From c7f1cf1d58cf50118c18b1afc4c938eafba81492 Mon Sep 17 00:00:00 2001 From: Gabe Black Date: Fri, 13 Apr 2007 13:59:31 +0000 Subject: Remove most of the special handling for delay slots since they have to be squashed anyway on a mispredict. This is because the NNPC value they saw when executing was incorrect. --HG-- extra : convert_revision : b42c4eb28b4fbba66c65cbd0a5033bf886c1532d --- src/cpu/o3/iew_impl.hh | 74 ++++---------------------------------------------- 1 file changed, 6 insertions(+), 68 deletions(-) (limited to 'src/cpu/o3/iew_impl.hh') diff --git a/src/cpu/o3/iew_impl.hh b/src/cpu/o3/iew_impl.hh index 62e656e93..050785818 100644 --- a/src/cpu/o3/iew_impl.hh +++ b/src/cpu/o3/iew_impl.hh @@ -69,7 +69,6 @@ DefaultIEW::DefaultIEW(O3CPU *_cpu, Params *params) dispatchStatus[i] = Running; stalls[i].commit = false; fetchRedirect[i] = false; - bdelayDoneSeqNum[i] = 0; } wbMax = wbWidth * params->wbDepth; @@ -410,31 +409,14 @@ DefaultIEW::squash(unsigned tid) instQueue.squash(tid); // Tell the LDSTQ to start squashing. -#if ISA_HAS_DELAY_SLOT - ldstQueue.squash(fromCommit->commitInfo[tid].bdelayDoneSeqNum, tid); -#else ldstQueue.squash(fromCommit->commitInfo[tid].doneSeqNum, tid); -#endif updatedQueues = true; // Clear the skid buffer in case it has any data in it. DPRINTF(IEW, "[tid:%i]: Removing skidbuffer instructions until [sn:%i].\n", - tid, fromCommit->commitInfo[tid].bdelayDoneSeqNum); + tid, fromCommit->commitInfo[tid].doneSeqNum); while (!skidBuffer[tid].empty()) { -#if ISA_HAS_DELAY_SLOT - if (skidBuffer[tid].front()->seqNum <= - fromCommit->commitInfo[tid].bdelayDoneSeqNum) { - DPRINTF(IEW, "[tid:%i]: Cannot remove skidbuffer instructions " - "that occur before delay slot [sn:%i].\n", - fromCommit->commitInfo[tid].bdelayDoneSeqNum, - tid); - break; - } else { - DPRINTF(IEW, "[tid:%i]: Removing instruction [sn:%i] from " - "skidBuffer.\n", tid, skidBuffer[tid].front()->seqNum); - } -#endif if (skidBuffer[tid].front()->isLoad() || skidBuffer[tid].front()->isStore() ) { toRename->iewInfo[tid].dispatchedToLSQ++; @@ -445,8 +427,6 @@ DefaultIEW::squash(unsigned tid) skidBuffer[tid].pop(); } - bdelayDoneSeqNum[tid] = fromCommit->commitInfo[tid].bdelayDoneSeqNum; - emptyRenameInsts(tid); } @@ -462,38 +442,18 @@ DefaultIEW::squashDueToBranch(DynInstPtr &inst, unsigned tid) toCommit->mispredPC[tid] = inst->readPC(); toCommit->branchMispredict[tid] = true; - int instSize = sizeof(TheISA::MachInst); #if ISA_HAS_DELAY_SLOT - bool branch_taken = + int instSize = sizeof(TheISA::MachInst); + toCommit->branchTaken[tid] = !(inst->readNextPC() + instSize == inst->readNextNPC() && (inst->readNextPC() == inst->readPC() + instSize || inst->readNextPC() == inst->readPC() + 2 * instSize)); - DPRINTF(Sparc, "Branch taken = %s [sn:%i]\n", - branch_taken ? "true": "false", inst->seqNum); - - toCommit->branchTaken[tid] = branch_taken; - - bool squashDelaySlot = true; -// (inst->readNextPC() != inst->readPC() + sizeof(TheISA::MachInst)); - DPRINTF(Sparc, "Squash delay slot = %s [sn:%i]\n", - squashDelaySlot ? "true": "false", inst->seqNum); - toCommit->squashDelaySlot[tid] = squashDelaySlot; - //If we're squashing the delay slot, we need to pick back up at NextPC. - //Otherwise, NextPC isn't being squashed, so we should pick back up at - //NextNPC. - if (squashDelaySlot) { - toCommit->nextPC[tid] = inst->readNextPC(); - toCommit->nextNPC[tid] = inst->readNextNPC(); - } else { - toCommit->nextPC[tid] = inst->readNextNPC(); - toCommit->nextNPC[tid] = inst->readNextNPC() + instSize; - } #else toCommit->branchTaken[tid] = inst->readNextPC() != (inst->readPC() + sizeof(TheISA::MachInst)); - toCommit->nextPC[tid] = inst->readNextPC(); - toCommit->nextNPC[tid] = inst->readNextPC() + instSize; #endif + toCommit->nextPC[tid] = inst->readNextPC(); + toCommit->nextNPC[tid] = inst->readNextNPC(); toCommit->includeSquashInst[tid] = false; @@ -510,11 +470,7 @@ DefaultIEW::squashDueToMemOrder(DynInstPtr &inst, unsigned tid) toCommit->squash[tid] = true; toCommit->squashedSeqNum[tid] = inst->seqNum; toCommit->nextPC[tid] = inst->readNextPC(); -#if ISA_HAS_DELAY_SLOT toCommit->nextNPC[tid] = inst->readNextNPC(); -#else - toCommit->nextNPC[tid] = inst->readNextPC() + sizeof(TheISA::MachInst); -#endif toCommit->branchMispredict[tid] = false; toCommit->includeSquashInst[tid] = false; @@ -532,11 +488,7 @@ DefaultIEW::squashDueToMemBlocked(DynInstPtr &inst, unsigned tid) toCommit->squash[tid] = true; toCommit->squashedSeqNum[tid] = inst->seqNum; toCommit->nextPC[tid] = inst->readPC(); -#if ISA_HAS_DELAY_SLOT toCommit->nextNPC[tid] = inst->readNextPC(); -#else - toCommit->nextNPC[tid] = inst->readPC() + sizeof(TheISA::MachInst); -#endif toCommit->branchMispredict[tid] = false; // Must include the broadcasted SN in the squash. @@ -880,10 +832,8 @@ DefaultIEW::sortInsts() { int insts_from_rename = fromRename->size; #ifdef DEBUG -#if !ISA_HAS_DELAY_SLOT for (int i = 0; i < numThreads; i++) assert(insts[i].empty()); -#endif #endif for (int i = 0; i < insts_from_rename; ++i) { insts[fromRename->insts[i]->threadNumber].push(fromRename->insts[i]); @@ -894,21 +844,9 @@ template void DefaultIEW::emptyRenameInsts(unsigned tid) { - DPRINTF(IEW, "[tid:%i]: Removing incoming rename instructions until " - "[sn:%i].\n", tid, bdelayDoneSeqNum[tid]); + DPRINTF(IEW, "[tid:%i]: Removing incoming rename instructions\n", tid); while (!insts[tid].empty()) { -#if ISA_HAS_DELAY_SLOT - if (insts[tid].front()->seqNum <= bdelayDoneSeqNum[tid]) { - DPRINTF(IEW, "[tid:%i]: Done removing, cannot remove instruction" - " that occurs at or before delay slot [sn:%i].\n", - tid, bdelayDoneSeqNum[tid]); - break; - } else { - DPRINTF(IEW, "[tid:%i]: Removing incoming rename instruction " - "[sn:%i].\n", tid, insts[tid].front()->seqNum); - } -#endif if (insts[tid].front()->isLoad() || insts[tid].front()->isStore() ) { -- cgit v1.2.3