[llvm-dev] error: ordered comparison between pointer and zero ('address' (aka 'unsigned char *') and 'int')

[Thomas Schatzl via llvm-dev]

Hi Leslie,

On Fri, 2018-07-20 at 10:07 +0800, Leslie Zhai wrote:
> Hi Thomas,
> 
> Thanks for your kind response!
> 
> Please review my backport for hs25, thanks a lot!
> 

  I can't review the second hunk because it is out of my area of
expertise and it does not look a trivial change either. The other hunks
look good. Somebody else more proficient with the compiler needs to
look at this.

The further process for 8u fixes is then to send a request for approval
email to jdk8u-dev at openjdk.java.net with some information about the
original bug and this review; see e.g. http://mail.openjdk.java.net/pip
ermail/jdk8u-dev/2018-July/007708.html for an example.

If you need a sponsor, I could do that for you after approval (I am onjdk8u-dev, so I would notice :) ). 

Thanks,
  Thomas

> 
> 
> diff -r 3544d85cfe11 src/share/vm/opto/lcm.cpp
> --- a/src/share/vm/opto/lcm.cpp    Thu Jul 19 10:00:36 2018 +0100
> +++ b/src/share/vm/opto/lcm.cpp    Fri Jul 20 10:06:37 2018 +0800
> @@ -49,7 +49,7 @@
>   // Check whether val is not-null-decoded compressed oop,
>   // i.e. will grab into the base of the heap if it represents NULL.
>   static bool accesses_heap_base_zone(Node *val) {
> -  if (Universe::narrow_oop_base() > 0) { // Implies
> UseCompressedOops.
> +  if (Universe::narrow_oop_base() != NULL) { // Implies
> UseCompressedOops.
>       if (val && val->is_Mach()) {
>         if (val->as_Mach()->ideal_Opcode() == Op_DecodeN) {
>           // This assumes all Decodes with TypePtr::NotNull are
> matched 
> to nodes that
> diff -r 3544d85cfe11 src/share/vm/opto/loopPredicate.cpp
> --- a/src/share/vm/opto/loopPredicate.cpp    Thu Jul 19 10:00:36 2018
> +0100
> +++ b/src/share/vm/opto/loopPredicate.cpp    Fri Jul 20 10:06:37 2018
> +0800
> @@ -869,7 +869,7 @@
>         Node*          idx    = cmp->in(1);
>         assert(!invar.is_invariant(idx), "index is variant");
>         Node* rng = cmp->in(2);
> -      assert(rng->Opcode() == Op_LoadRange || _igvn.type(rng)-
> >is_int() 
>  >= 0, "must be");
> +      assert(rng->Opcode() == Op_LoadRange || 
> _igvn.type(rng)->is_int()->_lo >= 0, "must be");
>         assert(invar.is_invariant(rng), "range must be invariant");
>         int scale    = 1;
>         Node* offset = zero;
> diff -r 3544d85cfe11 src/share/vm/runtime/virtualspace.cpp
> --- a/src/share/vm/runtime/virtualspace.cpp    Thu Jul 19 10:00:36
> 2018 
> +0100
> +++ b/src/share/vm/runtime/virtualspace.cpp    Fri Jul 20 10:06:37
> 2018 
> +0800
> @@ -342,7 +342,7 @@
>                   (UseCompressedOops && (Universe::narrow_oop_base()
> != 
> NULL) &&
>                    Universe::narrow_oop_use_implicit_null_checks()) ?
>                     lcm(os::vm_page_size(), alignment) : 0) {
> -  if (base() > 0) {
> +  if (base() != NULL) {
>       MemTracker::record_virtual_memory_type((address)base(),
> mtJavaHeap);
>     }
> 
> 
> 
> 
> 在 2018年07月19日 19:37, Thomas Schatzl 写道:
> > Hi,
> > 
> > On Thu, 2018-07-19 at 18:56 +0800, Leslie Zhai wrote:
> > > Hi HotSpot and LLVM developers,
> > > 
> > > I am building OpenJDK8[1] with LLVM toolchain[2] for mips64el, it
> > > failed to build:
> > > 
> > > 
> > > /home/loongson/jdk8-mips/hotspot/src/share/vm/opto/lcm.cpp:52:35:
> > > error:
> > > ordered comparison between pointer and zero ('address' (aka
> > > 'unsigned
> > > char *') and 'int')
> > >     if (Universe::narrow_oop_base() > 0) { // Implies
> > > UseCompressedOops.
> > >         ~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~
> > > 
> > > 
> > > Just like compiling Linux kernel with LLVM for mips64el[3], the
> > > bug
> > > could be fixed both in Compiler side and HotSpot side, please
> > > give
> > > me some suggestion, thanks a lot! And my sincere thanks will go
> > > to
> > > Nick who helped me a lot!
> > 
> >    this has been fixed in the jvm in JDK10 with https://bugs.openjd
> > k.jav
> > a.net/browse/JDK-8174050 .
> > 
> > It has not been backported to jdk8; others may be able to tell you
> > if
> > it can/will be backported.
> > 
> > Thanks,
> >    Thomas
> > 
> > > 1. http://hg.loongnix.org/
> > > 2. Loongson clang version 7.0.0
> > > (git at github.com:Loong-Language/loong-clang.git
> > > c36069cffc57a30a20782bf327a87bed4e48a6c2)
> > > (git at github.com:Loong-Language/loong-llvm.git
> > > 59cb663e72874dda740aa2b18bf47ba65b32fe9b) (based on LLVM
> > > 7.0.0svn)
> > > Target: mips64el-redhat-linux
> > > Thread model: posix
> > > InstalledDir: /opt/loong-llvm/bin
> > > Found candidate GCC installation: /usr/lib/gcc/mips64el-redhat-
> > > linux/4.9.3
> > > Selected GCC installation: /usr/lib/gcc/mips64el-redhat-
> > > linux/4.9.3
> > > Candidate multilib: .;
> > > Selected multilib: .;
> > > 3. http://lists.llvm.org/pipermail/llvm-dev/2018-July/124620.html
> > > 
> 
>