This bug happens on a cross-compiler targetting x86_64-pc-mingw32, but not on a native x86_64-linux compiler. Both compilers are built with SVN trunk from the same revision (128540).
Witn -m64, it doesn't error out at -O0, there is an ICE at -O1 and a different error at -O2. With -m32, compilation seems fine in all cases. $ cat foo.c _Complex float product_c4 (_Complex float *src) { _Complex float res; int n; res = 1; for (n = 0; n < 10; n++) res *= src[n]; return res; } $ ./gcc/cc1 -O0 -std=c99 -quiet foo.c -m64 $ ./gcc/cc1 -O1 -std=c99 -quiet foo.c -m64 foo.c: In function product_c4: foo.c:11: internal compiler error: in reg_overlap_mentioned_p, at rtlanal.c:1398 Please submit a full bug report, with preprocessed source if appropriate. See <http://gcc.gnu.org/bugs.html> for instructions. $ ./gcc/cc1 -O2 -std=c99 -quiet foo.c -m64 foo.c: In function product_c4: foo.c:11: error: invalid rtl sharing found in the insn (insn 114 113 115 2 foo.c:9 (set (subreg:DI (reg:SC 92) 0) (reg:DI 133)) -1 (nil)) foo.c:11: error: shared rtx (subreg:DI (reg:SC 92) 0) foo.c:11: internal compiler error: internal consistency failure Please submit a full bug report, with preprocessed source if appropriate. See <http://gcc.gnu.org/bugs.html> for instructions. My cross-compiler is: $ ./gcc/xgcc -v Using built-in specs. Target: x86_64-pc-mingw32 Configured with: /home/fxcoudert/devel/trunk/configure --prefix=/home/fxcoudert/mingw64-cross/install --target=x86_64-pc-mingw32 --enable-languages=c,fortran --disable-werror --with-gmp=/home/fxcoudert/local Thread model: win32 gcc version 4.3.0 20070917 (experimental) [trunk revision 128540] (GCC) The backtrace for the ICE at -O1 is: #0 fancy_abort (file=0xb7d6e0 "/home/fxcoudert/devel/trunk/gcc/rtlanal.c", line=1398, function=0xb7d670 "reg_overlap_mentioned_p") at /home/fxcoudert/devel/trunk/gcc/diagnostic.c:654 #1 0x000000000067a8e9 in reg_overlap_mentioned_p (x=0x2b4d7a1fd180, in=0x2b4d7a1fa740) at /home/fxcoudert/devel/trunk/gcc/rtlanal.c:1398 #2 0x000000000067ac70 in reg_used_between_p (reg=0x2b4d7a1fd180, from_insn=<value optimized out>, to_insn=0xb7d670) at /home/fxcoudert/devel/trunk/gcc/rtlanal.c:721 #3 0x0000000000a0ec1e in can_combine_p (insn=0x2b4d7a1fe050, i3=0x2b4d7a1f29b0, pred=<value optimized out>, succ=0x2b4d7a1f2f50, pdest=0x7fff30e85460, psrc=0x7fff30e85458) at /home/fxcoudert/devel/trunk/gcc/combine.c:1605 #4 0x0000000000a15d18 in try_combine (i3=0x2b4d7a1f29b0, i2=<value optimized out>, i1=0x2b4d7a1fe050, new_direct_jump_p=0x7fff30e854f4) at /home/fxcoudert/devel/trunk/gcc/combine.c:2481 #5 0x0000000000a1a09d in rest_of_handle_combine () at /home/fxcoudert/devel/trunk/gcc/combine.c:1152 I can investigate further if need be, tell me what to do. If you have access to the GCC compiler farm, my build is available in /home/fxcoudert/mingw64-cross/ibin PS: the reason I found this bug is that it shows up while building libgfortran for this cross-compiler :( -- Summary: ICE and invalid rtl sharing on x86_64-mingw cross- compiler Product: gcc Version: 4.3.0 Status: UNCONFIRMED Keywords: ice-on-valid-code Severity: normal Priority: P3 Component: middle-end AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: fxcoudert at gcc dot gnu dot org GCC build triplet: x86_64-linux-gnu GCC host triplet: x86_64-linux-gnu GCC target triplet: x86_64-pc-mingw32 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33472