sembr src/profiling.md

Author: tshepang

src/profiling.md

@@ -33,10 +33,11 @@ Since most of the time compiling rustc is spent in LLVM, the idea is that by
 reducing the amount of code passed to LLVM, compiling rustc gets faster.
 
 To use `cargo-llvm-lines` together with somewhat custom rustc build process, you can use
-`-C save-temps` to obtain required LLVM IR. The option preserves temporary work products
-created during compilation. Among those is LLVM IR that represents an input to the
-optimization pipeline; ideal for our purposes. It is stored in files with `*.no-opt.bc`
-extension in LLVM bitcode format.
+`-C save-temps` to obtain required LLVM IR.
+The option preserves temporary work products created during compilation.
+Among those is LLVM IR that represents an input to the
+optimization pipeline; ideal for our purposes.
+It is stored in files with `*.no-opt.bc` extension in LLVM bitcode format.
 
 Example usage:
 ```
@@ -105,7 +106,8 @@ rust.codegen-units = 0  # num_cpus
 The llvm-lines output is affected by several options.
 `rust.optimize = false` increases it from 2.1GB to 3.5GB and `codegen-units = 0` to 4.1GB.
 
-MIR optimizations have little impact. Compared to the default `RUSTFLAGS="-Z
+MIR optimizations have little impact.
+Compared to the default `RUSTFLAGS="-Z
 mir-opt-level=1"`, level 0 adds 0.3GB and level 2 removes 0.2GB.
 As of <!-- date-check --> July 2022,
 inlining happens in LLVM and GCC codegen backends,