[AARCH64][PATCH] PR59695

[Kugan]

On 13/01/14 21:05, Richard Earnshaw wrote:
> On 11/01/14 23:42, Kugan wrote:
>> Hi,
>>
>> aarch64_build_constant incorrectly truncates the immediate when
>> constants are generated with MOVN. This causes coinor-osi tests to fail
>> (tracked also in https://bugs.launchpad.net/gcc-linaro/+bug/1263576)
>>
>> Attached patch fixes this. Also attaching a reduced testcase that
>> reproduces this. Tested on aarch64-none-linux-gnu with no new
>> regressions. Is this OK for trunk?
>>
>> Thanks,
>> Kugan
>>
>> gcc/
>> +2013-10-15  Matthew Gretton-Dann  <matthew.gretton-dann@linaro.org>
>> +	    Kugan Vivekanandarajah  <kuganv@linaro.org>
>> +
>> +	PR target/59588
>> +	* config/aarch64/aarch64.c (aarch64_build_constant): Fix incorrect
>> +	truncation.
>> +
>>
>>
>> gcc/testsuite/
>> +2014-01-11  Matthew Gretton-Dann  <matthew.gretton-dann@linaro.org>
>> +	    Kugan Vivekanandarajah  <kuganv@linaro.org>
>> +
>> +	PR target/59695
>> +	* g++.dg/pr59695.C: New file.
>> +
>>
>>
>> p.txt
>>
>>
>> diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
>> index 3d32ea5..854666f 100644
>> --- a/gcc/config/aarch64/aarch64.c
>> +++ b/gcc/config/aarch64/aarch64.c
>> @@ -2486,7 +2486,7 @@ aarch64_build_constant (int regnum, HOST_WIDE_INT val)
>>        if (ncount < zcount)
>>  	{
>>  	  emit_move_insn (gen_rtx_REG (Pmode, regnum),
>> -			  GEN_INT ((~val) & 0xffff));
>> +			  GEN_INT (~((~val) & 0xffff)));
> 
> I think that would be better written as
> 
> 	GEN_INT (val | ~(HOST_WIDE_INT) 0xffff);
> 
> Note the cast after the ~ to ensure we invert the right number of bits.
> 
> Otherwise OK.
> 

Thanks Richard. Is this OK for back-porting to 4.8 as well?

Thanks,
Kugan