The C compiler crashes upon seeing the 'log1p()' function, as follows: $ gcc-snap -ffast-math -c test-logsum.c test-logsum.c: In function 'test': test-logsum.c:6: error: unrecognizable insn: (insn 9 8 10 1 (set (reg:XF 63) (float_extend:XF (reg:XF 61))) -1 (nil) (expr_list:REG_DEAD (reg:XF 61) (nil))) test-logsum.c:6: internal compiler error: in extract_insn, at recog.c:2020 Please submit a full bug report, with preprocessed source if appropriate. See <URL:http://gcc.gnu.org/bugs.html> for instructions.
Here is the (short) test-case file: ---------------------- #include <math.h> double test () { return log1p(1.0); } ---------------------- $ gcc-snap -v Using built-in specs. Configured with: ../src/configure -v --enable-languages=c,c++,java,objc,ada --prefix=/usr/lib/gcc-snapshot --enable-shared --with-system-zlib --enable-nls --enable-threads=posix --without-included-gettext --disable-werror --enable-__cxa_atexit --enable-libstdcxx-allocator=mt --enable-clocale=gnu --enable-libstdcxx-debug --enable-java-gc=boehm --enable-java-awt=gtk i486-linux-gnu Thread model: posix gcc version 4.0.0 20041231 (experimental) NOTES: 1. BTW, this is a Debian snapshot. (2004-12-31) 2. The bug also occurs with a previous package: $ gcc-4.0 -v Reading specs from /usr/lib/gcc/i486-linux/4.0.0/specs Configured with: ../src/configure -v --enable-languages=c,c++,java,f95,objc,ada --prefix=/usr --libexecdir=/usr/lib --enable-shared --with-system-zlib --enable-nls --enable-threads=posix --without-included-gettext --program-suffix=-4.0 --enable-__cxa_atexit --enable-libstdcxx-allocator=mt --enable-clocale=gnu --enable-libstdcxx-debug --enable-java-gc=boehm --enable-java-awt=gtk --enable-mpfr i486-linux Thread model: posix gcc version 4.0.0 20041205 (experimental) (Debian 4.0-0pre2) 3. I am *fairly* sure that the Debian version 4.0-0pre1 was in November and did not have this problem. 4. The problem did not exist in HEAD in the beginning of October. -- Summary: ICE compiling logp(x) with -ffast-math Product: gcc Version: 4.0.0 Status: UNCONFIRMED Severity: normal Priority: P2 Component: rtl-optimization AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: bredelin at ucla dot edu CC: gcc-bugs at gcc dot gnu dot org GCC target triplet: i486-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19236