| Message ID | 20170803084645.GT2123@tucnak |
|---|---|
| State | New |
| Headers | show |
On Thu, 3 Aug 2017, Jakub Jelinek wrote: > Hi! > > The following testcase ICEs on s390x. The problem is that the bbpart pass > calls > df_set_flags (DF_DEFER_INSN_RESCAN); > because it wants to defer rescanning, but doesn't actually df_finish_pass > (it does in one case, but then calls df_set_flags with another changeable flag, > so it has the same issue), and if the IRA pass is invoked soon after it > without any df_finish_pass calls in between, we end up with deferred insn > rescanning during IRA which heavily relies on immediate insn rescanning. > > Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for > trunk? Maybe add a comment in case somebody wonders later? > 2017-08-03 Jakub Jelinek <jakub@redhat.com> > > PR target/81621 > * bb-reorder.c (pass_partition_blocks::execute): Return TODO_df_finish > after setting changeable df flags. > > * gcc.dg/pr81621.c: New test. > > --- gcc/bb-reorder.c.jj 2017-07-21 10:28:13.000000000 +0200 > +++ gcc/bb-reorder.c 2017-08-02 19:43:58.797243254 +0200 > @@ -2904,7 +2904,7 @@ pass_partition_blocks::execute (function > > crossing_edges = find_rarely_executed_basic_blocks_and_crossing_edges (); > if (!crossing_edges.exists ()) > - return 0; > + return TODO_df_finish; I suppose we can avoid this if we move the df_set_flags after this? I doubt find_rarely_executed_basic_blocks_and_crossing_edges modifies anything. Ok with those changes (if the latter is possible). Thanks, Richard. > crtl->has_bb_partition = true; > > @@ -2970,7 +2970,7 @@ pass_partition_blocks::execute (function > df_analyze (); > } > > - return 0; > + return TODO_df_finish; > } > > } // anon namespace > --- gcc/testsuite/gcc.dg/pr81621.c.jj 2017-08-02 19:52:08.435831121 +0200 > +++ gcc/testsuite/gcc.dg/pr81621.c 2017-08-02 19:52:00.026924067 +0200 > @@ -0,0 +1,5 @@ > +/* PR target/81621 */ > +/* { dg-do compile { target freorder } } */ > +/* { dg-options "-Og -fno-split-wide-types -freorder-blocks-and-partition" } */ > + > +#include "graphite/scop-10.c" > > Jakub > >
On Thu, Aug 03, 2017 at 11:02:51AM +0200, Richard Biener wrote: > On Thu, 3 Aug 2017, Jakub Jelinek wrote: > > > Hi! > > > > The following testcase ICEs on s390x. The problem is that the bbpart pass > > calls > > df_set_flags (DF_DEFER_INSN_RESCAN); > > because it wants to defer rescanning, but doesn't actually df_finish_pass > > (it does in one case, but then calls df_set_flags with another changeable flag, > > so it has the same issue), and if the IRA pass is invoked soon after it > > without any df_finish_pass calls in between, we end up with deferred insn > > rescanning during IRA which heavily relies on immediate insn rescanning. > > > > Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for > > trunk? > > Maybe add a comment in case somebody wonders later? Ok. > > --- gcc/bb-reorder.c.jj 2017-07-21 10:28:13.000000000 +0200 > > +++ gcc/bb-reorder.c 2017-08-02 19:43:58.797243254 +0200 > > @@ -2904,7 +2904,7 @@ pass_partition_blocks::execute (function > > > > crossing_edges = find_rarely_executed_basic_blocks_and_crossing_edges (); > > if (!crossing_edges.exists ()) > > - return 0; > > + return TODO_df_finish; > > I suppose we can avoid this if we move the df_set_flags after this? > I doubt find_rarely_executed_basic_blocks_and_crossing_edges modifies > anything. > > Ok with those changes (if the latter is possible). I was looking through find_rarely_executed_basic_blocks_and_crossing_edges before writing the patch and while I could prove for some functions that it doesn't modify anything, but e.g. for fix_up_crossing_landing_pad I'm pretty sure it can modify instructions in several ways. So I think we can't do that. Jakub
--- gcc/bb-reorder.c.jj 2017-07-21 10:28:13.000000000 +0200 +++ gcc/bb-reorder.c 2017-08-02 19:43:58.797243254 +0200 @@ -2904,7 +2904,7 @@ pass_partition_blocks::execute (function crossing_edges = find_rarely_executed_basic_blocks_and_crossing_edges (); if (!crossing_edges.exists ()) - return 0; + return TODO_df_finish; crtl->has_bb_partition = true; @@ -2970,7 +2970,7 @@ pass_partition_blocks::execute (function df_analyze (); } - return 0; + return TODO_df_finish; } } // anon namespace --- gcc/testsuite/gcc.dg/pr81621.c.jj 2017-08-02 19:52:08.435831121 +0200 +++ gcc/testsuite/gcc.dg/pr81621.c 2017-08-02 19:52:00.026924067 +0200 @@ -0,0 +1,5 @@ +/* PR target/81621 */ +/* { dg-do compile { target freorder } } */ +/* { dg-options "-Og -fno-split-wide-types -freorder-blocks-and-partition" } */ + +#include "graphite/scop-10.c"