COOPs: rounding up of heap size leads to unoptimal COOPs mode with any GC on solaris-sprcv9

Here is the corner case where zero-based coops could be used (HeapBaseMinAddress + Xmx + MaxPermSize == 64g), bet coops with base are used instead:

vmsqe-robot@vmsqe-b2500-03:~> /set/vmsqe/jdk/re/7/promoted/ea/b137/binaries/solaris-sparcv9/bin/java -d64 -server -Xmixed -XX:+PrintGCDetails -XX:+UseSerialGC -XX:ObjectAlignmentInBytes=16 -XX:HeapBaseMinAddress=32762m -Xmx16390m -XX:MaxPermSize=16384m -XX:+UnlockDiagnosticVMOptions -XX:+PrintCompressedOopsMode -version

Protected page at the reserved heap base: 0x00000007ff9f0000 / 65536 bytes

heap address: 0x00000007ffa00000, size: 32776 MB, Compressed Oops with base: 0x00000007ff9fe000

java version "1.7.0-ea"
Java(TM) SE Runtime Environment (build 1.7.0-ea-b137)
Java HotSpot(TM) 64-Bit Server VM (build 21.0-b07, mixed mode)
Heap
 def new generation total 9792K, used 522K [0x00000007ffa00000, 0x00000008004a0000, 0x0000000955200000)
  eden space 8704K, 6% used [0x00000007ffa00000, 0x00000007ffa82a00, 0x0000000800280000)
  from space 1088K, 0% used [0x0000000800280000, 0x0000000800280000, 0x0000000800390000)
  to space 1088K, 0% used [0x0000000800390000, 0x0000000800390000, 0x00000008004a0000)
 tenured generation total 21888K, used 0K [0x0000000955200000, 0x0000000956760000, 0x0000000c00200000)
   the space 21888K, 0% used [0x0000000955200000, 0x0000000955200000, 0x0000000955200200, 0x0000000956760000)
 compacting perm gen total 21248K, used 2229K [0x0000000c00200000, 0x0000000c016c0000, 0x0000001000200000)
   the space 21248K, 10% used [0x0000000c00200000, 0x0000000c0042d5e0, 0x0000000c0042d600, 0x0000000c016c0000)
No shared spaces configured.


The same with ParallelGC:

vmsqe-robot@vmsqe-b2500-03:~> /set/vmsqe/jdk/re/7/promoted/ea/b137/binaries/solaris-sparcv9/bin/java -d64 -server -Xmixed -XX:+PrintGCDetails -XX:+UseParallelGC -XX:ObjectAlignmentInBytes=16 -XX:HeapBaseMinAddress=32762m -Xmx16390m -XX:MaxPermSize=16384m -XX:+UnlockDiagnosticVMOptions -XX:+PrintCompressedOopsMode -version

Protected page at the reserved heap base: 0xfffffff6d8400000 / 4194304 bytes

heap address: 0xfffffff6d8800000, size: 32776 MB, Compressed Oops with base: 0xfffffff6d87fe000

java version "1.7.0-ea"
Java(TM) SE Runtime Environment (build 1.7.0-ea-b137)
Java HotSpot(TM) 64-Bit Server VM (build 21.0-b07, mixed mode)
Heap
 PSYoungGen total 10752K, used 553K [0xfffffffd83800000, 0xfffffffd84400000, 0xfffffffed9000000)
  eden space 9216K, 6% used [0xfffffffd83800000,0xfffffffd8388a510,0xfffffffd84100000)
  from space 1536K, 0% used [0xfffffffd84280000,0xfffffffd84280000,0xfffffffd84400000)
  to space 1536K, 0% used [0xfffffffd84100000,0xfffffffd84100000,0xfffffffd84280000)
 PSOldGen total 20480K, used 0K [0xfffffffad8800000, 0xfffffffad9c00000, 0xfffffffd83800000)
  object space 20480K, 0% used [0xfffffffad8800000,0xfffffffad8800000,0xfffffffad9c00000)
 PSPermGen total 24576K, used 2229K [0xfffffff6d8800000, 0xfffffff6da000000, 0xfffffffad8800000)
  object space 24576K, 9% used [0xfffffff6d8800000,0xfffffff6d8a2d5e0,0xfffffff6da000000)