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src/share/vm/c1/c1_LinearScan.cpp

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rev 8802 : G1 performance improvements: card batching, joining, sorting, prefetching and write barrier fence elision and simplification based on a global syncrhonization using handshakes piggybacking on thread-local safepoints.


6287       assert(cur_last_op->info() == NULL, "return instructions do not have debug information");
6288       assert(block->number_of_sux() == 0 ||
6289              (return_converted.at(block->block_id()) && block->number_of_sux() == 1),
6290              "blocks that end with return must not have successors");
6291 
6292       assert(cur_last_op->as_Op1() != NULL, "return must be LIR_Op1");
6293       LIR_Opr return_opr = ((LIR_Op1*)cur_last_op)->in_opr();
6294 
6295       for (int j = block->number_of_preds() - 1; j >= 0; j--) {
6296         BlockBegin* pred = block->pred_at(j);
6297         LIR_OpList* pred_instructions = pred->lir()->instructions_list();
6298         LIR_Op*     pred_last_op = pred_instructions->last();
6299 
6300         if (pred_last_op->code() == lir_branch) {
6301           assert(pred_last_op->as_OpBranch() != NULL, "branch must be LIR_OpBranch");
6302           LIR_OpBranch* pred_last_branch = (LIR_OpBranch*)pred_last_op;
6303 
6304           if (pred_last_branch->block() == block && pred_last_branch->cond() == lir_cond_always && pred_last_branch->info() == NULL) {
6305             // replace the jump to a return with a direct return
6306             // Note: currently the edge between the blocks is not deleted
6307             pred_instructions->at_put(pred_instructions->length() - 1, new LIR_Op1(lir_return, return_opr));
6308 #ifdef ASSERT
6309             return_converted.set_bit(pred->block_id());
6310 #endif
6311           }
6312         }
6313       }
6314     }
6315   }
6316 }
6317 
6318 
6319 #ifdef ASSERT
6320 void ControlFlowOptimizer::verify(BlockList* code) {
6321   for (int i = 0; i < code->length(); i++) {
6322     BlockBegin* block = code->at(i);
6323     LIR_OpList* instructions = block->lir()->instructions_list();
6324 
6325     int j;
6326     for (j = 0; j < instructions->length(); j++) {
6327       LIR_OpBranch* op_branch = instructions->at(j)->as_OpBranch();




6287       assert(cur_last_op->info() == NULL, "return instructions do not have debug information");
6288       assert(block->number_of_sux() == 0 ||
6289              (return_converted.at(block->block_id()) && block->number_of_sux() == 1),
6290              "blocks that end with return must not have successors");
6291 
6292       assert(cur_last_op->as_Op1() != NULL, "return must be LIR_Op1");
6293       LIR_Opr return_opr = ((LIR_Op1*)cur_last_op)->in_opr();
6294 
6295       for (int j = block->number_of_preds() - 1; j >= 0; j--) {
6296         BlockBegin* pred = block->pred_at(j);
6297         LIR_OpList* pred_instructions = pred->lir()->instructions_list();
6298         LIR_Op*     pred_last_op = pred_instructions->last();
6299 
6300         if (pred_last_op->code() == lir_branch) {
6301           assert(pred_last_op->as_OpBranch() != NULL, "branch must be LIR_OpBranch");
6302           LIR_OpBranch* pred_last_branch = (LIR_OpBranch*)pred_last_op;
6303 
6304           if (pred_last_branch->block() == block && pred_last_branch->cond() == lir_cond_always && pred_last_branch->info() == NULL) {
6305             // replace the jump to a return with a direct return
6306             // Note: currently the edge between the blocks is not deleted
6307             pred_instructions->at_put(pred_instructions->length() - 1, new LIR_Op1Safepoint(lir_return, return_opr, NULL));
6308 #ifdef ASSERT
6309             return_converted.set_bit(pred->block_id());
6310 #endif
6311           }
6312         }
6313       }
6314     }
6315   }
6316 }
6317 
6318 
6319 #ifdef ASSERT
6320 void ControlFlowOptimizer::verify(BlockList* code) {
6321   for (int i = 0; i < code->length(); i++) {
6322     BlockBegin* block = code->at(i);
6323     LIR_OpList* instructions = block->lir()->instructions_list();
6324 
6325     int j;
6326     for (j = 0; j < instructions->length(); j++) {
6327       LIR_OpBranch* op_branch = instructions->at(j)->as_OpBranch();
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