Compiling, debugging and executing design using AC data-types
Makefile bao gồm những thành phần sau để thực hiện được việc compiling C/C++ model
| Thư viện | IDIR =$(MGC_HOME)/shared/include |
| g++ | CC=$(MGC_HOME)/bin/g++ |
| C flag | CFLAGS=-g |
| Debugger | $(MGC_HOME)/bin/gdb |
Makefile example:
IDIR =$(MGC_HOME)/shared/include
TDIR ?= $(MGC_HOME)/tmp
CC=$(MGC_HOME)/bin/g++
CFLAGS=-g
tb0: tb_pod_err.cpp test_chan_assert.cpp
$(CC) -o $(TDIR)/tb tb_pod_err.cpp test.cpp -I$(IDIR) $(CFLAGS)
tb1: tb.cpp test_chan_assert.cpp
$(CC) -o $(TDIR)/tb tb.cpp test_chan_assert.cpp -I$(IDIR) $(CFLAGS)
$(TDIR)/tb
tb1_debug: tb.cpp test_chan_assert.cpp
$(CC) -o $(TDIR)/tb tb.cpp test_chan_assert.cpp -I$(IDIR) $(CFLAGS)
$(MGC_HOME)/bin/gdb $(TDIR)/tb
tb2: tb.cpp test_shift_loss.cpp
$(CC) -o $(TDIR)/tb tb.cpp test_shift_loss.cpp -I$(IDIR) $(CFLAGS)
$(TDIR)/tb
tb3: tb.cpp test.cpp
$(CC) -o $(TDIR)/tb tb.cpp test.cpp -I$(IDIR) $(CFLAGS)
$(TDIR)/tb
.PHONY: clean
clean:
rm -f $(TDIR)/tb
$(CC) -o $(TDIR)/tb tb.cpp tb.cpp test_chan_assert.cpp -I$(IDIR) $(CFLAGS)
-o $(TDIR)/tb : compile and put output file named tb at $(TDIR) test_chan_assert.cpp: source files-I$(IDIR) : include library which stores in IDIR variable$CFLAGS : C flag$(MGC_HOME)/bin/gdb $(TDIR)/tb
//test_chan_assert.cpp
#include "test.h"
void test(ac_int<4,false> data0,
ac_fixed<5,5,false> data1,
ac_channel<ac_int<4,false> > &chan_in,
ac_int<3,false> &wrap_behavior,
ac_fixed<3,3,false,AC_RND,AC_SAT> &sat_behavior,
ac_int<5,false> &shift_behavior,
ac_channel<ac_int<4,false> > &chan_out)
{
wrap_behavior = data0; // will wrap for values > 7
sat_behavior = data1; // will clamp to 7 for values > 7
shift_behavior = data0 << 1; // will lose MSB after shift
chan_out.write(chan_in.read()); // will assert if read of empty
// channel is attempted
}// tb_pod_err.cpp
#include "test.h"
#include <stdio.h>
#include <fstream>
using namespace std;
int main()
{
ac_int<4,false> data0; // 4 bit unsigned, 0 to 15
ac_fixed<5,5,false> data1;
ac_channel<ac_int<4,false> > chan_in;
ac_int<3,false> wrap_behavior;
ac_fixed<3,3,false,AC_RND,AC_SAT> sat_behavior;
ac_int<5,false> shift_behavior;
ac_channel<ac_int<4,false> > chan_out;
for (int i=0; i<16; i++) {
if (i>0) {
chan_in.write(i);
}
data0 = i;
data1 = i;
test(data0,data1,chan_in,wrap_behavior,sat_behavior,shift_behavior,chan_out);
printf("Input = %3d ",data0.to_uint());
printf("wrap_behavior = %3d, ",wrap_behavior.to_uint());
printf("sat_behavior = %3d, ",sat_behavior);
printf("shift_behavior = %3d\n",shift_behavior.to_uint());
}
return 0;
}Compiling status
[administrator@centos lab1]$ make tb0
/opt/tools/Mentor/Catapult_2022.1_1/Mgc_home/bin/g++ -o /opt/tools/Mentor/Catapult_2022.1_1/Mgc_home/tmp/tb tb_pod_err.cpp test.cpp -I/opt/tools/Mentor/Catapult_2022.1_1/Mgc_home/shared/include -g
tb_pod_err.cpp: In function ‘int main()’:
tb_pod_err.cpp:31:47: error: cannot pass objects of non-trivially-copyable type ‘class ac_fixed<3, 3, false, (ac_q_mode)1u, (ac_o_mode)1u>’ through ‘...’
printf("sat_behavior = %3d, ",sat_behavior);
^
make: *** [tb0] Error 1
sat_behavior là kiểu ac_fixed do đó nó cần gọi method để convert về dạng unsigned integer.
printf("sat_behavior = %3d, ",sat_behavior.to_uint());
// tb.cpp
#include "test.h"
#include <stdio.h>
#include <fstream>
using namespace std;
int main()
{
ac_int<4,false> data0; // 4 bit unsigned, 0 to 15
ac_fixed<5,5,false> data1;
ac_channel<ac_int<4,false> > chan_in;
ac_int<3,false> wrap_behavior;
ac_fixed<3,3,false,AC_RND,AC_SAT> sat_behavior;
ac_int<5,false> shift_behavior;
ac_channel<ac_int<4,false> > chan_out;
for (int i=0; i<16; i++) {
if (i>0) {
chan_in.write(i);
}
data0 = i;
data1 = i;
test(data0,data1,chan_in,wrap_behavior,sat_behavior,shift_behavior,chan_out);
printf("Input = %3d ",data0.to_uint());
printf("wrap_behavior = %3d, ",wrap_behavior.to_uint());
printf("sat_behavior = %3d, ",sat_behavior.to_uint());
printf("shift_behavior = %3d\n",shift_behavior.to_uint());
}
printf("\nChannel data = ");
while (chan_out.available(1)) { // while data in channel, keep reading
ac_int<4,false> data = chan_out.read();
printf("%2d ",data.to_uint());
}
printf("\n\n");
return 0;
}Compiling status
make tb1
/opt/tools/Mentor/Catapult_2022.1_1/Mgc_home/bin/g++ -o /opt/tools/Mentor/Catapult_2022.1_1/Mgc_home/tmp/tb tb.cpp test_chan_assert.cpp -I/opt/tools/Mentor/Catapult_2022.1_1/Mgc_home/shared/include -g
/opt/tools/Mentor/Catapult_2022.1_1/Mgc_home/tmp/tb
Assert in file /opt/tools/Mentor/Catapult_2022.1_1/Mgc_home/shared/include/ac_channel.h:229 Read from empty channel
tb: /opt/tools/Mentor/Catapult_2022.1_1/Mgc_home/shared/include/ac_channel.h:175: static void ac_channel<T>::ac_assert(bool, const char*, int, const ac_channel_exception::code&) [with T = ac_int<4, false>]: Assertion `0' failed.
make: *** [tb1] Aborted (core dumped)
[administrator@centos lab1]$
Lỗi này xảy ra khi xảy ra trường hợp đọc data từ empty channel. Ở error message, ta chỉ có thể nhìn thấy đoạn thông tin assert trong thư viện ac_channel. Để backtrack tới đoạn code lỗi, dbg được sử dụng như sau:
$(MGC_HOME)/bin/gdb $(TDIR)/tb
Chạy debugger (gdb)
(gdb) run
Gõ up để kiểm tra theo thứ tự từ trong ra ngoài của hierarchy, để phát hiện lỗi ở user source code.
Sau đó, gõ quit để thoát.
Program received signal SIGABRT, Aborted.
0x00007ffff7223387 in raise () from /lib64/libc.so.6
(gdb) up
#1 0x00007ffff7224a78 in abort () from /lib64/libc.so.6
(gdb) ip
Undefined command: "ip". Try "help".
(gdb) up
#2 0x00007ffff721c1a6 in __assert_fail_base () from /lib64/libc.so.6
(gdb) up
#3 0x00007ffff721c252 in __assert_fail () from /lib64/libc.so.6
(gdb) up
#4 0x0000000000401b1f in ac_channel<ac_int<4, false> >::ac_assert (condition=false,
file=0x4039c8 "/opt/tools/Mentor/Catapult_2022.1_1/Mgc_home/shared/include/ac_channel.h", line=229,
code=@0x7fffffffd88c: ac_channel_exception::read_from_empty_channel)
at /opt/tools/Mentor/Catapult_2022.1_1/Mgc_home/shared/include/ac_channel.h:175
175 assert(0);
(gdb) up
#5 0x00000000004026c2 in ac_channel<ac_int<4, false> >::fifo::fifo_ac_channel::read (this=0x608010)
at /opt/tools/Mentor/Catapult_2022.1_1/Mgc_home/shared/include/ac_channel.h:229
229 AC_CHANNEL_ASSERT(!empty(), ac_channel_exception::read_from_empty_channel);
(gdb) up
#6 0x0000000000401755 in ac_channel<ac_int<4, false> >::fifo::read (this=0x7fffffffd9e0)
at /opt/tools/Mentor/Catapult_2022.1_1/Mgc_home/shared/include/ac_channel.h:402
402 inline T read() { return f->read(); }
(gdb) up
#7 0x000000000040152e in ac_channel<ac_int<4, false> >::read (this=0x7fffffffd9e0)
at /opt/tools/Mentor/Catapult_2022.1_1/Mgc_home/shared/include/ac_channel.h:118
118 T read() { return chan.read(); }
(gdb) up
#8 0x0000000000403465 in test (data0=..., data1=..., chan_in=..., wrap_behavior=..., sat_behavior=...,
shift_behavior=..., chan_out=...) at test_chan_assert.cpp:18
18 chan_out.write(chan_in.read()); // will assert if read of empty channel is attempted
(gdb)
Ta thấy rằng dòng code chan_in.read() gây ra lỗi “read empty channel”
Giải pháp: Thực hiện kiểm tra channel có dữ liệu hay không trước khi thực hiện đọc như phần dưới đây
// test_chan_assert
//....
if (chan_in.available(1)) { // Only read if channel not empty
chan_out.write(chan_in.read());
}Khi thực hiện dịch trái một vector ac_* phải cast vector đó với một kích thước đủ lớn để đảm bảo giá trị của kết quả thu được phản ánh đúng toán tử dịch trái.