The abs instructions, short for absolute, are used to get the absolute value of a number. That is, it returns x if x is positive, and the negation of x if x is negative.

Try it


;; load a number onto the stack
f32.const -2

;; absolute

;; the top item on the stack will now be 2
Instruction Binary opcode
f32.abs 0x8b
f64.abs 0x99