Re: [Qemu-devel] [PATCH v3 2/3] target-i386:make hw_breakpoint_enabled return bool type

[Jan Kiszka]

On 2012-12-07 11:24, Peter Maydell wrote:
> On 7 December 2012 01:25, liguang <address@hidden> wrote:
>> Signed-off-by: liguang <address@hidden>
>> ---
>>  target-i386/cpu.h |   15 +++++++++++++--
>>  1 files changed, 13 insertions(+), 2 deletions(-)
>>
>> diff --git a/target-i386/cpu.h b/target-i386/cpu.h
>> index 29245d1..3646128 100644
>> --- a/target-i386/cpu.h
>> +++ b/target-i386/cpu.h
>> @@ -996,9 +996,20 @@ int cpu_x86_handle_mmu_fault(CPUX86State *env, 
>> target_ulong addr,
>>  #define cpu_handle_mmu_fault cpu_x86_handle_mmu_fault
>>  void cpu_x86_set_a20(CPUX86State *env, int a20_state);
>>
>> -static inline int hw_breakpoint_enabled(unsigned long dr7, int index)
>> +static inline bool hw_local_breakpoint_enabled(unsigned long dr7, int index)
>>  {
>> -    return (dr7 >> (index * 2)) & 3;
>> +    return !(((dr7 >> (index * 2)) ^ 1) & 3);
> 
> This is pretty confusing and I'm pretty sure the function is
> misnamed too. If we're checking "is local breakpoint enabled"
> then we only want to check one of the two enable bits, not both.
> 

Yes, and I already asked to define the proper constants that allow
checking for local vs. global enable bit. They have to be used here
instead of all the magic & 3 or ^ 1 stuff.

BTW, there is no need for "converting" ("!!") the result of the (value &
mask) to bool, the compiler will do this already.

Jan

> 
>> +}
>> +
>> +static inline bool hw_global_breakpoint_enabled(unsigned long dr7, int 
>> index)
>> +{
>> +    return !!((dr7 >> (index * 2)) & 2);
>> +}
>> +
>> +static inline bool hw_breakpoint_enabled(unsigned long dr7, int index)
>> +{
>> +    return (hw_global_breakpoint_enabled(dr7, index) ||
>> +            hw_local_breakpoint_enabled(dr7, index));
>>  }
> 
> -- PMM
> 

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