Pops a f32 value off the stack, converts it into an i32 value, and then pushes it back on to the stack. This looks at the i32 value as a signed integer (can be negative). Any decimal parts of the number will be lost. The value must exist within the range -2147483648 to +2147483647 (2^31). If the value is outside this range then a runtime error will be thrown.

i32.trunc_f32_s

;; Convert f32 1234.567 into an i32 value
f32.const 1234.567
i32.trunc_f32_s

;; The stack contains an i32 value of 1234

;; Convert f32 -3.142 into an i32 value
f32.const -3.142
i32.trunc_f32_s

;; The stack contains an i32 value of -3

;; Convert f32 2200000000 into an i32 value
f32.const 2200000000
i32.trunc_f32_s

;; This is out of range and will throw a runtime error