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#69 Relax address calculation of decode branch predictor by adding KEEP synthesis attribut

This commit is contained in:
Charles Papon 2019-04-12 15:56:22 +02:00
parent 41ff87f83b
commit 13b774b535
3 changed files with 11 additions and 5 deletions
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4
src/main/scala/vexriscv/plugin/Fetcher.scala
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@ -20,7 +20,8 @@ abstract class IBusFetcherImpl(val resetVector : BigInt,
val injectorReadyCutGen : Boolean, val injectorReadyCutGen : Boolean,
val prediction : BranchPrediction, val prediction : BranchPrediction,
val historyRamSizeLog2 : Int, val historyRamSizeLog2 : Int,
val injectorStage : Boolean) extends Plugin[VexRiscv] with JumpService with IBusFetcher{ val injectorStage : Boolean,
val relaxPredictorAddress : Boolean) extends Plugin[VexRiscv] with JumpService with IBusFetcher{
var prefetchExceptionPort : Flow[ExceptionCause] = null var prefetchExceptionPort : Flow[ExceptionCause] = null
var decodePrediction : DecodePredictionBus = null var decodePrediction : DecodePredictionBus = null
var fetchPrediction : FetchPredictionBus = null var fetchPrediction : FetchPredictionBus = null
@ -498,6 +499,7 @@ abstract class IBusFetcherImpl(val resetVector : BigInt,
predictionJumpInterface.valid := decodePrediction.cmd.hadBranch && decode.arbitration.isFiring //TODO OH Doublon de priorité predictionJumpInterface.valid := decodePrediction.cmd.hadBranch && decode.arbitration.isFiring //TODO OH Doublon de priorité
predictionJumpInterface.payload := decode.input(PC) + ((decode.input(BRANCH_CTRL) === BranchCtrlEnum.JAL) ? imm.j_sext | imm.b_sext).asUInt predictionJumpInterface.payload := decode.input(PC) + ((decode.input(BRANCH_CTRL) === BranchCtrlEnum.JAL) ? imm.j_sext | imm.b_sext).asUInt
if(relaxPredictorAddress) KeepAttribute(predictionJumpInterface.payload)
// when(predictionJumpInterface.payload((if(pipeline(RVC_GEN)) 0 else 1) downto 0) =/= 0){ // when(predictionJumpInterface.payload((if(pipeline(RVC_GEN)) 0 else 1) downto 0) =/= 0){
// decodePrediction.cmd.hadBranch := False // decodePrediction.cmd.hadBranch := False

6
src/main/scala/vexriscv/plugin/IBusCachedPlugin.scala
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@ -34,7 +34,8 @@ class IBusCachedPlugin(resetVector : BigInt = 0x80000000l,
config : InstructionCacheConfig, config : InstructionCacheConfig,
memoryTranslatorPortConfig : Any = null, memoryTranslatorPortConfig : Any = null,
injectorStage : Boolean = false, injectorStage : Boolean = false,
withoutInjectorStage : Boolean = false) extends IBusFetcherImpl( withoutInjectorStage : Boolean = false,
relaxPredictorAddress : Boolean = true) extends IBusFetcherImpl(
resetVector = resetVector, resetVector = resetVector,
keepPcPlus4 = keepPcPlus4, keepPcPlus4 = keepPcPlus4,
decodePcGen = compressedGen, decodePcGen = compressedGen,
@ -44,7 +45,8 @@ class IBusCachedPlugin(resetVector : BigInt = 0x80000000l,
injectorReadyCutGen = false, injectorReadyCutGen = false,
prediction = prediction, prediction = prediction,
historyRamSizeLog2 = historyRamSizeLog2, historyRamSizeLog2 = historyRamSizeLog2,
injectorStage = (!config.twoCycleCache && !withoutInjectorStage) || injectorStage){ injectorStage = (!config.twoCycleCache && !withoutInjectorStage) || injectorStage,
relaxPredictorAddress = relaxPredictorAddress){
import config._ import config._
assert(!(withoutInjectorStage && injectorStage)) assert(!(withoutInjectorStage && injectorStage))

6
src/main/scala/vexriscv/plugin/IBusSimplePlugin.scala
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@ -172,7 +172,8 @@ class IBusSimplePlugin(resetVector : BigInt,
pendingMax : Int = 7, pendingMax : Int = 7,
injectorStage : Boolean = true, injectorStage : Boolean = true,
rspHoldValue : Boolean = false, rspHoldValue : Boolean = false,
singleInstructionPipeline : Boolean = false singleInstructionPipeline : Boolean = false,
relaxPredictorAddress : Boolean = true
) extends IBusFetcherImpl( ) extends IBusFetcherImpl(
resetVector = resetVector, resetVector = resetVector,
keepPcPlus4 = keepPcPlus4, keepPcPlus4 = keepPcPlus4,
@ -183,7 +184,8 @@ class IBusSimplePlugin(resetVector : BigInt,
injectorReadyCutGen = false, injectorReadyCutGen = false,
prediction = prediction, prediction = prediction,
historyRamSizeLog2 = historyRamSizeLog2, historyRamSizeLog2 = historyRamSizeLog2,
injectorStage = injectorStage){ injectorStage = injectorStage,
relaxPredictorAddress = relaxPredictorAddress){
var iBus : IBusSimpleBus = null var iBus : IBusSimpleBus = null
var decodeExceptionPort : Flow[ExceptionCause] = null var decodeExceptionPort : Flow[ExceptionCause] = null