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

[Leslie Zhai via llvm-dev]

Hi Thomas,

Thanks for your kind response!

Please review my backport for hs25, thanks a lot!



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.openjdk.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
>>

-- 
Regards,
Leslie Zhai