diff options
| -rw-r--r-- | library/core/src/num/nonzero.rs | 22 | ||||
| -rw-r--r-- | tests/codegen/issues/issue-119422.rs | 83 |
2 files changed, 101 insertions, 4 deletions
diff --git a/library/core/src/num/nonzero.rs b/library/core/src/num/nonzero.rs index f5ecf501ce9..2df38ab5848 100644 --- a/library/core/src/num/nonzero.rs +++ b/library/core/src/num/nonzero.rs @@ -104,6 +104,18 @@ macro_rules! nonzero_integers { #[inline] #[rustc_const_stable(feature = "const_nonzero_get", since = "1.34.0")] pub const fn get(self) -> $Int { + // FIXME: Remove this after LLVM supports `!range` metadata for function + // arguments https://github.com/llvm/llvm-project/issues/76628 + // + // Rustc can set range metadata only if it loads `self` from + // memory somewhere. If the value of `self` was from by-value argument + // of some not-inlined function, LLVM don't have range metadata + // to understand that the value cannot be zero. + + // SAFETY: It is an invariant of this type. + unsafe { + intrinsics::assume(self.0 != 0); + } self.0 } @@ -114,7 +126,9 @@ macro_rules! nonzero_integers { #[doc = concat!("Converts a `", stringify!($Ty), "` into an `", stringify!($Int), "`")] #[inline] fn from(nonzero: $Ty) -> Self { - nonzero.0 + // Call nonzero to keep information range information + // from get method. + nonzero.get() } } @@ -233,7 +247,7 @@ macro_rules! nonzero_leading_trailing_zeros { #[inline] pub const fn leading_zeros(self) -> u32 { // SAFETY: since `self` cannot be zero, it is safe to call `ctlz_nonzero`. - unsafe { intrinsics::ctlz_nonzero(self.0 as $Uint) as u32 } + unsafe { intrinsics::ctlz_nonzero(self.get() as $Uint) as u32 } } /// Returns the number of trailing zeros in the binary representation @@ -257,7 +271,7 @@ macro_rules! nonzero_leading_trailing_zeros { #[inline] pub const fn trailing_zeros(self) -> u32 { // SAFETY: since `self` cannot be zero, it is safe to call `cttz_nonzero`. - unsafe { intrinsics::cttz_nonzero(self.0 as $Uint) as u32 } + unsafe { intrinsics::cttz_nonzero(self.get() as $Uint) as u32 } } } @@ -515,7 +529,7 @@ macro_rules! nonzero_unsigned_operations { without modifying the original"] #[inline] pub const fn ilog10(self) -> u32 { - super::int_log10::$Int(self.0) + super::int_log10::$Int(self.get()) } /// Calculates the middle point of `self` and `rhs`. diff --git a/tests/codegen/issues/issue-119422.rs b/tests/codegen/issues/issue-119422.rs new file mode 100644 index 00000000000..9c99d96317d --- /dev/null +++ b/tests/codegen/issues/issue-119422.rs @@ -0,0 +1,83 @@ +//! This test checks that compiler don't generate useless compares to zeros +//! for NonZero integer types. + +// compile-flags: -O --edition=2021 -Zmerge-functions=disabled +// only-64bit (because the LLVM type of i64 for usize shows up) + +#![crate_type = "lib"] + +use core::num::*; +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: NonZeroU8) -> 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: NonZeroU8) -> 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: NonZeroI8) -> 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: NonZeroI8) -> 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: NonZeroU32) -> NonZeroUsize { + // 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: NonZeroI32) -> NonZeroIsize { + // 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: NonZeroU64)->bool { + // CHECK-NOT: br + // CHECK: ret i1 false + // CHECK-NOT: br + let v: u64 = x.into(); + v == 0 +} |