Also reported as http://bugs.debian.org/466613 An ICE appeared twice while trying to build webkit on s390. The first file fails to build with -O2 but is OK with -O1, for the second file it is just the opposite. $ gcc -v Using built-in specs. Target: s390-linux-gnu Configured with: ../src/configure -v --enable-languages=c,c++,fortran,objc,obj-c++,treelang --prefix=/usr --enable-shared --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --enable-nls --with-gxx-include-dir=/usr/include/c++/4.2 --program-suffix=-4.2 --enable-clocale=gnu --enable-libstdcxx-debug --enable-objc-gc --enable-mpfr --disable-libmudflap --with-long-double-128 --enable-checking=release --build=s390-linux-gnu --host=s390-linux-gnu --target=s390-linux-gnu Thread model: posix gcc version 4.2.3 (Debian 4.2.3-1) $ g++ -c -O2 regexp_object.ii ../../../JavaScriptCore/kjs/regexp_object.cpp: In member function ‘KJS::JSObject* KJS::RegExpObjectImp::arrayOfMatches(KJS::ExecState*) const’: ../../../JavaScriptCore/kjs/regexp_object.cpp:333: error: insn does not satisfy its constraints: (insn 532 533 160 16 (set (reg:SI 2 %r2) (const_int -1146241297 [0xffffffffbbadbeef])) 56 {*movsi_esa} (nil) (nil)) ../../../JavaScriptCore/kjs/regexp_object.cpp:333: internal compiler error: in reload_cse_simplify_operands, at postreload.c:392 Please submit a full bug report, with preprocessed source if appropriate. See for instructions. For Debian GNU/Linux specific bug reporting instructions, see . $ g++ -c -O1 regexp_object.ii => OK $ g++ -c -O1 debugger.ii ../../../JavaScriptCore/wtf/HashTable.h: In member function ‘void WTF::HashTable::rehash(int) [with Key = int, Value = std::pair >, Extractor = WTF::PairFirstExtractor > >, HashFunctions = WTF::IntHash, Traits = WTF::PairHashTraits, WTF::HashTraits > >, KeyTraits = WTF::HashTraits]’: ../../../JavaScriptCore/wtf/HashTable.h:856: error: insn does not satisfy its constraints: (insn 796 797 58 7 (set (reg:SI 2 %r2) (const_int -1146241297 [0xffffffffbbadbeef])) 56 {*movsi_esa} (nil) (nil)) ../../../JavaScriptCore/wtf/HashTable.h:856: internal compiler error: in reload_cse_simplify_operands, at postreload.c:392 Please submit a full bug report, with preprocessed source if appropriate. See for instructions. For Debian GNU/Linux specific bug reporting instructions, see . $ g++ -c -O2 debugger.ii ==> OK -- Summary: ICE at postreload.c:392 while building webkit on s390 Product: gcc Version: 4.2.3 Status: UNCONFIRMED Severity: major Priority: P3 Component: c++ AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: joss at debian dot org GCC build triplet: s390-linux-gnu GCC host triplet: s390-linux-gnu GCC target triplet: s390-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35311