tree borrows editing

[web.git] / personal / _posts / 2018-07-24-pointers-and-bytes.md

diff --git a/personal/_posts/2018-07-24-pointers-and-bytes.md b/personal/_posts/2018-07-24-pointers-and-bytes.md
index f3c9133d73f134f09caa3206e0910672cf142865..6accd7dd68449b6e871ba4f3c9ac47ed2b34cafe 100644 (file)
--- a/personal/_posts/2018-07-24-pointers-and-bytes.md
+++ b/personal/_posts/2018-07-24-pointers-and-bytes.md
@@ -1,6 +1,6 @@
 ---
 title: "Pointers Are Complicated, or: What's in a Byte?"
 ---
 title: "Pointers Are Complicated, or: What's in a Byte?"

-categories: internship rust
+categories: internship rust programming

 forum: https://internals.rust-lang.org/t/pointers-are-complicated-or-whats-in-a-byte/8045
 ---
 
 forum: https://internals.rust-lang.org/t/pointers-are-complicated-or-whats-in-a-byte/8045
 ---
 


@@ -35,7 +35,7 @@ It would be beneficial to be able to optimize the final read of `y[0]` to just r
 C++ compilers regularly perform such optimizations as they are crucial for generating high-quality assembly.[^perf]
 The justification for this optimization is that writing to `x_ptr`, which points into `x`, cannot change `y`.
 
 C++ compilers regularly perform such optimizations as they are crucial for generating high-quality assembly.[^perf]
 The justification for this optimization is that writing to `x_ptr`, which points into `x`, cannot change `y`.
 

-[^perf]: To be fair, the are *claimed* to be crucial for generating high-quality assembly. The claim sounds plausible to me, but unfortunately, I do not know of a systematic study exploring the performance benefits of undefined behavior such as this.
+[^perf]: To be fair, the are *claimed* to be crucial for generating high-quality assembly. The claim sounds plausible to me, but unfortunately, I do not know of a systematic study exploring the performance benefits of such optimizations.

 
 However, given how low-level a language C++ is, we can actually break this assumption by setting `i` to `y-x`.
 Since `&x[i]` is the same as `x+i`, this means we are actually writing `23` to `&y[0]`.
 
 However, given how low-level a language C++ is, we can actually break this assumption by setting `i` to `y-x`.
 Since `&x[i]` is the same as `x+i`, this means we are actually writing `23` to `&y[0]`.