[Bug ipa/64481] New: [5 Regression] r219076 breaks bootstrap (x86_64-unknown-linux-gnu)

[Bug ipa/64481] New: [5 Regression] r219076 breaks bootstrap (x86_64-unknown-linux-gnu)

[david.abdurachmanov at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64481

            Bug ID: 64481
           Summary: [5 Regression] r219076 breaks bootstrap
                    (x86_64-unknown-linux-gnu)
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: blocker
          Priority: P3
         Component: ipa
          Assignee: unassigned at gcc dot gnu.org
          Reporter: david.abdurachmanov at gmail dot com

While doing testing, I found that I couldn't bootstrap GCC anymore during
holidays.

Using git bisect, I found first breaking commit:
d326c10c2de4a884476d099dbeca4794e145d8c1 / r219076.

Last good commit: 09196675b74bd04b562fe3b264a9648eb0568a59 / r219075
Last tested bad: 27f6a8a0012f8df67c88b9d28ab47c3492319a07 / r219158

Tested on Fedora 21 OpenStack image (clean setup). Commands executed on a new
virtual machine:

yum makecache
yum update
yum -y groupinstall "Development Tools"
yum -y groupinstall "C Development Tools and Libraries"
yum -y install zlib-devel
mkdir -p /build
cd /build/
git clone git://gcc.gnu.org/git/gcc.git
git checkout d326c10c2de4a884476d099dbeca4794e145d8c1
./contrib/download_prerequisites
mkdir obj
cd obj
../configure --prefix=/tmp/gccbuild --enable-bootstrap --disable-checking
--enable-languages=c,c++ --disable-multilib --with-system-zlib --enable-shared
--disable-nls
make -j4 bootstrap

[snip]

make[2]: Entering directory '/build/gcc/obj'
make[3]: Entering directory '/build/gcc/obj'
rm -f stage_current
make[3]: Leaving directory '/build/gcc/obj'
Comparing stages 2 and 3
warning: gcc/cc1-checksum.o differs
warning: gcc/cc1plus-checksum.o differs
Bootstrap comparison failure!
gcc/valtrack.o differs
gcc/rtlanal.o differs
gcc/tree-ssa-ccp.o differs
gcc/tree-nested.o differs
gcc/tree-vect-stmts.o differs
gcc/tree-ssa-loop-ivopts.o differs
gcc/tree-sra.o differs
gcc/dwarf2out.o differs
gcc/lto/lto.o differs
gcc/c/c-typeck.o differs
gcc/c/c-array-notation.o differs
gcc/c/c-decl.o differs
gcc/c/c-parser.o differs
gcc/tree-ssa-uninit.o differs
gcc/i386.o differs
gcc/tree-ssa.o differs
gcc/expr.o differs
gcc/except.o differs
gcc/tree-ssa-reassoc.o differs
gcc/rtl-error.o differs
gcc/tree-ssa-tail-merge.o differs
gcc/omp-low.o differs
gcc/ipa-icf.o differs
gcc/dominance.o differs
gcc/toplev.o differs
gcc/tree-ssa-structalias.o differs
gcc/ipa-pure-const.o differs
gcc/ipa-profile.o differs
gcc/coverage.o differs
gcc/ifcvt.o differs
gcc/tree-ssa-threadedge.o differs
gcc/tree-inline.o differs
gcc/trans-mem.o differs
gcc/lto-streamer-out.o differs
gcc/loop-iv.o differs
gcc/ipa-polymorphic-call.o differs
gcc/ipa-reference.o differs
gcc/tree-ssa-math-opts.o differs
gcc/graphite-sese-to-poly.o differs
gcc/cgraph.o differs
gcc/sese.o differs
gcc/ipa-split.o differs
gcc/tree-ssa-sccvn.o differs
gcc/tree-into-ssa.o differs
gcc/alias.o differs
gcc/attribs.o differs
gcc/c-family/c-pretty-print.o differs
gcc/c-family/array-notation-common.o differs
gcc/c-family/c-common.o differs
gcc/ipa-inline-analysis.o differs
gcc/vtable-verify.o differs
gcc/ipa-chkp.o differs
gcc/cfgrtl.o differs
gcc/ipa-inline-transform.o differs
gcc/tree-ssa-loop-im.o differs
gcc/dwarf2cfi.o differs
gcc/tree-ssa-dom.o differs
gcc/tree-eh.o differs
gcc/gcov.o differs
gcc/loop-invariant.o differs
gcc/tree-vrp.o differs
gcc/opts.o differs
gcc/combine-stack-adj.o differs
gcc/gimplify.o differs
gcc/varasm.o differs
gcc/tree-ssa-pre.o differs
gcc/ipa-cp.o differs     
gcc/tree-cfg.o differs
gcc/ipa-prop.o differs
gcc/cfgloop.o differs
gcc/tree-chkp.o differs
gcc/ipa-comdats.o differs
gcc/tree-vectorizer.o differs
gcc/postreload.o differs
gcc/lto-streamer-in.o differs
gcc/build/genmatch.o differs
gcc/ipa-icf-gimple.o differs
gcc/cfg.o differs
gcc/optabs.o differs
gcc/tsan.o differs
gcc/var-tracking.o differs
gcc/loop-unroll.o differs
gcc/cp/pt.o differs
gcc/cp/parser.o differs
gcc/cp/typeck2.o differs
gcc/cp/decl.o differs
gcc/cp/rtti.o differs
gcc/cp/call.o differs
gcc/cp/init.o differs
gcc/cp/cp-array-notation.o differs
gcc/cp/name-lookup.o differs
gcc/cp/constexpr.o differs
gcc/cp/semantics.o differs
gcc/tree-ssa-loop-niter.o differs
isl/isl_arg.o differs
isl/isl_ilp.o differs
isl/isl_tab_pip.o differs
isl/isl_space.o differs
isl/isl_transitive_closure.o differs
isl/isl_stream.o differs
isl/isl_output.o differs
libiberty/d-demangle.o differs
libiberty/pic/d-demangle.o differs
mpfr/lngamma.o differs
mpfr/gamma.o differs
Makefile:22563: recipe for target 'compare' failed
make[2]: *** [compare] Error 1
make[2]: Leaving directory '/build/gcc/obj'
Makefile:22542: recipe for target 'stage3-bubble' failed
make[1]: *** [stage3-bubble] Error 2
make[1]: Leaving directory '/build/gcc/obj'
Makefile:22605: recipe for target 'bootstrap' failed
make: *** [bootstrap] Error 2

[Bug ipa/64481] [5 Regression] r219076 breaks bootstrap (x86_64-unknown-linux-gnu)

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64481

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |5.0

[Bug ipa/64481] [5 Regression] r219076 breaks bootstrap (x86_64-unknown-linux-gnu)

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64481

--- Comment #1 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
Bootstrap worked for me yesterday. I guess disable-checking may be the reason,
I will try to reproduce this.

[Bug ipa/64481] [5 Regression] r219076 breaks bootstrap (x86_64-unknown-linux-gnu)

[maltsevm at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64481

Mikhail Maltsev <maltsevm at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |maltsevm at gmail dot com

--- Comment #2 from Mikhail Maltsev <maltsevm at gmail dot com> ---
Reproduced on recent revision (219345). Indeed, --disable-checking causes
comparison to fail.

Bootstrap fails:
configure --prefix=/usr/local/gcc-5.0.0 --enable-clocale=gnu --with-system-zlib
--enable-shared --enable-bootstrap --disable-checking --disable-multilib
--disable-nls --with-demangler-in-ld --with-fpmath=sse --enable-languages=c,c++

Bootstrap passes:
configure --prefix=/usr/local/gcc-5.0.0 --enable-clocale=gnu --with-system-zlib
--enable-shared --enable-bootstrap --disable-multilib --disable-nls
--with-demangler-in-ld --with-fpmath=sse --enable-languages=c,c++

[Bug ipa/64481] [5 Regression] r219076 breaks bootstrap (x86_64-unknown-linux-gnu)

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64481

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P1

[Bug ipa/64481] [5 Regression] r219076 breaks bootstrap (x86_64-unknown-linux-gnu)

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64481

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-01-13
                 CC|                            |jakub at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
This is caused by the
@@ -1695,10 +1680,9 @@
       if (!edge->inline_failed || !edge->callee->analyzed)
     continue;

-      /* Be sure that caches are maintained consistent.  
-         We can not make this ENABLE_CHECKING only because it cause different
-         updates of the fibheap queue.  */
-      cached_badness = edge_badness (edge, false);
+#ifdef ENABLE_CHECKING
+      /* Be sure that caches are maintained consistent.  */
+      sreal cached_badness = edge_badness (edge, false);
       reset_edge_growth_cache (edge);
       reset_node_growth_cache (edge->callee);

@@ -1708,10 +1692,18 @@
       current_badness = edge_badness (edge, false);
       gcc_assert (cached_badness == current_badness);
       gcc_assert (current_badness >= badness);
+#else
+      current_badness = edge_badness (edge, false);
+#endif

changes in particular, clearly the old comment was correct.  With
--disable-checking --enable-stage1-checking defaults to yes,types and because
of this #ifdef stage1 behaves differently from stage2.  But it is certainly bad
even if --disable-checking compiler behaves differently from
--enable-checking=yes one.
If I replace #ifdef ENABLE_CHECKING with #if 1 // ENABLE_CHECKING, 
--disable-checking bootstrap succeeds just fine.

[Bug ipa/64481] [5 Regression] r219076 breaks bootstrap (x86_64-unknown-linux-gnu)

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64481

--- Comment #4 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
The comment is no longer valid, because no updates are made inside of the ifdef
block.  What probably happens is that the edge growth cache is not up to date
but the problem is not noticed by the sanity check.

I fixed some of cache updates recently, does it solve the problem?

[Bug ipa/64481] [5 Regression] r219076 breaks bootstrap (x86_64-unknown-linux-gnu)

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64481

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
I've reproduced the bootstrap failure with r219533.  Did you mean r219536?

[Bug ipa/64481] [5 Regression] r219076 breaks bootstrap (x86_64-unknown-linux-gnu)

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64481

Jan Hubicka <hubicka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |hubicka at gcc dot gnu.org

--- Comment #6 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
On second thought it is easy to add function that verifies cache consistency
instead of resetting it that should catch any potential issues. I will look
into it today. It seems that there are some extra latent bugs surfaced by the
more sensitive sreal costs.

[Bug ipa/64481] [5 Regression] r219076 breaks bootstrap (x86_64-unknown-linux-gnu)

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64481

--- Comment #7 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
OK, there are at least two issues. First is that we mix up alias with its
target (i.e. clear caches on alias instead of alias target) and second that we
still use node growth cache in some cases. Major use in the badness calculation
was removed by Richard few releases back and its updating code was removed. The
cache however remained and it is used at the end of inlining to inline
functions called once etc.  I am testing full removal, but need to benchmark it
on firefox just to be sure.

[Bug ipa/64481] [5 Regression] r219076 breaks bootstrap (x86_64-unknown-linux-gnu)

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64481

--- Comment #8 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
Created attachment 34441
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34441&action=edit
Proposed fix

I am testing the attached patch. Seems that it has no negaitve impact on
firefox linktime.

[Bug ipa/64481] [5 Regression] r219076 breaks bootstrap (x86_64-unknown-linux-gnu)

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64481

--- Comment #9 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
Author: hubicka
Date: Wed Jan 14 03:47:17 2015
New Revision: 219572

URL: https://gcc.gnu.org/viewcvs?rev=219572&root=gcc&view=rev
Log:

    PR ipa/64481
    * ipa-inline-analysis.c (node_growth_cache): Remove.
    (initialize_growth_caches): Do not initialize it.
    (free_growth_caches): Do not free it.
    (do_estimate_growth): Rename to ...
    (estimate_growth): ... this one; drop growth cache code.
    (growth_likely_positive): Always go the heuristics way.
    * ipa-inline.c (can_inline_edge_p): Walk through aliases.
    (reset_edge_caches): Do not reset node growth.
    (heap_edge_removal_hook): Do not maintain cache.
    (inline_small_functions): Likewise; strenghten sanity check.
    (ipa_inline): Do not maintain caches.
    * ipa-inline.h (node_growth_cache): Remove.
    (do_estimate_growth): Remove to ...
    (estimate_growth): this one; remove inline version.
    (reset_node_growth_cache): Remove.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/ipa-inline-analysis.c
    trunk/gcc/ipa-inline.c
    trunk/gcc/ipa-inline.h

[Bug ipa/64481] [5 Regression] r219076 breaks bootstrap (x86_64-unknown-linux-gnu)

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64481

Jan Hubicka <hubicka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #10 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
Fixed.