On Tue, Apr 9, 2024 at 4:07 AM Kewen.Lin <li...@linux.ibm.com> wrote:
>
> on 2024/4/8 18:47, Richard Biener wrote:
> > On Mon, Apr 8, 2024 at 11:22 AM Kewen.Lin <li...@linux.ibm.com> wrote:
> >>
> >> Hi,
> >>
> >> As the comments in PR88309 show, there are two oversights
> >> in rs6000_gimple_fold_builtin that pass align in bytes to
> >> build_aligned_type but which actually requires align in
> >> bits, it causes unexpected ICE or hanging in function
> >> is_miss_rate_acceptable due to zero align_unit value.
> >>
> >> This patch is to fix them by converting bytes to bits, add
> >> an assertion on positive align_unit value and notes function
> >> build_aligned_type requires align measured in bits in its
> >> function comment.
> >>
> >> Bootstrapped and regtested on x86_64-redhat-linux,
> >> powerpc64-linux-gnu P8/P9 and powerpc64le-linux-gnu P9 and P10.
> >>
> >> Is it (the generic part code change) ok for trunk?
> >
> > OK
>
> Thanks, pushed as r14-9850, is it also ok to backport after burn-in time?
Sure.
> BR,
> Kewen
>
> >
> >> BR,
> >> Kewen
> >> -----
> >> PR target/88309
> >>
> >> Co-authored-by: Andrew Pinski <quic_apin...@quicinc.com>
> >>
> >> gcc/ChangeLog:
> >>
> >> * config/rs6000/rs6000-builtin.cc (rs6000_gimple_fold_builtin): Fix
> >> wrong align passed to function build_aligned_type.
> >> * tree-ssa-loop-prefetch.cc (is_miss_rate_acceptable): Add an
> >> assertion to ensure align_unit should be positive.
> >> * tree.cc (build_qualified_type): Update function comments.
> >>
> >> gcc/testsuite/ChangeLog:
> >>
> >> * gcc.target/powerpc/pr88309.c: New test.
> >> ---
> >> gcc/config/rs6000/rs6000-builtin.cc | 4 ++--
> >> gcc/testsuite/gcc.target/powerpc/pr88309.c | 27 ++++++++++++++++++++++
> >> gcc/tree-ssa-loop-prefetch.cc | 2 ++
> >> gcc/tree.cc | 3 ++-
> >> 4 files changed, 33 insertions(+), 3 deletions(-)
> >> create mode 100644 gcc/testsuite/gcc.target/powerpc/pr88309.c
> >>
> >> diff --git a/gcc/config/rs6000/rs6000-builtin.cc
> >> b/gcc/config/rs6000/rs6000-builtin.cc
> >> index 6698274031b..e7d6204074c 100644
> >> --- a/gcc/config/rs6000/rs6000-builtin.cc
> >> +++ b/gcc/config/rs6000/rs6000-builtin.cc
> >> @@ -1900,7 +1900,7 @@ rs6000_gimple_fold_builtin (gimple_stmt_iterator
> >> *gsi)
> >> tree lhs_type = TREE_TYPE (lhs);
> >> /* In GIMPLE the type of the MEM_REF specifies the alignment. The
> >> required alignment (power) is 4 bytes regardless of data type.
> >> */
> >> - tree align_ltype = build_aligned_type (lhs_type, 4);
> >> + tree align_ltype = build_aligned_type (lhs_type, 32);
> >> /* POINTER_PLUS_EXPR wants the offset to be of type 'sizetype'.
> >> Create
> >> the tree using the value from arg0. The resulting type will
> >> match
> >> the type of arg1. */
> >> @@ -1944,7 +1944,7 @@ rs6000_gimple_fold_builtin (gimple_stmt_iterator
> >> *gsi)
> >> tree arg2_type = ptr_type_node;
> >> /* In GIMPLE the type of the MEM_REF specifies the alignment. The
> >> required alignment (power) is 4 bytes regardless of data type.
> >> */
> >> - tree align_stype = build_aligned_type (arg0_type, 4);
> >> + tree align_stype = build_aligned_type (arg0_type, 32);
> >> /* POINTER_PLUS_EXPR wants the offset to be of type 'sizetype'.
> >> Create
> >> the tree using the value from arg1. */
> >> gimple_seq stmts = NULL;
> >> diff --git a/gcc/testsuite/gcc.target/powerpc/pr88309.c
> >> b/gcc/testsuite/gcc.target/powerpc/pr88309.c
> >> new file mode 100644
> >> index 00000000000..c0078cf2b8c
> >> --- /dev/null
> >> +++ b/gcc/testsuite/gcc.target/powerpc/pr88309.c
> >> @@ -0,0 +1,27 @@
> >> +/* { dg-require-effective-target powerpc_vsx_ok } */
> >> +/* { dg-options "-mvsx -O2 -fprefetch-loop-arrays" } */
> >> +
> >> +/* Verify there is no ICE or hanging. */
> >> +
> >> +#include <altivec.h>
> >> +
> >> +void b(float *c, vector float a, vector float, vector float)
> >> +{
> >> + vector float d;
> >> + vector char ahbc;
> >> + vec_xst(vec_perm(a, d, ahbc), 0, c);
> >> +}
> >> +
> >> +vector float e(vector unsigned);
> >> +
> >> +void f() {
> >> + float *dst;
> >> + int g = 0;
> >> + for (;; g += 16) {
> >> + vector unsigned m, i;
> >> + vector unsigned n, j;
> >> + vector unsigned k, l;
> >> + b(dst + g * 3, e(m), e(n), e(k));
> >> + b(dst + (g + 4) * 3, e(i), e(j), e(l));
> >> + }
> >> +}
> >> diff --git a/gcc/tree-ssa-loop-prefetch.cc b/gcc/tree-ssa-loop-prefetch.cc
> >> index bbd98e03254..70073cc4fe4 100644
> >> --- a/gcc/tree-ssa-loop-prefetch.cc
> >> +++ b/gcc/tree-ssa-loop-prefetch.cc
> >> @@ -739,6 +739,8 @@ is_miss_rate_acceptable (unsigned HOST_WIDE_INT
> >> cache_line_size,
> >> if (delta >= (HOST_WIDE_INT) cache_line_size)
> >> return false;
> >>
> >> + gcc_assert (align_unit > 0);
> >> +
> >> miss_positions = 0;
> >> total_positions = (cache_line_size / align_unit) * distinct_iters;
> >> max_allowed_miss_positions = (ACCEPTABLE_MISS_RATE * total_positions) /
> >> 1000;
> >> diff --git a/gcc/tree.cc b/gcc/tree.cc
> >> index f801712c9dd..6f8400e6640 100644
> >> --- a/gcc/tree.cc
> >> +++ b/gcc/tree.cc
> >> @@ -5689,7 +5689,8 @@ build_qualified_type (tree type, int type_quals
> >> MEM_STAT_DECL)
> >> return t;
> >> }
> >>
> >> -/* Create a variant of type T with alignment ALIGN. */
> >> +/* Create a variant of type T with alignment ALIGN which
> >> + is measured in bits. */
> >>
> >> tree
> >> build_aligned_type (tree type, unsigned int align)
> >> --
> >> 2.43.0
