I get this error when linking in most of my project's regression tests, but always at the same address in gimple.c.
/usr/local/bin/g++ -O3 -DNDEBUG -DUSE_INTL=1 -DUSE_MUTEX=1 -findirect-inlining -Winline -flto -pedantic-errors -Werror -ansi -fno-common -Wall -Wold-style-cast -Wsign-promo -Wpointer-arith -Wundef -Wwrite-strings -Winvalid-pch -Woverloaded-virtual -Wcast-qual -Wextra -Wredundant-decls -Wshadow -Wcast-align -Wcomment -fstrict-aliasing -Winit-self -Wmissing-include-dirs -Wswitch-default -Wswitch-enum -Wlogical-op -Wconversion -Wsign-conversion -Wmissing-declarations -Wdeprecated -ftree-switch-conversion -Wuninitialized -Wparentheses -Wunused -fvisibility-inlines-hidden -MMD -fimplicit-templates -Wl,-warn-common -L.. -o stest0.exe stest0.o -lPatternDriver -lintl -lpthread lto1: internal compiler error: in gimple_types_compatible_p, at gimple.c:3488 Please submit a full bug report, with preprocessed source if appropriate. See <http://gcc.gnu.org/bugs.html> for instructions. lto-wrapper: /usr/local/bin/g++ returned 1 exit status collect2: lto-wrapper returned 1 exit status uname -a Linux alpha1 2.4.9-40 #1 Mon Sep 23 08:14:02 EDT 2002 alpha unknown g++ -v Using built-in specs. COLLECT_GCC=g++ COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/alphaev56-unknown-linux-gnu/4.5.0/lto-wrapper Target: alphaev56-unknown-linux-gnu Configured with: ../gcc/configure --verbose --enable-languages=c++ --disable-linux-futex --disable-nls --disable-tls --enable-lto Thread model: posix gcc version 4.5.0 20091023 (experimental) (GCC) BUILDING: alias CONFIGURECVS='../gcc/configure --verbose --enable-languages=c++ --disable-linux-futex --disable-nls --disable-tls --enable-lto 2>&1 | tee clog' alias BUILD='nice gmake CFLAGS='\'''\'' BOOT_CFLAGS='\'''\'' LIBCFLAGS='\''-g'\'' LIBCXXFLAGS='\''-g'\'' bootstrap 2>&1 | tee log' -- Summary: ICE in LTO when linking Product: gcc Version: lto Status: UNCONFIRMED Severity: normal Priority: P3 Component: lto AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: mckelvey at maskull dot com GCC build triplet: alphaev56-unknown-linux-gnu GCC host triplet: alphaev56-unknown-linux-gnu GCC target triplet: alphaev56-unknown-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41821