Hello! I'm working on a binary translator that translates MIPS binaries into Java bytecode (http://spel.bth.se/index.php/Cibyl) with the goal of "recompiling" C programs to run on J2ME. To simplify things, I use compile programs for a subset of the MIPS1 instruction set, and ideally I would like to get rid of delayed instructions. So, I used the -fno-delayed-branch instruction when compiling, which is documented as If supported for the target machine, attempt to reorder instructions to exploit instruction slots available after delayed branch instructions. I use GCC 3.4.4 from the emdebian project, mips-linux-gcc (GCC) 3.4.4 20050314 (prerelease) (Debian 3.4.3-13) -fno-delayed-branch seems to mostly work, i.e., I get code as 10001d0: 27a40010 addiu a0,sp,16 10001d4: 0c400008 jal 1000020 <game_loop> 10001d8: 00000000 nop which is what I want. However, on conditional branches, it doesn't work as expected: 1000160: 8c670000 lw a3,0(v1) 1000164: 24020013 li v0,19 1000168: 0000000c syscall 100016c: 25080001 addiu t0,t0,1 1000170: 29020018 slti v0,t0,24 1000174: 1440fff9 bnez v0,100015c <game_init+0x7c> 1000178: 24630060 addiu v1,v1,96 Here, I would have expected that the addiu would go before bnez, and that a nop is inserted after the branch. So the question is if this is the intended behavior, or if it simply is a bug with the -fno-delayed-branch implementation? // Simon
