr | Imm2 | Imm16 | Label}
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| Description: | Unconditionally jump to Src
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JAL -- Jump and Link
| Syntax: | jal Src{Gpr | Imm2 | Imm16 | Label}
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| Description: | Unconditionally jump to Src. Save the
addressof the next
instruction in register $ra. Used for function calls.
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6. Load/Store Instructions
LW -- Load Word
| Syntax: | lw DestGpr, Src{Imm | Imm(Gpr) | Label}
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| Description: | Load word at address Src into Dest
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LI -- Load Immediate
| Syntax: | li DestGpr, SrcImm
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| Description: | Load constant Src into Dest
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LA -- Load Address
| Syntax: | la DestGpr, Src{Imm | Imm(Gpr) | Label}
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| Description: | Load address Src into Dest
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SW -- Store Word
| Syntax: | sw SrcGpr, Dest{Imm | Imm(Gpr) | Label}
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| Description: | Store word in Src at address Dest
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7. Constant and Data Moving
MOVE -- Move Register
| Syntax: | move DestGpr, SrcGpr
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| Description: | Move contents of register Src to Dest
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MIPS Register Convention
| $zero | constant zero
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| $at | compiler temporary register
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| $v0 ~ $v1 | used to return values
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| $a0 ~ $a3 | used to pass parameters
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| $t0 ~ $t7 | volatile registers (caller saves)
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| $s0 ~ $s6 | non-volatile registers (callee saves)
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| $t8 ~ $t9 | more volatile registers
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| $gp | global pointer
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| $sp | stack pointer
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| $fp | frame pointer
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| $ra | used to store return address
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| Hi, Lo | used to store results of Multiplication and Division
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