src/cpu/x86/vm/c1_CodeStubs_x86.cpp

rev 4136 : 7153771: array bound check elimination for c1
Summary: when possible optimize out array bound checks, inserting predicates when needed.
Reviewed-by:

*** 99,108 ****
--- 99,116 ----
  }
  
  
  void RangeCheckStub::emit_code(LIR_Assembler* ce) {
    __ bind(_entry);
+   if (_info->deoptimize_on_exception()) {
+     address a = Runtime1::entry_for(Runtime1::predicate_failed_trap_id);
+     __ call(RuntimeAddress(a));
+     ce->add_call_info_here(_info);
+     debug_only(__ should_not_reach_here());
+     return;
+   }
+ 
    // pass the array index on stack because all registers must be preserved
    if (_index->is_cpu_register()) {
      ce->store_parameter(_index->as_register(), 0);
    } else {
      ce->store_parameter(_index->as_jint(), 0);
*** 116,125 ****
--- 124,145 ----
    __ call(RuntimeAddress(Runtime1::entry_for(stub_id)));
    ce->add_call_info_here(_info);
    debug_only(__ should_not_reach_here());
  }
  
+ PredicateFailedStub::PredicateFailedStub(CodeEmitInfo* info) { 
+   _info = new CodeEmitInfo(info);
+ }
+ 
+ void PredicateFailedStub::emit_code(LIR_Assembler* ce) {
+   __ bind(_entry); 
+   address a = Runtime1::entry_for(Runtime1::predicate_failed_trap_id);
+   __ call(RuntimeAddress(a));
+   ce->add_call_info_here(_info);
+   ce->verify_oop_map(_info); 
+   debug_only(__ should_not_reach_here()); 
+ }
  
  void DivByZeroStub::emit_code(LIR_Assembler* ce) {
    if (_offset != -1) {
      ce->compilation()->implicit_exception_table()->append(_offset, __ offset());
    }
*** 412,424 ****
    DEBUG_ONLY(__ should_not_reach_here());
  }
  
  
  void ImplicitNullCheckStub::emit_code(LIR_Assembler* ce) {
    ce->compilation()->implicit_exception_table()->append(_offset, __ offset());
    __ bind(_entry);
!   __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::throw_null_pointer_exception_id)));
    ce->add_call_info_here(_info);
    debug_only(__ should_not_reach_here());
  }
  
  
--- 432,453 ----
    DEBUG_ONLY(__ should_not_reach_here());
  }
  
  
  void ImplicitNullCheckStub::emit_code(LIR_Assembler* ce) {
+  
+   address a;
+   if (_info->deoptimize_on_exception()) {
+     // Deoptimize, do not throw the exception, because it is probably wrong to do it here.
+     a = Runtime1::entry_for(Runtime1::predicate_failed_trap_id);
+   } else {
+     a = Runtime1::entry_for(Runtime1::throw_null_pointer_exception_id);
+   }
+ 
    ce->compilation()->implicit_exception_table()->append(_offset, __ offset());
    __ bind(_entry);
!   __ call(RuntimeAddress(a));
    ce->add_call_info_here(_info);
    debug_only(__ should_not_reach_here());
  }