Trying to compile the following (already pre-processed) code causes ICE: # 1 "gcc-ice.cpp" # 1 "" # 1 "" # 1 "gcc-ice.cpp" static float fraction( float _x ) { int tmp; asm ( "fld %0\n" "fld %%st(0)\n" "fisttp %1\n" "fild %1\n" "fxch\n" "fsub %%st(1),%%st(0)\n" : "=&t"( _x ), "=m"( tmp ) : "f"( _x ) : ); return( _x ); } int main( void ) { float x = fraction( 2.34634 ); } Command-line: g++ -O2 gcc-ice.cpp -save-temps Output: Using built-in specs. Target: i486-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu 4.3.1-7ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-4.3/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --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++/4.3 --program-suffix=-4.3 --enable-clocale=gnu --enable-libstdcxx-debug --enable-objc-gc --enable-mpfr --enable-targets=all --enable-checking=release --build=i486-linux-gnu --host=i486-linux-gnu --target=i486-linux-gnu Thread model: posix gcc version 4.3.1 (Ubuntu 4.3.1-7ubuntu1) COLLECT_GCC_OPTIONS='-v' '-O2' '-save-temps' '-msse3' '-mtune=generic' /usr/lib/gcc/i486-linux-gnu/4.3.1/cc1plus -E -quiet -v -D_GNU_SOURCE gcc-ice.cpp -D_FORTIFY_SOURCE=2 -msse3 -mtune=generic -O2 -fpch-preprocess -o gcc-ice.ii ignoring nonexistent directory "/usr/local/include/i486-linux-gnu" ignoring nonexistent directory "/usr/lib/gcc/i486-linux-gnu/4.3.1/../../../../i486-linux-gnu/include" ignoring nonexistent directory "/usr/include/i486-linux-gnu" #include "..." search starts here: #include <...> search starts here: /usr/include/c++/4.3 /usr/include/c++/4.3/i486-linux-gnu /usr/include/c++/4.3/backward /usr/local/include /usr/lib/gcc/i486-linux-gnu/4.3.1/include /usr/lib/gcc/i486-linux-gnu/4.3.1/include-fixed /usr/include End of search list. COLLECT_GCC_OPTIONS='-v' '-O2' '-save-temps' '-msse3' '-mtune=generic' /usr/lib/gcc/i486-linux-gnu/4.3.1/cc1plus -fpreprocessed gcc-ice.ii -quiet -dumpbase gcc-ice.cpp -msse3 -mtune=generic -auxbase gcc-ice -O2 -version -fstack-protector -o gcc-ice.s GNU C++ (Ubuntu 4.3.1-7ubuntu1) version 4.3.1 (i486-linux-gnu) compiled by GNU C version 4.3.1, GMP version 4.2.2, MPFR version 2.3.1. GGC heuristics: --param ggc-min-expand=98 --param ggc-min-heapsize=129034 Compiler executable checksum: 8789ae6462ba1c03375bc751bf9f310c gcc-ice.cpp: In function ‘int main()’: gcc-ice.cpp:20: error: unrecognizable insn: (insn:TI 7 6 41 gcc-ice.cpp:13 (parallel [ (set (reg:SF 8 st) (asm_operands:SF ("fld %0 fld %%st(0) fisttp %1 fild %1 fxch fsub %%st(1),%%st(0) ") ("=&t") 0 [ (reg:SF 8 st) ] [ (asm_input:SF ("f") 0) ] 2058)) (set (mem/c/i:SI (plus:SI (reg/f:SI 6 bp) (const_int -8 [0xfffffffffffffff8])) [2 tmp+0 S4 A32]) (asm_operands:SI ("fld %0 fld %%st(0) fisttp %1 fild %1 fxch fsub %%st(1),%%st(0) ") ("=m") 1 [ (reg:SF 8 st) ] [ (asm_input:SF ("f") 0) ] 2058)) (clobber (reg:QI 18 fpsr)) (clobber (reg:QI 17 flags)) ]) -1 (expr_list:REG_DEAD (reg:SF 8 st) (expr_list:REG_UNUSED (reg:QI 18 fpsr) (expr_list:REG_UNUSED (reg:QI 17 flags) (expr_list:REG_UNUSED (reg:SF 8 st) (nil)))))) gcc-ice.cpp:20: internal compiler error: in extract_constrain_insn_cached, at recog.c:1907 Please submit a full bug report, with preprocessed source if appropriate. See for instructions. -- Summary: Crashes with FPU inline-assembly Product: gcc Version: 4.3.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: inline-asm AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: tobias dot doerffel at gmail dot com GCC build triplet: i486-linux-gnu GCC host triplet: i486-linux-gnu GCC target triplet: i486-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36923