[llvm] r302905 - [NewGVN] Don't incorrectly reset the memory leader.

Fri May 12 20:03:23 PDT 2017

Galina,
does this test on any of the bots you own? If so, can I access it to
debug/take a look at the logs/etc.. ?
I tried very hard to reproduce the problem locally without luck.

On Fri, May 12, 2017 at 8:01 PM, Davide Italiano <davide at freebsd.org> wrote:
> I think this test is just exposing some underlying
> non-determinism/problem, but I can't take a look right now
> unforunately.
> Given NewGVN is not the default and the change is correct, I'm
> XFAIL'ing this for now, and I'll debug over the weekend (or monday at
> last). Sorry if this caused troubles, but I'm as puzzled as you are.
>
> --
> Davide
>
> On Fri, May 12, 2017 at 5:07 PM, Craig Topper <craig.topper at gmail.com> wrote:
>> This test seems to be randomly failing on the bots for example
>>
>> http://lab.llvm.org:8011/builders/clang-x86_64-linux-selfhost-modules/builds/5700
>>
>>
>>
>> http://lab.llvm.org:8011/builders/clang-ppc64be-linux-lnt/builds/5250
>>
>>
>>
>> http://lab.llvm.org:8011/builders/llvm-hexagon-elf/builds/6165
>>
>>
>> But it seems to pass on the previous build and the next build. But you can
>> go back through early builds and find a failure.  For example it also failed
>> on build 6160 on the hexagon bot above, but it passed on 6161-6164.
>>
>>
>>
>> ~Craig
>>
>> On Fri, May 12, 2017 at 8:22 AM, Davide Italiano via llvm-commits
>> <llvm-commits at lists.llvm.org> wrote:
>>>
>>> Author: davide
>>> Date: Fri May 12 10:22:45 2017
>>> New Revision: 302905
>>>
>>> URL: http://llvm.org/viewvc/llvm-project?rev=302905&view=rev
>>> Log:
>>> [NewGVN] Don't incorrectly reset the memory leader.
>>>
>>> This code was missing a check for stores, so we were thinking the
>>> congruency class didn't have any memory members, and reset the
>>> memory leader.
>>>
>>> Differential Revision:  https://reviews.llvm.org/D33056
>>>
>>> Added:
>>>     llvm/trunk/test/Transforms/NewGVN/pr32934.ll
>>> Modified:
>>>     llvm/trunk/lib/Transforms/Scalar/NewGVN.cpp
>>>
>>> Modified: llvm/trunk/lib/Transforms/Scalar/NewGVN.cpp
>>> URL:
>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/NewGVN.cpp?rev=302905&r1=302904&r2=302905&view=diff
>>>
>>> ==============================================================================
>>> --- llvm/trunk/lib/Transforms/Scalar/NewGVN.cpp (original)
>>> +++ llvm/trunk/lib/Transforms/Scalar/NewGVN.cpp Fri May 12 10:22:45 2017
>>> @@ -1409,7 +1409,7 @@ bool NewGVN::setMemoryClass(const Memory
>>>          NewClass->memory_insert(MP);
>>>          // This may have killed the class if it had no non-memory members
>>>          if (OldClass->getMemoryLeader() == From) {
>>> -          if (OldClass->memory_empty()) {
>>> +          if (OldClass->definesNoMemory()) {
>>>              OldClass->setMemoryLeader(nullptr);
>>>            } else {
>>>              OldClass->setMemoryLeader(getNextMemoryLeader(OldClass));
>>>
>>> Added: llvm/trunk/test/Transforms/NewGVN/pr32934.ll
>>> URL:
>>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/NewGVN/pr32934.ll?rev=302905&view=auto
>>>
>>> ==============================================================================
>>> --- llvm/trunk/test/Transforms/NewGVN/pr32934.ll (added)
>>> +++ llvm/trunk/test/Transforms/NewGVN/pr32934.ll Fri May 12 10:22:45 2017
>>> @@ -0,0 +1,68 @@
>>> +; RUN: opt -S -newgvn %s | FileCheck %s
>>> +
>>> +; CHECK: define void @tinkywinky() {
>>> +; CHECK-NEXT: entry:
>>> +; CHECK-NEXT:   %d = alloca i32, align 4
>>> +; CHECK-NEXT:   store i32 0, i32* null, align 4
>>> +; CHECK-NEXT:   br label %for.cond
>>> +; CHECK: for.cond:                                         ; preds =
>>> %if.end, %entry
>>> +; CHECK-NEXT:   %0 = load i32, i32* null, align 4
>>> +; CHECK-NEXT:   %cmp = icmp slt i32 %0, 1
>>> +; CHECK-NEXT:   br i1 %cmp, label %for.body, label %while.cond
>>> +; CHECK: for.body:                                         ; preds =
>>> %for.cond
>>> +; CHECK-NEXT:   %1 = load i32, i32* @a, align 4
>>> +; CHECK-NEXT:   store i32 %1, i32* %d, align 4
>>> +; CHECK-NEXT:   br label %L
>>> +; CHECK: L:                                                ; preds =
>>> %if.then, %for.body
>>> +; CHECK-NEXT:   %tobool = icmp ne i32 %1, 0
>>> +; CHECK-NEXT:   br i1 %tobool, label %if.then, label %if.end
>>> +; CHECK: if.then:                                          ; preds = %L
>>> +; CHECK-NEXT:   call void (i8*, ...) @printf(i8* getelementptr inbounds
>>> ([2 x i8], [2 x i8]* @patatino, i32 0, i32 0))
>>> +; CHECK-NEXT:   br label %L
>>> +; CHECK: if.end:                                           ; preds = %L
>>> +; CHECK-NEXT:   br label %for.cond
>>> +; CHECK: while.cond:                                       ; preds =
>>> %while.body, %for.cond
>>> +; CHECK-NEXT:   br i1 undef, label %while.body, label %while.end
>>> +; CHECK: while.body:                                       ; preds =
>>> %while.cond
>>> +; CHECK-NEXT:   call void (i8*, ...) @printf(i8* getelementptr inbounds
>>> ([2 x i8], [2 x i8]* @patatino, i32 0, i32 0))
>>> +; CHECK-NEXT:   br label %while.cond
>>> +; CHECK: while.end:
>>> +; CHECK-NEXT:   %2 = load i32, i32* @a, align 4
>>> +; CHECK-NEXT:   store i32 %2, i32* undef, align 4
>>> +; CHECK-NEXT:   ret void
>>> +
>>> + at a = external global i32, align 4
>>> + at patatino = external unnamed_addr constant [2 x i8], align 1
>>> +define void @tinkywinky() {
>>> +entry:
>>> +  %d = alloca i32, align 4
>>> +  store i32 0, i32* null, align 4
>>> +  br label %for.cond
>>> +for.cond:
>>> +  %0 = load i32, i32* null, align 4
>>> +  %cmp = icmp slt i32 %0, 1
>>> +  br i1 %cmp, label %for.body, label %while.cond
>>> +for.body:
>>> +  %1 = load i32, i32* @a, align 4
>>> +  store i32 %1, i32* %d, align 4
>>> +  br label %L
>>> +L:
>>> +  %2 = load i32, i32* %d, align 4
>>> +  %tobool = icmp ne i32 %2, 0
>>> +  br i1 %tobool, label %if.then, label %if.end
>>> +if.then:
>>> +  call void (i8*, ...) @printf(i8* getelementptr inbounds ([2 x i8], [2 x
>>> i8]* @patatino, i32 0, i32 0))
>>> +  br label %L
>>> +if.end:
>>> +  br label %for.cond
>>> +while.cond:
>>> +  br i1 undef, label %while.body, label %while.end
>>> +while.body:
>>> +  call void (i8*, ...) @printf(i8* getelementptr inbounds ([2 x i8], [2 x
>>> i8]* @patatino, i32 0, i32 0))
>>> +  br label %while.cond
>>> +while.end:
>>> +  %3 = load i32, i32* @a, align 4
>>> +  store i32 %3, i32* undef, align 4
>>> +  ret void
>>> +}
>>> +declare void @printf(i8*, ...) #1
>>>
>>>
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>>
>>
>
>
>
> --
> Davide
>
> "There are no solved problems; there are only problems that are more
> or less solved" -- Henri Poincare

-- 
Davide

"There are no solved problems; there are only problems that are more
or less solved" -- Henri Poincare