X-Git-Url: http://git.joshuawise.com/firearm.git/blobdiff_plain/4ddc4b728c3d77fc388140a549afe636d527cfbd..d64d6ef9fffab25e5fffa4263e9ceb6ff85267da:/Issue.v diff --git a/Issue.v b/Issue.v index c3e5791..7815a08 100644 --- a/Issue.v +++ b/Issue.v @@ -167,7 +167,7 @@ module Issue( (idxbit(rs) | idxbit(rm)) : (idxbit(rm)))) | (((alu_opc != `ALU_MOV) && (alu_opc != `ALU_MVN)) ? idxbit(rn) : 0); - def_cpsr = insn[20] /* S */ | alu_is_logical(alu_opc); + def_cpsr = insn[20] /* S */; def_regs = alu_flags_only(alu_opc) ? 0 : idxbit(rd); end `DECODE_LDRSTR_UNDEFINED: /* Undefined. I hate ARM */ @@ -282,16 +282,31 @@ module Issue( waiting_cpsr = use_cpsr & (cpsr_inflight[0] | cpsr_inflight[1]); waiting_regs = |(use_regs & (regs_inflight[0] | regs_inflight[1])); - outstall = (waiting && !inbubble) || stall; /* Happens in an always @*, because it is an exception. */ + outstall = (waiting && !inbubble && !flush) || stall; /* Happens in an always @*, because it is an exception. */ end + + reg delayedflush = 0; + always @(posedge clk) + if (flush && outstall /* halp! I can't do it now, maybe later? */) + delayedflush <= 1; + else if (!outstall /* anything has been handled this time around */) + delayedflush <= 0; /* Actually do the issue. */ always @(posedge clk) begin if (waiting) $display("ISSUE: Stalling instruction %08x because %d/%d", insn, waiting_cpsr, waiting_regs); - - if (!stall) + + if((flush || delayedflush) && !outstall) + begin + cpsr_inflight[0] = 1'b0; + cpsr_inflight[1] = 1'b0; + regs_inflight[0] = 16'b0; + regs_inflight[1] = 16'b0; + outbubble <= 1'b1; + end + else if (!stall) begin cpsr_inflight[0] <= cpsr_inflight[1]; /* I'm not sure how well selects work with arrays, and that seems like a dumb thing to get anusulated by. */ cpsr_inflight[1] <= (waiting || inbubble || !condition_met) ? 0 : def_cpsr;