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

[Richard Biener <rguenther@suse.de>]

On Thu, 13 Oct 2022, Andre Vieira (lists) wrote:

> 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

for the failure below we seem to require vectorizing shifts for which I
think we have a vect_* target to check?

> 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
> >
> 

-- 
Richard Biener <rguenther@suse.de>
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