https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66987
Bug ID: 66987 Summary: valgrind error in get_attr_length_nobnd Product: gcc Version: 6.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: dcb314 at hotmail dot com Target Milestone: --- I just tried a build of today's (20150724) trunk code with valgrind and got this /home/dcb/gcc/working/./gcc/xgcc -B/home/dcb/gcc/working/./gcc/ -B/home/dcb/gcc/results/x86_64-unknown-linux-gnu/bin/ -B/home/dcb/gcc/results/x86_64-unknown-linux-gnu/lib/ -isystem /home/dcb/gcc/results/x86_64-unknown-linux-gnu/include -isystem /home/dcb/gcc/results/x86_64-unknown-linux-gnu/sys-include -g -O2 -O2 -g -O2 -DIN_GCC -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition -isystem ./include -fpic -mlong-double-80 -DUSE_ELF_SYMVER -g -DIN_LIBGCC2 -fbuilding-libgcc -fno-stack-protector -fpic -mlong-double-80 -DUSE_ELF_SYMVER -I. -I. -I../.././gcc -I../../../src/trunk/libgcc -I../../../src/trunk/libgcc/. -I../../../src/trunk/libgcc/../gcc -I../../../src/trunk/libgcc/../include -I../../../src/trunk/libgcc/config/libbid -DENABLE_DECIMAL_BID_FORMAT -DHAVE_CC_TLS -DUSE_TLS -o _ashrdi3.o -MT _ashrdi3.o -MD -MP -MF _ashrdi3.dep -DL_ashrdi3 -c ../../../src/trunk/libgcc/libgcc2.c -fvisibility=hidden -DHIDE_EXPORTS ==31129== Conditional jump or move depends on uninitialised value(s) ==31129== at 0xC95F36: get_attr_length_nobnd(rtx_insn*) (i386.md:6342) ==31129== by 0xCA943A: insn_min_length(rtx_insn*) (i386.md:526) ==31129== by 0x759F9F: shorten_branches(rtx_insn*) (final.c:1197) ==31129== by 0x75A4DF: rest_of_handle_shorten_branches (final.c:4541) i386.md:6342 is this ;; Subtract with jump on overflow. (define_expand "subv<mode>4" [(parallel [(set (reg:CCO FLAGS_REG) (eq:CCO (minus:<DWI> (sign_extend:<DWI> (match_operand:SWI 1 "nonimmediate_operand")) Configure line is ../src/trunk/configure --prefix=/home/dcb/gcc/results \ --disable-werror \ --disable-multilib \ --enable-checking=valgrind \ --disable-bootstrap \ --enable-languages=c,c++,fortran