[llvm-dev] What kind of testcases should be required to test IPRA?

[vivek pandya via llvm-dev]

On Sun, Jun 5, 2016 at 9:15 AM, Mehdi Amini <mehdi.amini at apple.com> wrote:

>
> On Jun 4, 2016, at 8:32 PM, vivek pandya <vivekvpandya at gmail.com> wrote:
>
>
>
> On Sun, Jun 5, 2016 at 8:56 AM, Mehdi Amini <mehdi.amini at apple.com> wrote:
>
>>
>> > On Jun 4, 2016, at 7:56 PM, vivek pandya <vivekvpandya at gmail.com>
>> wrote:
>> >
>> > Hello Mehdi Amini,
>> >
>> > Sorry for slow progress this week but it was due to interesting mistake
>> of mine. I had build llvm with ipra enable by default and that build files
>> were on my path ! Due to that next time I tried to build llvm it was
>> terribly slow  (almost 1 hour for 10% build ). I spend to much time on
>> fixing this by playing around with environment variables, cmake options etc.
>> > But I think this is a serious concern, we need to think verify this
>> time complexity other wise building a large software with IPRA enable would
>> be very time consuming.
>>
>> Did you build your own clang in release mode or debug? That makes a very
>> important difference...
>>
> oh yes nice point, what I did is Debug mode with IPRA 😬 that is insane.
>
>>
>> >
>> > I studied tets case suggest by you on phabricator, for RegUsageInfo
>> passes I am thinking to print clobbered registers and verify that with
>> FileCheck as expected clobbered register for a particular test-case. Is
>> this approach fine?
>> >
>> > I did not find function call to CostModelAnalysis::print() , Is opt
>> -analyze making that call ?
>>
>> Yes.
>> (In general, if you find yourself in a situation where you can find the
>> caller for a function, run in a debugger and set a breakpoint)
>>
> Ok
>
>>
>> > I am not able to find similar option in llc.
>>
>> That's an issue. Looks it may not be feasible to test the analysis in llc
>> with the current infrastructure.
>>
>> I got the trick, actaully I am trying to do the same thing but let me
> figure out why it does not work?
> ./print-machineinstrs.ll:; RUN: llc < %s -O3 -debug-pass=Structure
> -print-machineinstrs=branch-folder -o /dev/null 2>&1 | FileCheck %s
> ./print-machineinstrs.ll:; RUN: llc < %s -O3 -debug-pass=Structure
> -print-machineinstrs -o /dev/null 2>&1 | FileCheck %s
> ./print-machineinstrs.ll:; RUN: llc < %s -O3 -debug-pass=Structure
> -print-machineinstrs= -o /dev/null 2>&1 | FileCheck %s
>
> The above example I found in test directory it feeds the .s file to
/dev/null and binds stderr to stdout so that FileCheck will have debug info
printed as input to work on.

>
>
I'm not sure what you're doing here, but considering that llc does not
> expose -analyze, I'd just keep it all in a single patch as originally
> planned.
>
> --
> Mehdi
>
>
>
> > I can't use info printed with dbgs() function as release build do not
>> add -debug-only option to llc executable.
>> >
>> > For the testcase sent by you earlier I have modified it as following :
>> > ;;;;; ip-regallco-simple.ll
>> > ; RUN: llc < %s | FileCheck %s -check-prefix=NOIPRA
>> > ; RUN: llc < %s -enable-ipra | FileCheck %s
>> > ; NOIPRA: foo:
>>
>> should be NOIPRA-LABEL:
>>
>> > ; NOIPRA: pushq       %r10
>> > ; NOIPRA: pushq       %r9
>> > ; NOIPRA: pushq       %r8
>> > ; NOIPRA: calls bar1
>>
>> If this is an exact sequence you want to match, you may use NOIPRA-NEXT
>
>
>> > ; CHECK: foo:
>> > ; CHECK-NOT: pushq %r10
>> > ; CHECK-NOT: pushq %r9
>> > ; CHECK-NOT: pushq %r8
>>
>> You can just write "CHECK-NOT: push"
>>
>> > ; CHECK: callq bar1
>> > target triple = "x86_64-unknown-unknown"
>> > define void @bar1() {
>> >       ret void
>> > }
>> > define preserve_allcc void @foo()#0 {
>> >       call void @bar1()
>> >       call void @bar2()
>> >       ret void
>> > }
>> > define void @bar2() {
>> >       ret void
>> > }
>> > attributes #0 = {nounwind}
>> >
>> > Is this correct approach to verify spills?
>>
>> Yes.
>>
>>
>> --
>> Mehdi
>>
>>
>
>
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