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comparison src/share/vm/opto/graphKit.cpp @ 647:bd441136a5ce

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Merge
author kvn
date Thu, 19 Mar 2009 09:13:24 -0700
parents 7bb995fbd3c0 c517646eef23
children be93aad57795
comparison
equal deleted inserted replaced
640:ba50942c8138 647:bd441136a5ce
2275 Node *bol2 = _gvn.transform( new (C, 2) BoolNode( cmp2, BoolTest::ne ) ); 2275 Node *bol2 = _gvn.transform( new (C, 2) BoolNode( cmp2, BoolTest::ne ) );
2276 IfNode *iff2 = create_and_xform_if( control(), bol2, PROB_LIKELY(0.63f), COUNT_UNKNOWN ); 2276 IfNode *iff2 = create_and_xform_if( control(), bol2, PROB_LIKELY(0.63f), COUNT_UNKNOWN );
2277 r_not_subtype->init_req(1, _gvn.transform( new (C, 1) IfTrueNode (iff2) ) ); 2277 r_not_subtype->init_req(1, _gvn.transform( new (C, 1) IfTrueNode (iff2) ) );
2278 set_control( _gvn.transform( new (C, 1) IfFalseNode(iff2) ) ); 2278 set_control( _gvn.transform( new (C, 1) IfFalseNode(iff2) ) );
2279 2279
2280 // Check for self. Very rare to get here, but its taken 1/3 the time. 2280 // Check for self. Very rare to get here, but it is taken 1/3 the time.
2281 // No performance impact (too rare) but allows sharing of secondary arrays 2281 // No performance impact (too rare) but allows sharing of secondary arrays
2282 // which has some footprint reduction. 2282 // which has some footprint reduction.
2283 Node *cmp3 = _gvn.transform( new (C, 3) CmpPNode( subklass, superklass ) ); 2283 Node *cmp3 = _gvn.transform( new (C, 3) CmpPNode( subklass, superklass ) );
2284 Node *bol3 = _gvn.transform( new (C, 2) BoolNode( cmp3, BoolTest::eq ) ); 2284 Node *bol3 = _gvn.transform( new (C, 2) BoolNode( cmp3, BoolTest::eq ) );
2285 IfNode *iff3 = create_and_xform_if( control(), bol3, PROB_LIKELY(0.36f), COUNT_UNKNOWN ); 2285 IfNode *iff3 = create_and_xform_if( control(), bol3, PROB_LIKELY(0.36f), COUNT_UNKNOWN );
2286 r_ok_subtype->init_req(2, _gvn.transform( new (C, 1) IfTrueNode ( iff3 ) ) ); 2286 r_ok_subtype->init_req(2, _gvn.transform( new (C, 1) IfTrueNode ( iff3 ) ) );
2287 set_control( _gvn.transform( new (C, 1) IfFalseNode( iff3 ) ) ); 2287 set_control( _gvn.transform( new (C, 1) IfFalseNode( iff3 ) ) );
2288 2288
2289 // -- Roads not taken here: --
2290 // We could also have chosen to perform the self-check at the beginning
2291 // of this code sequence, as the assembler does. This would not pay off
2292 // the same way, since the optimizer, unlike the assembler, can perform
2293 // static type analysis to fold away many successful self-checks.
2294 // Non-foldable self checks work better here in second position, because
2295 // the initial primary superclass check subsumes a self-check for most
2296 // types. An exception would be a secondary type like array-of-interface,
2297 // which does not appear in its own primary supertype display.
2298 // Finally, we could have chosen to move the self-check into the
2299 // PartialSubtypeCheckNode, and from there out-of-line in a platform
2300 // dependent manner. But it is worthwhile to have the check here,
2301 // where it can be perhaps be optimized. The cost in code space is
2302 // small (register compare, branch).
2303
2289 // Now do a linear scan of the secondary super-klass array. Again, no real 2304 // Now do a linear scan of the secondary super-klass array. Again, no real
2290 // performance impact (too rare) but it's gotta be done. 2305 // performance impact (too rare) but it's gotta be done.
2291 // (The stub also contains the self-check of subklass == superklass.
2292 // Since the code is rarely used, there is no penalty for moving it 2306 // Since the code is rarely used, there is no penalty for moving it
2293 // out of line, and it can only improve I-cache density.) 2307 // out of line, and it can only improve I-cache density.
2308 // The decision to inline or out-of-line this final check is platform
2309 // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2294 Node* psc = _gvn.transform( 2310 Node* psc = _gvn.transform(
2295 new (C, 3) PartialSubtypeCheckNode(control(), subklass, superklass) ); 2311 new (C, 3) PartialSubtypeCheckNode(control(), subklass, superklass) );
2296 2312
2297 Node *cmp4 = _gvn.transform( new (C, 3) CmpPNode( psc, null() ) ); 2313 Node *cmp4 = _gvn.transform( new (C, 3) CmpPNode( psc, null() ) );
2298 Node *bol4 = _gvn.transform( new (C, 2) BoolNode( cmp4, BoolTest::ne ) ); 2314 Node *bol4 = _gvn.transform( new (C, 2) BoolNode( cmp4, BoolTest::ne ) );