Request for reviews (XXL): 6961690: load oops from constant table on SPARC

[Vladimir Kozlov]

Most important is why it is not under flag?

Vladimir

Vladimir Kozlov wrote:
> Do you need to connect MachConstantBaseNode to root? For RA? And where 
> you emit it (call emit()) since you don't add it to any block:
> 
> +MachConstantBaseNode* Compile::mach_constant_base_node() {
> +  if (_mach_constant_base_node == NULL) {
> +    _mach_constant_base_node = new (C) MachConstantBaseNode();
> +    _mach_constant_base_node->set_req(0, C->root());
> 
> Why commented?:
> !     //assert(!n->pinned() || n->is_SafePointScalarObject(), "only 
> SafePointScalarObject pinned node is expected here");
> 
> You don't use is_MachConstantBase() so you don't need to add it to 
> DEFINE_CLASS in node.hpp and call init_class_id().
> 
> May be one line?:
> 
> +// Machine node that holds a constant which is stored in the constant
> +// table.
> 
> You don't need to check for is_Mach(), check directly n->is_MachConstant():
> 
> +        if (n->is_Mach()) {
> +          MachNode *mach = n->as_Mach();
> +
> +          // If the MachNode is a MachConstantNode evaluate the
> +          // constant value section.
> +          if (mach->is_MachConstant()) {
> +            MachConstantNode* machcon = mach->as_MachConstant();
> +            machcon->eval_constant();
> +          }
> +        }
> 
> Vladimir
> 
> Christian Thalinger wrote:
>> http://cr.openjdk.java.net/~twisti/6961690/webrev.01/
>>
>> 6961690: load oops from constant table on SPARC
>> Summary: oops should be loaded from the constant table of an nmethod 
>> instead of materializing them with a long code sequence.
>> Reviewed-by:
>>
>> oops should be loaded from the constant table of an nmethod instead of
>> materializing them with a long code sequence.
>>
>> This fix introduces two new ideal nodes MachConstantBaseNode and
>> MachConstantNode.  MachConstantBaseNode represents the base address of
>> the constant table, MachConstantNode a constant that should be read
>> from the constant table.
>>
>> ADLC was changed to support three new keywords: constantaddress,
>> constanttablebase, and constantoffset.  constantaddress represents the
>> absolute address of a constant and is used on x86.  constanttablebase
>> represents the register that holds the constant table base address and
>> constantoffset is the relative offset to constanttablebase.  The
>> latter two are used on SPARC.
>>
>> For SPARC a new command line option was added:
>> UseRDPCForConstantTableBase.  If that option is true the RDPC
>> instruction is used to get the constant table base address instead of
>> materializing the address.  This option is currently off by default
>> and may be switched on for future SPARC implementations.
>>
>> The patch also includes a change from Tom that fixes a bug that was
>> uncovered by this work:
>>
>> http://cr.openjdk.java.net/~twisti/6961690/webrev.01/src/share/vm/opto/postaloc.cpp.udiff.html 
>>
>>
>> src/cpu/sparc/vm/assembler_sparc.cpp
>> src/cpu/sparc/vm/assembler_sparc.hpp
>> src/cpu/sparc/vm/assembler_sparc.inline.hpp
>> src/cpu/sparc/vm/sparc.ad
>> src/cpu/x86/vm/assembler_x86.cpp
>> src/cpu/x86/vm/assembler_x86.hpp
>> src/cpu/x86/vm/x86_32.ad
>> src/cpu/x86/vm/x86_64.ad
>> src/os/linux/vm/vmError_linux.cpp
>> src/share/vm/adlc/adlparse.cpp
>> src/share/vm/adlc/adlparse.hpp
>> src/share/vm/adlc/archDesc.hpp
>> src/share/vm/adlc/formssel.cpp
>> src/share/vm/adlc/formssel.hpp
>> src/share/vm/adlc/output_c.cpp
>> src/share/vm/adlc/output_h.cpp
>> src/share/vm/asm/assembler.hpp
>> src/share/vm/asm/assembler.inline.hpp
>> src/share/vm/compiler/disassembler.cpp
>> src/share/vm/opto/c2_globals.hpp
>> src/share/vm/opto/compile.cpp
>> src/share/vm/opto/compile.hpp
>> src/share/vm/opto/gcm.cpp
>> src/share/vm/opto/machnode.cpp
>> src/share/vm/opto/machnode.hpp
>> src/share/vm/opto/node.hpp
>> src/share/vm/opto/output.cpp
>> src/share/vm/opto/postaloc.cpp
>> src/share/vm/utilities/debug.cpp
>>