>Can gcc not to emit nop nor noreorder when it tries to fill the delay >slot with nop? You never want the assembler to try to fill delay slots. Consider a compiler optimization like software pipelining. The compiler will schedule instructions inside a loop with full knowledge of the target pipeline to give maximum performance. Then the assembler picks a random instruction from the loop, puts it in a branch delay slot, and now your code runs twice as slow because the assembler introduced pipeline stalls. Of course, gcc isn't good enough yet to have this problem yet, but we will get there eventually. Meanwhile, we need to get out of the habit of relying on assembler optimizations. In the long run, assembler optimizations are bad, and we need to stop using them as soon as possible. Gcc should emit .set nomacro/noreorder/noat/etc at the begining of its assembly output, and never turn them on. Jim
