https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84799
Bug ID: 84799 Summary: ICE on valid code at -O1: in lra_split_hard_reg_for, at lra-assigns.c:1802 Product: gcc Version: unknown Status: UNCONFIRMED Severity: normal Priority: P3 Component: rtl-optimization Assignee: unassigned at gcc dot gnu.org Reporter: su at cs dot ucdavis.edu Target Milestone: --- It appears to be recent regression. $ gcctk -v Using built-in specs. COLLECT_GCC=gcctk COLLECT_LTO_WRAPPER=/home/su/software/tmp/gcc/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/8.0.1/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: ../gcc-source-trunk/configure --enable-languages=c,c++,lto --prefix=/home/su/software/tmp/gcc/gcc-trunk --disable-bootstrap Thread model: posix gcc version 8.0.1 20180309 (experimental) [trunk revision 258399] (GCC) $ $ gcctk -O0 small.c $ gcc-7.2.0 -O1 small.c $ $ gcctk -O1 small.c small.c: In function ‘main’: small.c:26:1: error: unable to find a register to spill } ^ small.c:26:1: error: this is the insn: (insn 32 113 108 3 (parallel [ (set (reg:DI 184 [149]) (div:DI (reg:DI 184 [149]) (reg:DI 185))) (set (reg:DI 192 [148]) (mod:DI (reg:DI 184 [149]) (reg:DI 185))) (clobber (reg:CC 17 flags)) ]) "small.c":10 373 {*divmoddi4} (expr_list:REG_UNUSED (reg:DI 184 [149]) (expr_list:REG_DEAD (reg:DI 185) (expr_list:REG_UNUSED (reg:CC 17 flags) (nil))))) during RTL pass: reload small.c:26:1: internal compiler error: in lra_split_hard_reg_for, at lra-assigns.c:1802 0x5f15ae _fatal_insn(char const*, rtx_def const*, char const*, int, char const*) ../../gcc-source-trunk/gcc/rtl-error.c:108 0xb0d849 lra_split_hard_reg_for() ../../gcc-source-trunk/gcc/lra-assigns.c:1802 0xb07f57 lra(_IO_FILE*) ../../gcc-source-trunk/gcc/lra.c:2507 0xabb899 do_reload ../../gcc-source-trunk/gcc/ira.c:5465 0xabb899 execute ../../gcc-source-trunk/gcc/ira.c:5649 Please submit a full bug report, with preprocessed source if appropriate. Please include the complete backtrace with any bug report. See <https://gcc.gnu.org/bugs/> for instructions. $ --------------------------------------------------------- int a, g; long b, f; short c, d, e; static void fn1 () { if (a) { long i = 5, j = b / i | c; int k = b % (d % i) & j; short l = ~f % (-d / j ^ -e), m = e << (d - l); if (k) m = d; i = d | (i & b); g = (c | ~f) % i + l; e = (c - f) & e; d = m; } } int main () { b |= 1; fn1 (); return 0; }