So I have this LLVM-IR code:

; ModuleID = 'example.-.input.c'
source_filename = "example.-.input.c"

define ptr @test() {
entry:
  %0 = alloca ptr, align 8
  %1 = alloca i32, align 4
  store i32 2, ptr %1, align 4
  store ptr %1, ptr %0, align 8
  br label %ret

ret:                                              ; preds = %entry
  %2 = load ptr, ptr %0, align 8
  ret ptr %2
}

define i32 @main() {
entry:
  %0 = alloca i32, align 4
  store i32 0, ptr %0, align 4
  %1 = call ptr @test()
  %2 = load i32, ptr %1, align 4
  store i32 %2, ptr %0, align 4
  br label %ret

ret:                                              ; preds = %entry
  %3 = load i32, ptr %0, align 4
  ret i32 %3
}

test returns a pointer to the local variable %1, a integer with the value of 2.
main calls test and extracts the integer from the pointer returned by test. But somehow main returns the “expected” value of 2 (%2 of main: pointed to %0 of test). But why? Shouldn’t the local variable %0 be destroyed at the end of test and the pointer returnd by test then invalid?