riscv/rocket-chip
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add FP recoding

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This commit is contained in:
Andrew Waterman
2012-02-12 23:31:50 -08:00
parent 25ecfb9bbc
commit 069037ff3a
4 changed files with 72 additions and 7 deletions
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74
rocket/src/main/scala/fpu.scala
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@ -176,6 +176,7 @@ class ioDpathFPU extends Bundle {
val toint_data = Bits(64, INPUT)
val dmem_resp_val = Bool(OUTPUT)
val dmem_resp_type = Bits(3, OUTPUT)
val dmem_resp_tag = UFix(5, OUTPUT)
val dmem_resp_data = Bits(64, OUTPUT)
}
@ -200,10 +201,12 @@ class rocketFPIntUnit extends Component
val exc = Bits(5, OUTPUT)
}
val unrecoded_s = io.in(31,0)
val unrecoded_d = io.in
val unrec_s = new hardfloat.recodedFloat32ToFloat32
val unrec_d = new hardfloat.recodedFloat64ToFloat64
unrec_s.io.in := io.in
unrec_d.io.in := io.in
io.store_data := Mux(io.single, Cat(unrecoded_s, unrecoded_s), unrecoded_d)
io.store_data := Mux(io.single, Cat(unrec_s.io.out, unrec_s.io.out), unrec_d.io.out)
val scmp = Bool(false)
val scmp_exc = Bits(0)
@ -219,10 +222,10 @@ class rocketFPIntUnit extends Component
// output muxing
val (out_s, exc_s) = (Wire() { Bits() }, Wire() { Bits() })
out_s := Cat(Fill(32, unrecoded_s(31)), unrecoded_s)
out_s := Cat(Fill(32, unrec_s.io.out(31)), unrec_s.io.out)
exc_s := Bits(0)
val (out_d, exc_d) = (Wire() { Bits() }, Wire() { Bits() })
out_d := unrecoded_d
out_d := unrec_d.io.out
exc_d := Bits(0)
when (io.cmd === FCMD_MTFSR || io.cmd === FCMD_MFFSR) {
@ -251,6 +254,51 @@ class rocketFPIntUnit extends Component
io.exc := Mux(io.single, exc_s, exc_d)
}
class rocketIntFPUnit extends Component
{
val io = new Bundle {
val single = Bool(INPUT)
val cmd = Bits(FCMD_WIDTH, INPUT)
val fsr = Bits(FSR_WIDTH, INPUT)
val in = Bits(64, INPUT)
val out = Bits(65, OUTPUT)
val exc = Bits(5, OUTPUT)
}
val rec_s = new hardfloat.float32ToRecodedFloat32
val rec_d = new hardfloat.float64ToRecodedFloat64
rec_s.io.in := io.in
rec_d.io.in := io.in
val i2s = Bits(0)
val i2s_exc = Bits(0)
val i2d = Bits(0)
val i2d_exc = Bits(0)
// output muxing
val (out_s, exc_s) = (Wire() { Bits() }, Wire() { Bits() })
out_s := rec_s.io.out
exc_s := Bits(0)
val (out_d, exc_d) = (Wire() { Bits() }, Wire() { Bits() })
out_d := rec_d.io.out
exc_d := Bits(0)
when (io.cmd === FCMD_CVT_FMT_W || io.cmd === FCMD_CVT_FMT_WU ||
io.cmd === FCMD_CVT_FMT_L || io.cmd === FCMD_CVT_FMT_LU) {
out_s := i2s
exc_s := i2s_exc
out_d := i2d
exc_d := i2d_exc
}
when (io.cmd === FCMD_MTFSR || io.cmd === FCMD_MFFSR) {
out_s := Cat(out_s(32,FSR_WIDTH), io.in(FSR_WIDTH-1,0))
}
io.out := Mux(io.single, Cat(Fill(32,UFix(1)), out_s), out_d)
io.exc := Mux(io.single, exc_s, exc_d)
}
class rocketFPU extends Component
{
val io = new Bundle {
@ -274,18 +322,25 @@ class rocketFPU extends Component
// load response
val load_wb = Reg(io.dpath.dmem_resp_val, resetVal = Bool(false))
val load_wb_single = Reg() { Bool() }
val load_wb_data = Reg() { Bits(width = 64) } // XXX WTF why doesn't bit width inference work for the regfile?!
val load_wb_tag = Reg() { UFix() }
when (io.dpath.dmem_resp_val) {
load_wb_single := io.dpath.dmem_resp_type === MT_W || io.dpath.dmem_resp_type === MT_WU
load_wb_data := io.dpath.dmem_resp_data
load_wb_tag := io.dpath.dmem_resp_tag
}
val rec_s = new hardfloat.float32ToRecodedFloat32
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 fsr_rm = Reg() { Bits(width = 3) }
val fsr_exc = Reg() { Bits(width = 5) }
// regfile
val regfile = Mem(32, load_wb, load_wb_tag, load_wb_data);
val regfile = Mem(32, load_wb, load_wb_tag, load_wb_data_recoded);
regfile.setReadLatency(0);
regfile.setTarget('inst);
@ -332,10 +387,15 @@ class rocketFPU extends Component
io.dpath.store_data := fpiu.io.store_data
io.dpath.toint_data := fpiu.io.toint_data
val ifpu = new rocketIntFPUnit
ifpu.io.single := ctrl.single
ifpu.io.cmd := ctrl.cmd
ifpu.io.in := fp_fromint_data
val retire_toint = Reg(!io.ctrl.killm && fp_toint_val, resetVal = Bool(false))
val retire_toint_exc = Reg(fpiu.io.exc)
val retire_fromint = Reg(!io.ctrl.killm && fp_fromint_val, resetVal = Bool(false))
val retire_fromint_wdata = Reg(fp_fromint_data)
val retire_fromint_wdata = Reg(ifpu.io.out)
val retire_fromint_waddr = Reg(fp_waddr)
when (retire_toint) {