| Message ID | oriq5pml7v.fsf@livre.localdomain |
|---|---|
| State | New |
| Headers | show |
On Fri, Jun 11, 2010 at 9:18 PM, Alexandre Oliva <aoliva@redhat.com> wrote: > A number of graphite -fcompare-debug bug reports were fixed with this > patch. The problem was that we inserted induction variable increment > stmts before the last stmt in the block, but if the block ended with a > fall-through, the insert would be before a non-debug stmt in the non-VTA > case, whereas in the VTA case it could be before a debug stmt, after the > non-debug stmt. Skipping trailing debug stmts so that we insert before > the last non-debug stmt removed the codegen differences. > > Bootstrapped the compiler, along with the upcoming patch for PR43656, on > x86_64-linux-gnu, with the following options: > > -O2 -g -fschedule-insns -fsched-pressure -funroll-loops -fgraphite-identity > > for stage2 and stage3 host, and for stage3 libs (also -fcompare-debug) > > I got build failures on zlib and libada, presumably because of this > unusual combination of flags, but no -fcompare-debug errors. > > Ok to install? Ok (is there a testcase that can be added to the testsuite?) Thanks, Richard. > > > -- > Alexandre Oliva, freedom fighter http://FSFLA.org/~lxoliva/ > You must be the change you wish to see in the world. -- Gandhi > Be Free! -- http://FSFLA.org/ FSF Latin America board member > Free Software Evangelist Red Hat Brazil Compiler Engineer > >
On Jun 11, 2010, Richard Guenther <richard.guenther@gmail.com> wrote: > On Fri, Jun 11, 2010 at 9:18 PM, Alexandre Oliva <aoliva@redhat.com> wrote: >> A number of graphite -fcompare-debug bug reports were fixed with this >> patch. > Ok (is there a testcase that can be added to the testsuite?) Nothing really useful, I'm afraid. I actually had to go back to earlier versions of the compiler to as much as duplicate the reported problems. They're quite sensitive to other changes in the compiler.
On Fri, Jun 11, 2010 at 12:18 PM, Alexandre Oliva <aoliva@redhat.com> wrote: > A number of graphite -fcompare-debug bug reports were fixed with this > patch. The problem was that we inserted induction variable increment > stmts before the last stmt in the block, but if the block ended with a > fall-through, the insert would be before a non-debug stmt in the non-VTA > case, whereas in the VTA case it could be before a debug stmt, after the > non-debug stmt. Skipping trailing debug stmts so that we insert before > the last non-debug stmt removed the codegen differences. > > Bootstrapped the compiler, along with the upcoming patch for PR43656, on > x86_64-linux-gnu, with the following options: > > -O2 -g -fschedule-insns -fsched-pressure -funroll-loops -fgraphite-identity > > for stage2 and stage3 host, and for stage3 libs (also -fcompare-debug) > > I got build failures on zlib and libada, presumably because of this > unusual combination of flags, but no -fcompare-debug errors. > This caused: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46885
for gcc/ChangeLog from Alexandre Oliva <aoliva@redhat.com> PR debug/43650 PR debug/44181 PR debug/44247 * tree-ssa-loop-manip.c (tree_transform_and_unroll_loop): Skip debug stmts. (canonicalize_loop_ivs): Likewise. Index: gcc/tree-ssa-loop-manip.c =================================================================== --- gcc/tree-ssa-loop-manip.c.orig 2010-06-11 09:16:28.000000000 -0300 +++ gcc/tree-ssa-loop-manip.c 2010-06-11 09:17:38.000000000 -0300 @@ -1081,7 +1081,7 @@ tree_transform_and_unroll_loop (struct l /* Finally create the new counter for number of iterations and add the new exit instruction. */ - bsi = gsi_last_bb (exit_bb); + bsi = gsi_last_nondebug_bb (exit_bb); exit_if = gsi_stmt (bsi); create_iv (exit_base, exit_step, NULL_TREE, loop, &bsi, false, &ctr_before, &ctr_after); @@ -1217,7 +1217,7 @@ canonicalize_loop_ivs (struct loop *loop gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts); } - gsi = gsi_last_bb (bump_in_latch ? loop->latch : loop->header); + gsi = gsi_last_nondebug_bb (bump_in_latch ? loop->latch : loop->header); create_iv (build_int_cst_type (type, 0), build_int_cst (type, 1), NULL_TREE, loop, &gsi, bump_in_latch, &var_before, NULL);