Chapter 9 edits

[dankamongmen]

Very clean chapter. Some comma splices (as always) and some irregular syntax.

• 9-1 p167: "Also, this code example is included in the dep_chains_2[ˆ] lab assignment"
  ** is there a missing reference here?

• 9-2 p170: "The same is true for functions with external linkage."
  ** i'd maybe expand upon this, as you haven't mentioned linkage previously. at the very least i'd point out -fvisibility and probably link to Ulrich Drepper's "How to Write Shared Libraries"

• 9-3 p171: "For more detailed information on each of the transformations discussed below, readers can refer to [Cooper & Torczon, 2012]"
  ** i'd maybe also reference Allen+Kennedy's 2001 "Optimizing Compilers for Modern Architectures". we used both in our compilers class at Georgia Tech, and the latter has more of this information IIRC.

• holy crap, i didn't realize you needed turn on polly at the command line. i thought it was the default!

• 9-4 i changed "auto-vectorization" to "autovectorization" because you were already using the latter form in previous sentences.

• p. 175 "one of the authors" who? i see only one author listed.

• removed periods at the end of section titles, as this is not done anywhere else

• p.177: maybe mention -fstrict-aliasing