(Sorry, doesn't seem worthwhile to split into separate binutils and gas reports.) At master c77852c (HEAD as of this writing), binutils configured with --target=mipsisa32r2el-linux-gnu with no other tools in $PATH (e.g. no target-gcc), gets these errors in the gas and binutils test-suites with "make check", respectively: gas: Running /xx/src/gas/testsuite/gas/mips/mips.exp ... FAIL: MIPS MIPS64 MIPS-3D ASE instructions (-mips3d flag) FAIL: MIPS MIPS64 MDMX ASE instructions (-mdmx flag) FAIL: mips module-defer-warn2 binutils: Running /xx/src/binutils/testsuite/binutils-all/mips/mips.exp ... FAIL: MIPS XPA and Virtualization ASE instruction disassembly 1 FAIL: MIPS XPA and Virtualization ASE instruction disassembly 2 FAIL: MIPS XPA and Virtualization ASE instruction disassembly 3 There are error messages in gas/testsuite/gas.log apparently due to the level defaulted by the "mipsisa32r2el" in the configure-tuple. In biutils/binutils.log, disassembly is different compared to the test-suite template. Maybe best to force a certain architecture in the assembly options and disassembly options, as applicable. Not seen if configured with --target=mipsel-linux-gnu.