[Bug c++/71009] New: g++: ICE on modified gdb/valarith.c with -Ofast

["egall at gwmail dot gwu.edu" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71009

            Bug ID: 71009
           Summary: g++: ICE on modified gdb/valarith.c with -Ofast
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: egall at gwmail dot gwu.edu
  Target Milestone: ---
              Host: i386-apple-darwin9.8.0
            Target: i386-apple-darwin9.8.0
             Build: i386-apple-darwin9.8.0

Full command line and output:

$ make CFLAGS="-g3 -Ofast -force_cpusubtype_ALL -gstrict-dwarf -gdwarf-2 -gfull
-save-temps" V=1
this target, 'config.h' just makes its dep, 'stamp-h'
/usr/local/bin/g++ -g3 -Ofast -force_cpusubtype_ALL -gstrict-dwarf -gdwarf-2
-gfull -save-temps -arch i386 -DTARGET_I386 -I./macosx -I./macosx -DWITH_CFM=0
-DUSE_PTHREADS=1 -D_DARWIN_UNLIMITED_STREAMS -mmacosx-version-min=10.5  -I. -I.
-I./config -DHAVE_CONFIG_H -DHAVE_SYS_TYPES_H
-DLOCALEDIR="\"/usr/local/share/locale\""   -I./../include/opcode
-I./../readline/.. -I./../zlib -I../bfd -I./../bfd -I./../include
-I./../mmalloc -I../mmalloc -I../intl -I./../intl  -DMI_OUT=1
-I/sw/include/libxml2 -I/sw/include -D__MigTypeCheck=1 -D__DARWIN_UNIX03=1
-Wreturn-type -Wcomment -Wtrigraphs -Wparentheses -Wpointer-arith
-Wchar-subscripts -Wno-unused -Wunused-value -Wunused-label -Wunused-result
-Wunused-variable -Wunused-but-set-variable -Wunused-function -Wempty-body
-Wmissing-declarations -Wignored-qualifiers -Wmissing-format-attribute
-Waddress -Wattributes -Wswitch -Wclobbered -Wcoverage-mismatch -Wdiv-by-zero
-Wdouble-promotion -Wfree-nonheap-object -Wsign-compare -Wtype-limits
-Winvalid-memory-model -Winvalid-pch -Wmain -Wmissing-braces
-Wmissing-include-dirs -Woverflow -Woverlength-strings -Wpragmas
-Wreturn-local-addr -Wsequence-point -Wsizeof-pointer-memaccess -Wtrampolines
-Wunknown-pragmas -Wnormalized=nfkc -Wlogical-op -Wfloat-conversion
-Wmissing-field-initializers -Wno-deprecated-declarations -Wbool-compare
-Wlogical-not-parentheses -Wsizeof-array-argument -Wswitch-bool
-Wshift-count-negative -Wshift-count-overflow -Wshift-negative-value
-Wshift-overflow=2 -Wmisleading-indentation -Wlto-type-mismatch
-Wtautological-compare -Wduplicated-cond -Wwrite-strings -Wenum-compare
-Wnonnull-compare -Wabi -Wabi-tag -Woverloaded-virtual -Wsign-promo -Wodr
-Wsubobject-linkage -Wctor-dtor-privacy -Wterminate -Wc++11-compat
-Wdelete-incomplete -Wdelete-non-virtual-dtor -Winherited-variadic-ctor
-Winvalid-offsetof -Wliteral-suffix -Wnoexcept -Wnon-template-friend
-Wnon-virtual-dtor -Wreorder -Wstrict-null-sentinel -Wmultiple-inheritance
-Wvirtual-inheritance -Wpmf-conversions -Wtemplates -Wvirtual-move-assign
-Wconversion-null -Weffc++ -Wsized-deallocation -Wplacement-new=2 -fpermissive
-Wendif-labels -Wformat -Wformat-y2k -Wformat-security -Wnonnull
-Wnonportable-cfstrings -Wno-unused-const-variable -std=gnu++03 -pedantic
-Wno-long-long -Wcast-align -Wuninitialized -Winit-self -Wmissing-noreturn
-Wvolatile-register-var -Wdisabled-optimization -Winline
-Waggressive-loop-optimizations -Wvector-operation-performance
-Wmaybe-uninitialized -Wstrict-overflow=1 -fno-strict-aliasing
-Wnull-dereference -Wframe-address -Wframe-larger-than=262144
-Wlarger-than=262144 -Wsuggest-attribute=const -Warray-bounds  -Wall -Wextra
-Wno-unused-parameter  -c -o valarith.o valarith.c
valarith.c: In function âvalue* value_binop(value*, value*, exp_opcode)â:
valarith.c:1408:1: internal compiler error: in gen_reg_rtx, at emit-rtl.c:1025
 }
 ^
libbacktrace could not find executable to open
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.
make: *** [valarith.o] Error 1

The file compiles fine with all the other optimization levels I've tested
recently (-O3, -O2, -O1, -Os, -Og, -O0).

g++ version info:

$ /usr/local/bin/g++ -v
Using built-in specs.
COLLECT_GCC=/usr/local/bin/g++
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/i386-apple-darwin9.8.0/7.0.0/lto-wrapper
Target: i386-apple-darwin9.8.0
Configured with: ../configure --disable-werror
--enable-languages=c,c++,lto,objc,obj-c++ --enable-stage1-checking=release -C
--with-system-libunwind --enable-secureplt --enable-frame-pointer
--enable-version-specific-runtime-libs --enable-assert --enable-fat
--enable-portable-binary --enable-browser-plugin --enable-gconf-peer
--enable-libgcj-debug --enable-gc-debug --enable-interpreter
--enable-aot-compile-rpm --enable-java-home --with-x --enable-collections
--enable-gstreamer-peer --enable-xmlj --enable-qt-peer --enable-debug
--enable-local-sockets --without-isl --enable-objc-gc --enable-maintainer-mode
--enable-host-shared CC=/usr/local/bin/gcc CXX=/usr/local/bin/g++
AUTOCONF=/usr/local/bin/autoconf AUTOHEADER=/usr/local/bin/autoheader
AUTOM4TE=/usr/local/bin/autom4te AUTORECONF=/usr/local/bin/autoreconf
AUTOSCAN=/usr/local/bin/autoscan AUTOUPDATE=/usr/local/bin/autoupdate
IFNAMES=/usr/local/bin/ifnames
Thread model: posix
gcc version 7.0.0 20160426 (experimental) (GCC)