|  | //! This test checks that compiler don't generate useless compares to zeros | 
|  | //! for `NonZero` integer types. | 
|  | //! | 
|  | //@ compile-flags: -Copt-level=3 -Zmerge-functions=disabled | 
|  | //@ edition: 2021 | 
|  | //@ only-64bit (because the LLVM type of i64 for usize shows up) | 
|  | #![crate_type = "lib"] | 
|  |  | 
|  | use core::num::NonZero; | 
|  | use core::ptr::NonNull; | 
|  |  | 
|  | // CHECK-LABEL: @check_non_null | 
|  | #[no_mangle] | 
|  | pub fn check_non_null(x: NonNull<u8>) -> bool { | 
|  | // CHECK: ret i1 false | 
|  | x.as_ptr().is_null() | 
|  | } | 
|  |  | 
|  | // CHECK-LABEL: @equals_zero_is_false_u8 | 
|  | #[no_mangle] | 
|  | pub fn equals_zero_is_false_u8(x: NonZero<u8>) -> bool { | 
|  | // CHECK-NOT: br | 
|  | // CHECK: ret i1 false | 
|  | // CHECK-NOT: br | 
|  | x.get() == 0 | 
|  | } | 
|  |  | 
|  | // CHECK-LABEL: @not_equals_zero_is_true_u8 | 
|  | #[no_mangle] | 
|  | pub fn not_equals_zero_is_true_u8(x: NonZero<u8>) -> bool { | 
|  | // CHECK-NOT: br | 
|  | // CHECK: ret i1 true | 
|  | // CHECK-NOT: br | 
|  | x.get() != 0 | 
|  | } | 
|  |  | 
|  | // CHECK-LABEL: @equals_zero_is_false_i8 | 
|  | #[no_mangle] | 
|  | pub fn equals_zero_is_false_i8(x: NonZero<i8>) -> bool { | 
|  | // CHECK-NOT: br | 
|  | // CHECK: ret i1 false | 
|  | // CHECK-NOT: br | 
|  | x.get() == 0 | 
|  | } | 
|  |  | 
|  | // CHECK-LABEL: @not_equals_zero_is_true_i8 | 
|  | #[no_mangle] | 
|  | pub fn not_equals_zero_is_true_i8(x: NonZero<i8>) -> bool { | 
|  | // CHECK-NOT: br | 
|  | // CHECK: ret i1 true | 
|  | // CHECK-NOT: br | 
|  | x.get() != 0 | 
|  | } | 
|  |  | 
|  | // CHECK-LABEL: @usize_try_from_u32 | 
|  | #[no_mangle] | 
|  | pub fn usize_try_from_u32(x: NonZero<u32>) -> NonZero<usize> { | 
|  | // CHECK-NOT: br | 
|  | // CHECK: zext i32 %{{.*}} to i64 | 
|  | // CHECK-NOT: br | 
|  | // CHECK: ret i64 | 
|  | x.try_into().unwrap() | 
|  | } | 
|  |  | 
|  | // CHECK-LABEL: @isize_try_from_i32 | 
|  | #[no_mangle] | 
|  | pub fn isize_try_from_i32(x: NonZero<i32>) -> NonZero<isize> { | 
|  | // CHECK-NOT: br | 
|  | // CHECK: sext i32 %{{.*}} to i64 | 
|  | // CHECK-NOT: br | 
|  | // CHECK: ret i64 | 
|  | x.try_into().unwrap() | 
|  | } | 
|  |  | 
|  | // CHECK-LABEL: @u64_from_nonzero_is_not_zero | 
|  | #[no_mangle] | 
|  | pub fn u64_from_nonzero_is_not_zero(x: NonZero<u64>) -> bool { | 
|  | // CHECK-NOT: br | 
|  | // CHECK: ret i1 false | 
|  | // CHECK-NOT: br | 
|  | let v: u64 = x.into(); | 
|  | v == 0 | 
|  | } |