[dpdk-dev] [PATCH v4 05/23] /lib/librte_eal: stage cast from uint64 to long

[Andy Green]

On 05/17/2018 06:47 PM, Bruce Richardson wrote:
> On Mon, May 14, 2018 at 01:09:52PM +0800, Andy Green wrote:
>> /projects/lagopus/src/dpdk/build/include/rte_random.h:
>> In function 'rte_srand':
>> /projects/lagopus/src/dpdk/build/include/rte_random.h:34:10:
>> warning: conversion to 'long int' from 'long unsigned int'
>> may change the sign of the result [-Wsign-conversion]
>>    srand48((long unsigned int)seedval);
>>
>> /projects/lagopus/src/dpdk/build/include/rte_random.h:51:8:
>> warning: conversion to 'uint64_t' {aka 'long unsigned int'}
>> from 'long int' may change the sign of the result
>> [-Wsign-conversion]
>>    val = lrand48();
>>          ^~~~~~~
>> /projects/lagopus/src/dpdk/build/include/rte_random.h:53:6:
>> warning: conversion to 'long unsigned int' from 'long int'
>> may change the sign of the result [-Wsign-conversion]
>>    val += lrand48();
>>
>> Signed-off-by: Andy Green <andy at warmcat.com>
>> ---
>>   lib/librte_eal/common/include/rte_random.h |    6 +++---
>>   1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/lib/librte_eal/common/include/rte_random.h b/lib/librte_eal/common/include/rte_random.h
>> index 63bb28088..e30777b83 100644
>> --- a/lib/librte_eal/common/include/rte_random.h
>> +++ b/lib/librte_eal/common/include/rte_random.h
>> @@ -31,7 +31,7 @@ extern "C" {
>>   static inline void
>>   rte_srand(uint64_t seedval)
>>   {
>> -	srand48((long unsigned int)seedval);
>> +	srand48((long)(unsigned long)seedval);
> 
> Is double-cast necessary here? Can we not just cast straight to long?

You're right, it can just go straight to long.

I'm going through adding the compiler errors into the patches that have 
them missing and doing this kind of small change, and I'll reissue in an 
hour or two (.

-Andy

>>   }
>>   
>>   /**
>> @@ -48,9 +48,9 @@ static inline uint64_t
>>   rte_rand(void)
>>   {
>>   	uint64_t val;
>> -	val = lrand48();
>> +	val = (uint64_t)lrand48();
>>   	val <<= 32;
>> -	val += lrand48();
>> +	val += (uint64_t)lrand48();
>>   	return val;
>>   }
>>   
>>
> 
> Apart from the one minor comment above LGTM
> 
> Acked-by: Bruce Richardson <bruce.richardson at intel.com>
>