[PATCH] Let llc and opt override "-target-cpu" and "-target-features" using command line options "-mcpu" and "-mattr"

[Eric Christopher]

On Wed, May 6, 2015 at 1:51 PM Akira Hatanaka <ahatanak at gmail.com> wrote:

> In http://reviews.llvm.org/D9537#167157, @echristo wrote:
>
> > I agree, no TargetOptions for this. I don't necessarily agree with
> rewriting, but it seems to be a small enough change and will work for what
> the overrides are meant to be for. Some discipline in reviewing testcases
> to make sure that a lot of overrides aren't there for incoming testcases is
> going to be necessary for clean tests. One inline comment which basically
> sums up to "why not two functions"? As long as you have a reasonable answer
> go ahead.
>
>
> I'm not sure if I understood your comment about testcases. Do you mean
> people shouldn't duplicate functions in test cases just to test different
> target-cpu and target-feature strings but instead should use -mcpu and
> -mattrs (which I think makes sense)? Should the one inline comment go into
> the test cases I added?
>
>
>
My comment about testcases is that someone shouldn't have:

; RUN: llc -march=foo

as the only run line with a function with:

target-cpu="notfoo"

when they could just change the arch on the function to say "foo" rather
than "notfoo".


> ================
> Comment at: include/llvm/CodeGen/CommandFlags.h:268
> @@ -262,1 +267,3 @@
>
> +static inline std::pair<std::string, std::string> getCPUFeaturesStr() {
> +  std::string CPUStr;
> ----------------
> echristo wrote:
> > Why a pair?
> Is it better to split this into two functions getCPUStr and
> getFeaturesStr? Or you meant the two strings (cpu and features strings)
> should be passed by reference?
>
>
I meant split into two functions, any particular reason?

-eric


> http://reviews.llvm.org/D9537
>
> EMAIL PREFERENCES
>   http://reviews.llvm.org/settings/panel/emailpreferences/
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20150506/2cee2b8f/attachment.html>