X-Git-Url: http://git.joshuawise.com/firearm.git/blobdiff_plain/149bcd1aae858c157cb51b351187c66a99410d6d..f5f16509c3105f1dc274f61c66317f3926463695:/Issue.v diff --git a/Issue.v b/Issue.v index ef53bc3..792fdbd 100644 --- a/Issue.v +++ b/Issue.v @@ -180,7 +180,7 @@ module Issue( `DECODE_LDRSTR: begin use_cpsr = `COND_MATTERS(cond); - use_regs = idxbit(rn) | (insn[20] /* L */ ? 0 : idxbit(rd)); + use_regs = idxbit(rn) | (insn[25] /* I */ ? idxbit(rm) : 0) | (insn[20] /* L */ ? 0 : idxbit(rd)); def_cpsr = 0; def_regs = insn[20] /* L */ ? idxbit(rd) : 0; end @@ -196,7 +196,7 @@ module Issue( use_cpsr = `COND_MATTERS(cond); use_regs = 0; def_cpsr = 0; - def_regs = 0; + def_regs = insn[24] /* L */ ? (16'b1 << 14) : 0; end `DECODE_LDCSTC: /* Coprocessor data transfer */ begin @@ -282,30 +282,30 @@ 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(flush) - begin - cpsr_inflight[0] = 1'b0; - cpsr_inflight[1] = 1'b0; - regs_inflight[0] = 16'b0; - regs_inflight[1] = 16'b0; - end - else if (!stall) + 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; regs_inflight[0] <= regs_inflight[1]; regs_inflight[1] <= (waiting || inbubble || !condition_met) ? 0 : def_regs; - outbubble <= inbubble | waiting | !condition_met | flush; + outbubble <= inbubble | waiting | !condition_met | flush | delayedflush; outpc <= inpc; outinsn <= insn; end