Thanks to all for taking time to report my errors. I missed @code_llvm's introduction into Julia. It let me shorten that section slightly. Jacob is right about the row/column index. I tend to think of the leftmost subscript as the "runs down the column" index. When I'm working with Fortran/Julia, I'm constantly thinking "runs down the column; runs down the column" to override my C++ habit. *B*ut I mistakenly phrased it as "column index". I changed the text to say "leftmost subscript". I think that I've fixed all the bugs reported up to the time this note is posted.
On Mon, Sep 15, 2014 at 5:55 PM, Jacob Quinn <quinn.jac...@gmail.com> wrote: > - Under the first bullet point of "What is Vectorization?", "Writing you > code" should be "Writing your code" > > - In the "Speedup Surprise" section, the last sentence says "The compiler > than...", should be "The compiler then...." > > - In the section "Inspecting Whether Code Vectorizes", you can actually > use the pattern > > > @code_llvm axpy(1.414f0, x, y) > > > (using the original example/function call). This gives the LLVM output of > the outermost function call and is quite handy vs. dealing with the tuple > of argument types (as is noted in your article). > > > - In the section "Trip Count must be Obvious", down to the bullet points, > I think your second bullet point should be > > > > - *first*(*r*) returns the first index value. > > - In the section "The Loop Body Should be Straight Line Code", there is > an extra period (.) after *type-stable code* > > - In the section "Subscripts should be Unit Stride", it says > > When working with nested loops on two-dimensional arrays, use *@simd* on > the inner loop and make that loop index the column index of the arrays. > > But then the example has `i` as the inner loop variable and the matrices > are indexed like A[i, j], which seems like `j` is column-index. Am I > misinterpreting this? > > > Loved the article! For those of us unable to make it to JuliaCon, it's > been awesome to be able to watch the videos and read up on articles like > this. Thanks for all the work! > > -Jacob > > On Mon, Sep 15, 2014 at 6:26 PM, Patrick O'Leary <patrick.ole...@gmail.com > > wrote: > >> Under "Inspecting Whether Code Vectorizes" >> >> code_llvm(axpy,(T1,T2,T2}) >> >> >> The next-to-last character should be a paren. >> >> This is a very informative article; thanks for putting it and the feature >> together! >> > >
