from alu_hier import ALU, BranchALU
from nmutil.latch import SRLatch
-from random import randint
+from random import randint, seed
class CompUnits(Elaboratable):
# Shadow Matrix. currently n_int_fus shadows, to be used for
# write-after-write hazards. NOTE: there is one extra for branches,
# so the shadow width is increased by 1
- m.submodules.shadows = shadows = ShadowMatrix(n_int_fus, n_int_fus+1)
+ m.submodules.shadows = shadows = ShadowMatrix(n_int_fus, n_int_fus)
+ m.submodules.bshadow = bshadow = ShadowMatrix(n_int_fus, 1)
# combined go_rd/wr + go_die (go_die used to reset latches)
go_rd_rst = Signal(n_int_fus, reset_less=True)
# connected to the FUReg and FUFU Matrices, to get them to reset
# NOTE: do NOT connect these to the Computation Units. The CUs need to
# do something slightly different (due to the revolving-door SRLatches)
- comb += go_rd_rst.eq(go_rd_o | shadows.go_die_o)
- comb += go_wr_rst.eq(go_wr_o | shadows.go_die_o)
+ anydie = Signal(n_int_fus, reset_less=True)
+ allshadown = Signal(n_int_fus, reset_less=True)
+ comb += allshadown.eq(shadows.shadown_o & bshadow.shadown_o)
+ comb += anydie.eq(shadows.go_die_o | bshadow.go_die_o)
+ comb += go_rd_rst.eq(go_rd_o | anydie)
+ comb += go_wr_rst.eq(go_wr_o | anydie)
#---------
# NOTE; this setup is for the instruction order preservation...
# connect shadows / go_dies to Computation Units
- comb += cu.shadown_i[0:n_int_fus].eq(shadows.shadown_o[0:n_int_fus])
- comb += cu.go_die_i[0:n_int_fus].eq(shadows.go_die_o[0:n_int_fus])
+ comb += cu.shadown_i[0:n_int_fus].eq(allshadown)
+ comb += cu.go_die_i[0:n_int_fus].eq(anydie)
# ok connect first n_int_fu shadows to busy lines, to create an
# instruction-order linked-list-like arrangement, using a bit-matrix
# XXX TODO
# when written, the shadow can be cancelled (and was good)
- comb += shadows.s_good_i[0:n_int_fus].eq(go_wr_o[0:n_int_fus])
+ for i in range(n_int_fus):
+ comb += shadows.s_good_i[i][0:n_int_fus].eq(go_wr_o[0:n_int_fus])
# work out the current-activated busy unit (by recording the old one)
with m.If(fn_issue_o): # only update prev bit if instruction issued
# tacked onto the ShadowMatrix (hence shadow_wid=n_int_fus+1)
# only needs to set shadow_i, s_fail_i and s_good_i
+ # issue captures shadow_i (if enabled)
+ comb += bshadow.issue_i.eq(fn_issue_o)
+
+ # instruction being issued (fn_issue_o) has a shadow cast by the branch
with m.If(self.branch_succ_i | self.branch_fail_i):
- comb += shadows.shadow_i[fn_issue_o][n_int_fus].eq(1)
+ comb += bshadow.shadow_i[fn_issue_o][0].eq(1)
# finally, we need an indicator to the test infrastructure as to
# whether the branch succeeded or failed, plus, link up to the
# "recorder" of whether the instruction was under shadow or not
with m.If(cu.br1.issue_i):
- sync += bspec.issue_i.eq(1)
- comb += bspec.good_i.eq(self.branch_succ_i)
- comb += bspec.fail_i.eq(self.branch_fail_i)
+ sync += bspec.active_i.eq(1)
+ with m.If(self.branch_succ_i):
+ comb += bspec.good_i.eq(fn_issue_o & 0xf)
+ with m.If(self.branch_fail_i):
+ comb += bspec.fail_i.eq(fn_issue_o & 0xf)
+
# branch is active (TODO: a better signal: this is over-using the
# go_write signal - actually the branch should not be "writing")
with m.If(cu.br1.go_wr_i):
sync += self.branch_direction_o.eq(cu.br1.data_o+Const(1, 2))
- sync += bspec.issue_i.eq(0)
+ sync += bspec.active_i.eq(0)
comb += bspec.br_i.eq(1)
# branch occurs if data == 1, failed if data == 0
- br_good = Signal(reset_less=True)
- comb += br_good.eq(cu.br1.data_o == 1)
- comb += bspec.br_good_i.eq(br_good)
- comb += bspec.br_fail_i.eq(~br_good)
- # the *expected* direction of the branch matched against *actual*
- comb += shadows.s_good_i[n_int_fus].eq(bspec.matched_o)
- # ... or it didn't
- comb += shadows.s_fail_i[n_int_fus].eq(~bspec.matched_o)
-
+ comb += bspec.br_ok_i.eq(cu.br1.data_o == 1)
+ for i in range(n_int_fus):
+ # *expected* direction of the branch matched against *actual*
+ comb += bshadow.s_good_i[i][0].eq(bspec.match_g_o[i])
+ # ... or it didn't
+ comb += bshadow.s_fail_i[i][0].eq(bspec.match_f_o[i])
#---------
# Connect Register File(s)
op = randint(0, max_opnums)
if shadowing:
- insts.append((src1, src2, dest, op, (False, False)))
+ insts.append((src1, src2, dest, op, (0, 0)))
else:
insts.append((src1, src2, dest, op))
return insts
def scoreboard_branch_sim(dut, alusim):
+ seed(0)
+
yield dut.int_store_i.eq(1)
for i in range(2):
alusim.setval(i, val)
# create some instructions: branches create a tree
- insts = create_random_ops(dut, 5)
+ insts = create_random_ops(dut, 1, True)
src1 = randint(1, dut.n_regs-1)
src2 = randint(1, dut.n_regs-1)
- op = randint(4, 7)
+ #op = randint(4, 7)
+ op = 4 # only BGT at the moment
- branch_ok = create_random_ops(dut, 5)
- branch_fail = create_random_ops(dut, 5)
+ branch_ok = create_random_ops(dut, 1, True)
+ branch_fail = create_random_ops(dut, 1, True)
insts.append((src1, src2, (branch_ok, branch_fail), op, (0, 0)))
is_branch = op >= 4
if is_branch:
branch_ok, branch_fail = dest
- dest = None
+ dest = -1
# ok zip up the branch success / fail instructions and
# drop them into the queue, one marked "to have branch success"
# the other to be marked shadow branch "fail".
shadow_on, shadow_off)
yield
yield from wait_for_issue(dut)
- branch_direction = dut.branch_direction_o # which way branch went
+ branch_direction = yield dut.branch_direction_o # way branch went
# wait for all instructions to stop before checking
yield
# create some instructions (some random, some regression tests)
instrs = []
- if False:
- instrs = create_random_ops(dut, 10, False, 4)
+ if True:
+ instrs = create_random_ops(dut, 10, True, 4)
if False:
instrs.append((2, 3, 3, 0))
instrs.append( (2, 6, 3, 0) )
instrs.append( (4, 2, 2, 1) )
- if True:
+ if False:
+ v1 = 4
+ yield dut.intregs.regs[5].reg.eq(v1)
+ alusim.setval(5, v1)
+ yield dut.intregs.regs[3].reg.eq(5)
+ alusim.setval(3, 5)
+ instrs.append((5, 3, 3, 4, (0, 0)))
+ instrs.append((4, 2, 1, 2, (0, 1)))
+
+ if False:
v1 = 6
yield dut.intregs.regs[5].reg.eq(v1)
alusim.setval(5, v1)
with open("test_scoreboard6600.il", "w") as f:
f.write(vl)
- run_simulation(dut, scoreboard_sim(dut, alusim),
+ #run_simulation(dut, scoreboard_sim(dut, alusim),
+ # vcd_name='test_scoreboard6600.vcd')
+
+ run_simulation(dut, scoreboard_branch_sim(dut, alusim),
vcd_name='test_scoreboard6600.vcd')
self.issue_i = Signal(n_fus, reset_less=True)
self.shadow_i = Array(Signal(shadow_wid, name="sh_i", reset_less=True) \
for f in range(n_fus))
- self.s_fail_i = Signal(shadow_wid, reset_less=True)
- self.s_good_i = Signal(shadow_wid, reset_less=True)
-
+ self.s_fail_i = Array(Signal(shadow_wid, name="fl_i", reset_less=True) \
+ for f in range(n_fus))
+ self.s_good_i = Array(Signal(shadow_wid, name="gd_i", reset_less=True) \
+ for f in range(n_fus))
# outputs
self.go_die_o = Signal(n_fus, reset_less=True)
self.shadown_o = Signal(n_fus, reset_less=True)
setattr(m.submodules, "sh%d" % i, sh)
shadows.append(sh)
# connect shadow/fail/good to all shadows
- m.d.comb += sh.s_fail_i.eq(self.s_fail_i)
- m.d.comb += sh.s_good_i.eq(self.s_good_i)
+ m.d.comb += sh.s_fail_i.eq(self.s_fail_i[i])
+ m.d.comb += sh.s_good_i.eq(self.s_good_i[i])
# this one is the matrix (shadow enables)
m.d.comb += sh.shadow_i.eq(self.shadow_i[i])
def __iter__(self):
yield self.issue_i
yield from self.shadow_i
- yield self.s_fail_i
- yield self.s_good_i
+ yield from self.s_fail_i
+ yield from self.s_good_i
yield self.go_die_o
yield self.shadown_o
self.n_fus = n_fus
# inputs: record *expected* status
- self.issue_i = Signal(reset_less=True)
- self.good_i = Signal(reset_less=True)
- self.fail_i = Signal(reset_less=True)
+ self.active_i = Signal(reset_less=True)
+ self.good_i = Signal(n_fus, reset_less=True)
+ self.fail_i = Signal(n_fus, reset_less=True)
# inputs: status of branch (when result was known)
self.br_i = Signal(reset_less=True)
- self.br_good_i = Signal(reset_less=True)
- self.br_fail_i = Signal(reset_less=True)
+ self.br_ok_i = Signal(reset_less=True)
# outputs: true if the *expected* outcome matched the *actual* outcome
- self.matched_o = Signal(reset_less=True)
+ self.match_f_o = Signal(n_fus, reset_less=True)
+ self.match_g_o = Signal(n_fus, reset_less=True)
def elaborate(self, platform):
m = Module()
# registers to record *expected* status
- good_r = Signal()
- fail_r = Signal()
-
- with m.If(self.br_i):
- # we expected fail, return OK that fail was EXPECTED... OR...
- # we expected good, return OK that good was EXPECTED
- success = Signal(reset_less=True)
- m.d.comb += success.eq((good_r & self.br_good_i) | \
- (fail_r & self.br_fail_i) )
- # ... but only set these where a good or fail *is* expected...
- with m.If(good_r | fail_r):
- m.d.comb += self.matched_o.eq(success)
- m.d.sync += good_r.eq(0) # might be set if issue set as well
- m.d.sync += fail_r.eq(0) # might be set if issue set as well
- with m.If(self.issue_i):
- m.d.sync += good_r.eq(good_r | self.good_i)
- m.d.sync += fail_r.eq(fail_r | self.fail_i)
+ good_r = Signal(self.n_fus)
+ fail_r = Signal(self.n_fus)
+
+ for i in range(self.n_fus):
+ with m.If(self.active_i):
+ m.d.sync += good_r[i].eq(good_r[i] | self.good_i[i])
+ m.d.sync += fail_r[i].eq(fail_r[i] | self.fail_i[i])
+ with m.If(self.br_i):
+ # we expected fail, return OK that fail was EXPECTED... OR...
+ # we expected good, return OK that good was EXPECTED
+ good = Signal(reset_less=True)
+ fail = Signal(reset_less=True)
+ with m.If(self.br_ok_i):
+ m.d.comb += good.eq(good_r[i])
+ m.d.comb += fail.eq(fail_r[i])
+ with m.Else():
+ m.d.comb += good.eq(~good_r[i])
+ m.d.comb += fail.eq(~fail_r[i])
+ # ... but only set these where a good or fail *is* expected...
+ with m.If(good_r[i]):
+ m.d.comb += self.match_g_o[i].eq(self.br_ok_i)
+ m.d.comb += self.match_f_o[i].eq(~self.br_ok_i)
+ with m.If(fail_r[i]):
+ m.d.comb += self.match_f_o[i].eq(~self.br_ok_i)
+ m.d.comb += self.match_g_o[i].eq(self.br_ok_i)
+ m.d.sync += good_r[i].eq(0) # might be set if issue set as well
+ m.d.sync += fail_r[i].eq(0) # might be set if issue set as well
return m
def __iter__(self):
- yield self.issue_i
+ yield self.active_i
yield self.good_i
yield self.fail_i
yield self.br_i
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