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picorv32
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Reset bugfix (bug found via scripts/smt2-bmc/mem_equiv.*)

This commit is contained in:
Clifford Wolf 2015-08-13 13:30:21 +02:00
parent 8397962424
commit 16f97a86a1
3 changed files with 108 additions and 15 deletions
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2
picorv32.v
View File

@ -175,7 +175,7 @@ module picorv32 #(
reg mem_do_wdata;
wire mem_busy = |{mem_do_prefetch, mem_do_rinst, mem_do_rdata, mem_do_wdata};
wire mem_done = (mem_ready && |mem_state && (mem_do_rinst || mem_do_rdata || mem_do_wdata)) || (&mem_state && mem_do_rinst);
wire mem_done = resetn && ((mem_ready && |mem_state && (mem_do_rinst || mem_do_rdata || mem_do_wdata)) || (&mem_state && mem_do_rinst));
assign mem_la_write = resetn && !mem_state && mem_do_wdata;
assign mem_la_read = resetn && !mem_state && (mem_do_rinst || mem_do_prefetch || mem_do_rdata);

113
scripts/smt2-bmc/mem_equiv.py
View File

@ -4,7 +4,11 @@ import os, sys, getopt
from time import time
import subprocess
steps = 20
steps = 12
words = 0
allmem = False
fastmem = False
initzero = False
debug_print = False
debug_file = open("debug.smt2", "w")
@ -82,6 +86,8 @@ def yices_parse(stmt):
return worker(stmt)[0]
def yices_bv2hex(v):
if v == "true": return "1"
if v == "false": return "0"
h = ""
while len(v) > 2:
d = 0
@ -95,6 +101,8 @@ def yices_bv2hex(v):
return h
def yices_bv2bin(v):
if v == "true": return "1"
if v == "false": return "0"
return v[2:]
def yices_get(expr):
@ -122,18 +130,43 @@ def yices_get_net_bin(mod_name, net_name, state_name):
start_time = time()
yices_write("(set-logic QF_AUFBV)")
regs_a = list()
regs_b = list()
with open("mem_equiv_a.smt2", "r") as f:
for line in f: yices_write(line)
for line in f:
if line.startswith("; yosys-smt2-register "):
line = line.split()
regs_a.append((line[2], int(line[3])))
else:
yices_write(line)
with open("mem_equiv_b.smt2", "r") as f:
for line in f: yices_write(line)
for line in f:
if line.startswith("; yosys-smt2-register "):
line = line.split()
regs_b.append((line[2], int(line[3])))
else:
yices_write(line)
for step in range(steps):
yices_write("(declare-fun a%d () main_a_s)" % step)
yices_write("(declare-fun b%d () main_b_s)" % step)
# reset in first two cycles
if step < 2:
if fastmem:
yices_write("(assert (|main_a_n domem| a%d))" % step)
yices_write("(assert (|main_b_n domem| b%d))" % step)
if words > 0:
if allmem:
yices_write("(assert (bvult (|main_a_n mem_addr| a%d) #x%08x))" % (step, words))
yices_write("(assert (bvult (|main_b_n mem_addr| b%d) #x%08x))" % (step, words))
else:
yices_write("(assert (or (not (|main_a_n mem_valid| a%d)) (bvult (|main_a_n mem_addr| a%d) #x%08x)))" % (step, step, words))
yices_write("(assert (or (not (|main_b_n mem_valid| b%d)) (bvult (|main_b_n mem_addr| b%d) #x%08x)))" % (step, step, words))
# reset in first cycle
if step < 1:
yices_write("(assert (not (|main_a_n resetn| a%d)))" % step)
yices_write("(assert (not (|main_b_n resetn| b%d)))" % step)
@ -190,11 +223,14 @@ for step in range(steps):
print("status %5s: resetn=%s, memvld=%s, domem=%s, memrdy=%s, trap=%s" % ("%s[%d]" % (mod, step), resetn, memvld, domem, memrdy, trap))
def print_mem_xfer(mod, step):
if yices_get("(and (|main_%s_n mem_valid| %s%d) (|main_%s_n mem_ready| %s%d))" % (mod, mod, step, mod, mod, step)) == 'true':
if allmem or yices_get("(and (|main_%s_n mem_valid| %s%d) (|main_%s_n mem_ready| %s%d))" % (mod, mod, step, mod, mod, step)) == 'true':
mem_addr = yices_get_net_hex("main_" + mod, "mem_addr", "%s%d" % (mod, step))
mem_wdata = yices_get_net_hex("main_" + mod, "mem_wdata", "%s%d" % (mod, step))
mem_wstrb = yices_get_net_bin("main_" + mod, "mem_wstrb", "%s%d" % (mod, step))
mem_rdata = yices_get_net_hex("main_" + mod, "mem_rdata", "%s%d" % (mod, step))
if allmem and yices_get("(and (|main_%s_n mem_valid| %s%d) (|main_%s_n mem_ready| %s%d))" % (mod, mod, step, mod, mod, step)) == 'true':
print("mem %5s: addr=%s, wdata=%s, wstrb=%s, rdata=%s <-" % ("%s[%d]" % (mod, step), mem_addr, mem_wdata, mem_wstrb, mem_rdata))
else:
print("mem %5s: addr=%s, wdata=%s, wstrb=%s, rdata=%s" % ("%s[%d]" % (mod, step), mem_addr, mem_wdata, mem_wstrb, mem_rdata))
def print_cpu_regs(step):
@ -205,6 +241,48 @@ for step in range(steps):
assert yices_read() == "sat"
if initzero:
for rn, rs in regs_a:
force_to_zero = True
if yices_get_net_bin("main_a", rn, "a0").count("1") != 0:
print("Looking for a solution with |main_a_n %s| initialized to all zeros.." % rn)
yices_write("(push 1)")
if rs == 1:
yices_write("(assert (not (|main_a_n %s| a0)))" % rn)
else:
yices_write("(assert (= (|main_a_n %s| a0) #b%s))" % (rn, "0" * rs))
yices_write("(check-sat)")
if yices_read() != "sat":
force_to_zero = False
yices_write("(pop 1)")
if force_to_zero:
if rs == 1:
yices_write("(assert (not (|main_a_n %s| a0)))" % rn)
else:
yices_write("(assert (= (|main_a_n %s| a0) #b%s))" % (rn, "0" * rs))
yices_write("(check-sat)")
assert yices_read() == "sat"
for rn, rs in regs_b:
force_to_zero = True
if yices_get_net_bin("main_b", rn, "b0").count("1") != 0:
print("Looking for a solution with |main_b_n %s| initialized to all zeros.." % rn)
yices_write("(push 1)")
if rs == 1:
yices_write("(assert (not (|main_b_n %s| b0)))" % rn)
else:
yices_write("(assert (= (|main_b_n %s| b0) #b%s))" % (rn, "0" * rs))
yices_write("(check-sat)")
if yices_read() != "sat":
force_to_zero = False
yices_write("(pop 1)")
if force_to_zero:
if rs == 1:
yices_write("(assert (not (|main_b_n %s| b0)))" % rn)
else:
yices_write("(assert (= (|main_b_n %s| b0) #b%s))" % (rn, "0" * rs))
yices_write("(check-sat)")
assert yices_read() == "sat"
print()
print_cpu_regs(0)
@ -235,11 +313,11 @@ for step in range(steps):
memory_datas = { "a": dict(), "b": dict() }
for i in range(step, 0, -1):
for mod in ["a", "b"]:
if yices_get("(and (|main_%s_n mem_valid| %s%d) (|main_%s_n mem_ready| %s%d))" % (mod, mod, i, mod, mod, i)) == 'true':
if allmem or yices_get("(and (|main_%s_n mem_valid| %s%d) (|main_%s_n mem_ready| %s%d))" % (mod, mod, i, mod, mod, i)) == 'true':
mem_addr = yices_get_net_hex("main_" + mod, "mem_addr", "%s%d" % (mod, i))
mem_rdata = yices_get_net_hex("main_" + mod, "mem_rdata", "%s%d" % (mod, i))
memory_datas[mod][mem_addr] = mem_rdata
memory_words = max(int(mem_addr, 16)+1, memory_words)
memory_words = max((int(mem_addr, 16) >> 2)+1, memory_words)
memory_data = dict()
for k, v in memory_datas["a"].items(): memory_data[k] = v
for k, v in memory_datas["b"].items(): memory_data[k] = v
@ -295,6 +373,14 @@ for step in range(steps):
print(" $dumpvars(0, testbench);", file=f)
print("", file=f)
for rn, rs in regs_a:
print(" main_a.%s = %d'b %s;" % (rn, rs, yices_get_net_bin("main_a", rn, "a0")), file=f)
print("", file=f)
for rn, rs in regs_b:
print(" main_b.%s = %d'b %s;" % (rn, rs, yices_get_net_bin("main_b", rn, "b0")), file=f)
print("", file=f)
for i in range(1, 32):
ra = yices_bv2hex(yices_get("a%d_r%d" % (0, i)))
rb = yices_bv2hex(yices_get("b%d_r%d" % (0, i)))
@ -302,8 +388,8 @@ for step in range(steps):
print("", file=f)
for addr, data in memory_data.items():
print(" main_a.memory['h %s] = 'h %s;" % (addr, data), file=f)
print(" main_b.memory['h %s] = 'h %s;" % (addr, data), file=f)
print(" main_a.memory['h %08x] = 'h %s;" % (int(addr, 16) >> 2, data), file=f)
print(" main_b.memory['h %08x] = 'h %s;" % (int(addr, 16) >> 2, data), file=f)
print("", file=f)
for i in range(step+1):
@ -319,12 +405,19 @@ for step in range(steps):
print(" check_mem('h %s);" % addr, file=f)
print("", file=f)
print(" @(posedge clk);", file=f)
print(" @(posedge clk);", file=f)
print(" $finish;", file=f)
print(" end", file=f)
print("endmodule", file=f)
secs = int(time() - start_time)
print("[%3d:%02d:%02d] Done." % (secs // (60*60), (secs // 60) % 60, secs % 60))
if words > 0:
print("running verilog test bench...")
os.system("iverilog -o mem_equiv_tb -s testbench mem_equiv_tb.v mem_equiv.v ../../picorv32.v && ./mem_equiv_tb")
break
else: # unsat

4
scripts/smt2-bmc/mem_equiv.ys
View File

@ -11,7 +11,7 @@ opt
memory -nordff -nomap
flatten
opt
write_smt2 -bv -mem mem_equiv_a.smt2
write_smt2 -bv -mem -regs mem_equiv_a.smt2
design -reset
read_verilog mem_equiv.v
@ -27,5 +27,5 @@ opt
memory -nordff -nomap
flatten
opt
write_smt2 -bv -mem mem_equiv_b.smt2
write_smt2 -bv -mem -regs mem_equiv_b.smt2
design -reset