Opcodes

This table is generated from the engine’s opcode table by scripts/Generate-OpcodeReference.cs. The stack column reads pops then pushes, using the abbreviations ILAsm uses: i for int32 or native int, i8 for int64, r4 and r8 for floats, ref for an object reference, 1 for any single value, and … when the count depends on the operand.

Opcode	Stack	Operand	Description
`add`	`1 1 → 1`	none	add
`add.ovf`	`1 1 → 1`	none	add (overflow check)
`add.ovf.un`	`1 1 → 1`	none	add unsigned (overflow check)
`and`	`1 1 → 1`	none	bitwise and
`arglist`	`→ i`	none	push argument list handle (vararg cells)
`beq`	`1 1 →`	label	branch if equal
`beq.s`	`1 1 →`	label	branch if equal
`bge`	`1 1 →`	label	branch if >=
`bge.s`	`1 1 →`	label	branch if >=
`bge.un`	`1 1 →`	label	branch if >= (unsigned or unordered)
`bge.un.s`	`1 1 →`	label	branch if >= (unsigned or unordered)
`bgt`	`1 1 →`	label	branch if >
`bgt.s`	`1 1 →`	label	branch if >
`bgt.un`	`1 1 →`	label	branch if > (unsigned or unordered)
`bgt.un.s`	`1 1 →`	label	branch if > (unsigned or unordered)
`ble`	`1 1 →`	label	branch if <=
`ble.s`	`1 1 →`	label	branch if <=
`ble.un`	`1 1 →`	label	branch if <= (unsigned or unordered)
`ble.un.s`	`1 1 →`	label	branch if <= (unsigned or unordered)
`blt`	`1 1 →`	label	branch if <
`blt.s`	`1 1 →`	label	branch if <
`blt.un`	`1 1 →`	label	branch if < (unsigned or unordered)
`blt.un.s`	`1 1 →`	label	branch if < (unsigned or unordered)
`bne.un`	`1 1 →`	label	branch if != (unordered)
`bne.un.s`	`1 1 →`	label	branch if != (unordered)
`box`	`1 → ref`	type	box value type
`br`	`→`	label	branch
`br.s`	`→`	label	branch (short)
`break`	`→`	none	breakpoint trap
`brfalse`	`i →`	label	branch if false, null, or zero
`brfalse.s`	`i →`	label	branch if false, null, or zero
`brtrue`	`i →`	label	branch if true or non-null
`brtrue.s`	`i →`	label	branch if true or non-null
`call`	`… → …`	method	call method
`calli`	`… → …`	signature	call through function pointer
`callvirt`	`… → …`	method	call virtual method on object
`castclass`	`ref → ref`	type	cast (throws on failure)
`ceq`	`1 1 → i`	none	compare equal, push int32
`cgt`	`1 1 → i`	none	compare greater, push int32
`cgt.un`	`1 1 → i`	none	compare greater (unsigned or unordered), push int32
`ckfinite`	`1 → r8`	none	throw if NaN or infinity
`clt`	`1 1 → i`	none	compare less, push int32
`clt.un`	`1 1 → i`	none	compare less (unsigned or unordered), push int32
`constrained.`	`→`	type	prefix: constrained callvirt
`conv.i`	`1 → i`	none	convert to native int
`conv.i1`	`1 → i`	none	convert to int8
`conv.i2`	`1 → i`	none	convert to int16
`conv.i4`	`1 → i`	none	convert to int32
`conv.i8`	`1 → i8`	none	convert to int64
`conv.ovf.i`	`1 → i`	none	convert to native int (overflow check)
`conv.ovf.i.un`	`1 → i`	none	convert to native int (unsigned source, overflow check)
`conv.ovf.i1`	`1 → i`	none	convert to int8 (overflow check)
`conv.ovf.i1.un`	`1 → i`	none	convert to int8 (unsigned source, overflow check)
`conv.ovf.i2`	`1 → i`	none	convert to int16 (overflow check)
`conv.ovf.i2.un`	`1 → i`	none	convert to int16 (unsigned source, overflow check)
`conv.ovf.i4`	`1 → i`	none	convert to int32 (overflow check)
`conv.ovf.i4.un`	`1 → i`	none	convert to int32 (unsigned source, overflow check)
`conv.ovf.i8`	`1 → i8`	none	convert to int64 (overflow check)
`conv.ovf.i8.un`	`1 → i8`	none	convert to int64 (unsigned source, overflow check)
`conv.ovf.u`	`1 → i`	none	convert to native uint (overflow check)
`conv.ovf.u.un`	`1 → i`	none	convert to native uint (unsigned source, overflow check)
`conv.ovf.u1`	`1 → i`	none	convert to uint8 (overflow check)
`conv.ovf.u1.un`	`1 → i`	none	convert to uint8 (unsigned source, overflow check)
`conv.ovf.u2`	`1 → i`	none	convert to uint16 (overflow check)
`conv.ovf.u2.un`	`1 → i`	none	convert to uint16 (unsigned source, overflow check)
`conv.ovf.u4`	`1 → i`	none	convert to uint32 (overflow check)
`conv.ovf.u4.un`	`1 → i`	none	convert to uint32 (unsigned source, overflow check)
`conv.ovf.u8`	`1 → i8`	none	convert to uint64 (overflow check)
`conv.ovf.u8.un`	`1 → i8`	none	convert to uint64 (unsigned source, overflow check)
`conv.r.un`	`1 → r8`	none	convert unsigned integer to float
`conv.r4`	`1 → r4`	none	convert to float32
`conv.r8`	`1 → r8`	none	convert to float64
`conv.u`	`1 → i`	none	convert to native uint
`conv.u1`	`1 → i`	none	convert to uint8
`conv.u2`	`1 → i`	none	convert to uint16
`conv.u4`	`1 → i`	none	convert to uint32
`conv.u8`	`1 → i8`	none	convert to uint64
`cpblk`	`i i i →`	none	copy memory block
`cpobj`	`i i →`	type	copy value type
`div`	`1 1 → 1`	none	divide
`div.un`	`1 1 → 1`	none	divide unsigned
`dup`	`1 → 1 1`	none	duplicate top of stack
`endfilter`	`i →`	none	end exception filter
`endfinally`	`→`	none	end finally or fault handler
`initblk`	`i i i →`	none	fill memory block
`initobj`	`i →`	type	zero-initialize value type at address
`isinst`	`ref → i`	type	type test (null when it fails)
`jmp`	`→`	method	jump to method (tail transfer)
`ldarg`	`→ 1`	local or argument	push argument
`ldarg.0`	`→ 1`	none	push argument 0
`ldarg.1`	`→ 1`	none	push argument 1
`ldarg.2`	`→ 1`	none	push argument 2
`ldarg.3`	`→ 1`	none	push argument 3
`ldarg.s`	`→ 1`	local or argument	push argument (byte index)
`ldarga`	`→ i`	local or argument	push argument address
`ldarga.s`	`→ i`	local or argument	push address of argument
`ldc.i4`	`→ i`	int32	push int32 immediate
`ldc.i4.0`	`→ i`	none	push int32 0
`ldc.i4.1`	`→ i`	none	push int32 1
`ldc.i4.2`	`→ i`	none	push int32 2
`ldc.i4.3`	`→ i`	none	push int32 3
`ldc.i4.4`	`→ i`	none	push int32 4
`ldc.i4.5`	`→ i`	none	push int32 5
`ldc.i4.6`	`→ i`	none	push int32 6
`ldc.i4.7`	`→ i`	none	push int32 7
`ldc.i4.8`	`→ i`	none	push int32 8
`ldc.i4.m1`	`→ i`	none	push int32 -1
`ldc.i4.s`	`→ i`	int8	push int32 (int8 immediate)
`ldc.i8`	`→ i8`	int64	push int64 immediate
`ldc.r4`	`→ r4`	float32	push float32 immediate
`ldc.r8`	`→ r8`	float64	push float64 immediate
`ldelem`	`ref i → 1`	type	load element of type
`ldelem.i`	`ref i → i`	none	load native int element
`ldelem.i1`	`ref i → i`	none	load int8 element
`ldelem.i2`	`ref i → i`	none	load int16 element
`ldelem.i4`	`ref i → i`	none	load int32 element
`ldelem.i8`	`ref i → i8`	none	load int64 element
`ldelem.r4`	`ref i → r4`	none	load float32 element
`ldelem.r8`	`ref i → r8`	none	load float64 element
`ldelem.ref`	`ref i → ref`	none	load object element
`ldelem.u1`	`ref i → i`	none	load uint8 element
`ldelem.u2`	`ref i → i`	none	load uint16 element
`ldelem.u4`	`ref i → i`	none	load uint32 element
`ldelema`	`ref i → i`	type	push element address
`ldfld`	`ref → 1`	field	load instance field
`ldflda`	`ref → i`	field	load instance field address
`ldftn`	`→ i`	method	push method pointer
`ldind.i`	`i → i`	none	load native int through pointer
`ldind.i1`	`i → i`	none	load int8 through pointer
`ldind.i2`	`i → i`	none	load int16 through pointer
`ldind.i4`	`i → i`	none	load int32 through pointer
`ldind.i8`	`i → i8`	none	load int64 through pointer
`ldind.r4`	`i → r4`	none	load float32 through pointer
`ldind.r8`	`i → r8`	none	load float64 through pointer
`ldind.ref`	`i → ref`	none	load object reference through pointer
`ldind.u1`	`i → i`	none	load uint8 through pointer
`ldind.u2`	`i → i`	none	load uint16 through pointer
`ldind.u4`	`i → i`	none	load uint32 through pointer
`ldlen`	`ref → i`	none	push array length
`ldloc`	`→ 1`	local or argument	push local
`ldloc.0`	`→ 1`	none	push local 0
`ldloc.1`	`→ 1`	none	push local 1
`ldloc.2`	`→ 1`	none	push local 2
`ldloc.3`	`→ 1`	none	push local 3
`ldloc.s`	`→ 1`	local or argument	push local (byte index)
`ldloca`	`→ i`	local or argument	push local address
`ldloca.s`	`→ i`	local or argument	push address of local
`ldnull`	`→ ref`	none	push null reference
`ldobj`	`i → 1`	type	load value type through pointer
`ldsfld`	`→ 1`	field	load static field
`ldsflda`	`→ i`	field	load static field address
`ldstr`	`→ ref`	string	push string literal
`ldtoken`	`→ i`	token	push runtime handle
`ldvirtftn`	`ref → i`	method	push virtual method pointer
`leave`	`→`	label	exit protected region
`leave.s`	`→`	label	exit protected region (short)
`localloc`	`i → i`	none	allocate stack memory
`mkrefany`	`i → 1`	type	make typed reference
`mul`	`1 1 → 1`	none	multiply
`mul.ovf`	`1 1 → 1`	none	multiply (overflow check)
`mul.ovf.un`	`1 1 → 1`	none	multiply unsigned (overflow check)
`neg`	`1 → 1`	none	negate
`newarr`	`i → ref`	type	allocate array
`newobj`	`… → ref`	method	allocate object and call constructor
`nop`	`→`	none	do nothing
`not`	`1 → 1`	none	bitwise complement
`or`	`1 1 → 1`	none	bitwise or
`pop`	`1 →`	none	discard top of stack
`readonly.`	`→`	none	prefix: readonly ldelema
`refanytype`	`1 → i`	none	typed reference to type handle
`refanyval`	`1 → i`	type	typed reference to address
`rem`	`1 1 → 1`	none	remainder
`rem.un`	`1 1 → 1`	none	remainder unsigned
`ret`	`… →`	none	return
`rethrow`	`→`	none	rethrow current exception
`shl`	`1 1 → 1`	none	shift left
`shr`	`1 1 → 1`	none	shift right (arithmetic)
`shr.un`	`1 1 → 1`	none	shift right (logical)
`sizeof`	`→ i`	type	push size of type
`starg`	`1 →`	local or argument	pop into argument
`starg.s`	`1 →`	local or argument	pop into argument
`stelem`	`ref i 1 →`	type	store element of type
`stelem.i`	`ref i i →`	none	store native int element
`stelem.i1`	`ref i i →`	none	store int8 element
`stelem.i2`	`ref i i →`	none	store int16 element
`stelem.i4`	`ref i i →`	none	store int32 element
`stelem.i8`	`ref i i8 →`	none	store int64 element
`stelem.r4`	`ref i r4 →`	none	store float32 element
`stelem.r8`	`ref i r8 →`	none	store float64 element
`stelem.ref`	`ref i ref →`	none	store object element
`stfld`	`ref 1 →`	field	store instance field
`stind.i`	`i i →`	none	store native int through pointer
`stind.i1`	`i i →`	none	store int8 through pointer
`stind.i2`	`i i →`	none	store int16 through pointer
`stind.i4`	`i i →`	none	store int32 through pointer
`stind.i8`	`i i8 →`	none	store int64 through pointer
`stind.r4`	`i r4 →`	none	store float32 through pointer
`stind.r8`	`i r8 →`	none	store float64 through pointer
`stind.ref`	`i i →`	none	store object reference through pointer
`stloc`	`1 →`	local or argument	pop into local
`stloc.0`	`1 →`	none	pop into local 0
`stloc.1`	`1 →`	none	pop into local 1
`stloc.2`	`1 →`	none	pop into local 2
`stloc.3`	`1 →`	none	pop into local 3
`stloc.s`	`1 →`	local or argument	pop into local
`stobj`	`i 1 →`	type	store value type through pointer
`stsfld`	`1 →`	field	store static field
`sub`	`1 1 → 1`	none	subtract
`sub.ovf`	`1 1 → 1`	none	subtract (overflow check)
`sub.ovf.un`	`1 1 → 1`	none	subtract unsigned (overflow check)
`switch`	`i →`	labels	jump table on int32
`tail.`	`→`	none	prefix: tail call
`throw`	`ref →`	none	throw exception
`unaligned.`	`→`	int8	prefix: unaligned access
`unbox`	`ref → i`	type	unbox to value type address
`unbox.any`	`ref → 1`	type	unbox, or castclass for reference types
`volatile.`	`→`	none	prefix: volatile access
`xor`	`1 1 → 1`	none	bitwise xor

218 opcodes. calli takes a signature, switch takes a label list, and the prefixes constrained., unaligned., volatile., tail., and readonly. apply to the next instruction.