riscv/rocket-chip
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declaring success on FPU for now

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This commit is contained in:
Andrew Waterman 2012-02-14 19:11:57 -08:00
parent 297223a13c
commit 0ec7767c13
3 changed files with 151 additions and 24 deletions
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6
rocket/src/main/scala/ctrl.scala
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@ -546,7 +546,7 @@ class rocketCtrl extends Component
var id_stall_fpu = Bool(false)
if (HAVE_FPU) {
val fp_sboard = new rocketCtrlSboard(32, 4, 2);
val fp_sboard = new rocketCtrlSboard(32, 4, 3);
fp_sboard.io.r(0).addr := id_raddr1.toUFix
fp_sboard.io.r(1).addr := id_raddr2.toUFix
fp_sboard.io.r(2).addr := id_raddr3.toUFix
@ -560,6 +560,10 @@ class rocketCtrl extends Component
fp_sboard.io.w(1).data := Bool(false)
fp_sboard.io.w(1).addr := io.dpath.fp_sboard_clra
fp_sboard.io.w(2).en := io.fpu.sboard_clr
fp_sboard.io.w(2).data := Bool(false)
fp_sboard.io.w(2).addr := io.fpu.sboard_clra
id_stall_fpu = io.fpu.dec.ren1 && fp_sboard.io.r(0).data ||
io.fpu.dec.ren2 && fp_sboard.io.r(1).data ||
io.fpu.dec.ren3 && fp_sboard.io.r(2).data ||

163
rocket/src/main/scala/fpu.scala
View File

@ -120,10 +120,21 @@ class rocketFPUDecoder extends Component
FMIN_S -> List(Y,FCMD_MIN, Y,N,Y,Y,N,Y,N,N,Y,N,N,N,N),
FMAX_S -> List(Y,FCMD_MAX, Y,N,Y,Y,N,Y,N,N,Y,N,N,N,N),
FMIN_D -> List(Y,FCMD_MIN, Y,N,Y,Y,N,N,N,N,Y,N,N,N,N),
FMAX_D -> List(Y,FCMD_MAX, Y,N,Y,Y,N,N,N,N,Y,N,N,N,N)
// FADD_S -> List(Y,FCMD_ADD, Y,Y,Y,Y,N,Y,N,N,N,Y,N,N,N),
// FSUB_S -> List(Y,FCMD_SUB, Y,Y,Y,Y,N,Y,N,N,N,Y,N,N,N),
// FMUL_S -> List(Y,FCMD_MUL, Y,Y,Y,Y,N,Y,N,N,N,Y,N,N,N),
FMAX_D -> List(Y,FCMD_MAX, Y,N,Y,Y,N,N,N,N,Y,N,N,N,N),
FADD_S -> List(Y,FCMD_ADD, Y,Y,Y,Y,N,Y,N,N,N,Y,N,N,N),
FSUB_S -> List(Y,FCMD_SUB, Y,Y,Y,Y,N,Y,N,N,N,Y,N,N,N),
FMUL_S -> List(Y,FCMD_MUL, Y,Y,Y,Y,N,Y,N,N,N,Y,N,N,N),
FADD_D -> List(Y,FCMD_ADD, Y,Y,Y,Y,N,N,N,N,N,Y,N,N,N),
FSUB_D -> List(Y,FCMD_SUB, Y,Y,Y,Y,N,N,N,N,N,Y,N,N,N),
FMUL_D -> List(Y,FCMD_MUL, Y,Y,Y,Y,N,N,N,N,N,Y,N,N,N),
FMADD_S -> List(Y,FCMD_MADD, Y,Y,Y,Y,Y,Y,N,N,N,Y,N,N,N),
FMSUB_S -> List(Y,FCMD_MSUB, Y,Y,Y,Y,Y,Y,N,N,N,Y,N,N,N),
FNMADD_S -> List(Y,FCMD_NMADD, Y,Y,Y,Y,Y,Y,N,N,N,Y,N,N,N),
FNMSUB_S -> List(Y,FCMD_NMSUB, Y,Y,Y,Y,Y,Y,N,N,N,Y,N,N,N),
FMADD_D -> List(Y,FCMD_MADD, Y,Y,Y,Y,Y,N,N,N,N,Y,N,N,N),
FMSUB_D -> List(Y,FCMD_MSUB, Y,Y,Y,Y,Y,N,N,N,N,Y,N,N,N),
FNMADD_D -> List(Y,FCMD_NMADD, Y,Y,Y,Y,Y,N,N,N,N,Y,N,N,N),
FNMSUB_D -> List(Y,FCMD_NMSUB, Y,Y,Y,Y,Y,N,N,N,N,Y,N,N,N)
))
val valid :: cmd :: wen :: sboard :: ren1 :: ren2 :: ren3 :: single :: fromint :: toint :: fastpipe :: fma :: store :: rdfsr :: wrfsr :: Nil = decoder
@ -164,6 +175,8 @@ class ioCtrlFPU extends Bundle {
val killx = Bool(OUTPUT)
val killm = Bool(OUTPUT)
val dec = new rocketFPUCtrlSigs().asInput
val sboard_clr = Bool(INPUT)
val sboard_clra = UFix(5, INPUT)
}
class rocketFPIntUnit extends Component
@ -192,8 +205,8 @@ class rocketFPIntUnit extends Component
val scmp = new hardfloat.recodedFloat32Compare
scmp.io.a := io.in1
scmp.io.b := io.in2
val scmp_out = (io.cmd(1,0) & Cat(scmp.io.a_lt_b, scmp.io.a_eq_b)).orR
val scmp_exc = (io.cmd(1,0) & Cat(scmp.io.a_lt_b_invalid, scmp.io.a_eq_b_invalid)).orR << UFix(4)
val scmp_out = (io.cmd & Cat(scmp.io.a_lt_b, scmp.io.a_eq_b)).orR
val scmp_exc = (io.cmd & Cat(scmp.io.a_lt_b_invalid, scmp.io.a_eq_b_invalid)).orR << UFix(4)
val s2i = new hardfloat.recodedFloat32ToAny
s2i.io.in := io.in1
@ -203,8 +216,8 @@ class rocketFPIntUnit extends Component
val dcmp = new hardfloat.recodedFloat64Compare
dcmp.io.a := io.in1
dcmp.io.b := io.in2
val dcmp_out = (io.cmd(1,0) & Cat(dcmp.io.a_lt_b, dcmp.io.a_eq_b)).orR
val dcmp_exc = (io.cmd(1,0) & Cat(dcmp.io.a_lt_b_invalid, dcmp.io.a_eq_b_invalid)).orR << UFix(4)
val dcmp_out = (io.cmd & Cat(dcmp.io.a_lt_b, dcmp.io.a_eq_b)).orR
val dcmp_exc = (io.cmd & Cat(dcmp.io.a_lt_b_invalid, dcmp.io.a_eq_b_invalid)).orR << UFix(4)
val d2i = new hardfloat.recodedFloat64ToAny
d2i.io.in := io.in1
@ -258,7 +271,7 @@ class rocketFPUFastPipe extends Component
val in2 = Bits(65, INPUT)
val lt_s = Bool(INPUT)
val lt_d = Bool(INPUT)
val out_s = Bits(65, OUTPUT)
val out_s = Bits(33, OUTPUT)
val exc_s = Bits(5, OUTPUT)
val out_d = Bits(65, OUTPUT)
val exc_d = Bits(5, OUTPUT)
@ -346,12 +359,96 @@ class rocketFPUFastPipe extends Component
exc_d := Reg(i2d.io.exceptionFlags)
}
io.out_s := Cat(Fill(32,UFix(1)), out_s)
io.out_s := out_s
io.exc_s := exc_s
io.out_d := out_d
io.exc_d := exc_d
}
class rocketFPUSFMAPipe(latency: Int) extends Component
{
val io = new Bundle {
val valid = Bool(INPUT)
val cmd = Bits(FCMD_WIDTH, INPUT)
val rm = Bits(3, INPUT)
val in1 = Bits(33, INPUT)
val in2 = Bits(33, INPUT)
val in3 = Bits(33, INPUT)
val out = Bits(33, OUTPUT)
val exc = Bits(5, OUTPUT)
}
val cmd = Reg() { Bits() }
val rm = Reg() { Bits() }
val in1 = Reg() { Bits() }
val in2 = Reg() { Bits() }
val in3 = Reg() { Bits() }
val cmd_fma = io.cmd === FCMD_MADD || io.cmd === FCMD_MSUB ||
io.cmd === FCMD_NMADD || io.cmd === FCMD_NMSUB
val cmd_addsub = io.cmd === FCMD_ADD || io.cmd === FCMD_SUB
when (io.valid) {
cmd := Cat(io.cmd(1) & (cmd_fma || cmd_addsub), io.cmd(0))
rm := io.rm
in1 := io.in1
in2 := Mux(cmd_addsub, Bits("h80000000"), io.in2)
in3 := Mux(cmd_fma, io.in3, Mux(cmd_addsub, io.in2, Bits(0)))
}
val fma = new hardfloat.mulAddSubRecodedFloat32_1
fma.io.op := cmd
fma.io.roundingMode := rm
fma.io.a := in1
fma.io.b := in2
fma.io.c := in3
io.out := ShiftRegister(latency-1, fma.io.out)
io.exc := ShiftRegister(latency-1, fma.io.exceptionFlags)
}
class rocketFPUDFMAPipe(latency: Int) extends Component
{
val io = new Bundle {
val valid = Bool(INPUT)
val cmd = Bits(FCMD_WIDTH, INPUT)
val rm = Bits(3, INPUT)
val in1 = Bits(65, INPUT)
val in2 = Bits(65, INPUT)
val in3 = Bits(65, INPUT)
val out = Bits(65, OUTPUT)
val exc = Bits(5, OUTPUT)
}
val cmd = Reg() { Bits() }
val rm = Reg() { Bits() }
val in1 = Reg() { Bits() }
val in2 = Reg() { Bits() }
val in3 = Reg() { Bits() }
val cmd_fma = io.cmd === FCMD_MADD || io.cmd === FCMD_MSUB ||
io.cmd === FCMD_NMADD || io.cmd === FCMD_NMSUB
val cmd_addsub = io.cmd === FCMD_ADD || io.cmd === FCMD_SUB
when (io.valid) {
cmd := Cat(io.cmd(1) & (cmd_fma || cmd_addsub), io.cmd(0))
rm := io.rm
in1 := io.in1
in2 := Mux(cmd_addsub, Bits("h8000000000000000"), io.in2)
in3 := Mux(cmd_fma, io.in3, Mux(cmd_addsub, io.in2, Bits(0)))
}
val fma = new hardfloat.mulAddSubRecodedFloat64_1
fma.io.op := cmd
fma.io.roundingMode := rm
fma.io.a := in1
fma.io.b := in2
fma.io.c := in3
io.out := ShiftRegister(latency-1, fma.io.out)
io.exc := ShiftRegister(latency-1, fma.io.exceptionFlags)
}
class rocketFPU(sfma_latency: Int, dfma_latency: Int) extends Component
{
val io = new Bundle {
@ -388,7 +485,8 @@ class rocketFPU(sfma_latency: Int, dfma_latency: Int) extends Component
val rec_d = new hardfloat.float64ToRecodedFloat64
rec_s.io.in := load_wb_data
rec_d.io.in := load_wb_data
val load_wb_data_recoded = Mux(load_wb_single, Cat(Fill(32,UFix(1)), rec_s.io.out), rec_d.io.out)
val sp_msbs = Fill(32, UFix(1,1))
val load_wb_data_recoded = Mux(load_wb_single, Cat(sp_msbs, rec_s.io.out), rec_d.io.out)
val fsr_rm = Reg() { Bits(width = 3) }
val fsr_exc = Reg() { Bits(width = 5) }
@ -403,7 +501,6 @@ class rocketFPU(sfma_latency: Int, dfma_latency: Int) extends Component
val ex_rs3 = regfile.read(reg_inst(16,12))
val ex_rm = Mux(reg_inst(11,9) === Bits(7), fsr_rm, reg_inst(11,9))
val mem_fromint_val = Reg(resetVal = Bool(false))
val mem_fromint_data = Reg() { Bits() }
val mem_toint_val = Reg(resetVal = Bool(false))
val mem_rs1 = Reg() { Bits() }
@ -412,13 +509,11 @@ class rocketFPU(sfma_latency: Int, dfma_latency: Int) extends Component
val mem_rm = Reg() { Bits() }
val mem_wrfsr_val = Reg(resetVal = Bool(false))
mem_fromint_val := Bool(false)
mem_toint_val := Bool(false)
mem_wrfsr_val := Bool(false)
when (reg_valid) {
mem_rm := ex_rm
when (ctrl.fromint || ctrl.wrfsr) {
mem_fromint_val := !io.ctrl.killx
mem_fromint_data := io.dpath.fromint_data
}
when (ctrl.wrfsr) {
@ -453,6 +548,7 @@ class rocketFPU(sfma_latency: Int, dfma_latency: Int) extends Component
io.dpath.store_data := fpiu.io.store_data
io.dpath.toint_data := fpiu.io.toint_data
// 2-cycle pipe for int->FP and non-FMA FP->FP ops
val fastpipe = new rocketFPUFastPipe
fastpipe.io.single := mem_ctrl.single
fastpipe.io.cmd := mem_ctrl.cmd
@ -463,12 +559,31 @@ class rocketFPU(sfma_latency: Int, dfma_latency: Int) extends Component
fastpipe.io.lt_s := fpiu.io.lt_s
fastpipe.io.lt_d := fpiu.io.lt_d
val cmd_fma = mem_ctrl.cmd === FCMD_MADD || mem_ctrl.cmd === FCMD_MSUB ||
mem_ctrl.cmd === FCMD_NMADD || mem_ctrl.cmd === FCMD_NMSUB
val cmd_addsub = mem_ctrl.cmd === FCMD_ADD || mem_ctrl.cmd === FCMD_SUB
val sfma = new rocketFPUSFMAPipe(sfma_latency-1)
sfma.io.valid := Reg(reg_valid && ctrl.fma && ctrl.single)
sfma.io.in1 := mem_rs1
sfma.io.in2 := mem_rs2
sfma.io.in3 := mem_rs3
sfma.io.cmd := mem_ctrl.cmd
sfma.io.rm := mem_rm
val dfma = new rocketFPUDFMAPipe(dfma_latency-1)
dfma.io.valid := Reg(reg_valid && ctrl.fma && !ctrl.single)
dfma.io.in1 := mem_rs1
dfma.io.in2 := mem_rs2
dfma.io.in3 := mem_rs3
dfma.io.cmd := mem_ctrl.cmd
dfma.io.rm := mem_rm
val wb_wrfsr_val = Reg(!io.ctrl.killm && mem_wrfsr_val, resetVal = Bool(false))
val wb_toint_val = Reg(!io.ctrl.killm && mem_toint_val, resetVal = Bool(false))
val wb_toint_exc = Reg(fpiu.io.exc)
// writeback arbitration
val wen = Reg(resetVal = Bits(0, dfma_latency-1))
val wen = Reg(resetVal = Bits(0, dfma_latency))
val winfo = Vec(dfma_latency-1) { Reg() { Bits() } }
val mem_wen = Reg(resetVal = Bool(false))
@ -478,8 +593,8 @@ class rocketFPU(sfma_latency: Int, dfma_latency: Int) extends Component
Mux(ctrl.single, UFix(sfma_latency-1),
UFix(dfma_latency-1)))
val mem_fu_latency = Reg(ex_stage_fu_latency - UFix(1))
val write_port_busy = ctrl.fastpipe && wen(fastpipe_latency-1) ||
Bool(sfma_latency < dfma_latency) && ctrl.fma && ctrl.single && wen(sfma_latency-1) ||
val write_port_busy = ctrl.fastpipe && wen(fastpipe_latency) ||
Bool(sfma_latency < dfma_latency) && ctrl.fma && ctrl.single && wen(sfma_latency) ||
mem_wen && mem_fu_latency === ex_stage_fu_latency
mem_wen := reg_valid && !io.ctrl.killx && (ctrl.fma || ctrl.fastpipe)
val ex_stage_wsrc = Cat(ctrl.fastpipe, ctrl.single)
@ -503,15 +618,15 @@ class rocketFPU(sfma_latency: Int, dfma_latency: Int) extends Component
}
val wsrc = winfo(0)(1,0)
val wdata = Mux(wsrc === UFix(0), UFix(0), // DFMA
Mux(wsrc === UFix(1), UFix(0), // SFMA
val wdata = Mux(wsrc === UFix(0), dfma.io.out, // DFMA
Mux(wsrc === UFix(1), Cat(sp_msbs, sfma.io.out), // SFMA
Mux(wsrc === UFix(2), fastpipe.io.out_d,
fastpipe.io.out_s)))
val wexc = Mux(wsrc === UFix(0), Bits(0), // DFMA
Mux(wsrc === UFix(1), Bits(0), // SFMA
Cat(sp_msbs, fastpipe.io.out_s))))
val wexc = Mux(wsrc === UFix(0), dfma.io.exc, // DFMA
Mux(wsrc === UFix(1), sfma.io.exc, // SFMA
Mux(wsrc === UFix(2), fastpipe.io.exc_d,
fastpipe.io.exc_s)))
val waddr = winfo(0) >> UFix(2)
val waddr = winfo(0).toUFix >> UFix(2)
regfile.write(waddr, wdata, wen(0))
when (wb_toint_val || wen(0)) {
@ -531,4 +646,6 @@ class rocketFPU(sfma_latency: Int, dfma_latency: Int) extends Component
io.ctrl.dec <> fp_decoder.io.sigs
// we don't currently support round-max-magnitude (rm=4)
io.ctrl.illegal_rm := ex_rm(2)
io.ctrl.sboard_clr := wen(0) && !wsrc(1).toBool // only for FMA pipes
io.ctrl.sboard_clra := waddr
}

6
rocket/src/main/scala/util.scala
View File

@ -71,6 +71,12 @@ object LFSR16
}
}
object ShiftRegister
{
def apply [T <: Data](n: Int, in: T): T =
if (n > 0) Reg(apply(n-1, in)) else in
}
object Mux1H
{
//TODO: cloning in(0) is unsafe if other elements have different widths, but