[Qemu-devel] Re: [PATCH 11/12] ppc: avoid write only variables

[Blue Swirl]

On Fri, Oct 8, 2010 at 9:32 PM, Alexander Graf <address@hidden> wrote:
>
> On 08.10.2010, at 23:25, Blue Swirl wrote:
>
>> Compiling with GCC 4.6.0 20100925 produced warnings:
>> /src/qemu/target-ppc/op_helper.c: In function 'helper_icbi':
>> /src/qemu/target-ppc/op_helper.c:351:14: error: variable 'tmp' set but
>> not used [-Werror=unused-but-set-variable]
>> /src/qemu/target-ppc/op_helper.c: In function 'do_6xx_tlb':
>> /src/qemu/target-ppc/op_helper.c:3805:28: error: variable 'EPN' set
>> but not used [-Werror=unused-but-set-variable]
>> /src/qemu/target-ppc/op_helper.c: In function 'do_74xx_tlb':
>> /src/qemu/target-ppc/op_helper.c:3838:28: error: variable 'EPN' set
>> but not used [-Werror=unused-but-set-variable]
>>
>> Fix by adding a dummy cast so that the variable is not unused. Delete tmp.
>>
>> Signed-off-by: Blue Swirl <address@hidden>
>> ---
>> target-ppc/op_helper.c |   12 +++++++-----
>> 1 files changed, 7 insertions(+), 5 deletions(-)
>>
>> diff --git a/target-ppc/op_helper.c b/target-ppc/op_helper.c
>> index 45f1655..13502ae 100644
>> --- a/target-ppc/op_helper.c
>> +++ b/target-ppc/op_helper.c
>> @@ -348,15 +348,13 @@ void helper_dcbz_970(target_ulong addr)
>>
>> void helper_icbi(target_ulong addr)
>> {
>> -    uint32_t tmp;
>> -
>>     addr &= ~(env->dcache_line_size - 1);
>>     /* Invalidate one cache line :
>>      * PowerPC specification says this is to be treated like a load
>>      * (not a fetch) by the MMU. To be sure it will be so,
>>      * do the load "by hand".
>>      */
>> -    tmp = ldl(addr);
>> +    ldl(addr);
>>     tb_invalidate_page_range(addr, addr + env->icache_line_size);
>> }
>>
>> @@ -3802,7 +3800,8 @@ void helper_tlbie (target_ulong addr)
>> /* PowerPC 602/603 software TLB load instructions helpers */
>> static void do_6xx_tlb (target_ulong new_EPN, int is_code)
>> {
>> -    target_ulong RPN, CMP, EPN;
>> +    target_ulong RPN, CMP;
>> +    target_ulong EPN;
>
> That one's no longer necessary then, right?
>
>>     int way;
>>
>>     RPN = env->spr[SPR_RPA];
>> @@ -3814,6 +3813,7 @@ static void do_6xx_tlb (target_ulong new_EPN, int 
>> is_code)
>>         EPN = env->spr[SPR_DMISS];
>>     }
>>     way = (env->spr[SPR_SRR1] >> 17) & 1;
>> +    (void)EPN; /* avoid a compiler warning */
>>     LOG_SWTLB("%s: EPN " TARGET_FMT_lx " " TARGET_FMT_lx " PTE0 " 
>> TARGET_FMT_lx
>>               " PTE1 " TARGET_FMT_lx " way %d\n", __func__, new_EPN, EPN, 
>> CMP,
>>               RPN, way);
>> @@ -3835,13 +3835,15 @@ void helper_6xx_tlbi (target_ulong EPN)
>> /* PowerPC 74xx software TLB load instructions helpers */
>> static void do_74xx_tlb (target_ulong new_EPN, int is_code)
>> {
>> -    target_ulong RPN, CMP, EPN;
>> +    target_ulong RPN, CMP;
>> +    target_ulong EPN;
>
> Same here.

Right, I'll remove both.