8.3. Integer

An integer is a signed 32-bit value. An integer can be represented by an i32 in MLIR.

8.3.1. Declaration

An integer value is declared with the keyword integer. If the variable is not initialized explicitly, it is set to 0 (its zero value).

8.3.2. Literals

An integer literal is specified in base 10. For example:

1234
2
0

An integer literal must be a representable i32 value; the compiler must emit a LiteralError (see Errors) otherwise.

8.3.3. Operations

The following operations are defined between integer values. In all of the usage examples int-expr means some integer yielding expression.

Class	Operation	Symbol	Usage
Grouping	parentheses	()	(int-expr)
Arithmetic	addition	+	int-expr + int-expr
	subtraction	-	int-expr - int-expr
	multiplication	*	int-expr * int-expr
	division	/	int-expr / int-expr
	remainder	%	int-expr % int-expr
	exponentiation	^	int-expr ^ int-expr
	unary negation	-	- int-expr
	unary plus (no-op)	+	+ int-expr
Comparison	less than	<	int-expr < int-expr
	greater than	>	int-expr > int-expr
	less than or equal to	<=	int-expr <= int-expr
	greater than or equal to	>=	int-expr >= int-expr
	equals	==	int-expr == int-expr
	not equals	!=	int-expr != int-expr

Unary negation produces the additive inverse of the integer expression. Unary plus always produces the same result as the integer expression it is applied to. Remainder mirrors the behavior of remainder in C99, and division / truncates toward zero (also as in C99), so (a / b) * b + a % b == a.

Exponentiation between integers gives an integer result, computed exactly by integer multiplication rather than by converting to real: for a non-negative exponent it is the exact integer power (so 3 ^ 16 == 43046721, converting this to a floating point power operation will yield an incorrect result), and for a negative exponent it is b ^ e truncated toward zero (0 whenever |b| > 1). A result outside the i32 range raises a MathError as for any other overflowing integer arithmetic (see below).

Signed 32-bit arithmetic that overflows the i32 range (+, -, *, /, ^, and unary -) causes the implementation to raise a MathError (see Errors) at compile time or run time. This includes INT_MIN / -1 and -INT_MIN, whose mathematical results are not representable as an i32, and INT_MIN % -1, which is a MathError too: although its mathematical result 0 is representable, evaluating the remainder overflows because it requires the same out-of-range quotient INT_MIN / -1. Division and remainder (%) where the right operand is 0, and exponentiation where the base is 0 and the exponent is <= 0, cause the implementation to raise a MathError (see Errors) at compile time or run time.

Operator precedence and associativity are specified once, for all types, in the table of operator precedence.

8.3.4. Type Casting and Implicit Casts

To see the types that integer may be cast and/or implicitly cast to, see the sections on Type Casting and Implicit Casts respectively.