On 10/07/11 09:50, BELBACHIR Selim wrote: > (asm result) > > load d($C2),$R1 <--1st operand for comparison ctrl,readmem,nothing > loadi 0,$C4 <- 2nd operand for comparison ctrl,nothing > load d($C2+4),$R2 <--no data dependancies ctrl,readmem,nothing > cmp $C4,$R1 (gsr+ctrl),gsr*2 > nop > nop > jmpifeq .L5 (ctrl+gsr) > > (.sched2) > ;; 20--> 81 $C4=0x0 :ctrl,nothing > ;; dependencies resolved: insn 22 > ;; Ready-->Q: insn 22: queued for 2 cycles. > ;; tick updated: insn 22 into queue with cost=2
Insn 22 is the compare, and the compiler thinks that its operand $C4 becomes available only after two cycles. Presumably the first load to $R1 has a delay of 3 cycles. So the scheduler places the compare at the point where its operands are ready. The load to $R2 occurs before it because it can execute earlier. If the delays are modeled correctly, I think there's no way to get the code to run faster. Bernd
