X-Git-Url: https://git.ralfj.de/web.git/blobdiff_plain/b76918f23bf348b4ed3cf42a80db9c1caf6ffca3..960222ebaeb2cd974bc00bb50e9b1e7a633bfe1a:/personal/_drafts/provenance-matters.md?ds=inline

diff --git a/personal/_drafts/provenance-matters.md b/personal/_drafts/provenance-matters.md
index ceb1be5..959aadd 100644
--- a/personal/_drafts/provenance-matters.md
+++ b/personal/_drafts/provenance-matters.md
@@ -15,10 +15,10 @@ There is also a larger message here about how we could prevent such issues from
 <!-- MORE -->
 
 I will show a series of three compiler transformations that each seem "intuitively justified", but when taken together they lead to a clearly incorrect result.
-We will use LLVM for these examples, but the goal is not to pick on LLVM---other compilers suffer from similar issues.
+I will use LLVM for these examples, but the goal is not to pick on LLVM---other compilers suffer from similar issues.
 The goal is to convince you that to build a correct compiler for languages permitting unsafe pointer manipulation such as C, C++, or Rust,
 we need to take IR semantics (and specifically provenance) more seriously.
-We use LLVM for the examples because it is particularly easy to study with its single, (comparatively) well-documented IR that a lot of infrastructure evolved around.
+I use LLVM for the examples because it is particularly easy to study with its single, (comparatively) well-documented IR that a lot of infrastructure evolved around.
 Let's get started!
 
 ## Warm-up: Why IRs need a precise semantics
@@ -112,7 +112,7 @@ if (iq == ip) {
   print(q[0]);
 }
 {% endhighlight %}
-We are using C syntax here just as a convenient way to write programs in LLVM IR.
+I am using C syntax here just as a convenient way to write programs in LLVM IR.
 For simplicity, we assume that `int` has the right size to hold a pointer value; just imagine we used `uintptr_t` if you want to be more general.
 
 This program has two possible behaviors: either `ip` (the address one-past-the-end of `p`) and `iq` (the address of `q`) are different, and nothing is printed.
@@ -167,7 +167,7 @@ That's why the LLVM LangRef will not give us a clear answer here, and indeed obt
 
 To proceed, we will use the three optimizations that we considered above as cues: assuming that the optimization is correct for LLVM IR, what does that tell us about the semantics?
 
-We start with the last optimization, where the `print` argument is changed from `q[0]` to `0`.
+Let us start with the last optimization, where the `print` argument is changed from `q[0]` to `0`.
 This optimization is based on alias analysis:
 `q[0]` gets initialized to `0` at the beginning of the program, and the only write between that initialization and the `print` is to the pointer `p+1`.
 Since `q` and `p` point to different local variables, a pointer derived from `p` cannot alias `q[0]`, and hence we know that this write cannot affect the value stored at `q[0]`.