Hi, > -----Original Message----- > From: Richard Sandiford [mailto:richard.sandif...@arm.com] > Sent: Friday, June 12, 2020 2:29 AM > To: Yangfei (Felix) <felix.y...@huawei.com> > Cc: gcc-patches@gcc.gnu.org > Subject: Re: [PATCH PR95570] vect: ICE: Segmentation fault in > vect_loop_versioning > > "Yangfei (Felix)" <felix.y...@huawei.com> writes: > > From 30a0196b0afd45bae9291cfab3fee4ad6b90cbcb Mon Sep 17 00:00:00 > 2001 > > From: Fei Yang <felix.y...@huawei.com> > > Date: Thu, 11 Jun 2020 19:33:22 +0800 > > Subject: [PATCH] vect: Fix an ICE in vect_loop_versioning [PR95570] > > > > In the test case for PR95570, the only data reference in the loop is a > > gather-statter access. Scalar evolution analysis for this data > > reference failed, so DR_STEP is NULL_TREE. This leads to the segmentation > fault. > > We should filter out scatter-gather access in > vect_enhance_data_refs_alignment. > > Looks good, just a couple of very minor details… > > > 2020-06-11 Felix Yang <felix.y...@huawei.com> > > > > gcc/ > > PR tree-optimization/95570 > > * tree-vect-data-refs.c (vect_relevant_for_alignment_p): New > function. > > (vect_verify_datarefs_alignment): Call it to filter out data > > references > > in the loop whose alignment is irrelevant. > > (vect_get_peeling_costs_all_drs): Likewise. > > (vect_peeling_supportable): Likewise. > > (vect_enhance_data_refs_alignment): Likewise. > > > > gcc/testsuite/ > > > > PR tree-optimization/95570 > > * gcc.dg/vect/pr95570.c: New test. > > --- > > gcc/testsuite/gcc.dg/vect/pr95570.c | 11 ++++ > > gcc/tree-vect-data-refs.c | 83 ++++++++++++----------------- > > 2 files changed, 45 insertions(+), 49 deletions(-) create mode > > 100644 gcc/testsuite/gcc.dg/vect/pr95570.c > > > > diff --git a/gcc/testsuite/gcc.dg/vect/pr95570.c > > b/gcc/testsuite/gcc.dg/vect/pr95570.c > > new file mode 100644 > > index 00000000000..b9362614004 > > --- /dev/null > > +++ b/gcc/testsuite/gcc.dg/vect/pr95570.c > > @@ -0,0 +1,11 @@ > > +/* { dg-do compile } */ > > +/* { dg-additional-options "-march=armv8.2-a+sve > > +-msve-vector-bits=256 -mstrict-align -fwrapv" { target aarch64*-*-* } > > +} */ > > + > > +int x[8][32]; > > + > > +void > > +foo (int start) > > +{ > > + for (int i = start; i < start + 16; i++) > > + x[start][i] = i; > > +} > > diff --git a/gcc/tree-vect-data-refs.c b/gcc/tree-vect-data-refs.c > > index 39d5a1b554c..98f6fb76ff9 100644 > > --- a/gcc/tree-vect-data-refs.c > > +++ b/gcc/tree-vect-data-refs.c > > @@ -1129,6 +1129,35 @@ vect_update_misalignment_for_peel > (dr_vec_info *dr_info, > > SET_DR_MISALIGNMENT (dr_info, DR_MISALIGNMENT_UNKNOWN); } > > > > +/* Return TRUE if alignment is relevant for DR_INFO. */ > > Just “Return true …“ for new code. TRUE is a hold-over from C days.
OK.
> > +static bool
> > +vect_relevant_for_alignment_p (dr_vec_info *dr_info) {
> > + stmt_vec_info stmt_info = dr_info->stmt;
> > +
> > + if (!STMT_VINFO_RELEVANT_P (stmt_info))
> > + return false;
> > +
> > + /* For interleaving, only the alignment of the first access
> > + matters. */ if (STMT_VINFO_GROUPED_ACCESS (stmt_info)
> > + && DR_GROUP_FIRST_ELEMENT (stmt_info) != stmt_info)
> > + return false;
> > +
> > + /* For scatter-gather or invariant accesses, alignment is irrelevant
> > + for them. */
>
> Maybe:
>
> /* Scatter-gather and invariant accesses continue to address individual
> scalars, so vector-level alignment is irrelevant. */
Much better : - ) Updated accordingly.
Also bootstrapped and tested on x86_64-linux-gnu.
Thanks,
Felix
gcc/
+2020-06-12 Felix Yang <felix.y...@huawei.com>
+
+ PR tree-optimization/95570
+ * tree-vect-data-refs.c (vect_relevant_for_alignment_p): New function.
+ (vect_verify_datarefs_alignment): Call it to filter out data references
+ in the loop whose alignment is irrelevant.
+ (vect_get_peeling_costs_all_drs): Likewise.
+ (vect_peeling_supportable): Likewise.
+ (vect_enhance_data_refs_alignment): Likewise.
gcc/testsuite/
+2020-06-12 Felix Yang <felix.y...@huawei.com>
+
+ PR tree-optimization/95570
+ * gcc.dg/vect/pr95570.c: New test.
pr95570-v3.diff
Description: pr95570-v3.diff
