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8137167: JEP165: Compiler Control: Implementation task

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Compiler Control JEP

Reviewed-by: roland, twisti, zmajo, simonis
This commit is contained in:
Nils Eliasson 2015-10-20 18:07:28 +02:00
parent 857b7eb968
commit 5a5faf94bf
66 changed files with 3965 additions and 307 deletions
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48
hotspot/src/share/vm/compiler/abstractCompiler.hpp
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@ -26,6 +26,7 @@
#define SHARE_VM_COMPILER_ABSTRACTCOMPILER_HPP
#include "ci/compilerInterface.hpp"
#include "compiler/compilerDirectives.hpp"
typedef void (*initializer)(void);
@ -114,36 +115,33 @@ class AbstractCompiler : public CHeapObj<mtCompiler> {
// Determine if the current compiler provides an intrinsic
// for method 'method'. An intrinsic is available if:
// - the intrinsic is enabled (by using the appropriate command-line flag) and
// - the intrinsic is enabled (by using the appropriate command-line flag,
// the command-line compile ommand, or a compiler directive)
// - the platform on which the VM is running supports the intrinsic
// (i.e., the platform provides the instructions necessary for the compiler
// to generate the intrinsic code).
//
// The second parameter, 'compilation_context', is needed to implement functionality
// related to the DisableIntrinsic command-line flag. The DisableIntrinsic flag can
// be used to prohibit the compilers to use an intrinsic. There are three ways to
// disable an intrinsic using the DisableIntrinsic flag:
// The directive provides the compilation context and includes pre-evaluated values
// dependent on VM flags, compile commands, and compiler directives.
//
// (1) -XX:DisableIntrinsic=_hashCode,_getClass
// Disables intrinsification of _hashCode and _getClass globally
// (i.e., the intrinsified version the methods will not be used at all).
// (2) -XX:CompileCommand=option,aClass::aMethod,ccstr,DisableIntrinsic,_hashCode
// Disables intrinsification of _hashCode if it is called from
// aClass::aMethod (but not for any other call site of _hashCode)
// (3) -XX:CompileCommand=option,java.lang.ref.Reference::get,ccstr,DisableIntrinsic,_Reference_get
// Some methods are not compiled by C2. Instead, the C2 compiler
// returns directly the intrinsified version of these methods.
// The command above forces C2 to compile _Reference_get, but
// allows using the intrinsified version of _Reference_get at all
// other call sites.
//
// From the modes above, (1) disable intrinsics globally, (2) and (3)
// disable intrinsics on a per-method basis. In cases (2) and (3) the
// compilation context is aClass::aMethod and java.lang.ref.Reference::get,
// respectively.
virtual bool is_intrinsic_available(methodHandle method, methodHandle compilation_context) {
// Usually, the compilation context is the caller of the method 'method'.
// The only case when for a non-recursive method 'method' the compilation context
// is not the caller of the 'method' (but it is the method itself) is
// java.lang.ref.Referene::get.
// For java.lang.ref.Reference::get, the intrinsic version is used
// instead of the compiled version so that the value in the referent
// field can be registered by the G1 pre-barrier code. The intrinsified
// version of Reference::get also adds a memory barrier to prevent
// commoning reads from the referent field across safepoint since GC
// can change the referent field's value. See Compile::Compile()
// in src/share/vm/opto/compile.cpp or
// GraphBuilder::GraphBuilder() in src/share/vm/c1/c1_GraphBuilder.cpp
// for more details.
virtual bool is_intrinsic_available(methodHandle method, DirectiveSet* directive) {
return is_intrinsic_supported(method) &&
!vmIntrinsics::is_disabled_by_flags(method, compilation_context);
!directive->is_intrinsic_disabled(method) &&
!vmIntrinsics::is_disabled_by_flags(method);
}
// Determines if an intrinsic is supported by the compiler, that is,
@ -176,7 +174,7 @@ class AbstractCompiler : public CHeapObj<mtCompiler> {
void set_state (int state);
void set_shut_down () { set_state(shut_down); }
// Compilation entry point for methods
virtual void compile_method(ciEnv* env, ciMethod* target, int entry_bci) {
virtual void compile_method(ciEnv* env, ciMethod* target, int entry_bci, DirectiveSet* directive) {
ShouldNotReachHere();
}