Mercurial > jdk8-mips64-public > hotspot / file comparison
comparison: src/share/vm/opto/subnode.cpp
src/share/vm/opto/subnode.cpp
- changeset 647
- 99bf1609e2a5
- parent 548
- ba764ed4b6f2
- child 656
- 1e026f8da827
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| 623:c0ecab83e6f3 | 647:99bf1609e2a5 |
|---|---|
| 43 in(2)->Opcode() == Opcode() && | 43 in(2)->Opcode() == Opcode() && |
| 44 phase->type( in(2)->in(1) )->higher_equal( zero ) ) { | 44 phase->type( in(2)->in(1) )->higher_equal( zero ) ) { |
| 45 return in(2)->in(2); | 45 return in(2)->in(2); |
| 46 } | 46 } |
| 47 | 47 |
| 48 // Convert "(X+Y) - Y" into X | 48 // Convert "(X+Y) - Y" into X and "(X+Y) - X" into Y |
| 49 if( in(1)->Opcode() == Op_AddI ) { | 49 if( in(1)->Opcode() == Op_AddI ) { |
| 50 if( phase->eqv(in(1)->in(2),in(2)) ) | 50 if( phase->eqv(in(1)->in(2),in(2)) ) |
| 51 return in(1)->in(1); | 51 return in(1)->in(1); |
| 52 if (phase->eqv(in(1)->in(1),in(2))) | |
| 53 return in(1)->in(2); | |
| 54 | |
| 52 // Also catch: "(X + Opaque2(Y)) - Y". In this case, 'Y' is a loop-varying | 55 // Also catch: "(X + Opaque2(Y)) - Y". In this case, 'Y' is a loop-varying |
| 53 // trip counter and X is likely to be loop-invariant (that's how O2 Nodes | 56 // trip counter and X is likely to be loop-invariant (that's how O2 Nodes |
| 54 // are originally used, although the optimizer sometimes jiggers things). | 57 // are originally used, although the optimizer sometimes jiggers things). |
| 55 // This folding through an O2 removes a loop-exit use of a loop-varying | 58 // This folding through an O2 removes a loop-exit use of a loop-varying |
| 56 // value and generally lowers register pressure in and around the loop. | 59 // value and generally lowers register pressure in and around the loop. |
