Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

miri: helper methods for max values of machine's usize/isize #66410

Merged
merged 1 commit into from
Nov 15, 2019
Merged

miri: helper methods for max values of machine's usize/isize #66410

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
13 changes: 13 additions & 0 deletions src/librustc/mir/interpret/pointer.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,4 +1,5 @@
use std::fmt::{self, Display};
use std::convert::TryFrom;

use crate::mir;
use crate::ty::layout::{self, HasDataLayout, Size};
Expand Down Expand Up @@ -40,6 +41,18 @@ pub trait PointerArithmetic: layout::HasDataLayout {
self.data_layout().pointer_size
}

#[inline]
fn usize_max(&self) -> u64 {
let max_usize_plus_1 = 1u128 << self.pointer_size().bits();
u64::try_from(max_usize_plus_1-1).unwrap()
}

#[inline]
fn isize_max(&self) -> i64 {
let max_isize_plus_1 = 1u128 << (self.pointer_size().bits()-1);
i64::try_from(max_isize_plus_1-1).unwrap()
}

/// Helper function: truncate given value-"overflowed flag" pair to pointer size and
/// update "overflowed flag" if there was an overflow.
/// This should be called by all the other methods before returning!
Expand Down