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Add BranchPlugin.decodeBranchSrc2 for branch target configs

This commit is contained in:
Charles Papon 2019-11-07 21:40:39 +01:00
parent 4fe7fa56c7
commit 6d0d70364c
1 changed files with 8 additions and 4 deletions
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12
src/main/scala/vexriscv/plugin/BranchPlugin.scala
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@ -53,7 +53,8 @@ trait PredictionInterface{
class BranchPlugin(earlyBranch : Boolean,
catchAddressMisaligned : Boolean = false,
fenceiGenAsAJump : Boolean = false,
fenceiGenAsANop : Boolean = false) extends Plugin[VexRiscv] with PredictionInterface{
fenceiGenAsANop : Boolean = false,
decodeBranchSrc2 : Boolean = false) extends Plugin[VexRiscv] with PredictionInterface{
def catchAddressMisalignedForReal = catchAddressMisaligned && !pipeline(RVC_GEN)
@ -310,6 +311,8 @@ class BranchPlugin(earlyBranch : Boolean,
//Do branch calculations (conditions + target PC)
object NEXT_PC extends Stageable(UInt(32 bits))
object TARGET_MISSMATCH extends Stageable(Bool)
object BRANCH_SRC2 extends Stageable(UInt(32 bits))
val branchSrc2Stage = if(decodeBranchSrc2) decode else execute
execute plug new Area {
import execute._
@ -328,15 +331,16 @@ class BranchPlugin(earlyBranch : Boolean,
)
)
val imm = IMM(input(INSTRUCTION))
val branch_src1 = (input(BRANCH_CTRL) === BranchCtrlEnum.JALR) ? input(RS1).asUInt | input(PC)
val branch_src2 = input(BRANCH_CTRL).mux(
val imm = IMM(branchSrc2Stage.input(INSTRUCTION))
branchSrc2Stage.insert(BRANCH_SRC2) := branchSrc2Stage.input(BRANCH_CTRL).mux(
BranchCtrlEnum.JAL -> imm.j_sext,
BranchCtrlEnum.JALR -> imm.i_sext,
default -> imm.b_sext
).asUInt
val branchAdder = branch_src1 + branch_src2
val branchAdder = branch_src1 + input(BRANCH_SRC2)
insert(BRANCH_CALC) := branchAdder(31 downto 1) @@ "0"
insert(NEXT_PC) := input(PC) + (if(pipeline(RVC_GEN)) ((input(IS_RVC)) ? U(2) | U(4)) else 4)
insert(TARGET_MISSMATCH) := decode.input(PC) =/= input(BRANCH_CALC)