[Bug bootstrap/67761] New: [6 Regression] Bootstrap failure on x86

[Bug bootstrap/67761] New: [6 Regression] Bootstrap failure on x86

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67761

            Bug ID: 67761
           Summary: [6 Regression] Bootstrap failure on x86
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hjl.tools at gmail dot com
                CC: ienkovich at gcc dot gnu.org
  Target Milestone: ---

On Linux/x86, r228231 gave

make[6]: Leaving directory '/export/gnu/import/git/gcc-test-ia32/bld'
Comparing stages 2 and 3
warning: gcc/cc1obj-checksum.o differs
warning: gcc/cc1plus-checksum.o differs
warning: gcc/cc1-checksum.o differs
Bootstrap comparison failure!
gcc/coverage.o differs
gcc/dwarf2out.o differs
gcc/loop-iv.o differs
gcc/cp/init.o differs
gcc/tree-ssa-loop-ivcanon.o differs
gcc/predict.o differs
gcc/cfgloopmanip.o differs
gcc/tree-ssa-math-opts.o differs
gcc/function.o differs
gcc/tree-ssa-forwprop.o differs
gcc/tree-ssa-reassoc.o differs
gcc/tree-vect-loop.o differs
gcc/gimple-fold.o differs
gcc/loop-unroll.o differs
gcc/double-int.o differs
gcc/tree-ssa-alias.o differs
gcc/expr.o differs
gcc/gcov.o differs
gcc/i386-c.o differs
gcc/combine.o differs
gcc/tree-ssa-ccp.o differs
gcc/tree-chkp.o differs
gcc/fortran/trans-common.o differs
gcc/tree-vrp.o differs
gcc/var-tracking.o differs
gcc/tree-dfa.o differs
gcc/ipa-prop.o differs
gcc/gimple-ssa-strength-reduction.o differs
gcc/fold-const.o differs
gcc/dwarf2cfi.o differs
gcc/tree-ssa-sccvn.o differs
gcc/reload1.o differs
gcc/gcov-dump.o differs
gcc/mcf.o differs
gcc/tree-affine.o differs
gcc/tree-ssa-loop-niter.o differs
gcc/value-prof.o differs
libbacktrace/dwarf.o differs
libbacktrace/.libs/dwarf.o differs
libcpp/expr.o differs
libiberty/simple-object-coff.o differs
libiberty/pic/simple-object-coff.o differs
libiberty/pic/simple-object-xcoff.o differs
libiberty/simple-object-xcoff.o differs
Makefile:23262: recipe for target 'compare' failed
make[5]: *** [compare] Error 1
make[5]: Leaving directory '/export/gnu/import/git/gcc-test-ia32/bld'
Makefile:23241: recipe for target 'stage3-bubble' failed
make[4]: *** [stage3-bubble] Error 2
make[4]: Leaving directory '/export/gnu/import/git/gcc-test-ia32/bld'
Makefile:23304: recipe for target 'bootstrap' failed
make[3]: *** [bootstrap] Error 2
make[3]: Leaving directory '/export/gnu/import/git/gcc-test-ia32/bld'
14439.95user 447.65system 1:10:45elapsed 350%CPU (0avgtext+0avgdata
542356maxresident)k
144528inputs+14881128outputs (6202major+106936680minor)pagefaults 0swaps
Makefile:291: recipe for target 'bootstrap' failed
make[2]: *** [bootstrap] Error 2

when configured with

--with-arch=core2 --with-cpu=slm --prefix=/usr/6.0.0 --enable-clocale=gnu
--with-system-zlib --enable-shared --with-demangler-in-ld --enable-libmpx
i686-linux --with-fpmath=sse --enable-languages=c,c++,fortran,java,lto,objc

[Bug bootstrap/67761] [6 Regression] Bootstrap failure on x86

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67761

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|                            |i?86-*-*
   Target Milestone|---                         |6.0

[Bug bootstrap/67761] [6 Regression] Bootstrap failure on x86

[ienkovich at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67761

Ilya Enkovich <ienkovich at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2015-09-29
           Assignee|unassigned at gcc dot gnu.org      |ienkovich at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from Ilya Enkovich <ienkovich at gcc dot gnu.org> ---
The problem is in debug insns which are not ignored by introduced
transformation. It results in cost model affected by debug info and causes
these comparison failures.  I'm testing this fix:

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 6f2380f..7b3ffb0 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -2919,6 +2919,10 @@ scalar_chain::analyze_register_chain (bitmap candidates,
df_ref ref)
   for (chain = DF_REF_CHAIN (ref); chain; chain = chain->next)
     {
       unsigned uid = DF_REF_INSN_UID (chain->ref);
+
+      if (!NONDEBUG_INSN_P (DF_REF_INSN (chain->ref)))
+       continue;
+
       if (!DF_REF_REG_MEM_P (chain->ref))
        {
          if (bitmap_bit_p (insns, uid))
@@ -3279,7 +3283,7 @@ scalar_chain::convert_reg (unsigned regno)
            bitmap_clear_bit (conv, DF_REF_INSN_UID (ref));
          }
       }
-    else
+    else if (NONDEBUG_INSN_P (DF_REF_INSN (ref)))
       {
        replace_rtx (DF_REF_INSN (ref), reg, scopy);
        df_insn_rescan (DF_REF_INSN (ref));

[Bug bootstrap/67761] [6 Regression] Bootstrap failure on x86

[ienkovich at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67761

Ilya Enkovich <ienkovich at gcc dot gnu.org> changed:

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

--- Comment #2 from Ilya Enkovich <ienkovich at gcc dot gnu.org> ---
Fixed by r228292