Re: ifcvt: Fix bitpos calculation in bitfield lowering [PR107229]

["Andre Vieira (lists)" <andre.simoesdiasvieira@arm.com>]

Hi Rainer,

Thanks for reporting, I was actually expecting these! I thought about 
pre-empting them by using a positive filter on the tests for aarch64 and 
x86_64 as I knew those would pass, but I thought it would be better to 
let other targets report failures since then you get a testsuite that 
covers more targets than just what I'm able to check.

Are there any sparc architectures that would support these or should I 
just xfail sparc*-*-* ?

For instance: I also saw PR107240 for which one of the write tests fails 
on Power 7 BE. I'm suggesting adding an xfail for that one

Kind regards,
Andre

On 13/10/2022 12:39, Rainer Orth wrote:
> Hi Andre,
>
>> The bitposition calculation for the bitfield lowering in loop if conversion
>> was not
>> taking DECL_FIELD_OFFSET into account, which meant that it would result in
>> wrong bitpositions for bitfields that did not end up having representations
>> starting at the beginning of the struct.
>>
>> Bootstrappend and regression tested on aarch64-none-linux-gnu and
>> x86_64-pc-linux-gnu.
> I tried this patch together with the one for PR tree-optimization/107226
> on sparc-sun-solaris2.11 to check if it cures the bootstrap failure
> reported in PR tree-optimization/107232.  While this restores bootstrap,
> several of the new tests FAIL:
>
> +FAIL: gcc.dg/vect/vect-bitfield-read-1.c -flto -ffat-lto-objects  scan-tree-dump-times vect "vectorized 1 loops" 1
> +FAIL: gcc.dg/vect/vect-bitfield-read-1.c scan-tree-dump-times vect "vectorized 1 loops" 1
> +FAIL: gcc.dg/vect/vect-bitfield-read-2.c -flto -ffat-lto-objects  scan-tree-dump-times vect "vectorized 1 loops" 1
> +FAIL: gcc.dg/vect/vect-bitfield-read-2.c scan-tree-dump-times vect "vectorized 1 loops" 1
> +FAIL: gcc.dg/vect/vect-bitfield-read-3.c -flto -ffat-lto-objects  scan-tree-dump-times vect "vectorized 2 loops" 1
> +FAIL: gcc.dg/vect/vect-bitfield-read-3.c scan-tree-dump-times vect "vectorized 2 loops" 1
> +FAIL: gcc.dg/vect/vect-bitfield-read-4.c -flto -ffat-lto-objects  scan-tree-dump-times vect "vectorized 1 loops" 1
> +FAIL: gcc.dg/vect/vect-bitfield-read-4.c scan-tree-dump-times vect "vectorized 1 loops" 1
> +FAIL: gcc.dg/vect/vect-bitfield-read-6.c -flto -ffat-lto-objects  scan-tree-dump-times vect "vectorized 1 loops" 1
> +FAIL: gcc.dg/vect/vect-bitfield-write-1.c -flto -ffat-lto-objects  scan-tree-dump-times vect "vectorized 1 loops" 1
> +FAIL: gcc.dg/vect/vect-bitfield-write-1.c scan-tree-dump-times vect "vectorized 1 loops" 1
> +FAIL: gcc.dg/vect/vect-bitfield-write-2.c -flto -ffat-lto-objects  scan-tree-dump-times vect "vectorized 1 loops" 1
> +FAIL: gcc.dg/vect/vect-bitfield-write-2.c scan-tree-dump-times vect "vectorized 1 loops" 1
> +FAIL: gcc.dg/vect/vect-bitfield-write-3.c -flto -ffat-lto-objects  scan-tree-dump-times vect "vectorized 1 loops" 1
> +FAIL: gcc.dg/vect/vect-bitfield-write-3.c scan-tree-dump-times vect "vectorized 1 loops" 1
> +FAIL: gcc.dg/vect/vect-bitfield-write-5.c -flto -ffat-lto-objects  scan-tree-dump-times vect "vectorized 1 loops" 1
> +FAIL: gcc.dg/vect/vect-bitfield-write-5.c scan-tree-dump-times vect "vectorized 1 loops" 1
>
> For vect-bitfield-read-1.c, the dump has
>
> gcc.dg/vect/vect-bitfield-read-1.c:25:23: note:   ==> examining pattern def statement: patt_31 = patt_30 >> 1;
> gcc.dg/vect/vect-bitfield-read-1.c:25:23: note:   ==> examining statement: patt_31 = patt_30 >> 1;
> gcc.dg/vect/vect-bitfield-read-1.c:25:23: note:   vect_is_simple_use: operand _ifc__27 & 4294967294, type of def: internal
> gcc.dg/vect/vect-bitfield-read-1.c:25:23: note:   vect_is_simple_use: vectype vector(2) unsigned int
> gcc.dg/vect/vect-bitfield-read-1.c:25:23: note:   vect_is_simple_use: operand 1, type of def: constant
> gcc.dg/vect/vect-bitfield-read-1.c:25:23: missed:   op not supported by target.
> gcc.dg/vect/vect-bitfield-read-1.c:23:1: missed:   not vectorized: relevant stmt not supported: patt_31 = patt_30 >> 1;
> gcc.dg/vect/vect-bitfield-read-1.c:25:23: missed:  bad operation or unsupported loop bound.
> gcc.dg/vect/vect-bitfield-read-1.c:25:23: note:  ***** Analysis  failed with vector mode V2SI
>
> 	Rainer
>