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Perform all illegal-instruction detection in ID stage

Browse Source 
This is simpler, reduces what would have become a critical path in
the commit stage, and will make it easier to support the mbadinst
CSR if it is implemented.
This commit is contained in:
Andrew Waterman
2017-03-07 14:33:51 -08:00
parent 7668827741
commit 24a2278fc4
4 changed files with 135 additions and 143 deletions
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133
src/main/scala/tile/FPU.scala
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@ -60,7 +60,6 @@ trait HasFPUCtrlSigs {
val fma = Bool()
val div = Bool()
val sqrt = Bool()
val round = Bool()
val wflags = Bool()
}
@ -72,71 +71,71 @@ class FPUDecoder(implicit p: Parameters) extends FPUModule()(p) {
val sigs = new FPUCtrlSigs().asOutput
}
val default = List(FCMD_X, X,X,X,X,X,X,X,X,X,X,X,X,X,X,X,X)
val default = List(FCMD_X, X,X,X,X,X,X,X,X,X,X,X,X,X,X,X)
val f =
Array(FLW -> List(FCMD_X, Y,Y,N,N,N,X,X,Y,N,N,N,N,N,N,N,N),
FSW -> List(FCMD_MV_XF, Y,N,N,Y,N,Y,X,Y,N,Y,N,N,N,N,N,N),
FMV_S_X -> List(FCMD_MV_FX, N,Y,N,N,N,X,X,Y,Y,N,N,N,N,N,Y,N),
FCVT_S_W -> List(FCMD_CVT_FI, N,Y,N,N,N,X,X,Y,Y,N,N,N,N,N,Y,Y),
FCVT_S_WU-> List(FCMD_CVT_FI, N,Y,N,N,N,X,X,Y,Y,N,N,N,N,N,Y,Y),
FCVT_S_L -> List(FCMD_CVT_FI, N,Y,N,N,N,X,X,Y,Y,N,N,N,N,N,Y,Y),
FCVT_S_LU-> List(FCMD_CVT_FI, N,Y,N,N,N,X,X,Y,Y,N,N,N,N,N,Y,Y),
FMV_X_S -> List(FCMD_MV_XF, N,N,Y,N,N,N,X,Y,N,Y,N,N,N,N,Y,N),
FCLASS_S -> List(FCMD_MV_XF, N,N,Y,N,N,N,X,Y,N,Y,N,N,N,N,Y,N),
FCVT_W_S -> List(FCMD_CVT_IF, N,N,Y,N,N,N,X,Y,N,Y,N,N,N,N,Y,Y),
FCVT_WU_S-> List(FCMD_CVT_IF, N,N,Y,N,N,N,X,Y,N,Y,N,N,N,N,Y,Y),
FCVT_L_S -> List(FCMD_CVT_IF, N,N,Y,N,N,N,X,Y,N,Y,N,N,N,N,Y,Y),
FCVT_LU_S-> List(FCMD_CVT_IF, N,N,Y,N,N,N,X,Y,N,Y,N,N,N,N,Y,Y),
FEQ_S -> List(FCMD_CMP, N,N,Y,Y,N,N,N,Y,N,Y,N,N,N,N,N,Y),
FLT_S -> List(FCMD_CMP, N,N,Y,Y,N,N,N,Y,N,Y,N,N,N,N,N,Y),
FLE_S -> List(FCMD_CMP, N,N,Y,Y,N,N,N,Y,N,Y,N,N,N,N,N,Y),
FSGNJ_S -> List(FCMD_SGNJ, N,Y,Y,Y,N,N,N,Y,N,N,Y,N,N,N,N,N),
FSGNJN_S -> List(FCMD_SGNJ, N,Y,Y,Y,N,N,N,Y,N,N,Y,N,N,N,N,N),
FSGNJX_S -> List(FCMD_SGNJ, N,Y,Y,Y,N,N,N,Y,N,N,Y,N,N,N,N,N),
FMIN_S -> List(FCMD_MINMAX, N,Y,Y,Y,N,N,N,Y,N,N,Y,N,N,N,N,Y),
FMAX_S -> List(FCMD_MINMAX, N,Y,Y,Y,N,N,N,Y,N,N,Y,N,N,N,N,Y),
FADD_S -> List(FCMD_ADD, N,Y,Y,Y,N,N,Y,Y,N,N,N,Y,N,N,Y,Y),
FSUB_S -> List(FCMD_SUB, N,Y,Y,Y,N,N,Y,Y,N,N,N,Y,N,N,Y,Y),
FMUL_S -> List(FCMD_MUL, N,Y,Y,Y,N,N,N,Y,N,N,N,Y,N,N,Y,Y),
FMADD_S -> List(FCMD_MADD, N,Y,Y,Y,Y,N,N,Y,N,N,N,Y,N,N,Y,Y),
FMSUB_S -> List(FCMD_MSUB, N,Y,Y,Y,Y,N,N,Y,N,N,N,Y,N,N,Y,Y),
FNMADD_S -> List(FCMD_NMADD, N,Y,Y,Y,Y,N,N,Y,N,N,N,Y,N,N,Y,Y),
FNMSUB_S -> List(FCMD_NMSUB, N,Y,Y,Y,Y,N,N,Y,N,N,N,Y,N,N,Y,Y),
FDIV_S -> List(FCMD_DIV, N,Y,Y,Y,N,N,N,Y,N,N,N,N,Y,N,Y,Y),
FSQRT_S -> List(FCMD_SQRT, N,Y,Y,N,N,Y,X,Y,N,N,N,N,N,Y,Y,Y))
Array(FLW -> List(FCMD_X, Y,Y,N,N,N,X,X,Y,N,N,N,N,N,N,N),
FSW -> List(FCMD_MV_XF, Y,N,N,Y,N,Y,X,Y,N,Y,N,N,N,N,N),
FMV_S_X -> List(FCMD_MV_FX, N,Y,N,N,N,X,X,Y,Y,N,N,N,N,N,N),
FCVT_S_W -> List(FCMD_CVT_FI, N,Y,N,N,N,X,X,Y,Y,N,N,N,N,N,Y),
FCVT_S_WU-> List(FCMD_CVT_FI, N,Y,N,N,N,X,X,Y,Y,N,N,N,N,N,Y),
FCVT_S_L -> List(FCMD_CVT_FI, N,Y,N,N,N,X,X,Y,Y,N,N,N,N,N,Y),
FCVT_S_LU-> List(FCMD_CVT_FI, N,Y,N,N,N,X,X,Y,Y,N,N,N,N,N,Y),
FMV_X_S -> List(FCMD_MV_XF, N,N,Y,N,N,N,X,Y,N,Y,N,N,N,N,N),
FCLASS_S -> List(FCMD_MV_XF, N,N,Y,N,N,N,X,Y,N,Y,N,N,N,N,N),
FCVT_W_S -> List(FCMD_CVT_IF, N,N,Y,N,N,N,X,Y,N,Y,N,N,N,N,Y),
FCVT_WU_S-> List(FCMD_CVT_IF, N,N,Y,N,N,N,X,Y,N,Y,N,N,N,N,Y),
FCVT_L_S -> List(FCMD_CVT_IF, N,N,Y,N,N,N,X,Y,N,Y,N,N,N,N,Y),
FCVT_LU_S-> List(FCMD_CVT_IF, N,N,Y,N,N,N,X,Y,N,Y,N,N,N,N,Y),
FEQ_S -> List(FCMD_CMP, N,N,Y,Y,N,N,N,Y,N,Y,N,N,N,N,Y),
FLT_S -> List(FCMD_CMP, N,N,Y,Y,N,N,N,Y,N,Y,N,N,N,N,Y),
FLE_S -> List(FCMD_CMP, N,N,Y,Y,N,N,N,Y,N,Y,N,N,N,N,Y),
FSGNJ_S -> List(FCMD_SGNJ, N,Y,Y,Y,N,N,N,Y,N,N,Y,N,N,N,N),
FSGNJN_S -> List(FCMD_SGNJ, N,Y,Y,Y,N,N,N,Y,N,N,Y,N,N,N,N),
FSGNJX_S -> List(FCMD_SGNJ, N,Y,Y,Y,N,N,N,Y,N,N,Y,N,N,N,N),
FMIN_S -> List(FCMD_MINMAX, N,Y,Y,Y,N,N,N,Y,N,N,Y,N,N,N,Y),
FMAX_S -> List(FCMD_MINMAX, N,Y,Y,Y,N,N,N,Y,N,N,Y,N,N,N,Y),
FADD_S -> List(FCMD_ADD, N,Y,Y,Y,N,N,Y,Y,N,N,N,Y,N,N,Y),
FSUB_S -> List(FCMD_SUB, N,Y,Y,Y,N,N,Y,Y,N,N,N,Y,N,N,Y),
FMUL_S -> List(FCMD_MUL, N,Y,Y,Y,N,N,N,Y,N,N,N,Y,N,N,Y),
FMADD_S -> List(FCMD_MADD, N,Y,Y,Y,Y,N,N,Y,N,N,N,Y,N,N,Y),
FMSUB_S -> List(FCMD_MSUB, N,Y,Y,Y,Y,N,N,Y,N,N,N,Y,N,N,Y),
FNMADD_S -> List(FCMD_NMADD, N,Y,Y,Y,Y,N,N,Y,N,N,N,Y,N,N,Y),
FNMSUB_S -> List(FCMD_NMSUB, N,Y,Y,Y,Y,N,N,Y,N,N,N,Y,N,N,Y),
FDIV_S -> List(FCMD_DIV, N,Y,Y,Y,N,N,N,Y,N,N,N,N,Y,N,Y),
FSQRT_S -> List(FCMD_SQRT, N,Y,Y,N,N,Y,X,Y,N,N,N,N,N,Y,Y))
val d =
Array(FLD -> List(FCMD_X, Y,Y,N,N,N,X,X,N,N,N,N,N,N,N,N,N),
FSD -> List(FCMD_MV_XF, Y,N,N,Y,N,Y,X,N,N,Y,N,N,N,N,N,N),
FMV_D_X -> List(FCMD_MV_FX, N,Y,N,N,N,X,X,N,Y,N,N,N,N,N,Y,N),
FCVT_D_W -> List(FCMD_CVT_FI, N,Y,N,N,N,X,X,N,Y,N,N,N,N,N,Y,Y),
FCVT_D_WU-> List(FCMD_CVT_FI, N,Y,N,N,N,X,X,N,Y,N,N,N,N,N,Y,Y),
FCVT_D_L -> List(FCMD_CVT_FI, N,Y,N,N,N,X,X,N,Y,N,N,N,N,N,Y,Y),
FCVT_D_LU-> List(FCMD_CVT_FI, N,Y,N,N,N,X,X,N,Y,N,N,N,N,N,Y,Y),
FMV_X_D -> List(FCMD_MV_XF, N,N,Y,N,N,N,X,N,N,Y,N,N,N,N,Y,N),
FCLASS_D -> List(FCMD_MV_XF, N,N,Y,N,N,N,X,N,N,Y,N,N,N,N,Y,N),
FCVT_W_D -> List(FCMD_CVT_IF, N,N,Y,N,N,N,X,N,N,Y,N,N,N,N,Y,Y),
FCVT_WU_D-> List(FCMD_CVT_IF, N,N,Y,N,N,N,X,N,N,Y,N,N,N,N,Y,Y),
FCVT_L_D -> List(FCMD_CVT_IF, N,N,Y,N,N,N,X,N,N,Y,N,N,N,N,Y,Y),
FCVT_LU_D-> List(FCMD_CVT_IF, N,N,Y,N,N,N,X,N,N,Y,N,N,N,N,Y,Y),
FCVT_S_D -> List(FCMD_CVT_FF, N,Y,Y,N,N,N,X,Y,N,N,Y,N,N,N,Y,Y),
FCVT_D_S -> List(FCMD_CVT_FF, N,Y,Y,N,N,N,X,N,N,N,Y,N,N,N,Y,Y),
FEQ_D -> List(FCMD_CMP, N,N,Y,Y,N,N,N,N,N,Y,N,N,N,N,N,Y),
FLT_D -> List(FCMD_CMP, N,N,Y,Y,N,N,N,N,N,Y,N,N,N,N,N,Y),
FLE_D -> List(FCMD_CMP, N,N,Y,Y,N,N,N,N,N,Y,N,N,N,N,N,Y),
FSGNJ_D -> List(FCMD_SGNJ, N,Y,Y,Y,N,N,N,N,N,N,Y,N,N,N,N,N),
FSGNJN_D -> List(FCMD_SGNJ, N,Y,Y,Y,N,N,N,N,N,N,Y,N,N,N,N,N),
FSGNJX_D -> List(FCMD_SGNJ, N,Y,Y,Y,N,N,N,N,N,N,Y,N,N,N,N,N),
FMIN_D -> List(FCMD_MINMAX, N,Y,Y,Y,N,N,N,N,N,N,Y,N,N,N,N,Y),
FMAX_D -> List(FCMD_MINMAX, N,Y,Y,Y,N,N,N,N,N,N,Y,N,N,N,N,Y),
FADD_D -> List(FCMD_ADD, N,Y,Y,Y,N,N,Y,N,N,N,N,Y,N,N,Y,Y),
FSUB_D -> List(FCMD_SUB, N,Y,Y,Y,N,N,Y,N,N,N,N,Y,N,N,Y,Y),
FMUL_D -> List(FCMD_MUL, N,Y,Y,Y,N,N,N,N,N,N,N,Y,N,N,Y,Y),
FMADD_D -> List(FCMD_MADD, N,Y,Y,Y,Y,N,N,N,N,N,N,Y,N,N,Y,Y),
FMSUB_D -> List(FCMD_MSUB, N,Y,Y,Y,Y,N,N,N,N,N,N,Y,N,N,Y,Y),
FNMADD_D -> List(FCMD_NMADD, N,Y,Y,Y,Y,N,N,N,N,N,N,Y,N,N,Y,Y),
FNMSUB_D -> List(FCMD_NMSUB, N,Y,Y,Y,Y,N,N,N,N,N,N,Y,N,N,Y,Y),
FDIV_D -> List(FCMD_DIV, N,Y,Y,Y,N,N,N,N,N,N,N,N,Y,N,Y,Y),
FSQRT_D -> List(FCMD_SQRT, N,Y,Y,N,N,Y,X,N,N,N,N,N,N,Y,Y,Y))
Array(FLD -> List(FCMD_X, Y,Y,N,N,N,X,X,N,N,N,N,N,N,N,N),
FSD -> List(FCMD_MV_XF, Y,N,N,Y,N,Y,X,N,N,Y,N,N,N,N,N),
FMV_D_X -> List(FCMD_MV_FX, N,Y,N,N,N,X,X,N,Y,N,N,N,N,N,N),
FCVT_D_W -> List(FCMD_CVT_FI, N,Y,N,N,N,X,X,N,Y,N,N,N,N,N,Y),
FCVT_D_WU-> List(FCMD_CVT_FI, N,Y,N,N,N,X,X,N,Y,N,N,N,N,N,Y),
FCVT_D_L -> List(FCMD_CVT_FI, N,Y,N,N,N,X,X,N,Y,N,N,N,N,N,Y),
FCVT_D_LU-> List(FCMD_CVT_FI, N,Y,N,N,N,X,X,N,Y,N,N,N,N,N,Y),
FMV_X_D -> List(FCMD_MV_XF, N,N,Y,N,N,N,X,N,N,Y,N,N,N,N,N),
FCLASS_D -> List(FCMD_MV_XF, N,N,Y,N,N,N,X,N,N,Y,N,N,N,N,N),
FCVT_W_D -> List(FCMD_CVT_IF, N,N,Y,N,N,N,X,N,N,Y,N,N,N,N,Y),
FCVT_WU_D-> List(FCMD_CVT_IF, N,N,Y,N,N,N,X,N,N,Y,N,N,N,N,Y),
FCVT_L_D -> List(FCMD_CVT_IF, N,N,Y,N,N,N,X,N,N,Y,N,N,N,N,Y),
FCVT_LU_D-> List(FCMD_CVT_IF, N,N,Y,N,N,N,X,N,N,Y,N,N,N,N,Y),
FCVT_S_D -> List(FCMD_CVT_FF, N,Y,Y,N,N,N,X,Y,N,N,Y,N,N,N,Y),
FCVT_D_S -> List(FCMD_CVT_FF, N,Y,Y,N,N,N,X,N,N,N,Y,N,N,N,Y),
FEQ_D -> List(FCMD_CMP, N,N,Y,Y,N,N,N,N,N,Y,N,N,N,N,Y),
FLT_D -> List(FCMD_CMP, N,N,Y,Y,N,N,N,N,N,Y,N,N,N,N,Y),
FLE_D -> List(FCMD_CMP, N,N,Y,Y,N,N,N,N,N,Y,N,N,N,N,Y),
FSGNJ_D -> List(FCMD_SGNJ, N,Y,Y,Y,N,N,N,N,N,N,Y,N,N,N,N),
FSGNJN_D -> List(FCMD_SGNJ, N,Y,Y,Y,N,N,N,N,N,N,Y,N,N,N,N),
FSGNJX_D -> List(FCMD_SGNJ, N,Y,Y,Y,N,N,N,N,N,N,Y,N,N,N,N),
FMIN_D -> List(FCMD_MINMAX, N,Y,Y,Y,N,N,N,N,N,N,Y,N,N,N,Y),
FMAX_D -> List(FCMD_MINMAX, N,Y,Y,Y,N,N,N,N,N,N,Y,N,N,N,Y),
FADD_D -> List(FCMD_ADD, N,Y,Y,Y,N,N,Y,N,N,N,N,Y,N,N,Y),
FSUB_D -> List(FCMD_SUB, N,Y,Y,Y,N,N,Y,N,N,N,N,Y,N,N,Y),
FMUL_D -> List(FCMD_MUL, N,Y,Y,Y,N,N,N,N,N,N,N,Y,N,N,Y),
FMADD_D -> List(FCMD_MADD, N,Y,Y,Y,Y,N,N,N,N,N,N,Y,N,N,Y),
FMSUB_D -> List(FCMD_MSUB, N,Y,Y,Y,Y,N,N,N,N,N,N,Y,N,N,Y),
FNMADD_D -> List(FCMD_NMADD, N,Y,Y,Y,Y,N,N,N,N,N,N,Y,N,N,Y),
FNMSUB_D -> List(FCMD_NMSUB, N,Y,Y,Y,Y,N,N,N,N,N,N,Y,N,N,Y),
FDIV_D -> List(FCMD_DIV, N,Y,Y,Y,N,N,N,N,N,N,N,N,Y,N,Y),
FSQRT_D -> List(FCMD_SQRT, N,Y,Y,N,N,Y,X,N,N,N,N,N,N,Y,Y))
val insns = fLen match {
case 32 => f
@ -146,7 +145,7 @@ class FPUDecoder(implicit p: Parameters) extends FPUModule()(p) {
val s = io.sigs
val sigs = Seq(s.cmd, s.ldst, s.wen, s.ren1, s.ren2, s.ren3, s.swap12,
s.swap23, s.single, s.fromint, s.toint, s.fastpipe, s.fma,
s.div, s.sqrt, s.round, s.wflags)
s.div, s.sqrt, s.wflags)
sigs zip decoder map {case(s,d) => s := d}
}
@ -710,7 +709,7 @@ class FPU(cfg: FPUParams)(implicit p: Parameters) extends FPUModule()(p) {
io.sboard_clr := !wb_cp_valid && (divSqrt_wen || (wen(0) && useScoreboard(x => wbInfo(0).pipeid === UInt(x._2))))
io.sboard_clra := waddr
// we don't currently support round-max-magnitude (rm=4)
io.illegal_rm := ex_rm(2) && ex_ctrl.round
io.illegal_rm := io.inst(14) && (io.inst(13,12) < 3 || io.fcsr_rm >= 4)
divSqrt_wdata := 0
divSqrt_flags := 0
@ -750,7 +749,7 @@ class FPU(cfg: FPUParams)(implicit p: Parameters) extends FPUModule()(p) {
divSqrt_wdata := Mux(divSqrt_single, divSqrt_toSingle.io.out, divSqrt_wdata_double)
divSqrt_flags := divSqrt_flags_double | Mux(divSqrt_single, divSqrt_toSingle.io.exceptionFlags, Bits(0))
} else {
when (ex_ctrl.div || ex_ctrl.sqrt) { io.illegal_rm := true }
when (id_ctrl.div || id_ctrl.sqrt) { io.illegal_rm := true }
}
}