| Message ID | 20210715122054.2002001-1-aldyh@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | [PUSHED] Abstract out non_null adjustments in ranger. | expand |
As I mentioned when I pushed the patch in this thread, I have run into cases where a pointer has a non-varying range, but it includes 0. The varying check causes no further refinements to be done. The previous cases I had seen were in follow-up threader work, so I was delaying pushing this until then. But I'm now going through VRP cases that evrp is missing, and this is one of the main culprits. I will push this once tests are done. If for some reason, varying restrictions are needed, we can always adjust the callers to adjust_range. Aldy On Thu, Jul 15, 2021 at 2:21 PM Aldy Hernandez <aldyh@redhat.com> wrote: > > There are 4 exact copies of the non-null range adjusting code in the > ranger. This patch abstracts the functionality into a separate method. > > As a follow-up I would like to remove the varying_p check, since I have > seen incoming ranges such as [0, 0xff....ef] which are not varying, but > are not-null. Removing the varying restriction catches those. > > Tested on x86-64 Linux. > > Pushed to trunk. > > p.s. Andrew, what are your thoughts on removing the varying_p() check as > a follow-up? > > gcc/ChangeLog: > > * gimple-range-cache.cc (non_null_ref::adjust_range): New. > (ranger_cache::range_of_def): Call adjust_range. > (ranger_cache::entry_range): Same. > * gimple-range-cache.h (non_null_ref::adjust_range): New. > * gimple-range.cc (gimple_ranger::range_of_expr): Call > adjust_range. > (gimple_ranger::range_on_entry): Same. > --- > gcc/gimple-range-cache.cc | 35 ++++++++++++++++++++++++++--------- > gcc/gimple-range-cache.h | 2 ++ > gcc/gimple-range.cc | 8 ++------ > 3 files changed, 30 insertions(+), 15 deletions(-) > > diff --git a/gcc/gimple-range-cache.cc b/gcc/gimple-range-cache.cc > index 98ecdbbd68e..23597ade802 100644 > --- a/gcc/gimple-range-cache.cc > +++ b/gcc/gimple-range-cache.cc > @@ -81,6 +81,29 @@ non_null_ref::non_null_deref_p (tree name, basic_block bb, bool search_dom) > return false; > } > > +// If NAME has a non-null dereference in block BB, adjust R with the > +// non-zero information from non_null_deref_p, and return TRUE. If > +// SEARCH_DOM is true, non_null_deref_p should search the dominator tree. > + > +bool > +non_null_ref::adjust_range (irange &r, tree name, basic_block bb, > + bool search_dom) > +{ > + // Check if pointers have any non-null dereferences. Non-call > + // exceptions mean we could throw in the middle of the block, so just > + // punt for now on those. > + if (!cfun->can_throw_non_call_exceptions > + && r.varying_p () > + && non_null_deref_p (name, bb, search_dom)) > + { > + int_range<2> nz; > + nz.set_nonzero (TREE_TYPE (name)); > + r.intersect (nz); > + return true; > + } > + return false; > +} > + > // Allocate an populate the bitmap for NAME. An ON bit for a block > // index indicates there is a non-null reference in that block. In > // order to populate the bitmap, a quick run of all the immediate uses > @@ -857,9 +880,8 @@ ranger_cache::range_of_def (irange &r, tree name, basic_block bb) > r = gimple_range_global (name); > } > > - if (bb && r.varying_p () && m_non_null.non_null_deref_p (name, bb, false) && > - !cfun->can_throw_non_call_exceptions) > - r = range_nonzero (TREE_TYPE (name)); > + if (bb) > + m_non_null.adjust_range (r, name, bb, false); > } > > // Get the range of NAME as it occurs on entry to block BB. > @@ -878,12 +900,7 @@ ranger_cache::entry_range (irange &r, tree name, basic_block bb) > if (!m_on_entry.get_bb_range (r, name, bb)) > range_of_def (r, name); > > - // Check if pointers have any non-null dereferences. Non-call > - // exceptions mean we could throw in the middle of the block, so just > - // punt for now on those. > - if (r.varying_p () && m_non_null.non_null_deref_p (name, bb, false) && > - !cfun->can_throw_non_call_exceptions) > - r = range_nonzero (TREE_TYPE (name)); > + m_non_null.adjust_range (r, name, bb, false); > } > > // Get the range of NAME as it occurs on exit from block BB. > diff --git a/gcc/gimple-range-cache.h b/gcc/gimple-range-cache.h > index ecf63dc01b3..f842e9c092a 100644 > --- a/gcc/gimple-range-cache.h > +++ b/gcc/gimple-range-cache.h > @@ -34,6 +34,8 @@ public: > non_null_ref (); > ~non_null_ref (); > bool non_null_deref_p (tree name, basic_block bb, bool search_dom = true); > + bool adjust_range (irange &r, tree name, basic_block bb, > + bool search_dom = true); > private: > vec <bitmap> m_nn; > void process_name (tree name); > diff --git a/gcc/gimple-range.cc b/gcc/gimple-range.cc > index 1851339c528..b210787d0b7 100644 > --- a/gcc/gimple-range.cc > +++ b/gcc/gimple-range.cc > @@ -69,9 +69,7 @@ gimple_ranger::range_of_expr (irange &r, tree expr, gimple *stmt) > if (def_stmt && gimple_bb (def_stmt) == bb) > { > range_of_stmt (r, def_stmt, expr); > - if (!cfun->can_throw_non_call_exceptions && r.varying_p () && > - m_cache.m_non_null.non_null_deref_p (expr, bb)) > - r = range_nonzero (TREE_TYPE (expr)); > + m_cache.m_non_null.adjust_range (r, expr, bb, true); > } > else > // Otherwise OP comes from outside this block, use range on entry. > @@ -95,9 +93,7 @@ gimple_ranger::range_on_entry (irange &r, basic_block bb, tree name) > if (m_cache.block_range (entry_range, bb, name)) > r.intersect (entry_range); > > - if (!cfun->can_throw_non_call_exceptions && r.varying_p () && > - m_cache.m_non_null.non_null_deref_p (name, bb)) > - r = range_nonzero (TREE_TYPE (name)); > + m_cache.m_non_null.adjust_range (r, name, bb, true); > } > > // Calculate the range for NAME at the end of block BB and return it in R. > -- > 2.31.1 >
Well, arbitrarily allowing everything caused some -Wnonnull regressions. I've changed the check to !r.zero_p() && !r.nonzero_p(), as the only reasonable ranges for pointers besides varying/undefined are zero and non-zero. Attached is the final version of the patch I have pushed. Tested on x86-64 Linux. On Wed, Jul 21, 2021 at 5:29 PM Aldy Hernandez <aldyh@redhat.com> wrote: > > As I mentioned when I pushed the patch in this thread, I have run into > cases where a pointer has a non-varying range, but it includes 0. The > varying check causes no further refinements to be done. The previous > cases I had seen were in follow-up threader work, so I was delaying > pushing this until then. But I'm now going through VRP cases that > evrp is missing, and this is one of the main culprits. > > I will push this once tests are done. If for some reason, varying > restrictions are needed, we can always adjust the callers to > adjust_range. > > Aldy > > On Thu, Jul 15, 2021 at 2:21 PM Aldy Hernandez <aldyh@redhat.com> wrote: > > > > There are 4 exact copies of the non-null range adjusting code in the > > ranger. This patch abstracts the functionality into a separate method. > > > > As a follow-up I would like to remove the varying_p check, since I have > > seen incoming ranges such as [0, 0xff....ef] which are not varying, but > > are not-null. Removing the varying restriction catches those. > > > > Tested on x86-64 Linux. > > > > Pushed to trunk. > > > > p.s. Andrew, what are your thoughts on removing the varying_p() check as > > a follow-up? > > > > gcc/ChangeLog: > > > > * gimple-range-cache.cc (non_null_ref::adjust_range): New. > > (ranger_cache::range_of_def): Call adjust_range. > > (ranger_cache::entry_range): Same. > > * gimple-range-cache.h (non_null_ref::adjust_range): New. > > * gimple-range.cc (gimple_ranger::range_of_expr): Call > > adjust_range. > > (gimple_ranger::range_on_entry): Same. > > --- > > gcc/gimple-range-cache.cc | 35 ++++++++++++++++++++++++++--------- > > gcc/gimple-range-cache.h | 2 ++ > > gcc/gimple-range.cc | 8 ++------ > > 3 files changed, 30 insertions(+), 15 deletions(-) > > > > diff --git a/gcc/gimple-range-cache.cc b/gcc/gimple-range-cache.cc > > index 98ecdbbd68e..23597ade802 100644 > > --- a/gcc/gimple-range-cache.cc > > +++ b/gcc/gimple-range-cache.cc > > @@ -81,6 +81,29 @@ non_null_ref::non_null_deref_p (tree name, basic_block bb, bool search_dom) > > return false; > > } > > > > +// If NAME has a non-null dereference in block BB, adjust R with the > > +// non-zero information from non_null_deref_p, and return TRUE. If > > +// SEARCH_DOM is true, non_null_deref_p should search the dominator tree. > > + > > +bool > > +non_null_ref::adjust_range (irange &r, tree name, basic_block bb, > > + bool search_dom) > > +{ > > + // Check if pointers have any non-null dereferences. Non-call > > + // exceptions mean we could throw in the middle of the block, so just > > + // punt for now on those. > > + if (!cfun->can_throw_non_call_exceptions > > + && r.varying_p () > > + && non_null_deref_p (name, bb, search_dom)) > > + { > > + int_range<2> nz; > > + nz.set_nonzero (TREE_TYPE (name)); > > + r.intersect (nz); > > + return true; > > + } > > + return false; > > +} > > + > > // Allocate an populate the bitmap for NAME. An ON bit for a block > > // index indicates there is a non-null reference in that block. In > > // order to populate the bitmap, a quick run of all the immediate uses > > @@ -857,9 +880,8 @@ ranger_cache::range_of_def (irange &r, tree name, basic_block bb) > > r = gimple_range_global (name); > > } > > > > - if (bb && r.varying_p () && m_non_null.non_null_deref_p (name, bb, false) && > > - !cfun->can_throw_non_call_exceptions) > > - r = range_nonzero (TREE_TYPE (name)); > > + if (bb) > > + m_non_null.adjust_range (r, name, bb, false); > > } > > > > // Get the range of NAME as it occurs on entry to block BB. > > @@ -878,12 +900,7 @@ ranger_cache::entry_range (irange &r, tree name, basic_block bb) > > if (!m_on_entry.get_bb_range (r, name, bb)) > > range_of_def (r, name); > > > > - // Check if pointers have any non-null dereferences. Non-call > > - // exceptions mean we could throw in the middle of the block, so just > > - // punt for now on those. > > - if (r.varying_p () && m_non_null.non_null_deref_p (name, bb, false) && > > - !cfun->can_throw_non_call_exceptions) > > - r = range_nonzero (TREE_TYPE (name)); > > + m_non_null.adjust_range (r, name, bb, false); > > } > > > > // Get the range of NAME as it occurs on exit from block BB. > > diff --git a/gcc/gimple-range-cache.h b/gcc/gimple-range-cache.h > > index ecf63dc01b3..f842e9c092a 100644 > > --- a/gcc/gimple-range-cache.h > > +++ b/gcc/gimple-range-cache.h > > @@ -34,6 +34,8 @@ public: > > non_null_ref (); > > ~non_null_ref (); > > bool non_null_deref_p (tree name, basic_block bb, bool search_dom = true); > > + bool adjust_range (irange &r, tree name, basic_block bb, > > + bool search_dom = true); > > private: > > vec <bitmap> m_nn; > > void process_name (tree name); > > diff --git a/gcc/gimple-range.cc b/gcc/gimple-range.cc > > index 1851339c528..b210787d0b7 100644 > > --- a/gcc/gimple-range.cc > > +++ b/gcc/gimple-range.cc > > @@ -69,9 +69,7 @@ gimple_ranger::range_of_expr (irange &r, tree expr, gimple *stmt) > > if (def_stmt && gimple_bb (def_stmt) == bb) > > { > > range_of_stmt (r, def_stmt, expr); > > - if (!cfun->can_throw_non_call_exceptions && r.varying_p () && > > - m_cache.m_non_null.non_null_deref_p (expr, bb)) > > - r = range_nonzero (TREE_TYPE (expr)); > > + m_cache.m_non_null.adjust_range (r, expr, bb, true); > > } > > else > > // Otherwise OP comes from outside this block, use range on entry. > > @@ -95,9 +93,7 @@ gimple_ranger::range_on_entry (irange &r, basic_block bb, tree name) > > if (m_cache.block_range (entry_range, bb, name)) > > r.intersect (entry_range); > > > > - if (!cfun->can_throw_non_call_exceptions && r.varying_p () && > > - m_cache.m_non_null.non_null_deref_p (name, bb)) > > - r = range_nonzero (TREE_TYPE (name)); > > + m_cache.m_non_null.adjust_range (r, name, bb, true); > > } > > > > // Calculate the range for NAME at the end of block BB and return it in R. > > -- > > 2.31.1 > >
diff --git a/gcc/gimple-range-cache.cc b/gcc/gimple-range-cache.cc index 98ecdbbd68e..23597ade802 100644 --- a/gcc/gimple-range-cache.cc +++ b/gcc/gimple-range-cache.cc @@ -81,6 +81,29 @@ non_null_ref::non_null_deref_p (tree name, basic_block bb, bool search_dom) return false; } +// If NAME has a non-null dereference in block BB, adjust R with the +// non-zero information from non_null_deref_p, and return TRUE. If +// SEARCH_DOM is true, non_null_deref_p should search the dominator tree. + +bool +non_null_ref::adjust_range (irange &r, tree name, basic_block bb, + bool search_dom) +{ + // Check if pointers have any non-null dereferences. Non-call + // exceptions mean we could throw in the middle of the block, so just + // punt for now on those. + if (!cfun->can_throw_non_call_exceptions + && r.varying_p () + && non_null_deref_p (name, bb, search_dom)) + { + int_range<2> nz; + nz.set_nonzero (TREE_TYPE (name)); + r.intersect (nz); + return true; + } + return false; +} + // Allocate an populate the bitmap for NAME. An ON bit for a block // index indicates there is a non-null reference in that block. In // order to populate the bitmap, a quick run of all the immediate uses @@ -857,9 +880,8 @@ ranger_cache::range_of_def (irange &r, tree name, basic_block bb) r = gimple_range_global (name); } - if (bb && r.varying_p () && m_non_null.non_null_deref_p (name, bb, false) && - !cfun->can_throw_non_call_exceptions) - r = range_nonzero (TREE_TYPE (name)); + if (bb) + m_non_null.adjust_range (r, name, bb, false); } // Get the range of NAME as it occurs on entry to block BB. @@ -878,12 +900,7 @@ ranger_cache::entry_range (irange &r, tree name, basic_block bb) if (!m_on_entry.get_bb_range (r, name, bb)) range_of_def (r, name); - // Check if pointers have any non-null dereferences. Non-call - // exceptions mean we could throw in the middle of the block, so just - // punt for now on those. - if (r.varying_p () && m_non_null.non_null_deref_p (name, bb, false) && - !cfun->can_throw_non_call_exceptions) - r = range_nonzero (TREE_TYPE (name)); + m_non_null.adjust_range (r, name, bb, false); } // Get the range of NAME as it occurs on exit from block BB. diff --git a/gcc/gimple-range-cache.h b/gcc/gimple-range-cache.h index ecf63dc01b3..f842e9c092a 100644 --- a/gcc/gimple-range-cache.h +++ b/gcc/gimple-range-cache.h @@ -34,6 +34,8 @@ public: non_null_ref (); ~non_null_ref (); bool non_null_deref_p (tree name, basic_block bb, bool search_dom = true); + bool adjust_range (irange &r, tree name, basic_block bb, + bool search_dom = true); private: vec <bitmap> m_nn; void process_name (tree name); diff --git a/gcc/gimple-range.cc b/gcc/gimple-range.cc index 1851339c528..b210787d0b7 100644 --- a/gcc/gimple-range.cc +++ b/gcc/gimple-range.cc @@ -69,9 +69,7 @@ gimple_ranger::range_of_expr (irange &r, tree expr, gimple *stmt) if (def_stmt && gimple_bb (def_stmt) == bb) { range_of_stmt (r, def_stmt, expr); - if (!cfun->can_throw_non_call_exceptions && r.varying_p () && - m_cache.m_non_null.non_null_deref_p (expr, bb)) - r = range_nonzero (TREE_TYPE (expr)); + m_cache.m_non_null.adjust_range (r, expr, bb, true); } else // Otherwise OP comes from outside this block, use range on entry. @@ -95,9 +93,7 @@ gimple_ranger::range_on_entry (irange &r, basic_block bb, tree name) if (m_cache.block_range (entry_range, bb, name)) r.intersect (entry_range); - if (!cfun->can_throw_non_call_exceptions && r.varying_p () && - m_cache.m_non_null.non_null_deref_p (name, bb)) - r = range_nonzero (TREE_TYPE (name)); + m_cache.m_non_null.adjust_range (r, name, bb, true); } // Calculate the range for NAME at the end of block BB and return it in R.