riscv/rocket-chip
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Get I$ ECC check further off critical path

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This commit is contained in:
Andrew Waterman 2017-08-04 14:59:56 -07:00
parent 4bfbe75d74
commit df7f09b9ce
1 changed files with 5 additions and 4 deletions
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9
src/main/scala/rocket/IBuf.scala
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@ -76,10 +76,11 @@ class IBuf(implicit p: Parameters) extends CoreModule {
val icMask = (~UInt(0, fetchWidth*coreInstBits) << (nBufValid << log2Ceil(coreInstBits)))(fetchWidth*coreInstBits-1,0) val icMask = (~UInt(0, fetchWidth*coreInstBits) << (nBufValid << log2Ceil(coreInstBits)))(fetchWidth*coreInstBits-1,0)
val inst = icData & icMask | buf.data & ~icMask val inst = icData & icMask | buf.data & ~icMask
val valid = (UIntToOH(nValid) - 1)(fetchWidth-1, 0) val valid = UIntToOH1(nValid, fetchWidth)
val bufMask = UIntToOH(nBufValid) - 1 val bufMask = UIntToOH1(nBufValid, fetchWidth)
val xcpt = (0 until bufMask.getWidth).map(i => Mux(bufMask(i), buf.xcpt, io.imem.bits.xcpt)) val xcpt = (0 until bufMask.getWidth).map(i => Mux(bufMask(i), buf.xcpt, io.imem.bits.xcpt))
val ic_replay = valid & (Mux(buf.replay, bufMask, UInt(0)) | Mux(io.imem.bits.replay, ~bufMask, UInt(0))) val buf_replay = Mux(buf.replay, bufMask, UInt(0))
val ic_replay = buf_replay | Mux(io.imem.bits.replay, valid & ~bufMask, UInt(0))
val ibufBTBHitMask = Mux(ibufBTBHit, UIntToOH(ibufBTBResp.bridx), UInt(0)) val ibufBTBHitMask = Mux(ibufBTBHit, UIntToOH(ibufBTBResp.bridx), UInt(0))
assert(!io.imem.valid || !io.imem.bits.btb.valid || io.imem.bits.btb.bits.bridx >= pcWordBits) assert(!io.imem.valid || !io.imem.bits.btb.valid || io.imem.bits.btb.bits.bridx >= pcWordBits)
val icBTBHitMask = Mux(io.imem.bits.btb.valid, UIntToOH(io.imem.bits.btb.bits.bridx +& nBufValid - pcWordBits), UInt(0)) val icBTBHitMask = Mux(io.imem.bits.btb.valid, UIntToOH(io.imem.bits.btb.bits.bridx +& nBufValid - pcWordBits), UInt(0))
@ -97,7 +98,7 @@ class IBuf(implicit p: Parameters) extends CoreModule {
if (usingCompressed) { if (usingCompressed) {
val replay = ic_replay(j) || (!exp.io.rvc && (btbHitMask(j) || ic_replay(j+1))) val replay = ic_replay(j) || (!exp.io.rvc && (btbHitMask(j) || ic_replay(j+1)))
val full_insn = exp.io.rvc || valid(j+1) || xcpt(j+1).asUInt.orR || replay val full_insn = exp.io.rvc || valid(j+1) || xcpt(j+1).asUInt.orR || buf_replay(j)
io.inst(i).valid := valid(j) && full_insn io.inst(i).valid := valid(j) && full_insn
io.inst(i).bits.xcpt0 := xcpt(j) io.inst(i).bits.xcpt0 := xcpt(j)
io.inst(i).bits.xcpt1 := Mux(exp.io.rvc, 0.U, xcpt(j+1).asUInt).asTypeOf(new FrontendExceptions) io.inst(i).bits.xcpt1 := Mux(exp.io.rvc, 0.U, xcpt(j+1).asUInt).asTypeOf(new FrontendExceptions)