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

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