To avoid warninigs about “unconditional jump or move depends on uninitialized value(s)”, I simplified my programs so that the warnings remain only through SNESSolve(). Some of them are appended below. My question is if such warnings really matter and affect the simulation results? Thank you for your kind advice. Jiannan ==1988731== Conditional jump or move depends on uninitialised value(s) ==1988731== at 0xA19178C: sqrt (w_sqrt_compat.c:31) ==1988731== by 0x4EA9E4C: VecNorm_Seq (bvec2.c:227) ==1988731== by 0x4F705C8: VecNorm (rvector.c:228) ==1988731== by 0x6678D91: SNESSolve_NEWTONTR (tr.c:300) ==1988731== by 0x673093F: SNESSolve (snes.c:4809) ==1988731== by 0x122FA7: main (iditm3d.cpp:138) ==1988731== ==1988731== Conditional jump or move depends on uninitialised value(s) ==1988731== at 0x667495C: PetscIsInfOrNanReal (petscmath.h:788) ==1988731== by 0x6678E0C: SNESSolve_NEWTONTR (tr.c:301) ==1988731== by 0x673093F: SNESSolve (snes.c:4809) ==1988731== by 0x122FA7: main (iditm3d.cpp:138) ==1988731== ==1988731== Conditional jump or move depends on uninitialised value(s) ==1988731== at 0xA347078: __printf_fp_l (printf_fp.c:387) ==1988731== by 0xA360547: printf_positional (vfprintf-internal.c:2072) ==1988731== by 0xA361DCC: __vfprintf_internal (vfprintf-internal.c:1733) ==1988731== by 0xA376F99: __vsnprintf_internal (vsnprintf.c:114) ==1988731== by 0x4A77784: PetscVSNPrintf (mprint.c:176) ==1988731== by 0x4A77EF4: PetscVFPrintfDefault (mprint.c:292) ==1988731== by 0x4BCBB92: PetscViewerASCIIPrintf (filev.c:607) ==1988731== by 0x674764B: SNESMonitorDefault (snesut.c:296) ==1988731== by 0x6728A3E: SNESMonitor (snes.c:4059) ==1988731== by 0x6679743: SNESSolve_NEWTONTR (tr.c:309) ==1988731== by 0x673093F: SNESSolve (snes.c:4809) ==1988731== by 0x122FA7: main (iditm3d.cpp:138) ==1988731== ==1988731== Conditional jump or move depends on uninitialised value(s) ==1988731== at 0xA342B34: __mpn_extract_double (dbl2mpn.c:56) ==1988731== by 0xA34738E: __printf_fp_l (printf_fp.c:387) ==1988731== by 0xA360547: printf_positional (vfprintf-internal.c:2072) ==1988731== by 0xA361DCC: __vfprintf_internal (vfprintf-internal.c:1733) ==1988731== by 0xA376F99: __vsnprintf_internal (vsnprintf.c:114) ==1988731== by 0x4A77784: PetscVSNPrintf (mprint.c:176) ==1988731== by 0x4A77EF4: PetscVFPrintfDefault (mprint.c:292) ==1988731== by 0x4BCBB92: PetscViewerASCIIPrintf (filev.c:607) ==1988731== by 0x674764B: SNESMonitorDefault (snesut.c:296) ==1988731== by 0x6728A3E: SNESMonitor (snes.c:4059) ==1988731== by 0x6679743: SNESSolve_NEWTONTR (tr.c:309) ==1988731== by 0x673093F: SNESSolve (snes.c:4809)